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Selection and evaluation of feedstuffs for urban and peri-urban small ruminant production in Ghana: a… Baah, John 1994

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SELECTION AND EVALUATION OF FEEDSTLWFS FOR URBAN AND PERI-URBANSMALL RUMINANT PRODUCTION IN GHANA - A SYSTEMS APPROACHbyJOHN BAAIIB.Sc. (Hons.) Agriculture, University of Science and Technology, Kumasi, Ghana, 1980M.Sc., Animal Science, University ofBritish Columbia, Vancouver, Canada, 1990A THESIS SUBMITTED IN PARTIAL FULFILMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYhiTHE FACULTY OF GRADUATE STUDIES(Department ofAnimal Science)We accept this thesis as conformingto the required standardTHE UNIVERSITY OF BRITISH COLUMBIAOctober 1994©JohnBaah, 1994In presenting this thesis in partial fulfilment of the requirements for an advanceddegree at the University of British Columbia, I agree that the Library shall make itfreely available for reference and study. I further agree that permission for extensivecopying of this thesis for scholarly purposes may be granted by the head of mydepartment or by his or her representatives. It is understood that copying orpublication of this thesis for financial gain shall not be allowed without my writtenpermission.(Signature)_________________________________Department of A N i I.—. Ci E C_&.The University of British ColumbiaVancouver, CanadaDate OcioLeiZ... 29frDE-6 (2188)11ABSTRACTThe objective of this research was to develop a feed package for small ruminants in the urbancentres of Ghana. A survey of 120 households indicated that cassava peels were the most abundantfeedstuff. However, the level of nitrogen (1.02%) was inadequate to support optimum rumenflnction.The degradation of cassava peels and leaves of ficus, terminalia and chaya in the rumen wasdetermined using the in sacco technique (Experiment 1). The respective rates of degradation ofnitrogen fractions were 0.087, 0.052 and 0.133% If1 (P<0.05). The ratios of nitrogen released fromterminalia, ficus and chaya leaves to organic matter fermented from cassava peels during the first 12 hof incubation were; 1:60, 1:30 and 1:15.5, respectively.In Experiment 2, six wethers fitted with permanent rumen cannulae were fed cassava peelssupplemented with either 0, 50, 100, 150, 200, or 250 g d’ of ficus leaves. Supplementation increased(P<0.05) the potentially degradable fraction (55.9 to 68.2%) of dry matter (DM) in cassava peels.The corresponding value for ficus was 72.5 to 78.7%.In Experiment three, 48 individually housed wethers and ewe lambs, were fed cassava peels adlibitum and randomly allocated to one of six dietary supplements used in Experiment 2. Daily DMintake increased P<0.05) from 44.0 g kg1 LW°75 (no supplement) to 81.2 g kg’ LW°75 (250 g d’ officus leaves). Supplementation depressed apparent DM digestibility coefficients (78.1 to 73.9%,P<0.05). Animals which received 250 g d1 of ficus leaves had the fastest growth rate (53.6 g d’,P<0.05).Scanning electron microscopy was combined with electron dispersive x-ray analysis (EDXA)in Experiment 4 to study rumen microbial digestion of cassava peels and ficus leaves. The outer layerof cassava peels and epidermis of ficus leaves, except damaged regions were, resistant to microbialcolonization and digestion. In digestible tissues, 4 h was close to initiation of digestion. EDXA of ficusleaf surfaces indicated that the entire epidermis was covered with silica.It was concluded from the series of studies that a successfiul small ruminant feeding systemcould be based on feeding cassava peels adlibitum and 200-250 g d’ of ficus leaves.111TABLE OF CONTENTSABSTRACTTABLE OF CONTENTS iiiLIST OF TABLES viiLIST OF FIGURES ixLIST OF PLATES xACKNOWLEDGEMENTS xiCHAPTER 1 CONCEPTUAL FRAMEWORK 1A. Introduction 1B. Small Ruminant Production in the Urban Communities in Ghana 3C. Feed Resources for Small Ruminants 4D. Structure and Degradation of Feed Particles in the Rumen 5E. Role ofRumen Microbes in the Digestion ofFeedstuffs 7F. Improvement of Low Quality Feedstuffs 8G. General Research Methodology 11H. Farming Systems Approach to Research 11I. Research Methods Adopted in this Study 13J. General Research Objectives 14CHAPTER 2 URBAN HOUSEHOLDS AI]) SMALL RUMINANT PRODUCTION 16A. Introduction 16B. Methodology 17C. Results and Discussion 18iv1. Reasons for keeping small ruminants 182. Ownership patterns 223. Flock types and sizes 244. Labor 265. Feed Resources 276. Management practices 317. Marketing 338. Constraints in urban livestock production. 34D. Conclusions 39CHAPTER 3 IDENTIFICATION AN]) SELECTION OF FEEDSTUFFS FOR SMALLRUMINANTS iN THE URBAN AND PERI-URBAN CENTERS OF GHANA 42A. Introduction 42B. Preliminary Studies 431. Selection of basal feedstuff 431.1. Nature and chemical composition of cassava peels 432. Selection of browse supplement 442.1. Principles of nitrogen supplementation of ruminant diets 45C. Materials and Methods 461. Feeds 462. Animals and feeding 463. Supplements and incubation procedures 474. Chemical analysis and calculations 47D. Results and Discussion 491. Chemical composition 492. Dry matter disappearance 513. Nitrogen disappearance 55E. Conclusions 57CHAPTER 4 MICROBIAL DIGESTION OF CASSAVA PEELS AND FICUS LEAVES 59A. Introduction 59B. Materials and Methods 611. Animals and feeding 612. Incubation procedure 613. Calculations and statistical analyses 62C. Results and Discussion 631. Degradation of dry matter and nitrogen in cassava peels 632. Degradation of dry matter and nitrogen in ficus leaves 67VD. Conclusions 70CHAPTER 5 EFFECT OF SUPPLEMENTATION WITH GRADED LEVELS OF FICUSLEAVES ON THE UTILIZATION OF CASSAVA PEELS BY SHEEP. 71A. Introduction 71B. Materials and Methods 731. Feeds and experimental diets 732. Animals and experimental design 733. Sampling and analytical procedures 744. Calculations and statistical analyses 74C. Results and Discussion 751. Chemical composition 752. Feed intake 773. Apparent digestibility coefficients 804. Weight gain 825. Prediction of nutritive value 84D. Conclusions 87CHAPTER 6 MICROBIAL COLONIZATION OF FEED PARTICLES ANDENUMERATION OF BACTERIA IN THE RUMEN OF SHEEP FED CASSAVA PEELSAND GRADED LEVELS OF FICUS LEAVES 88A. Introduction 881. Microbial colonization and digestion of feedstuffs 892. The rumen bacterial population 903. The ciliate protozoa and fungi 91B. Materials and Methods 931. Animals and feeding 932. Incubation and sample preparation for SEM 933. Sampling, media and cultural methods for bacterial counts 94C. Results and Discussion 951. Colonization and digestion of feed particles 952. Viable counts of total and cellulolytic bacteria populations 104D. General Discussion 106E. Conclusions 108CHAPTER 7 GENERAL CONCLUSIONS AND RECOMMENDATIONS 110viLITERATURE CITED 113APPENDICES 129viiLIST OF TABLESTable 2.1. Reasons for keeping small ruminants. 19Table 2.2. Number ofanimals in the breeding herd. 19Table 2.3. Preferred age, sex and time ofdisposal of small ruminants. 21Table 2,4. Ownership patterns of small ruminants by age, sex and educational level of owners. 23Table 2.5. Occupational distribution of small ruminant owners. 23Table 2.6. Mode of acquisition of small ruminants and assets of owners. 24Table 2.7. Small ruminant distribution by location. 25Table 2.8. Herd/Flock sizes of small ruminants. 25Table 2.9. Management decision making and allocation of labour within households. 26Table 2.10 Sources of feed and methods of feeding small ruminants. 28Table 2.11 Processing and storage of feed among small ruminant producers. 29Table 2.12. Yearly expenditure on acquisition offeed (cost, transportation and storage). 30Table 2.13. Prevalence of some management practices among small ruminant producers. 32Table 2.14. Causes of small ruminant losses. 35Table 2.15. Constraints on production of small ruminants. 36Table 3.1. Organic matter, nitrogen and neutral detergent fibre content of different varietiesof cassava peels, and cassava peels collected from different locations in Kumasi(%DM). 50Table 3.2. Organic matter, nitrogen and neutral detergent fibre content ofFicus sp., Terminalia sp.and chaya leaves (% DM). 51Table 3.3. Rumen degradation characteristics (%) of dry matter and nitrogen of cassava peels, andleaves of chaya, ficus and terminalia incubated in rumen of sheep. 54Table 4.1. Rumen degradation characteristics of dry matter and nitrogen of cassava peels insheep receiving different levels of ficus leaves as supplement. 64viiiTable 4.2. Rumen degradation characteristics of diy matter and nitrogen of ficus leavessheep receiving different levels of ficus leaves as supplement. 65Table 5.1. Chemical composition of dry cassava peels and ficus leaves. 76Table 5.2. Daily intake of dry matter (DM) and nitrogen and growth rate of sheep fed cassava peels-based diets with graded levels officus leaves. 78Table 5.3. Apparent digestion coefficients of cassava peels-based diets (%). 81Table 5.4. Prediction of dry matter intake, dry matter digestibility, organic matterdigestibility and growth rate in sheep from rumen degradation characteristics. 85Table 6.1. Effect of different dietary treatments on total culturable and cellulolyticbacteria populations and pH in ruminal fluid of sheep. 105ixLIST OF FIGURESFigure 1.1. Schematic representation ofFarming Systems Research (FSR). 12Figure 2.1. Schematic Representation of Small Ruminant Production Systems in Urbanand Pen-urban centres of Ghana. 40Figure 3.1. Disappearance of dry matter from cassava peels, and from leaves of chaya, ficus andterminalia incubated in mmen of sheep. 53Figure 3.2. Fermentation of organic matter in cassava peels and release ofnitrogen fromleaves of chaya, ficus and terminalia in mmen of sheep. 56Figure 4.1 .a. Dry matter disappearance (%) from cassava peels incubated in the rumenof sheep consuming cassava peels ad libitum and graded levels of ficus leaves. 68Figure 4.1 .b. Nitrogen disappearance (%) from cassava peels incubated in the rumen of sheepconsuming cassava peels ad libitum and graded levels of ficus leaves. 68Figure 4.2.a. Dry matter disappearance (%) from ficus leaves incubated in the rumen of sheepconsuming cassava peels ad libitum and graded levels of ficus leaves. 69Figure 4.2.b. Nitrogen disappearance (%) from ficus leaves incubated in the rumen of sheepconsuming cassava peels ad libitum and graded levels of ficus leaves. 69Figure 5.1. Effect of level of ficus leaf supplementation on daily voluntary intake (g/kg°75)of organic matter by sheep. 79Figure 5.2. Effect of level of ficus leaf supplementation on liveweight changes in sheep. 83Figure 6.1. Electron dispersive x-ray analysis (EDXA) of a silicon body on the upper surface ofa Ficus exasperata leaf showing elemental composition. 103xLIST OF PLATESPlate 1 a, b, c, d. Micrographs depicting the morphological diversity of the microbialpopulation in the rumen of sheep consuming cassava peels and ficus leaves. 96Plate 2a. Micrograph of the cortex of cassava peel incubated in sheep rumen (4 h). 97Plate 2b. Micrograph of the outer epidermis of cassava peel incubated in sheep rumen (24 h). 97Plate 2c. Micrograph of parenchyma cells of the cortex of cassava peel in sheep rumen (24 h). 97Plate 2d. Micrograph of starch grains of cassava peel in sheep rumen (4 h). 97Plate 3a. Micrograph of the cortex of cassava peel in sheep rumen (4 h) showing heavymicobial colonization of starch grains. 99Plate 3b. Micrograph of starch grains of cassava peel in sheep rumen showing distinct pitformations (24 h). 99Plate 3o Micrograph of starch grains in parenchyma cells of cassva peel exposed in sheeprumen (24 h). 99Plate 3d. Micrograph of starch grains of cassava peel in sheep rumen with deep cavitations(24h). 99Plate 4a. Micrograph of the upper surface ofFicus exasperata leaf showing trichomesand silica bodies. 100Plate 4b. Silicon elemental dispersion map of the surface ofFicus exasperata leaf. 100Plate 4c. Micrograph of the damaged leaf surface ofFicus exasperata in the rumen of sheep 100Plate 4d. Micrograph of damaged regions ofFicus exasperata leaf. 100Plate 5. Micrograph of the surface ofFicus exasperata leaf with silicon body broken off 101xiACKNOWLEDGEMENTSI would like to express my sincere appreciation to Dr. R. M. Tait, my graduatesupervisor. His encouragement, guidance and various forms of assistance during my training andpreparation of this thesis is gratefully acknowledged.I would also like to thank members of my graduate committee; Dr. 3. A. Shelford, Dr. G.Kennedy, Dr. J. R. Thomson, Dr. K-J. Cheng, Agriculture Canada, Lethbridge, and Dr. A. K.Tuah, U. S. T., Kumasi, for their invaluable suggestions and assistance. The guidance of Dr. TimMcAllister and K. Jakober, through the complex and exciting field of rumen microbiology issincerely acknowledged. The material and financial assistance of Dr. K-J. Cheng, and his entireteam at Lethbridge and the encouragement and help of Dr. 0. B. Smith, (]DRC, Dakar)), Dr. D.B. Okai and Mrs. C. C. Atuahene, both of U. S. T., Kumasi, require special mention.The technical assistance of Staff of the Departments of Animal Science in U. B. C.,Vancouver, and U.S.T., Kumasi, is acknowledged. The help of Daniel Adu, K. Manu, K. Tobiahand K. Ntiamoah in management of research animals and obtaining cassava peels and ficus leavesis also appreciated. The help and moral support of numerous friends also contributed to thesuccessful completion of this thesis. The names of two special friends come to mind, Dr. GeorgeOwusu and Mr. Mark Agyei Sarpong.The financial support provided by the International Development and Research Centre,(IDRC), Ottawa through a Program Related Award and the Rockefeller Foundation New York,through the African Dissertation Internship Awards Program made this study possible.This thesis is dedicated to my wife, Stella, and children, Vera, Marilyn and John Jr. fortheir understanding, patience and assistance during the difficult and often stressful times of thelast three years; and my mother Madam Akosua Donkor for all her love.1CHAPTER 1 CONCEPTUAL FRAMEWORKA. IntroductionThis research is a component of a joint project between the International Developmentand Research Centre (TDRC), Ottawa, and the University of Science and Technology (UST),Kumasi, Ghana. The University of British Columbia (UBC), Vancouver, Canada. The Laboratoryof Dr. K-J. Cheng (Agriculture Canada Research Station, Lethbridge, Alberta), also providedtechnical and material support. The general objective of the IDRC/UST project is to improvesmall ruminant production in Ghana through the development of feed packages based on cropresidues and agricultural by-products for animals in the villages and the urban centres of Ghana.The main objective of this component of the project was to develop a nutritionally balanced andeconomically viable feed package, based on available feed resources, which could berecommended for small ruminant feeding systems in the urban centres of Ghana.Livestock have traditionally been an important component in the economy of Ghana butlittle progress has been made towards either using available resources more efficiently orimproving productivity. The livestock sector in Ghana contributed about 9 percent of agriculturalGDP between 1990 and 1993. Meat was the predominant livestock product, amounting to about67,000 mt in 1990 of which 22,000 mt was beef, 14,000 mt was pork, 16,000 mt was frompoultry, and 14,000 mt was from mutton and goat meat (FAO, 1992). The West AfricanShorthorn is the predominant cattle breed in Ghana, and together with its crosses, and the Sanys,accounts for about 80% percent of the national cattle herd. Three quarters of all cattle are in theUpper East, Upper West and Northern regions. Sheep and goats are more evenly distributedthroughout the country, being the main source of domestic meat supply for the rural farmingcommunity and increasingly assuming prominence in the urban-meat supply. They are keptmostly in small units of fewer than ten animals. Most sheep and goats are of the West Africandwarf breeds with no more than ten percent being crosses with the Sahelian types (Sarris andShams, 1991). Sheep and goats generally serve as a minor, but critical component of balanced2agricultural production systems. Their main roles in most parts of the country are to producemeat and generate income, usually to the direct benefit of some of the poorest people. Despitetheir importance, small ruminants and their producers have received relatively little attention fromgovernment and development agencies in terms of research, financial assistance andinfrastructural support.The human population of Ghana presently stands at 15 million and is increasing at the rateof about 3 percent per annum. At this rate the population has been projected to double between1990 and the year 2020 (WHO, 1986). It has been estimated that livestock inventories wouldalso have to double by the end of the century to meet total consumption requirements if there isno change in per capita consumption level. The current intake of animal protein is abysmally low,below 10 g per person per day, compared to 25 g recommended by WHO (1986). Increasedlevels of consumption can be met primarily by productivity increases since lack of foreignexchange limits extensive importations. A major potential for the livestock industry therefore liesin the rapid increase in population which assures a sustained demand for years to come.In 1988 the Government of Ghana launched its Medium Term Agricultural DevelopmentProgram (Medium-Term Agricultural Development Program, Working Paper No. 4, 1988). Inthis program it was envisaged that the sheep population would be increased from 2 million to 6million by the year 2000. The goat population was expected to increase from about 2.5 million to9 million during the same period. Although modest progress has been made, much more needs tobe done if these targets are to be achieved.It cannot be emphasised enough that the success of the program depends on properidentification of the constraints and opportunities of existing production systems, and, in the lightof these, formulate appropriate policies which would be most effective in developing the animalindustries.3B. Small Ruminant Production in the Urban Communities in GhanaOf the 4.5 million small ruminants in Ghana (FAO, 1992), it has been estimated that about25 percent are raised by people living in and around cities and towns. In recent times, these urbanand peri-urban livestock producers have emerged as an important distinct sector of the livestockindustry. The contribution of these farmers towards the provision of animal protein to the urbancommunity is substantial; not to mention the tremendous economic return and improvement inthe standard of living of these farmers as a result of livestock activities.The production of small ruminants in these communities, though a minor agriculturalenterprise, is also complementary to the other agricultural activities e.g. food processingindustries. This often adds value to agricultural by-products by conversion to preferred animalproducts. The animals also play important social and cultural roles in the lives of some of theseurban and peri-urban households. In spite of all these contributions, only rarely are theseproducers mentioned in descriptions of farming systems in the country. It is therefore notsurprising that there has been no systematic attempt by the government or development agenciesto understand the small ruminant production system in the urban and pen-urban areas with theultimate aim of helping these farmers to increase their productivity. It is envisaged that byidentifying and analysing some of the production constraints, appropriate recommendations couldbe made which would lead to optimum exploitation of this under-utilised agricultural resource.Most of the animals in the urban centres are confined within households or in penserected behind houses because of restrictions imposed on their movement by local authorities.Even in the pen-urban areas, traditional husbandry systems are being modified by high humanpopulation density and increasing pressure on agricultural land. In these areas, free-roaminganimals also pose an increasingly important threat to growing crops and ornamental plants onprivate properties. Therefore, sheep and goats have to be either tethered or kept in pens. As aresult, the backyard production of small ruminants has assumed a greater degree of“sophistication”. It has evolved from a minor low-input household enterprise into a more4intensive, specialised enterprise demanding greater management input and demand for highquality feed.C. Feed Resources for Small RuminantsA major constraint within the production system is the provision of adequate feedthroughout the year for the animals. Presently, the main sources of feed are from householdagricultural wastes such as cassava peels, plantain/banana peels, yamlcocoyam peels, and byproducts from the brewery and milling industries. Many producers purchase some of theseagricultural wastes from other households not engaged in livestock rearing activities or from theagro-processing industries. In some situations these agricultural wastes are used as supplementswhile in others they are the only source of feed. Animals raised in the pen-urban areas alsosubsist on agricultural by-products such as cassava peels and plantain peels in addition to the fewforage plants along roadsides and on abandoned farms or undeveloped plots of land. Thesesources of feed, though often abundant, are not being utilised efficiently because of certainproblems associated with their use. Some of the problems associated with the utilisation of theseagricultural by-products include collection, transportation, processing and storage and perhapsmost importantly, their poor nutritive value.The nutritive value of these feedstuffs depend upon the crop species, seasonal growingconditions and post harvest treatment or processing conditions. In addition a commoncharacteristic of most of them is that they are deficient in nitrogen and essential minerals; notably,sodium, calcium, phosphorus and sulphur. The feedstuffs are also very fibrous. The consequencesof such a profile for ruminants are a low intake and, a low digestibility both of which are reflectedin poor levels of animal performance (Smith, 1993).Low intakes and digestibilities are often the result of high lignin content in the feedstuffand the chemical bonding between the lignin and potentially nutritious cell wall fractions such ascellulose and hemicellulose (Welch, 1982; Van Soest, et al., 1991). Therefore, most strategiesdeveloped to promote the efficient utilisation of such feed resources first aim at maximising5rumen function through the maximisation of the rate of degradation of the cell wallcarbohydrates. However, a second approach, the supply of a suitable supplement which wouldprovide the animal with otherwise deficient nutrients, is also called for in most cases.Appropriate strategies for supplementation of feedstuffs require an understanding of thedigestion and associated constraints with the use of those feedstuffs by the animals involved.D. Structure and Degradation of Feed Particles in the RumenThe plant materials that comprise the bulk of ruminant feed are composed of a vast arrayof nitrogenous compounds and polysaccharides. Among the nitrogenous compounds, protein isthe most abundant, but nucleic acids always occur in association with the proteins, andsubstantial amounts of nitrate and ammonia may be present depending on the diet. On the otherhand, most polysaccharides entering the rumen can be divided into two general groups; plantstorage polysaccharides such as starch and the fructosans, or the structural polysaccharideswhich compose the greater part of the plant cell walls and which are loosely considered to formthe fibrous component of animal feedstuffs. The polysaccharides that may be extracted fromintact cell walls are considered conventionally to belong to one of three groups: cellulose,hemicellulose and the pectic substances.Cellulose has unique properties conferred by its secondary, rather than its primary,structure. The linear chains of 13 1-4 linked glucose units aggregate to form microscopicallyvisible fibrils in which the individual glucan chains are extensively cross-linked by hydrogenbonding. The degree of order found within and between fibrils varies from regions in which theglucan chains are held firmly in parallel (and where x-ray diffIaction studies have indicated a highdegree of crystallinity), to regions in which this order is somewhat reduced (amorphous regions)(Chesson and Forsberg, 1988). Microfibrils are hydrophobic in nature, and show considerablymore resistance to chemical or enzymatic hydrolysis than the glucan chains from which they areformed (Krassig, 1985). Resistance is directly related to the degree of order within the molecule,6with celluloses with a high crystallinity index showing the lowest rates of degradation whenincubated in the rumen (Chesson, 1981).Hemicellulose is the most complex of the plant polysaccharides. Its composition variesamong plant parts and between species. Hemicellulose is a mixture of polysaccharides often withthe common factor of 131-4 linkage in the main xylan core polymer, although branching with avariety of other glucosidic linkages occurs. Hemicelluloses of leaf and stem and legumes seems tobe largely arabinoxylan with associated linkages to glucuronic acid and probably lignin (VanSoest, 1982).Pectic substances are a complex of polysaccharides which form the cementing substancein plant cell walls and are based on chains of ct-i- linked galacturonic acid units in which thecarboxylic acid groups are variably esterified with methanol and the uronic acid residues variablysubstituted at carbon-2 with acetyl groups. Rhamnose units are found throughout the chain,linked 1-2 to adjacent uronic acid residues (Stephen, 1983). Like starch, pectin is linked ct 1-4leading to non-linearity and coiling of the polygalacturonic acid chain. Pectin differs from starch,however, in the axial position of the linkage on carbon 4, and pectins are not attacked byamylases (Van Soest, 1982). Pectic substances are found in all plant feedstuffs but occur in farhigher proportions in cell walls of dicotoledonous plants (Chesson and Forsberg, 1988).Feed protein is usually hydrolysed rapidly in the rumen, although the precise rate andextent of breakdown depend on a number of factors, which ultimately determine its nutritivevalue. Apart from factors related to the nature of the protein itself (i.e. secondary and tertiarystructure) and the number of disulphide bonds, the hydrolysis of non-protein polymers, such aspolysaceharides may limit access of proteolytic organisms to their substrates (Siddon andParadine, 1981; Wallace and Cotta, 1988).The nature of the basal diet has a major influence on the proteolytic activity of the rumencontents. Fresh herbage promotes activity up to nine times higher than that found with dryrations (Nugent et aL, 1983). Cereal diets also yield higher activities than dry forage diets,probably because proteolytic rumen micro-organisms tend to be amylolytic rather than7cellulolytic (Siddon and Paradine, 1981). The nature of the protein substrate in a supplement alsoaffects proteolytic activity. Hydrolysis of leafFraction I protein was stimulated, relative to casein,by fresh fodder (in which it would be abundant), more than in a diet consisting of hay andconcentrates (Hazlewood et at., 1983; Nugent et at., 1983). In contrast, when albumin replacedcasein as the protein supplement in a sheep diet, the rate of breakdown of albumin relative tocasein was unchanged, despite a modified proteolytic flora (Wallace et at., 1987). Furthermore,the proteolytic activity of rumen contents was hardly changed. The effect of different dietaryproteins on ruminal proteolysis therefore appears to vary from protein to protein and with theother constituents of the diet.Whatever the mechanism of digestion of feedstuffs at the molecular level, microbialattachment to the solid feed particles entering the rumen is an important prerequisite of digestionof the feedstuffs (Cheng et a!., 1984). Bacteria and protozoa are the predominant microbialforms in the rumen, but it has also been demonstrated that appreciable numbers of anaerobicfungi are associated with the feed particles and also contribute to the digestion of feedstuffs(0rpm, 1983).E. Role of Rumen Microbes in the Digestion of FeedstuffsMicro-organisms capable of degrading plant fibre (i.e., cell walls consisting of celluloseand hemicellulose) comprise an important part of the microbial population. Rumen bacteria arethe most important degraders of the cellulosic materials that ruminants ingest as part of their dietryant, 1973).Some species of cellulolytic rumen bacteria are Bacteroides succinogenes, Ruminococcusatbus, R. flavefaciens, Clostridium tongisporum, C. locheadii, Ciltobacterium cellulosotvens,Cellulomonas fimi and Butyrivibrio fibrisolvens (Hungate, 1966). The most importantcellulolytic species, based on numbers and ability to degrade cellulose, are B. succinogenes, R.atbus, and R. flavefaciens (Bryant, 1973). Ruminococcus spp. are hemicellulolytic as well ascellulolytic. Although B. succinogenes has been reported to degrade hemicellulose it cannot8utilize xylan, which comprises a large part of hemicellulose (Dehority and Scott, 1967). B.fibrisolvens and Eubacterium degrade hemicellulose.A polymer not present in cell walls but important in many feeds, especially grains, rootsand tubers is starch. The ability to utilize starch as a carbon source is widespread among strainsof rumen bacteria, protozoa and fungi. Principal among the amylolytic rumen organisms are thebacteria Bacteriodes amylophilus, Streptococcus bovis, Succinomonas amylolytica, many strainsof Selemonas ruminantium, Bulyrivibrio flbrisolvens and Eubacterium ruminantium, andClostridium spp. (Russell and Hespell, 1981; Marounek and Bartos, 1986), virtually all of thelarger entodiniomorph protozoa, and the chytrid fungus Neocallimastrix frontalis (0rpm andLetcher, 1979; Pearce and Bauchop, 1985).Even though amylolytic protozoa and fungi are not considered essential in starchdigestion, it has been suggested that engulfing of starch granules by protozoa limits the amountof starch available for the rapid bacterial fermentation and so helps to prevent a detrimentallowering of rumen pH (Williams and Coleman, 1988; Dawson and Allison, 1988). The ability ofthe larger rumen ciliates to engulf and subsequently metabolize starch granules is well known.Among the holotrichs this ability is limited to Isotricha, but among the entodiniomorphs it isvirtually universal.F. Improvement of Low Quality FeedstuffsVarious methods have been developed based on knowledge of the structure of feedstuffs,the ecology of the rumen environment and the mode of action of the rumen micro-organisms toimprove the utilization of feedstuffs. These include physical processing, and chemical andmicrobiological treatments of the feedstuffs. Physical processes such as grinding, chopping andcompacting have been used to improve the intake of low quality feedstuffs by animals. The effecton intake is partly due to the reduction in the bulk of the feed and the chewing time required toreduce the particle size of the ingested feedstuffs to sizes that can pass through the reticuloomasal orifice (Welch, 1982). It is, however, unlikely that many of the commonly used physical9processes like chopping and milling actually increase the digestibility of cellulose or hemicelluloseby rumen micro-organisms. Only extreme milling treatments (such as ball milling) which disruptfibre structures at the molecular level are capable of increasing the digestibility of cellulose andhemicellulose to any appreciable extent (Walker, 1984). Steam treatment of materials at highpressures have been shown to increase digestibility but this has lost its appeal due to its highenergy demand. Compaction of roughages through cubing or pelleting has advantages such asincreased density (reduction in dustiness), improvement in handling and, reduction in wastage.These treatments or processes subsequently lead to increased intake of the roughages by animals.However, the initial capital investments are high and is therefore of limited value to the Ghanaiansituation.Chemical treatment is considered to be the most effective method of improving thefeeding value of low quality lignocellulosic agricultural by-products (Jackson, 1977). Sodiumhydroxide is accepted as the most effective chemical for treatment of crop residues. The in vivoorganic matter digestibilities of chemically treated materials are usually superior to those ofuntreated materials. The effect usually being more pronounced in highly lignified materials(Jayasuriya and Owen, 1975, Jackson, 1977). The increase in the extent of digestion is thought tobe the result ofbreaking bonds between ligmn and cellulose or hemicellulose (Van Soest, 1975).The disruption of the bonds between lignin and cell wall carbohydrates makes the lattermore accessible to hydrolysing enzymes (Theander and Aman, 1984; Lindberg et a!., 1984).Although sodium hydroxide treatment of crop residues can significantly improve intake anddigestibility, it has several drawbacks which preclude its use in Ghana. Some of these drawbacksinclude; the high cost of the chemical, concerns about human safety due to its corrosive nature,contamination of the soils and water as well as concern regarding possible mineral imbalances inanimals consuming sodium treated material.Ensilage is the preferred microbiological method for preserving and utilizing wetagricultural by-products especially from the fruit and vegetable industry. However, when dry byproducts are ensiled very little improvement in animal productivity is observed (Kiflewahid,101982). Ensuing wet by-products could be of value to feedlot operators but not to the small scalefarmer in view of expenses associated with processing the materials and maintenance of the silos.Most of the above treatments often result in increased intake and/or digestibility of thetreated materials. However, the materials treated are usually inherently deficient and/orunbalanced in most of the nutrients required for efficient rumen digestion and utilization of thefermentative products of digestion. Therefore, these increases are often not reflected in animalproductivity.Preston and Leng (1981) suggested that in order to optimize the utilization of fibrousagricultural by-products, animals must be provided with readily fermentable energy and protein;rumen by-pass protein and by-pass energy; and, micronutrients like sulphur, phosphorus and Bvitamins. Urea, animal by-products, oilseed cakes and cereal milling by-products are the logicalnitrogenous and energy supplements when available (Preston, 1986). The costs of protein andenergy supplements, and the technical difficulties of using physical, chemical and microbiologicaltreatment preclude their use in Ghana.In Ghana the cheapest means by which requirements for essential nutrients could beprovided would be through the strategic use of fodder trees and shrubs such as Acacia (Acaciasp.), ficus (Ficus spp.), gliricidia (Gliricidia maculata), terminalia (Terminalia sp.) and leucaena(Leucaena leucocephala) as supplements. These fodder trees are found in relative abundance inand around the urban areas. They constitute a valuable production resource which has not beenexploited in any systematic manner as supplements (Smith, 1992). The improvement indigestibility, intake and growth rate of ruminants through supplementation of diets based onagricultural by-products with fodder trees and shrubs have been demonstrated by Reed et al.,(1990), Kass, et al., (1992), Smith and van Houtert (1987), Ndolvu and Buchanan-Smith,(1985).11G. General Research MethodologyThe efficient utilization of production resources is an indication of the economic successof a production system. The magnitude of this success would largely be determined by themanner in which production resources are utilized. The scope for increasing the efficiency of feedutilization in innovative feeding systems in a situation like the one that exists in Ghana isenormous as demonstrated by Devendra (1979) with goats and by Soetanto (1986) with sheep inAsia. The components of such a strategy include the use of a wider selection of traditional andnon-conventional feeds in dietary formulations and feeding systems that can sustain year-roundfeeding and intensive systems of production in proximity to the location of the feed sources. Thisstrategy has long been recognized in Ghana and a considerable amount of research has beenconducted in the country to ensure the efficient utilization of most of the agricultural by-productsand fodder trees by livestock (Osei 1990; Tuah, 1989; Tuah et al. 1985; Okai and OpokuMensah, 1988; Okai et a!., 1985). Most of the research identified new non-conventionalfeedstuffs or developed methods to improve their utilization by livestock. However, very little, ifany, of the findings have actually been adopted by livestock producers in the country.The reason for this could be due to the fact that researchers have usually overlooked orignored the systemic inter-linkages of biological and socio-economic conditions within farminghouseholds. As a consequence, significant relationships have been missed and envisionedimprovements have not always materialized. To avoid a similar situation and to deal with theseinter-linkages, a multi-disciplinary research approach and an overall systems perspective wasadopted in this study.H. Farming Systems Approach to ResearchThe approach to research, commonly called Farming Systems Research (FSR), is definedas applied, farmer-oriented, agro-biological research which is supported by the socio-economicsciences in a team effort to generate appropriate technology (Byerlee et a!., 1982). Farming12Description and Analysis of Existing Farming Systems• Partitioning Into Homogenous Farming Systems• Identification of Problems/ConstraintsTechnology Design and Development• Biological Research on Experimental Stations• On-Farm Trials With Farmer Participation• Farmer-Managed Trials• Evaluation of TechnologyResults Dissemination in Recommendation Domains• Continued Evaluation of TechnologyFigure 1.1. Schematic representation of Farming Systems Research (FSR).13Systems Research usually includes extension responsibilities. The principal product in FSR istechnology and the primary clients are the farmers. Although FSR is flexible enough to fit theagricultural and institutional conditions found in different countries and under different culturalconditions, it usually involves three major steps (Norman and Baker, 1986). A typical schematicrepresentation ofFSR (adapted from Hildebrand and Waugh, 1986) is presented in Figure 1.1.Hildebrand and Waugh (1986) have observed that in many ways this sequence parallelswhat farmers have always done. Farmers manage a complex set of biological processes whichtransform the resources at their disposal into useful products, either for home consumption or forsale. The choice of livestock enterprise and husbandry methods are determined not only byphysical and biological constraints, but also by economic and socio-political factors, which makeup the larger milieu within which the farmer operates.I. Research Methods Adopted in this StudyBecause of time constraints all the steps above were not completed in this study. The on-farm trials are to be conducted by Staff of the Animal Science Department of the University ofScience and Technology and, the Ministry of Agriculture in Ghana. The sequence of steps takento achieve the main objective of this component of the (IDRCIUST) project were:1. Description and analysis of the existing farming systems through closeconsultation with farmers. The methods employed included diagnostic surveys(modified Rapid Rural Appraisal, RRA), and a formal survey with semi-structuredinterviewing. This facilitated the characterization and analyses of constraints andopportunities.2. Identification and pre-screening of available feedstuffs which could form the basisof a feeding system. This involved chemical analyses; and dry matter and nitrogendegradability estimates. Selection of feedstuffs was based on socio-economicconsiderations and results of the pre-screening exercise.143. Nutritional evaluation of selected feedstuffs under research station conditions.Among other things, this involved the measurement of intake, digestibility andgrowth rate of sheep and, microbial colonization and digestion of the feedstuffs.4. Development of a set of recommendations for the development of the urban smallruminant industry.As mentioned earlier small ruminant production in the urban communities is only one of anumber of enterprises that contribute to the diversity of the larger household economy.Moreover, because of the intricate role of small ruminants in these households, the overallstrategy adopted in the development of recommendations was based more on socio-economicconsiderations than technical achievement alone. This was to ensure that recommendedtechnologies are compatible with the established production systems and other activities in thehouseholds. The advantages of matching feed resources with existing livestock systems in amaimer that aims for economic and social optimization rather than biological maximization havebeen demonstrated in several instances by Preston (1982) and Preston and Leng (1987).J. General Research ObjectivesThe overall objective of this thesis was therefore to identify and evaluate feedstuffs whichcould be recommended for use in the development of a nutritionally balanced and economicallyviable feed package for small ruminants in the urban centres of Ghana. The specific objectiveswere:1. To describe the small ruminant production systems in the urban and pen-urbancentres in Ghana, and to identify the major production constraints and recommendmeasures to overcome these constraints (Chapter 2).2. To identify a basal and a supplementary feedstuff available in and around theurban areas of Ghana for small ruminant feeding (Chapter 3).3. To assess the nutritional quality of the feedstuffs identified in (2) above (Chapters4 and 5), and4. To study the microbial digestion of the feedstuffs and the effect of the feedstuffson the bacteria! population in the rumen of sheep (Chapter 6).1516CHAPTER 2 URBAN HOUSEHOLDS AND SMALL RUMINANTPRODUCTIONA. IntroductionSmall ruminants have been an integral part of most urban and peri-urban households inGhana for a long time. Moreover, it is unlikely that current production systems and the resourcesused to support them will change substantially in the foreseeable future. However, in most urbanhouseholds their production is only one of a number of enterprises that contribute to the diversityof the larger household economy. It is therefore essential that any research or developmentstrategy should take into account most of the socio-economic variables and other external factorsthat impinge on the household.Any particular farming system is the result of a set of elements or components that areinterrelated and interact among themselves toward the realization of the goals of individualfarmers or the system as a whole. At the centre of this interaction is the farmer or household.Thus both farm production and household decisions of farmers are intimately linked and shouldbe analyzed as such. A specific farming system arises from the decisions taken by the fanner orfarming household with respect to allocating different quantities and qualities of land, labour,capital and management to crop, livestock and off-farm enterprises, in a manner which given theknowledge the household possesses, will maximize the attainment of the family goals (Jahnke,1982). It is therefore essential to understand the existing production system in light of the socioeconomic environment of the household within which farmers operate before any attempts aremade to introduce any changes.Therefore, the objectives of this component of the study were to describe the smallruminant production system within urban households; identify the opportunities and constraintsof urban livestock development; and in the light of these, make recommendations to improve thesystem.17B. MethodologyAs mentioned earlier, very little is known about the small ruminant production system inthe urban and pen-urban areas; therefore, a diagnostic survey was conducted in Kumasi andEffiduasi. These two cities, in the Ashanti Region of Ghana, are in the humid forest zone of thecentral part of the country. The main objective of the diagnostic component of the study was toexplore details of some key topics such as feed resources, management practices, constraints andopportunities (Appendix 2. 1).This information was required to formulate a detailed questionnairefor a formal survey and also provide a better understanding of the small ruminant productionsystems in the urban communities.The method used in the diagnostic survey was semi-structured interviews of producersand direct observation of their households. This technique was chosen because of its inherentflexibility in probing a largely unknown research topic (Lovelace et at., 1990).A total of 48 households in the two locations (24 in each of Kumasi and Effiduasi) wereinterviewed. Sampling of suburbs and households in the two towns was purposeful. Within eachtown only suburbs known to have a significant livestock population were sampled. While withineach suburb only households engaged in small ruminant production were subsampled. The list ofsuburbs and households which fell into each group from each of the towns was obtained from theAshanti Regional office of the Department of Animal Health and Production. A random sampleof three households from each of eight suburbs in Kumasi and two households from each of 12suburbs in Effiduasi were selected. In addition ten operators of “chop bars” (local restaurants),two workers at “gari” (fermented cassava product) processing factories and the Secretary of theKumasi Small Ruminant Sellers Association were interviewed. Two officials of the Departmentof Animal Health and Production Division of the Ministry of Agriculture were also interviewed.The District Chief Executive of the Efigya-Sekyere District Council, of which Effiduasi is thecapital, was also consulted.The results of the diagnostic survey was used to formulate a detailed questionnaire whichcontained structured and open-ended questions (Appendix 2.2). The questionnaire consisted of18two schedules; household information (socio-economic questions) and, animal rearing activities(animal numbers, production resources and constraints).The questionnaire was tested, refined and finally administered to 120 households. Thiswas made up of 58 households from 12 suburbs in Effiduasi and at least six households fromeach often suburbs in Kumasi (62 households). The households were randomly selected from thelist of households in the selected suburbs which was compiled during the diagnostic survey in thetwo towns. The questionnaires were administered with the help of two officials of theDepartment of Animal Health and Production Division of the Ministry of Agriculture, twoteachers and one official of the Committee for the Defence of the Revolution (CDR).Most of the data, except open-ended questions, were coded and analyzed with SPSS-x(1988) software package.C. Results and DiscussionApart from the types of small ruminants kept and the main feed resources, there were nosignificant differences between any of the variables measured between producers in Kumasi andEffiduasi. Producers in Effiduasi kept more goats than sheep and relied more on pastures andforages to feed their animals than producers in Kumasi. Therefore all the data except that of thetype of animal and feed resources were pooled and analyzed as one. The main breed of sheepkept by urban producers was the Djallonke. Most of the goats were of the West African Dwarftypes. They are both “indigenous” breeds and are trypanotolerant. There were, however, fewcrosses with the Sahelian type.1. Reasons for keeping small ruminantsRespondents gave a number of reasons for keeping their animals. Irrespective ofbackground, the majority of them (62% of goat owners and; 52% of sheep owners) citedfinancial considerations as the primary reason for keeping small ruminants (Table 2.1).19Table 2.1. Reasons for keeping small ruminants.1Reason Ruminant TypeGoats SheepFinancial only 28 25Meat only 2 4Religious and social only 4 5Financial and others 34 27Meat and others 25 14Religious/social and others 7 25‘Values are percent of respondentsNumber of respondents in each category: goats only = 95; sheep only = 80.No. of animals1-3 80.54-6 14.67-9 0______10+ 4.9‘Values are percent of respondents2Number of respondents 923Number of respondents = 64Table 2.2. Number of animals in the breeding herd.’Goats2 Sheep3Males Females Males FemalesPercent Percent56.5 83.7 43.821.7 16.3 29.710.9 0 7.810.9 0 18.820Some of the financial reasons given were provision of cash for paying school fees of dependantsand meeting both anticipated and unanticipated expenditures like hospital bills and emergencies.In earlier times, “prestige” was a term used, often in a derogatory manner, to describe therationale behind keeping livestock by traditional livestock owners (Wilson, 1991). Traditionallivestock owners were also described as conservative and not motivated by economic or profitconsiderations. While the studies ofNtifo-Siaw and Ghartey (1988) and Adebowale eta!. (1993)appear to support this position, the present study does not. While the present study was based onurban and peri-urban populations, the earlier studies were done in rural communities. Economicand social demands made on these populations may be different and may probably account forthe different production objectives observed. Both Ntifo-Siaw and Ghartey (1988) andAdebowale eta!. (1993) reported that the majority of producers kept livestock for traditional andcommercial reasons. Only 7% of producers in their studies kept livestock for purely commercialreasons as opposed to more than 25% reported in the present study. This study supports theview that the reasons why urban producers keep livestock are rarely irrational and that thereasons are related to their particular needs either in the long or short term.This observation was further supported by the sex structure of flocks (Table 2.2). Therewas always a preponderance of females in larger flocks (>4). The emphasis here is that almost allanimals in the flock are “productive”, whether “production” consists of giving birth to young orsimply undergoing the process of growth to a size at which another product (meat orreproduction) becomes the principal one. Similar flock structures in small ruminants kept by theMoors in Mauritania, the Fulani in Mali, and the “Arabs” in Chad have been reported by Wilson(1991).The major management practice used to obtain stability in the flocks was culling andpreferentially disposing of males not required for breeding (Table 2.3). Animals not required forbreeding were sold. Table 2.2 indicates that the number of males in breeding herds was, strictlyspeaking, in excess of those required. However, as noted by Wilson (1991), this is a sort ofinsurance against sterile and temporary infertility in the males.21Dietary factors (provision of meat for the household) was an important consideration inthe Islamic and the more affluent households where animals were slaughtered and consumedduring religious festivals like Id dir Kabir”, Christmas and Easter holidays and social occasionslike naming ceremonies and birthday celebrations. Only 7% of respondents kept goats forreligious and social reasons while the corresponding figure for sheep was 25%. The higher figurefor sheep could be a reflection on the role of this species in the religious activities of Moslemswho invariably kept more sheep than goats. Among the Moslem community, sheep werepreferred to goats because of their religious significance. During the celebrations of some IslamicfestivalsTable 2.3. Preferred age, sex and time of disposal of small ruminants.Category Goats SheepPreferred age (yr)1 33.7 18.32 10.9 11.53 27.7 20.2>3 27.7 45.2Preferred timeReligious or social 27.4 35.2Financial need 6.5 7.1“When price is right” 66.1 57.4Preferred sexMales 48.7 32.8Females 29.7 26.2Both 21.6 41.0Number of respondents = 12022the slaughter of intact male rams is required by all families so each house tends to keep sheepwith the aim of not having to buy a ram at the time of the celebrations, although those who couldnot afford sheep could slaughter intact goats.2. Ownership patternsSmall ruminants were owned by individual men and women, rather than by domesticunits. In this respect it may represent a unique resource in terms of empowerment of women andother disadvantaged groups such as the aged, illiterate and unemployed. The percent of women,aged (60 years and over), illiterate and unemployed who possessed small ruminants were 33, 27,43, and 6% of respondents, respectively (Tables 2.4 and 2.5). Table 2.5 shows that smallruminant production in the urban centres is a secondary household activity. Only 20% ofrespondents were full-time farmers (i.e., total household income was derived from the sale ofcrops and/or animals only). The rest of the producers were engaged full-time in other activities.The implication of this for development is that any changes in the practices of farmers whichwould require substantially more “farm” work (when they are already burdened with off-farmwork), or a substantially greater expenditure on inputs (when cash is very scarce), might involvesacrifices of opportunities for off-farm employment or of consumption that would make thechanges seem impractical to such farmers. Another positive aspect of these observations is thatthe small ruminant rearing activity in these areas is not the predominant activity of one gender orthe aged as found in other agricultural activities such as cocoa farming and food processing(Sarris and Shams, 1991). This ensures a broad base for the supply of labour.The small ruminant foundation stock of most producers was acquired mainly throughpurchasing (72%). About 22% of respondents received their first animals as gifts while the rest(6%) were care-takers who used their share of the flock to build their own herds (Table 2.6). Theacquisition of small ruminants was relatively easy and so even the “poor” (people with nothingthey can call assets) can afford to raise them. This could be inferred from the assets ofrespondents (Table 2.6).23Table 2.4. Ownership patterns of small ruminants by age, sex and educational level of owners.Category Proportion of owners (%)Age (yr)<29 1530-39 2240-49 2150-59 1660+ 27Educational LevelNo formal education 43Up to High school 49Above High school 8SexMales 67Females 33Number of respondents = 120Table 2.5. Occupational distribution of small ruminant owners.Type of Occupation %Farmers 20Civil servants 2Technicians/artisans 24Traders 14Pensioners 7Others 27Unemployed 6Number of respondents = 12024Table 2.6: Mode of acquisition of small ruminants and assets of ownersMode of Acquisition % Type of Asset %Purchase 72 Houses 58Gift 22 Machines 6Caretaker 6 Others 4None 32Number of respondents in each category = 1203. Flock types and sizesGoat ownership was more widespread than sheep ownership in the two locations. About31% of households owned only goats while 27% kept only sheep. Twenty one percent kept bothgoats and sheep and; 22% kept other types of livestock (e.g., cattle, rabbits, guinea pigs andpoultry) in addition to goats and sheep (Table 2.7). Similar findings were reported by 1LCA(1980) for countries in West Africa. In the humid zone ofNigeria it was reported that 3 7.4% and8.3% of households kept goats and sheep, respectively. In Cote D’Ivoire 27.1% kept goats and23.2% kept sheep. However, in terms of number of animals owned, producers kept more sheepthan goats. About 41% of households kept between 6-10 sheep, 13% kept between 11-15 and21% kept more than 15 sheep. The corresponding figures for goats were; 36%, 17% and 15%(Table 2.8).There was a difference in the types of animals kept in the two locations (Table 2.7).Livestock owners in Effiduasi kept more goats than sheep compared to those in Kumasi. About52% of producers in Effiduasi kept only goats while about 17.2% kept only sheep. Thecorresponding figures for producers in Kumasi were 11.3% and 3 5.5%. About equal numbers ofowners (20.7% in Effiduasi and 21% in Kumasi) kept both sheep and goats. The proportionwhich kept both sheep and goats with other types of livestock was higher in Kumasi (32.2%),than in Effiduasi (10.4%). The main reason given by respondents for their preference for goats25was that goats are hardier and required less attention (i.e., they are better browsers than sheepand can therefore obtain their nutrient requirements from browsing or scavenging). Therestriction on animal movement in Effiduasi was not as strict as that imposed by authorities inKumasi, animals could, therefore, be left on their own for a considerable amount of time andrespondents believed that goats were better at taking care of themselves.Wilson (1991) also noted that livestock owners in tropical Africa keep a higherproportion of goats compared to sheep because goats are generally more prolific and capable offoraging more widely and on more feed types than sheep. This would make goats easier tomanage for people with little experience with animals.Table 2.7. Small ruminant distribution by location.Class Prevalence (%)Kumasi Efilduasi TotalGoatsonly 11.3 51.7 30.8Sheep only 35.5 17.2 26.7Goatsand Sheep 21.0 20.7 20.8Goats, Sheep and Others 32.2 10.4 21.7Number of respondents 62 58 120Table 2.8. Herd/Flock sizes of small ruminants.No. of animals Goats (%) Sheep (%)1-5 32 256-10 36 4111-15 17 13>15 15 21Number of respondents = 12026Table 2.9. Management decision making and allocation of labour within housholds.Category FrequencyManagement decisionsProducer 79.2Household-head 10.0Spouse 5.8Consultations 5.0Labour for feedingProducer only 55.0Children/Family members only 31.7Hired-hand only 1.0Family members and Hired -hand 12.3Labour for sanitation dutiesProducer only 38.3ChildrenlFamily members only 25.8Hired-hand only 6.7Family members and Hired-hand 29.2Number of respondents = 1204. LaborLabour requirements were dependent upon the production system and herd/flock size.Generally it was observed that the labour requirements for the daily activities was low. The mainactivities which required labour were feeding and sanitation. In most cases labour was suppliedby members of the household (the producer, children and other family members). There seemedto be a pattern of allocation of tasks between family members (Table 2.9). In 55% of cases,producers themselves were responsible for feeding their animals. Children and other familymembers were responsible for feeding in about 32% of the cases. The use of hired-hands was27low. In sanitation related duties, children and hired-hands performed the bulk of the duties (5 5%)which included sweeping of pens and cleaning of feeding and drinking troughs. The sanitationrelated duties were regarded as menial and had to be performed by children or hired-hands.Differences between level of confinement was a function of population density yEs a yEsavailability of undeveloped lands or available pasture in the locality. The closer one gets to thecentre of the cities, the more intensive the system and the greater the labour requirements forfeeding and sanitation related duties. The low labour requirements and the limited skill requiredto maintain a small flock made it possible for the household to generate an economic return fromfamily labour that has little or no opportunity cost.5. Feed ResourcesIn a farming system context, ruminant production systems are particularly dependent onvegetation, and arable and perennial cropping for their feed base. The feed component isespecially relevant as it is the primary link between crops and animals. The interaction betweencrops and animals provides for important socio-economic factors advantageous to the farmhousehold and provides stability in farming systems.The feed resources identified were permanent pastures and forages, and agro-industrialby-products from agricultural processing industries and households (Table 2.10). The permanentpastures were found along roadsides and undeveloped or partially developed plots of land. Only3% of respondents used only pastures or browse to feed their animals. About 8% of respondentsused only cereal (milling by-products and brewers spent grains) and root and tuber crop (cassavaand yam) by-products. The majority of respondents (32%) used household garbage from foodpreparation (peels of cassava, plantain, cocoyam, yam, etc.). An equally large number ofrespondents used a combination of pasture/browse, cereal by-products and household garbage.The last group of respondents (25%) used a combination of pasture/browse and cereal byproducts.28Table 2.10. Sources of feed and methods of feeding small ruminants.Classification %Source ofFeedPasture/browse 3Cereal and root by-products 8Household garbage from food preparation 32Pasture/browse + by-products 25Pasture/browse + by-products + household garbage 32Method of feedingHand feeding/cut-and-carry 45Free range - grazing/browsing/scavenging 3Herding - on roadside/abandoned plots 7Free range and hand feeding 33Herding and hand feeding 12Number of respondents = 120These results show that agro-industrial by-products such as brewers spent grains and maltfrom the brewery industries, and cassava peels from household food preparation, “gari” and“chop bar” operations were the most important feed resources.The agro-industrial feedstuffs were usually obtained in the “wet form” i.e. contained ahigh moisture content. About 85% of respondents processed these before feeding or storage(Table 2.1 1). Processing involved chopping and drying. Almost 53% of respondents had oneform of feed storage facility or another. These consisted of stores (14%), baskets (25%), bags(18%). The duration of storage was, however, usually less than one month (97% of cases).Overall, the fiscal cost of production was low (Table 2.12). The direct cost,transportation and storage of feed was negligible in most cases. The opportunity cost of labourinvolved in acquisition of feed by children was also said to be minimal. Less than 20% of29respondents spent more than 10,000 cedis per year to purchase feed for their animals. Theamount was spent as occasional gifts to 11chop-bar” operators for cassava peels. A few of them,however, usually purchased brewers spent grains from the breweries and cassava peels from the“gari” processing factories.The predominant forage species in the pastures found in these areas were Guinea grass(Panicum sp.) and Elephant grass (Penisetum purperum). The main legume species wasCentrocema sp. Producers had no control over this source of feed and had to share it with othermembers of the community. In some cases its availability throughout the year could not beguaranteed as the roadsides were weeded periodically by local government officials andundeveloped pieces of land were cleared for development.Ficus sp. and Terminalia sp. were the major browse species fed to the animals byrespondents. Occasionally, others fed leaves of the mango, banana, plantain and cassava plants.Ficus was the most widely used browse and according to respondents, the most preferred by theanimals.Table 2.11. Processing and storage of feed among small ruminant producers.Category Proportion of respondents’ (%)Processing 85.0 (120)Storage 52.5 (120)Processing before Storage 84.1(64)Duration of Storage (64)<1 month 96.81-6months 1.6>6 months 1.6‘Numbers in parentheses indicate the number of respondents30Grazing on roadsides and on communal (undeveloped) land was practised mainly byproducers living near the fringes of the cities. In a few cases tethering of animals was done onroadsides and undeveloped plots. This was mostly the case when the location was close to theproducer’s house or where there was a lot of commercial activities going on so the danger oftheft was reduced. In Effiduasi, free-roaming systems were predominant, probably because ofTable 2.12. Yearly expenditure on acquisition of feed (cost, transportation and storage).Category Cost in Ghanaian Cedis % of respondentsFeedNegligible 75.7<4,000 7.54,000 - 10,000 1.0>10,000 15.8TransportationNegligible 67.5<4,000 28.24,000 - 10,000 1.0>10,000 3.3StorageNegligible 61.2<4,000 8.34,000-10,000 11.1>10,000 19.4Number of respondents = 12031less pressure on land. Under such conditions animals do not make heavy demands on the time,cash or management resources of producers. Also because land used under these situations iscommunal, even the landless may engage in small ruminant production.Some livestock owners practised what is called a cut-and-carry system. In this case,forage was brought in from outside the house and fed to the animals. In some situations this feedserved a supplementary role, whereas in situations where herd/flock size was small it could be theonly source of feed. This system, however, required a high investment in labour and alsodepended on the seasonal abundance or shortage of forage. Because the supply of feed wassporadic, and in most cases inadequate, animals raised under this system usually fair worse thanunder the free-roaming and other systems.6. Management practicesMajor management decisions (marketing, flock structure maintenance and disposal) wereusually taken by the producers (79% of cases) or by the household head - in situations whereowners were themselves dependants (10%). The proportion of goat owners who practisedculling, castration, vaccination and deworming of their goat herds, was 54%, 60.5%, 95.4% and69%, respectively. The corresponding figures for sheep flock owners were; 39.4%, 47%, 78.9%and 81.7%, respectively (Table 2.13). The reason given for the high incidence of castration ingoats was to remove the taint associated with goat meat and to make the animals moremanageable. Male sheep were usually not castrated because intact males are usually sold at apremium during Islamic religious festivities. Culling was practised to remove unproductivefemales and slow growing animals.Feed sanitation was identified as the practice of cleaning feeding and drinking troughs atleast twice weekly. Animal sanitation involved washing animals periodically to control mites, andhousing sanitation was identified as the practice of cleaning the pens and holding areas of animalsat least twice a week. Goats were, however, not washed as frequently as sheep because of thebelieve that goats do not like to get wet. Most producers used domestic detergents and water to32Table 2.13. Prevalence of some management practices among small ruminant producers.’Type of practice Goats SheepCulling 54.0 39.4Castration 60.5 47.0Vaccination 95.4 78.9Deworming 69.0 81.7Animal sanitation 12.5 56.8Feed sanitation2 94.0 --Housing sanitation2 100.01 Values are percent of respondents2Combined value for goats and sheepNumber of respondents = 120wash their animals while a few prepared solutions with lindane-based insecticides such asGammalin-20.The present observations support the hypothesis that the traditional livestock producer isvery much aware of the role of management in the avoidance and control of diseases (Ibrahim,1986; cited by Ntifo-Siaw and Ghartey, 1988). Many producers were aware of some of theprevalent diseases such as peste de petits ruminants (PPR), diarrhoea and worm infestations, and,as discussed later, took precautions such as routine vaccinations and deworming to prevent theiroccurrence.Producers did not practice any form of controlled mating (90% of matings were random).The reason given for this was that animals were usually kept together or were allowed to movetogether with animals of other households, so there was no way of controlling breeding. Theproblem with this practice is that producers had no means of preventing or controllinginbreeding. On the whole one could conclude that the urban livestock producer is very33knowledgeable in terms of animal management. This is a valuable resource which should beexploited in any development strategy.7. MarketingSheep and goat meat is an important source of animal protein in the urban and peri-urbancentres throughout the year. The major route of disposal was by direct sale by producers at thefarmgate. Buyers were mainly local restaurant (chop bar) operators, butchers, consumers andmiddlemen depending on the purpose for which animals were purchased. While restaurantoperators, butchers and consumers slaughtered animals and sold the meat in one form or theother; the middlemen resold the animals, usually on the local small ruminant market at Asuasi.While it appeared that there was no particular time for disposing of animals, producers wereinclined to market their animals during religious and social occasions because buyers wereinclined to pay more for the animals than during other times of the year. All buyers identified,except the occasional consumer, are in the business to make profit, whereas urban producerskeep their animals for a variety of reasons. The implication of this is that when producers requirecash immediately to pay for unexpected expenditures, the price offered by the buyers is usuallyfar below the market price, Some producers, however, did not consider this a major problemsince they thought that they always recoup their profit during the religious holidays among theMoslem and Christian communities.Another route of disposal in these areas was that sheep and goats were slaughtered onoccasions by the producer and part or all the meat sold and consumed among neighbours.Because of the rapid increases in population, rural-urban migration and increases in income,demand for sheep and goat meat would continue to increase. Goat meat is now considered adelicacy among the urban elite and the not-so-wealthy folks so product market demand does notappear to be a problem for now and in the foreseeable future.348. Constraints in urban livestock production.Constraints were prioritized by respondents without prompting from the enumerators.Producers perceived lack of capital/credit as the single most important constraint. However, anex ante analysis of the production system indicated that animal losses, due to health-relatedproblems, could be the main factor retarding the small ruminant industry in the urban centres.Losses were very high among the flocks. About 56% of owners had lost between fourand ten goats the previous year. Sixty-three percent of owners lost between four and ten sheep.The main causes were theft (17%), accidents (12%), identifiable diseases (14%), unidentifiablediseases (20%) and miscellaneous causes such as poisonings, complications arising fromcastration, pregnancy and parturition (Table 2.14). If losses due to miscellaneous causes aregrouped with diseases as health-related, then the health-related factors accounted for more than70% of all losses. In Kumasi the second most important cause of loss was theft. The loss ofanimals through accidents and poisonings usually came about when producers allowed theiranimals to wander about without supervision or stray onto people’s properties.While losses involving vehicles (accidents) were not blamed on drivers, very few lossesdue to poisonings were deemed accidental by respondents. They believed that neighbours,opposed to their keeping animals, deliberately poison the animals in retaliation for the destructionof their food and ornamental crops or for what they consider as the nuisances they have to putup with all the time (e.g., noise, smell of manure and fouling of their compounds). Fights andlitigations have occasionally broken out among producers and neighbours over these complaints.According to local government officials those are the main reasons why they have had to restrictthe movement of animals within the municipalities. Within certain suburbs, animals found outsideare impounded by local government officials and the owners fined before the animals are returnedto them. Some producers complained that the amount demanded for the return of the animalswas in most cases more than the market value of the animals.As indicated earlier, mortality due to diseases among small ruminants in the urban areas isunacceptably high. The epidemic diseases such as peste des petits ruminants (PPR), contagious35caprine pleuropneumonia, mite and worm infestations are nation-wide health risks. In a study ofthe causes of mortality on farms in a district near Kumasi, Tuah et al., (1988) found that PPRwas the disease that caused the most deaths while parasitic gastro-enteritis was the mostwidespread disease among the farms. The same observation holds true for the Kumasi District,according to the Kumasi District Veterinary Officer (Dr. Akyeampong, personal communication).PPR is a viral disease of sheep and goats characterized by fever, diarrhoea and pneumonia.Infected animals usually die within a week after the start of the fever (Koper-Limbourg andOyeyemi, 1993). PPR cannot be treated effectively but it can be prevented through yearlyvaccination with the Tissue Cultured Rinderpest Vaccine (TCRV).About 69% of respondents had taken measures, including vaccinations, to control theirlosses. Among those who had taken measures about 76% of them had found the measures takento be effective. It is pertinent to note that most measures taken to reduce losses had been taken inconsultation with veterinary officials. The competence and expertise of these officials is welldocumented but their efforts have occasionally been thwarted by logistical problems. Sarris andShams (1991) in a publication for the International Fund for Agricultural Development noted thatthe Animal Health and Production Department of the Ministry of Agriculture (i.e., theVeterinary Services Department) is one of the most effective in West Africa. However, becauseTable 2.14. Causes of small ruminant losses.Cause %Identifiable diseases 14Non identifiable diseases 20Accidents 12Theft 17Miscellaneous 37Number of respondents = 12036of delays in procuring drugs and vaccines due to fiscal constraints, some vaccination programsare not carried out on schedule with the result that outbreaks occur before measures are taken tobring them under control. Private companies are now allowed to procure and sell veterinarydrugs and chemicals, including anthelmintics, coccidostats, disinfectants, feed additives, dressingsand acaricides. With the availability of drugs and vaccines on the local market what is needed isto motivate veterinary officials so that they can pay frequent visits to producers to advise andassist them when necessary. This could effectively reduce most of the losses attributable todiseases.It is to the credit of producers that they practice routine vaccinations but as noted above,occasionally there have been reports of lack of vaccines and/or ineffective vaccines being used(the result of ineffectual quality control and/or monitoring of the companies engaged in theimportation and distribution of veterinary drugs). For example, the TCRV comes in vials withdoses for 100 to 200 animals and once opened has a life span of only an hour. The small numberTable 2.15. Constraints on production of small ruminants.Classification %Single constraintsHealth only 8Credit only 20Feeding 5Multiple constraintsHealth and credit 15Health and feeding 18Credit and feeding 21Others (e.g. space, theft, labour, etc.) 13Number of respondents = 12037of animals and the spread of households in the urban centres indicate that fewer than 100 animalswould be vaccinated within the one hour time frame. The need, therefore, exists for producers toorganize themselves especially for PPR treatment. The huge losses suffered by producers as aresult of diseases indicate that if improved control of diseases could be achieved, the potential forincreasing flock sizes and production would be tremendous.As reported earlier, the majority of respondents cited lack of credit/capital as the singlemost important constraint to increased productivity (20% compared with 8% who cited health,and 5% who cited problems related to feeding; Table 2.15). Credit/capital was required to (1)improve existing infrastructures (e.g., build pens/barns), (2) increase flock size, and (3) purchasedrugs for routine drenching and vaccinations of animals. Respondents noted that credit from theformal sectors of the economy (financial institutions) was almost impossible to obtain becausethey lacked the collateral usually demanded by the institutions.As noted by Winrock International (1983), the problems in supplying credit to smallruminant producers are similar to those for small holder credit problems in general. Some of theproblems cited are that: (1) institutions are not geared to meet the needs of the small holder; (2)commercial institutions are reluctant to make loans because of high administrative costs; (3) lackof viable technologies needed to provide high rates of return needed to repay the loan; (4) theproblem where loan proceeds are used for other purposes and; (5) problems of loan security andloan repayment difficulties. While it will take a considerable amount of time and goodwill on thepart of producers and lenders to resolve these difficulties it is pertinent to note that thegovernment and aid agencies can alleviate this situation by providing assistance in the form ofwhat Winrock International (1983) calls production system support activities (i.e., research,extension and marketing infrastructure).One major advantage of sheep and goats is their ability to reproduce rapidly and build upherd/flock numbers quickly. To some extent, this obviates the need for large amounts of capitalfor herd expansion. Another argument in favour of capital investments in production system38support activities is that the breeds of sheep and goats in the country have very good ability torespond to higher levels of feeding, management and health.Devendra (1989) demonstrated that in situations like those described above the twoprimary considerations in the improvement of ruminant production systems and increasingproductivity in ruminants under such circumstances is making maximum use of the animal geneticresources and taking full advantage of the available feed resources, with the ultimate objective ofcombining production with economic animal performance. This is essentially what the presentresearch seeks to achieve (i.e., to match the existing livestock resources with the available feedresources in the most effective manner possible), and as much as possible reduce or eliminate theneed for producers to depend on external sources to sustain the industry.The feed constraint has both quantitative and qualitative dimensions. In most cases,producers provided enough feed in ad libitum amounts to their animals (as evidenced by largeamounts of orts in most feeding troughs in households) but the quality of the feed wasquestionable in most cases. As noted in Table 2.10, about 40% of producers fed only byproducts such as cassava peels, plantain peels, milling and brewing by-products. These feedstuffsare in most cases nutritionally inadequate or unbalanced in terms of essential nutrients. Apartfrom this, during the dry season producers who relied solely on pastures and browse found itdifficult to provide enough feed for their animals during this time. However, they indicated thatthey could obtain cassava peels from the ‘thop bars” and ‘ari” factories if necessary. Ittherefore appears that if emphasis is placed on simple practices like processing (cutting anddrying), storage of the most available feedstuffs (cassava peels), and supplementation to providethe deficient nutrients, alleviation of the feeding problem could be achieved. However, researchon types of supplements and methods of supplementation are called for before specificrecommendations can be made. The impact of attending to the feed problem is often spectacular.A comparison of goats fed under traditional village systems with those adequately fed in anexperimental group showed more than a 50% increase in liveweight at comparable age(Devendra, 1989).39Past opinion in developing countries considered local animals to be low producers andtherefore required to be replaced by superior breeds whenever development strategies wereformulated. Such thinking resulted in the failure to see the potential of optimizing the use ofindigenous breeds and locally available feed resources. Fortunately, the inherent potential ofindigenous breeds has now been recognized. Small ruminants have been part and parcel of mosturban and peri-urban households for a long time and their (sheep and goats) small sizes and lowcost of production make them a unique resource particularly suited to the limited resource baseof these households.D. ConclusionsFigure 2.1 is a schematic representation of the small ruminant production system in theurban and pen-urban centres of Ghana. It summarises production resources, feeding systems,main product, marketing channels and constraints of the system. Current production resourcesare ecologically, socially and economically suited, and adequate to support a viable smallruminant industry. However, improvement of the feeding value of the feed resources through thestrategic use of readily available and inexpensive supplements is required to ensure efficientutilization of the feed resources by the animals. Whatever supplement or method ofsupplementation chosen should be something producers can afford.Constraints in the small ruminant production system were identified and discussed as ifthey were discrete factors, the interactions among them are the rule and not the exception. Thatwas why it was necessary to consider the total system so that multiple interacting constraintscould be identified and systematically resolved in order to achieve any improvement. Forexample, reduction in animal losses due to better disease control measures and adequatesupervision to prevent accidents, poisonings and theft would dramatically increase animalnumbers and would require higher management inputs. This could pose other problems sincemost producers are already engaged in other economic activities outside the household and mayhave to consider the opportunity cost of labour and the extra inputs.40ResourcesI I IMeat ProductionFigure 2.1. Schematic Representation of the Small Ruminant Production System in Urbanand Pen-urban Centres of Ghana.Figures in parentheses represent the proportion of producers in each category.Number of respondents = 120.Animals• Sheep (27%)• Goat (31%)•Sheep&Goats (21%)• Sheep & Goats&Others (21%)Peed• Pastures & Browse (3%)• By-products (40%)• Pastures & Agricby-products (57%)Labour• Family (87%)• Hired & Other (13%)Feeding Systems• Hand feeding/Cut & Carry (45010)• FrecRange&HandFeeding (36°bo)• Herding & Hand Feeding (12%)• Herding (7%)Marketing• Direct Sale at Farm gate (97%)• Middlemen (3%)ConstraintsSingle Factors• Credit (20%)• Health (8%)• Feeding (5%)Multiple Factors• Health & Credit (15%)• Health & Feeding (18%)• Credit & Feeding (21%)• Others (13%)41Inspite of all the problems associated with urban small ruminant production, 92% ofrespondents were willing to increase their flock sizes. However, problems such as housing,conflicts with neighbours and diseases would require a very clear vision on the part ofgovernment to resolve. One cannot deny the fact that small ruminant production in the urban andpen-urban centres would continue to play essential economic and social roles in these householdsbut if the ultimate objective of government is to provide adequate and cheap animal protein to thepopulation then a vision of the type of production system to promote is required.Because small ruminants tend to be dispersed in small herds/flocks among manyproducers in the urban centres, providing direct credit and extension services to the producersmay not be technically or economically feasible in most cases. Therefore innovative schemes atthe community level (co-operatives) should be encouraged among producers so that they canhandle some of the routine vaccination and disease control measures themselves.The need for research and extension efforts on small farm systems cannot be denied.However, it must be stressed that in order to meet the objective of providing affordable meatand animal products to society, attention would have to be focused on stimulation of operationsoutside residential areas and sufficiently large to adopt known technologies. This calls for greaterencouragement of individuals and companies willing to go into commercial livestock production.The success of such an undertaking is exemplified in recent developments in the poultry industry.The level of production in some of these poultry enterprises in the country is comparable to thatin some developed countries. In the short-term, however, because the movement of smallruminants has been restricted by producers themselves (to prevent losses among their animalsdue to accidents and poisonings), and by local government authorities because of the destructiveactivities of the animals, the need to provide adequate and nutritious feed to the animals is ofparamount importance. Therefore, research on the available feed resources in these areas isrequired to identify and select feedstuffs which could be used to meet this nutritional demand.42CHAPTER 3 IDENTIFICATION AND SELECTION OF FEEDSTUFFSFOR SMALL RUMINANTS IN THE URBAN AND PERI-URBANCENTERS OF GHANAA. IntroductionThe purpose of this chapter is to report on the selection of a basal and a supplementaryfeedstuff for feeding small ruminants in the urban and pen-urban areas of Ghana. The selectioncriteria and description of the basal feed and, supplementation principles are first reviewed.The identified ruminant feed resources in the urban and pen-urban areas of Ghana weremainly agro-industrial by-products. Limited quantities of native pastures along roadsides and onabandoned or undeveloped pieces of land were also available but the agro-industrial by-productsconstituted the largest feed resource (Chapter 2). Considerable differences exist in the nutritivevalue of the different types of agro-industrial by-products. Even within the same by-productdifferences exist due to processing technique and duration of storage (Tuah and Orskov, 1989;Adegbola et al. 1989). Despite these differences the by-products share some common featuressuch as being extremely fibrous and low in nitrogen and soluble cell wall contents. A primarylimitation in the use of such feedstuffs by ruminants is the low digestibility and the slow rate atwhich the feed particles break down to sizes that can leave the rumen - these factors couldreduce feed intake and ultimately animal productivity (Welch, 1982). For these reasons wheneveragro-industrial by-products are used as feed, everything possible is done to optimize intake anddigestibility through processing (physical, chemical or biological) and/or optimization of therumen environment.43B. Preliminary Studies1. Selection of basal feedstuffAmong the agro-industrial by-products identified during the survey of urban households,cassava peels was chosen as the basal feedstuff. The following were the major considerationswhich led to the choice of cassava peels over other feedstuffs:1) The annual production of cassava in Ghana is about 3.6 million mt (FAO, 1992).The peels constitute approximately 11% of the root. This means that if all thepeels were collected about 400,000 mt (on dry matter basis) of cassava peelswould be available for livestock feeding annually.2) Cassava is produced throughout the year and this makes the peels resulting fromhousehold food preparation and from factories in the cities available to livestockall year round. Minimal transportation costs are incurred, if any, in transportingthe peels from the sites of production to animals.3) It was the main household refuse/garbage currently fed in substantial quantities tolivestock in the urban households.4) Nearly every household surveyed produced a sizeable quantity of cassava peels asa result of food preparation and,5) Cassava peels could also be obtained from neighbours, “chop bar” (localrestaurant) operators and “gari” (fermented cassava product) processing factoriesat little or no cost.1.1. Nature and chemical composition of cassava peelsCassava peel is the main by-product from the processing of cassava roots (Manihotesculenta Crantz) for human consumption. The genus Manihot (Family: Euphorbiaceae) includesover 200 species of which Manihot esculenta Crantz is the most important, from the nutritionaland economic points of view. Mature stem cuttings are universally used as propagating materials.44Adventitious roots, which form at nodes in the soil are all initially fibrous, but gradually someundergo enlargement. At maturity they become large, tuberous storage roots which may assumedifferent shapes and sizes. The mature root possesses three distinct regions, namely, thephelloderm or peel, the cortex or flesh, and the central vascular core. The phelloderm is generally1-4 mm thick and may account for about 10-12% of the total dry matter of the root (Nartey,1979). The phelloderm is composed of an outer epidermis, a sub-epidermis and an inner layerreadily separable from the bulk of the tuber. The cortex consists of a mass of parenchyma cellsthat constitutes the region of carbohydrate storage. Processing the tuber usually leaves asubstantial amount of the storage tissues attached to the sub-epidermis.Several researchers have reported on the chemical composition of cassava peels. Thegeneral conclusion drawn by all these researchers is that cassava peel has a low crude proteincontent (2.8 to 6.5% of dry matter; Adegbola et al. 1989; Ifut, 1989; Osei, 1990). The efficientexploitation of this feed resource by ruminants would require that the animals be provided with aprotein supplement.Preston and Leng (1981) have suggested that in order to optimize the utilization offibrous agricultural by-products, animals must be provided with readily fermentable energy andprotein; by-pass protein and by-pass energy and; micronutrients like sulphur, phosphorus and Bvitamins. In Ghana, the cheapest means by which these requirements could be provided would bethrough the strategic use of fodder trees and shrubs as supplements. The improvement indigestibility, intake and growth rate of ruminants through supplementation of diets based onagricultural by-products with fodder trees and shrubs have been demonstrated by numerousworkers (Fomunyam and Mbomi, 1989; Ifut, 1989; Yilala, 1989).2. Selection of browse supplementThe survey of the sources of feed for small ruminants in the urban and pen-urban areas ofGhana revealed that the leaves ofFicus exasperata and Terminalia sp. have been an integral partof the traditional livestock production systems in these areas. Further investigations revealed that45Ficus sp. has traditionally been fed to livestock in the country. These two forages and Chaya (aforage with a crude protein content of 20% at full maturity and currently under investigation atthe Department of Animal Science, University of Science and Technology, Kumasi), wereevaluated as possible protein supplements for a cassava peel-based diet.2.1. Principles of nitrogen supplementation of ruminant dietsThe choice of an appropriate supplement requires a knowledge and an understanding ofthe nutritional value (digestion and associated constraints) of the available feedstuffs, the nutrientrequirements of the animals involved and the economic realities of the production system.Microbial protein synthesized in the rumen is the major source of nitrogen to the hostanimal, accounting for 60-85% of the total amino acids entering the small intestine (Orskov,1982). Synchronization of the rate of degradation of feed nitrogen and carbohydrate componentsin the rumen is important for the synthesis of microbial protein (Meggison et a!., 1979; Satterand Roffler, 1981). Optimum microbial synthesis usually results from the synchronous release ofruminally degraded protein and carbohydrates from dietary ingredients (Russell and Hespell,1981).The rate of fermentation of feed in the rumen depends on the nature of the rumenenvironment. The rate of fermentation is reduced when the microbes cannot obtain sufficientquantities of nitrogen, sulphur and, probably some peptides or amino acids (Engels, 1986). Theneed for nitrogen is related to the fermentability of the plant material. When this is low, littleenergy becomes available per unit time, and so only small amounts of nitrogen are required andvice versa.A rapid release of nitrogen not matched to the release of organic matter from thecarbohydrate source could lead to a high absorption of ammonia from the rumen (Meggison eta!., 1979). The availability of suitable carbon skeletons and ATP is a requirement for theammonia to be used for microbial protein synthesis (Czerkawski, 1986). The ammonia notcaptured in the rumen is absorbed and converted into urea in the liver, partly to be transferred to46the rumen or lost in the urine (Kennedy and Milligan, 1980) at a cost to the animal. This isbecause the synthesis of urea requires an expenditure of energy; synthesis of each mole of urearequires four moles of ATP (Martin and Blaxter, 1965). Degradation of the basal feedstufftherefore, has a tremendous influence on the choice of nitrogen source for efficient utilization.The main objective of this experiment was therefore to select a browse supplement whosenitrogen might be released in synchrony with the release of the organic matter from the cassavapeels in the rumen. In addition, the chemical composition of cassava peels collected fromdifferent locations in the urban centres was also determined in an effort to investigate the extentof variation in chemical composition of the peels.C. Materials and Methods1. FeedsCassava peels were obtained from “gari” processing factories and dried on concrete floorsfor about 5 d. The leaves ofFicus exasperata were also harvested from farms near the Universityof Science and Technology, Kumasi, Ghana, and dried for about 4 d. Both the intensity andduration of the sunlight determined the length of the drying period. The dried cassava peels andficus leaves were then stored in bags until they were required for feeding. In addition, samples ofcassava peels were collected every other day over a 2 wk period from ten different locations inKumasi for chemical analyses. Another group of samples of cassava peels from seven differentvarieties of cassava were also obtained from the Crops Research Institute of Ghana, KumasiStation, for chemical analyses.2. Animals and feedingFour wether sheep of the Djallonke breed (average weight, 37.8 kg; ± 0.92 kg) fitted withpermanent rumen cannulae, were housed in individual slatted floor pens and given ad libitumaccess to water and a basal diet of dried cassava peels. In addition each animal received 200 g of47dried ficus leaves per day on an as-fed basis. The ficus leaves were offered in two equal portionsat 0800 and 1600 hours. All animals used in this and subsequent experiments were cared forunder guidelines similar to those outlined by the Canadian Council of Animal Care.3. Supplements and incubation proceduresFresh leaves of ficus, terminalia and chaya were also harvested from farms near theUniversity and dried at 60°C to constant weight in a forced draught oven. The dried leaves andpeels were then ground through a 2.5 mm screen. Duplicate samples of each (4 g) were weighedinto nylon bags and inserted into the rumen of each sheep at the time of the morning feeding. Thebags were made of monofilament nylon mesh (53 urn pore size, 5 cm x 20 cm; Ankom, Fairport,New York). The bags were retrieved after 4, 8, 12, 36, 48, 72 and 96 h of incubation.Immediately after removal, bags were immersed in a plastic bucket of cold water andgently washed by hand under running tap water until the water from the bags was clear. The bagsand contents were then dried at 60°C to constant weight in a forced draught oven. A duplicateset of bags containing samples of cassava peels and ficus leaves were immersed in water at 39°Cfor 1 h and treated as above. This was used as an estimate of 0 h disappearance. The aboveincubation procedure was repeated three times. Animals were given another 2 wk to adapt totheir new experimental diets before incubations started.4. Chemical analysis and calculationsSamples from the oven-dried cassava peels, ficus leaves, terminalia leaves and chayaleaves were analyzed for dry matter, organic matter and Kjeldahl nitrogen according to AOAC(1985) procedures. Neutral detergent fibre analysis was performed as described by Goering andVan Soest (1970).The degradation characteristics of DM and nitrogen in cassava peels, ficus leaves,terminalia leaves and chaya leaves were determined by fitting the following modified version ofthe exponential equation of Orskov and McDonald (1979) to accommodate a lag phase:48p = a + b(1_e t1a))) for t> lag; [1]where p is the disappearance (%) of DM or nitrogen from the bag, a is the fraction whichdisappears rapidly, b is the slowly disappearing fraction, e is the base at the natural logarithm, c isthe fractional rate of disappearance (%Ih), and t is time (h) of incubation. The a, b, c and lagwere estimated by an iterative least-square procedure (Appendix 3.1) with the SAS (1990)software package. Effective disappearance (EFFD) was then calculated from the estimates of a, band c assuming a fractional outflow rate of solids from the rumen (Kf) of 0.06% W1 using thefollowing equation:EFFD = a + (((bc)e)/ (c + Kf))e + Kf)Iag) [ 2 ]where a, b and c are as defined in equation [1]. The potential disappearance of a component suchas dry matter or nitrogen was calculated as the sum of the a and b fractions of that componenti.e. (a+b).The rumen degradation characteristics of dry matter and nitrogen in cassava peels andleaves of chaya, ficus and terminalia were analyzed as a randomised incomplete complete blockdesign with animals as blocks and type of feed as treatments. The model used was:Y J.t++tj+E3j [3]where Yj represents an observation in the th animal, 3, (i = 1 to 4), receiving the th treatment, t,(j 1 to 4). The overall mean was expressed as ii, and the residual error as 8ij. Differencesbetween treatment means were determined with Tukey’ s studentized range test (HSD). TheGeneral Linear Model of the Statistical Analysis Institute (SAS, 1990) was used for the analysis.49D. Results and Discussion1. Chemical compositionThe chemical composition of cassava peels obtained from different sources in Kumasiand the three tree leaves are presented in Tables 3.1 and 3.2. Most of the cassava cultivated inGhana is of the Ankra variety. Varietal trials comparing this variety with new high yieldingvarieties developed at the International Institute for Tropical Agriculture (IITA), Thadan, Nigeriaare currently underway at the Crops Research Institute of Ghana. The peels collected from thedifferent locations were therefore all of the Ankra variety grown and brought into Kumasi fromdifferent parts of the country. Local 1 and 2 were composite samples of cassava peels (producedas a result of daily food preparation) collected over the 2 wk period from two households.The organic matter of the cassava peel samples ranged from 91.6% to 96.7%. Thenitrogen and neutral detergent fibre contents ranged from 0.59 to 1.34% (mean, 1.02%) and46.8to 69.3% (mean, 54.1%), respectively. The difference between the chemical composition ofcassava peels from the various locations could be due to the edaphic and climatic conditionsunder which they were grown. In terms of the nitrogen content of the peels, Ankra appears to beslightly superior to all the new varieties undergoing trials.The level of nitrogen in the cassava peels observed in this study is in close agreement withvalues reported in the literature. Osei and Twumasi (1989) working with a variety grown inGhana reported a value of 0.912% while Ifut (1989) in Nigeria reported a value of 0.96% (SE,0.38). The extent of variation in nitrogen content of the peels offers the possibility for selectionin breeding programs.50Table 3.1. Organic matter, nitrogen and neutral detergent fibre content of different varieties ofcassava peels, and cassava peels collected from different locations in Kumasi (% DM).Source of peels Organic matter Nitrogen Neutral detergent fibreRailways 96.2 1.0 46.8Mbrom 91.6 0.59 49.3Ayigya 96.4 1.04 48.1Kadjetia 95.5 1.07 53.6Asokwa 94.7 1.28 49.3Asafo 94.3 0.99 50.2Atonsu 96.4 1.02 62.3Stadium 96.3 0.93 51.6Local-i 95.3 0.99 49.0Local-2 96.5 1.13 48.1Variety of cassavaAnkra 94.9 1.34 60.7TMS63397 92.9 0.93 64.4TMSOO11O 96.7 0.78 58.7TMS00942 94.5 1.11 57.1TMS30572 93.2 1.23 53.3TMS80441 96.1 0.89 69.3TMS00058 96.2 1.10 48.1Mean (SD) 95.2 (1.4) 1.02(0.17) 54.1 (6.6)51Table 3.2. Organic matter, nitrogen and neutral detergent fibre content of leaves of Ficus sp.,Terminalia sp. and chaya (% DM).Description Organic matter Nitrogen Neutral detergent fibreFicus leaves 83.8 3.1 44.1Terminalia leaves 90.3 1.7 56.2Chaya leaves 93.1 3.4 40.3The organic matter content of the tree leaves ranged from 83.8 for ficus to 93.1% forchaya leaves. The nitrogen content of chaya leaves was highest (3.42%), followed by ficus(3.11%). The nitrogen content of terminalia was the lowest at 1.66%. While there are noliterature values for comparison of the values of chaya it is, however, important to note that thevalue 3.42 compares favourably with the predominant browse legumes notably, Leucaenaleucocephala (3.58%), Gliricidia sepium (3.68%) and Sesbania grandflora (3.76%) as reportedby Smith (1992). The nitrogen content of the Ficus exasperata leaves found in the present studywas, however, higher than the value of 2.37% reported by Smith (1992). In a review of potentialfodder trees and shrubs in range and farming systems in tropical Africa, Smith (1992) classifiedFicus exasperata as of medium quality in terms of its protein content and in vitro organic matterdigestibility. He reported values of 90.5, 25.0 14.8% for organic matter, neutral detergent fibre,crude protein content and 45.5% for in vitro organic matter digestibility. Growing conditionsand stage of maturity could be partly responsible for differences in some of the chemicalcomponents observed in the present study and by Smith (1992).2. Dry matter disappearanceA number of variables affect the degradation of feedstuffs in the rumen. ARC (1980)recognized that feedstuffs did not have a constant degradability value but that values would varywith the nature of the basal diet fed and the level of feeding. Apart from that, the proportion of52roughage to concentrate, particle size of feed and environmental temperature are among thefactors known to alter rumen liquid turnover rate. Consequently, the mean retention time of smallparticles in the rumen is likely to vary with the same factors and this ultimately influences theextent of degradation of components in the feed (e.g., dry matter and nitrogen).The cassava peels consumed by the animals contained 95% organic matter, 60% neutraldetergent fibre and 1.3% nitrogen on DM basis. The ficus leaves contained 3.5% nitrogen and53% neutral detergent fibre. Average daily dry matter intake of animals was 1.3 kg ± 0.23 kg.The nylon bag studies revealed large differences in the rumen degradation patterns of DMin cassava peels and the tree leaves. The dry matter disappearance of cassava peels was 43% at24 h of incubation. At 48 h of incubation, 53% of the DM had disappeared (Figure 3.1). Theproportion, which if given enough time would disappear (potential disappearance) was about71%. Chaya leaves were rapidly degraded in the rumen, about 79% of the DM had disappearedafter 24 h incubation. In contrast, only about 36% of the DM in terminalia leaves haddisappeared by 24 h. After 48 h of incubation 91% of the DM of chaya leaves had disappeared.This was inclose agreement with 90% DM disappearance in sesbania (Jong Ho Ahn et at., 1989).The disappearance of the DM of ficus leaves was intermediate; about 48% of it had disappearedat 24 .h and 64% by 48 h. The disappearance of DM in terminalia leaves at 48 h was close to the73% reported for gliricidia (Veereswara Rao et at., 1993).The degradation characteristics of cassava peels, chaya leaves, ficus leaves and terminalialeaves are presented in Table 3.3. The rapidly disappearing DM fraction ‘h” of chaya leaves(38.8%) was highest, followed by that of terminalia leaves (29.4) and ficus leaves (25.5%)(P<0.05). The high ‘s” value for chaya leaves was similar to values reported for Sesbania(40.5%) and Gliricidia (3 5%) by Veereswara Rao et a!. (1993). The ‘h” fractions in bothterminalia leaves and ficus leaves were higher than the value for Leucaena (17.5%) also reportedby Veereswara Rao et at. (1993). The disappearance rate (c), of the ‘b” fractions of chaya leavesand terminalia leaves were similar (P>0.05), however, they were about twice the value of ficusleaves. Among the tree leaves, the rate of disappearance of the “b” fraction of ficus leaves was53100-90- --70Cua)00.Cu 60-Co050Eo 4030200 4 8 12 24 36 48 72 96Period of Incubation (h)Cassava peels —I-— Chaya leaves —*— Ficus leaves —2— Terminalia leavesFigure 3.1. Disappearance of dry matter from cassava peels, and from leaves of ficus, chaya andterminalia incubated in rumen of sheep.54Table 3.3. Rumen degradation characteristics (%) of dry matter and nitrogen of cassava peels,and leaves of chaya, ficus and terminalia incubated in rumen of sheep.’Degradation characteristics Feed type2Cassava Chaya Ficus Terminalia SEM3Dry mattera 29.5a 388b 25.5c 29.4a 0.32b 41.3a 472C 0.31c (%/h) o.o2oa 0063b 0.026a 0062b 0.004lag(h) o.3a 23b 28b 6.8 0.92Effective disappearance 43. la 683b 446a 42.4a 1.06Potential disappearance 70.8a 931b 799C 766d 0.63Nitrogena 18.la 20.2a 26.1c 1.12b 57.2a 465 515d 0.22c(%Ih) 0.145a 0.133a 0.087e 0052d 0.006lag(h) 20b 1.la 2,9a 6.6e 0.85Effective disappearance 539a 726b 433C 42.2c 1.26Potential disappearance 753a 92013 66.7c 77.6a 1.34‘Rumen degradation constants, and potential disappearance of DM and N were calculated fromthe following equation, a modified version of the Orskov and McDonald (1979) model:p = a + )for t> lag where; a = rapidly disappearing fraction; b = slowly disappearingfraction; c = rate constant of b and; a+b = potential disappearance.Effective disappearance (EFFD) = a + (((bc)e’ )/(c + Kf))e° + Ki1ag ; Kf, assumed to be 0.06.Number of observations per treatment =4.2Means within rows with different letters are significantly different (P<0.05).3Standard error of pooled mean.55closest to that of cassava peels (0.020).The lag phase of the degradation of dry matter in chaya leaves (2.3 h) and ficus leaves(2.8 h) were not significantly different (P>0.05). Both were, however, significantly (P<0.05) lessthan the value for terminalia leaves (6.8 h). However, the rapid rate at which the disappearanceof the “b” fraction in terminalia leaves proceeded apparently compensated for the long lag phase;so that at 48 h of incubation about the same amount of DM in terminalia leaves, ficus leaves andcassava peels had been effectively degraded. The proportion of chaya leaves which, if givenenough time wOuld disappear (potential disappearance), was 93%, followed by that of ficus(80%) and terminalia leaves (77%). The differences were significant (P<0.05).3. Nitrogen disappearanceThere were significant (P<0.05) differences among the disappearance rates and lag phasesin the disappearance of nitrogen of the browses. The initial lag phase (6.60 h) in disappearance ofterminalia leaves (Table 3.3), was the longest (P<0.05). Most of the nitrogen disappearance interminalia leaves and ficus leaves occurred between 8 and 48 h (Figure 3.2). In contrast almostall of the nitrogen disappearance in chaya leaves occurred between 4 and 24 h. Chaya leaves alsohad the shortest lag phase, 1.1 h (P<0.05).As noted earlier, the presence of nitrogen in a forage does not always guarantee itsavailability to the rumen microbes. It is influenced by the pattern of its release and the outflowrate from the rumen (Orskov and Robinson, 1981). Balancing the rate of supply of nitrogen andenergy yielding substrates to rumen micro-organisms ensures maximization of the capture ofrumen degradable nitrogen. It also leads to the optimization of microbial growth and efficiencyby ensuring the synchronous release of nitrogen and energy.Based on the release of organic matter from the cassava peels, the three supplementswere assessed as to their ability to release nitrogen in synchrony with the fermentation of organicmatter from the cassava peels. The ARC (1980) estimated that the required ratio of nitrogenreleased in the rumen (rumen degradable nitrogen) to rumen degradable organic matter for56a0a.E0•000‘S0EC,C90I•000C00,e:tzFigure 3.2. Fermentation of organic matter in cassava peels and release of nitrogen from leaves ofchaya, ficus and terminalia in the rumen of sheep.Period of incubation (h)-B Cassava peels —I-— Chaya leaves —?+E— Ficus leaves —9—Terrninalia leaves 157optimum microbial synthesis was 1:33. An examination of the degradation characteristics of thethree forages and that of cassava peels indicated that ficus leaves would be a suitable supplementto cassava peels because the rate of release of nitrogen from the degradation of the ficus leaveswould match the rate of degradation of the organic matter in the peels. This would ensuresynchrony in the release of energy and nitrogen.The ratio of nitrogen released from terminalia leaves to organic matter fermented fromthe cassava peels between 4 and 12 h of incubation was always more than 1:60. Even at 72 h theratio was 1:40. This clearly indicates that if terminalia leaves were fed as the sole nitrogensupplement with a cassava peel based diet, the organic matter from the cassava peels may not beefficiently utilized due to an inadequacy of nitrogen released. However, the long lag phase and itsslow rate of degradation could make terminalia leaves a potential by-pass protein source. But if itis to be used as a supplement to provide nitrogen to the rumen microbes it may not be the idealsupplement. The release of nitrogen from the chaya leaves on the other hand was too rapidcompared to the release of organic matter from the cassava peels. If chaya leaves and cassavapeels were fed together, it could lead to a situation where the rumen microbes may not getenough energy from the organic matter released to make efficient use of the nitrogen releasedfrom the chaya leaves (the ratio of nitrogen released from chaya leaves to organic matterfermented from the cassava peels was 1:15.5 or less). Part of the excess nitrogen could be lost inthe urine (Kennedy and Milligan, 1980).E. ConclusionsUnder the prevailing Ghanaian conditions, the provision of nitrogen to ruminants isexpensive; therefore, everything possible must be done to avoid wastage. Among the tree leavesonly ficus leaves appeared to be suitable in terms of supplying nitrogen in synchrony with thefermentation of organic matter in cassava peels. During the initial phases of the degradation i.e.during 4 and 8 h of incubation the ratio of nitrogen released to organic matter fermented wasabout 1:30. This value fell to 1:23 at 24 h.58As noted earlier the leaves of Ficus exasperata have traditionally been fed to livestock inGhana and is found in relative abundance on the outskirts of cities and towns in Ghana; so, basedon its nitrogen content, degradation characteristics and availability, it was selected as thesupplement for sheep on a cassava peel-based diet.59CHAPTER 4 MICROBIAL DIGESTION OF CASSAVA PEELS ANDFICUS LEAVESA. IntroductionThe voluntary intake and digestion of low quality feedstuffs by ruminants depends to alarge extent on the rate of feed degradation in the mouth and forestomachs. Particles longer than1 mm are selectively withheld for a longer time in the forestomachs, and this reduces thepossibility of renewed feed intake (Nicholson, 1984; Minson, 1985). The reduction in particlesize is accomplished principally through chewing during ingestion and rumination, and to a lesserextent, microbial degradation. Generally, microbial digestion proceeds best when degradableorganic matter, and nitrogen and minerals in the rumen, are present in sufficient quantitiesthroughout the day (Kellaway and Leibholz, 1983). It is therefore important that the microbes inthe forestomachs are provided with an environment conducive for their function. This is more sobecause their growth results in an important, and often, the main source of protein for the hostanimal (Orskov, 1989).Most methods of feedstuff improvement aim at altering the feedstuff to increasedegradation or creating favourable conditions within the rumen to increase digestion andsubsequently improve intake. Several aspects of roughages including solubility, potentialdigestibility and rate at which the insoluble components are fermented contribute to the feedingvalue of the roughage. Alkali treatment of straw for example, increases the rate of degradation ofstraw samples incubated in nylon bags in the mmen. In addition, the degradation of untreatedstraw is improved when it is incubated in the rumen of animals given alkali-treated strawcompared with those given untreated straw because of an increase in digestible celluloses andhemicelluloses (Silva and Orskov, 1987). Wagner (1989) also demonstrated that legumesupplementation of grass diets with less than 7% crude protein increased digestion, dry matterintake and animal performance.60Orskov et al. (1983) demonstrated differences in degradation of protein supplements insheep which received either concentrate or hay diets. Also, protein supplements of vegetableorigin, e.g. soybean meal and groundnut meal, were degraded more slowly in animals given ahigh-concentrate compared with a high-roughage diet. Therefore the degradation of feedsubstances in the rumen appears to be profoundly affected by the environment within the rumen.Devendra (1988) suggested that the optimum dietary level of proteinaceous foragesshould be 30-50% of diet dry matter or 0.9-1.5% of liveweight. Therefore, in the determinationof the optimum feeding level of Ficus exasperata as a supplement, it was necessary to evaluatefirst, the effect of level of supplementation on the rumen environment.Most methods of feedstuff evaluation have routinely involved laboratory analyses ofvarious chemical fractions in an effort to develop relationships between the chemical fractionsand nutritive value. The relevance of some routine measurements are difficult to justify becauseanimal performance cannot be reliably predicted from chemical analyses (Orskov and Reid,1989).The critical role of micro-organisms in degradation of feedstuffs, and the myriad offactors which affect their activity makes it imperative that whenever possible, feedstuffs must beevaluated within the rumen environment. Measurement of the degradation characteristics offeedstuffs using the nylon bag technique (Orskov and McDonald, 1979) was chosen as themethod of evaluation of the different rumen environments because the exponential equation usedin the description of the degradation curve has important biological attributes. Each of the factorsin the exponential equation has some relationship with animal performance through their effecton voluntary feed intake. The general form of the equation is given as:P = a + b(1et) where;lip” is the amount of the feedstuff or a portion of a nutrient in the feedstuff which disappears or isdegraded at time ‘t”, “a” is the immediately soluble or fraction which disappears rapidly, sb” is61the insoluble but degradable fraction (slowly disappearing fraction), ‘s” is the base at the naturallogarithm, and “c” is the fractional rate of degradation or disappearance of “b”. The immediatelysoluble fraction “a”, occupy little space in the rumen and therefore reduces rumen “fill”; (100-(a+b)) the totally undegradable material determines the amount which will occupy space in therumen at all times and therefore contributes to rumen “ff1”. The rate constant “c” determines thetime during which the degradable portion occupies space in the rumen. The method is therefore auseful diagnostic tool in feedstuff evaluation.The objective of the present study was therefore to determine the influence of level ofsupplementation of leaves from Ficus exasperata on the degradation characteristics of dry matterand nitrogen of both cassava peels and ficus leaves in nylon bags incubated separately in therumens of sheep on a cassava peels-based diet.B. Materials and Methods1. Animals and feedingSix Djallonke wethers (body weight 33 ± 2.7 kg) fitted with permanent ruminal cannulaewere used in the following experiment. Animals were kept in individual pens with wooden slattedfloors. Each animal had ad libitum access to sun-dried cassava peels and water. In addition eachanimal was given one of the following levels of sun-dried ficus leaves; 0, 50, 100, 150, 200, or250 g per day on an as-fed basis. The daily allowances of ficus leaves were offered in two equalportions at 08.30 and 16.30 hours.2. Incubation procedureAfter a 14-day adaptation period, the six animals were used in a randomized incompleteblock experimental design to investigate the effect of level of ficus leaf supplementation on therumen degradation characteristics of cassava peels and ficus leaves.62Samples of cassava peels and ficus leaves were milled to pass through a 2.5 mm screen.Duplicate samples of each feed (4 g) were placed in separate nylon bags (53 p.m pore size, 5 cmx 20 cm; Ankom, Fairport, New York) and incubated in the rumen of each animal during eachincubation period. The four bags (two containing each feed type) were inserted in the rumen ofeach animal just before the morning feeding. Each set of four bags was withdrawn from therumens after 2, 4, 6, 9, 12, 24, 48, 72, and 96 h of incubation.Immediately after removal, bags were immersed in a plastic bucket of cold water andgently washed by hand under running tap water until the water from the bags was clear. The bagsand contents were then dried at 60°C to constant weight in a forced draught oven. Dry matterand nitrogen disappearance from each bag were measured. Dry matter and nitrogen wereanalyzed according AOAC (1985) procedures. A duplicate set of bags containing samples ofcassava peels and ficus leaves were immersed in water at 39°C for 1 h and treated as above. Thiswas used as an estimate of 0 h disappearance.The above incubation procedure was repeated once after re-randomization of the level officus leaf supplementation among the animals. Animals were given another 2 wk to adapt to theirnew experimental diets before incubations started.3. Calculations and statistical analysesThe DM and N losses from each bag were fitted to a modified version of the exponentialmodel of Orskov and Mcdonald (1979) with a lag phase:p a + for t > lag; [1]where p is the disappearance (%) after t hours, a is the fraction which disappears rapidly, b is theslowly disappearing fraction, c is the fractional rate of disappearance (%/h) of fraction b, and t istime (h) of incubation. The a, b, c and lag were estimated by an iterative least-square procedure(Appendix 3.1) with the SAS (1990) software package. Effective disappearance (EFFD) was63then calculated from the estimates of a, b and c assuming a fractional outflow rate of solids fromthe rumen (kf) of 0.06% h’ using the following equation:EFFD = a+ (((bC)C(claS)) / (c + kf))e + kf)lag) [2 1where a, b and c are as defined in equation [1]. The potential degradation or disappearance of acomponent such as dry matter or nitrogen was calculated as the sum of the a and b fractions ofthat component i.e. (a+b).The rumen degradation characteristics of cassava peels and ficus leaves were analyzed asseparate experiments using a randomised incomplete block design with animals as blocks andlevel of supplementation as treatments. The model used was:[3]where Y1 represents an observation on the th animal, 13, (i = 1 to 6), receiving the th treatment, t,(j = 1 to 6). The overall mean was expressed as .t, and the residual error as.The GeneralLinear Model of the Statistical Analysis Institute (SAS, 1990) was used for the analysis.Whenever the model was significant, mean differences between treatments were determined withTukey’s studentized range test (HSD).C. Results and DiscussionThe average daily intake of dry matter by the animals was 1.2 kg (± 0.33 kg). The cassavapeels consumed contained 94% organic matter, 58% neutral detergent fibre and 1.2% nitrogenon DM basis. The ficus leaves contained 3.3% nitrogen and 54% neutral detergent fibre.1. Degradation of dry matter and nitrogen in cassava peelsThe degradation characteristics of cassava peels and ficus leaves incubated in the rumensof sheep receiving different levels of ficus leaf supplementation are presented in Tables 4.1 and64Table 4.1. Rumen degradation characteristics of dry matter and nitrogen of cassava peels insheep receiving different levels of ficus leaves as supplement.2Characteristic Level of supplement (g d’)0 50 100 150 200 250 SEM4Dry matter3a(%) 12.8a 143b 15.8° 18.9e i8.i 0.31b (%) 43.la 417b 44.0c 464d 48.8e 50.1” 0.32c (%/h) 0.093c 0 .096’ 0086d 0.109a 0.093c 0102b 0.002a+b(%) 559d 560d 59.8° 67.7a 68.2a 0.63lag(h) 1.5a 1.3a 1.5a 1.5a 18b 1.4k 0.023Nitrogen3a(%) 13.7° 14.0c 14.3° 162b 17.5 0.23b (%) 39.4° 448b 46.8a 467a 0.31c (%/h) 0070d O.O89x 0076d 0.125a 0103bc 0119ab005a+b(%) 531d 533d 58.2G 610b 63.ga 64.2a 0.54Iag(h) 53a 4113 4413 0.182Rumen degradation constants and potential disappearance of DM and nitrogen were calculatedfrom the following equation, a modified version of the Orskov and McDonald (1979) model:p = a + b(1e& t-la&)) for t > lag where; a = rapidly disappearing fraction; b = slowly disappearingfraction; c = rate constant of b and; a+b potential degradability or disappearance.Number of observations per treatment = 4.3Means within rows with different superscripts are significantly different, (P<0.05).4Standard error of the pooled mean.65Table 4.2. Rumen degradation characteristics of dry matter and nitrogen of ficus leaves in sheepreceiving different levels of ficus leaves as supplement.2Characteristic Level of supplement (g d’)0 50 100 150 200 250 SEM4Dry matter3a(%) 15.7° 15.7° 15.7° 167b 17.Sa 17.2a 0.11b (%) 56.8e 575de 581cd 58.4° 595b 61.5a 0.18c (%/h) 0.028° 0027”° 0027d 0066b 0.075a 0.076a 0.0003a+b(%) 72.5e 73.2” 738d 75.1° 770b 78.7a 0.29lag(h) 37a 36ab 35ab 36ab 35ab 35ab 0.04Nitrogen3a (%) 147d 12.9e 135de 18.2° 216d 22.8a 0.28b (%) 479e 52.4’ 55.la 519bc 501d 51.3° 0.25c(%/h) o.185a 0.133° 0.1220 0159b 0.186a 0162” 0.0046a+b (%) 62.6” 65.3e 682d 701C 717b 74.la 0.53lag(h) 5.2a 21” 2.1” 3.2° 3.9” 33° 0.122Rumen degradation constants and potential disappearance of DM and nitrogen were calculatedfrom the following equation, a modified version of the Orskov and McDonald (1979) model:p a + b(1-e°t )) for t > lag where; a = rapidly disappearing fraction; b slowly disappearingfraction; c = rate constant of b and; a+b = potential degradability or disappearance.Number of observations per treatment =4.3Means within rows with different superscripts are significantly different, (P<0.05).4Standard error of the pooled mean.664.2. Ficus leaf supplementation significantly increased (P<0.05) the rapidly disappearing fractionand the potentially degradable fraction of the DM in cassava peels. The values for the rapidlydisappearing, slowly disappearing and potentially degradable DM fractions from cassava peelsincubated in animals which received no supplement were 12.8%, 43.1% and 55.9% respectively;compared with 18.1%, 50.1% and 68.2% in animals which received 250 g d1. Similarly, therapidly disappearing, slowly disappearing and potentially degradable nitrogen fractions fromcassava peels in the rumens of animals which did not receive any supplement were 13.7%, 39.4%and 53.1%, respectively compared to 17.5%, 46.7% and 64.3% in animals which received 250 gd’ of ficus leaves. The potentially degradable fraction of cassava peels was raised (P<0.05) from55.9% (no supplementation) to 68.2% (250 g d4 of ficus leaves). The greater ruminaldisappearance of DM and nitrogen of cassava peels as a result of increases in the level of ficusleaf supplementation underscores the importance of creating a conducive mmen environment forthe digestion of low quality feedstuffs. It also lends support to the use of supplementation as amethod of improving the digestibility of low quality feedstuffs. Appropriate supplementationwould usually lead to the development of a microbial population that is suitable for the digestionof the ingested feedstuffs.There was no consistent trend in the influence of level of supplementation on the lagphase in the disappearance of DM and nitrogen in cassava peels. The lag in the degradation ofDM in the rumen of animals which received 200 g d’ of ficus leaves was higher (1.8 h; P<0.05)than all the other treatments. The differences between the others were not significant (P>0.05).The reason for the long lag phase in the disappearance of DM in rumen of animals whichreceived 200 g d’ of ficus leaves was not apparent.There was also no consistent trend in the effect of level of supplementation on the rate ofdisappearance of the slowly degradable DM fraction. However, the rate of disappearance of thenitrogen in cassava peels increased significantly (P<0.05), with increasing level of ficus leafsupplementation. The lowest rate of disappearance was observed in animals which did notreceive any supplement (0.07% h’). The fastest rate of disappearance (0.125% h’), observed in67animals which received 150 g d of ficus leaves, was significantly (P<0.05) higher than the valueof 0.103% h’ observed in animals which received 200 g d of ficus leaves.2. Degradation of dry matter and nitrogen in ficus leavesThe rapidly and slowly disappearing fractions of DM in ficus leaves were significantly(P<0.05) affected by the level of ficus leaves supplementation. The rapidly disappearing fractionof the DM from ficus leaves incubated in the rumen of animals which did not receive anysupplement and those which received 50 and 100 g d was 15.7%. Values from the rumen ofanimals which received 200 and 250 g d were not significantly different (P>0.05) from eachother (17.5% and 17.2%); but both were significantly higher than those which received 150 g d1.The rapidly disappearing fraction of nitrogen was also influenced by the level ofsupplementation; from a low level of 12.9% for animals on 50 g d’ to 22.8% for animals on 250g d’. The potentially degradable nitrogen fractions increased from 62.6% in animals which didnot receive any supplement to 74.1% in animal that received 250 g d’.The increase in the lag phase of the disappearance of nitrogen in ficus leaves withincreasing level of supplementation could be due to the difference in nitrogen contents of thebasal feed and the ficus leaves incubated (Chapter 3, Tables 3.1 and 3.2). The incubation of ficusleaves with its higher level of nutrients (in a rumen environment deficient in these nutrients),would probably lead to some diffusion of the nutrients from the ficus leaves which would act aschemo-attractants for the rumen microbes (0rpm and Letcher, 1978). This could lead to a fasterrate of colonization and/or establishment of microcolonies and digestion of the ficus leaves in thenutrient “deficient environment” compared to the other treatments with appreciable levels ofthese nutrients in the rumen as a result of ficus leaves supplementation. However, this faster rateof colonization and initiation of digestion would not necessarily lead to a higher and/orsustainable rate of degradation because of the eventual depletion of nutrients.Irrespective of level of supplementation, maximum DM and nitrogen disappearance fromcassava peels (Figures 4.1 .a and 4.1 .b) and ficus leaves (Figures 4.2.a and 4.2.b) occurred about48 h post incubation. Very little change in disappearance of DM and nitrogen occurred after 4868Figure 4.1..aNoficus-4--—. 50 g/d ficus60-100 g/dficus50-150 g/dficus0.40 200 g/d tlcusAI :: 250 g/d10U.1’2 2’4 48 72Period of incubation (h)Figure 4.1.b80-70- No ficus—I60- 50 g/d ficus-*--//Z”100 g/d ficus50--a150 gfd ficus200 g/dflcusA30 250 gfd ficus0)220p I0 2 1’2 4 4 72 6Period of incubation (h)Figure 4.1 .a. Dry matter disappearance (%) from cassava peels incubated in rumen of sheep consumingcassava peels ad libitum and graded levels of ficus leaves.Figure 4.1 .b. Nitrogen disappearance (%) from cassava peels incubated in rumen of sheepconsuming cassava peels ad libitum and graded levels of ficus leaves.69Figure 4.2.a80-70- Noficus60 50 g/d ficus-lOOg/dficus50-a-150 g/dficus0.0.200g/dficus--30- 250 g/d ficusE20-10-0-0 2 4 6 9 12 24 48 72 96Period of incubation (h)Figure 4.2b80-70- No ficus60- 50 g/d ficus-*-100 gId ficus50.—s150g/dficusVa40200 g/dflcusA30 250 g/d flcus0)0Iz 2010I I I I0 2 4 6 9 12 24 48 72 96Period of incubation (h)Figure 4.2.a. Dry matter disappearance (%) from ficus leaves incubated in rumen of sheep consumingcassava peels ad libitum and graded levels of ficus leaves.Figure 4.2.b. Nitrogen disappearance (%) from ficus leaves incubated in rumen of sheepconsuming cassava peels ad libitum and graded levels of ficus leaves.70h. This is in agreement with Negi et at. (1990) and Veereswara Rao et at. (1993) who alsoreported maximum disappearance of DM and nitrogen at 48 h in tree forages incubated in nylonbags in sheep rumen.The difference between the rate of disappearance of the slowly disappearing nitrogenfractions in ficus leaves and cassava peels could be due to the nature of the protein substrates inficus leaves and cassava peels and the effect of the proteolytic activity in the rumen. Hazlewoodet at., (1983) reported that the nature of the protein substrate in the basal diet inf’uences theproteolytic activity in the rumen. They observed that hydrolysis of leaf Fraction I protein wasstimulated relative to casein, when fresh fodder was used as a supplement, compared to a dietconsisting of hay and concentrates. Nugent et al., (1983) also made similar observations. Theyreported that fresh herbage promoted an activity up to nine times higher than that found with dryrations.D. ConclusionsThe present results show that supplementation of a cassava peel-based diets with smallquantities of ficus leaves could improve the rumen environment. The study also indicated that thenylon bag technique is a useful tool in feedstuff evaluation which should be employed in the studyof rumen environments.The composition of a feed, its rate and extent of degradation and the characteristics of therumen environment are indicative of the nutritive value of the feed. However, the ultimatecriterion for the selection of one feed over another is the performance of animals. Long termfeeding trials are therefore required to fully evaluate and determine the ultimate supplementationlevel of ficus for sheep.71CHAPTER 5 EFFECT OF SUPPLEMENTATION WITH GRADEDLEVELS OF FICUS LEAVES ON THE UTILIZATION OF CASSAVAPEELS BY SHEEP.A. IntroductionThis chapter describes the second experiment conducted to determine the optimum levelof feeding ficus leaves to sheep given ad libitum access to dry cassava peels, The experimentswere conducted to determine nutrient intake, in vivo digestibility and growth rate of sheep on thecassava peels-based diets.The nutritive value of a feedstuff is an intrinsic characteristic which enables it to supplynutrients to meet all or part of the physiological requirements of the animal. Nutritive value cantherefore be divided into four components; relative proportion of nutrients, the digestibility of thenutrients, the animal’s voluntary intake and the metabolism of the products of digestion (Seone,1983). Because of this, most procedures of feedstuff evaluation have routinely involvedlaboratory analysis, intake and digestibility of the feedstuff. In some cases the end products ofdigestion (e.g., volatile fatty acids and amino acids), have been quantified. It must, however, benoted that the performance of animals (e.g., growth rate or milk production) is the ultimatemeasure of the usefulness or quality of the feedstuff. The relevance of the other measurements, inmost cases, lie in their ability to identify factors within the feed, which could either increase orreduce the performance of animals. The identification of such factors is required to developappropriate strategies or techniques to promote the efficient utilization of the feed.Most agricultural by-products are deficient in protein, essential minerals and in somecases have a high fibre content. The consequences of such a profile for ruminants are a lowintake (1-1.25 kg dry matter/100 kg live weight), poor digestibility (30-45%) and, a low level ofperformance (Smith, 1993). Low intake and poor digestibility, which ultimately reflect in pooranimal performance, could be due in part, to factors such as the high lignin content and itsassociation with other cell wall carbohydrates, i.e. cellulose and hemicellulose (Van Soest, 1975).72Cassava peels have been evaluated by a number of workers as a feedstuff for sheep(Adebowale, 1981; Adegbola and Asaolu, 1986; Adegbola et a!., 1989), goats (Iflit, 1989),poultry (Osei eta!. 1990) and pigs (Obioha and Anikwe, 1982). The results of the analysis of thechemical composition of cassava peels reported by the above researchers indicate the followingchemical composition: dry matter (86.5 to 94.5%), organic matter (89.0 to 93.9%), crude protein(4.2 to 6.5%), neutral detergent fibre (34.3%) and lignin (8.4%). The protein and mineral contentof the peels has in most cases been inadequate to support optimum rumen function andproductivity in animals raised solely on this feedstuff (Ifut, 1989; Adegbola et al., 1989; A. K.Tuah, personal communication). The efficient utilization of this abundant resource by ruminantsin Ghana would require that the animals be provided with an appropriate supplement whichwould supply the deficient nutrients.The study of the degradation characteristics of cassava peels in the rumen of sheep whichreceived different amounts of the leaves of ficus as a supplement indicated that significantimprovement in degradation could be achieved through supplementation (Chapter 4). By givinganimals about 200 g d’ of ficus leaves the potential dry matter degradability of cassava peels inthe rumen could be increased from about 56% (no supplementation) to 68%. There weresignificant improvements in other rumen degradation characteristics as a result of increasing thelevel of ficus leaf supplementation. Even though the leaves are found in relative abundance theiracquisition has its associated cost, i.e. labour and transportation. Hence the need to determine itsoptimum feeding level in order to avoid wastage and to reduce the overall cost of production ofanimals fed this supplement.The overall objective of this experiment was therefore to use animal performance as thecriterion to determine the optimum feeding level of ficus leaves when used as a supplement forsheep fed a cassava peels based diet. The specific objectives were to determine the effect of levelof ficus leaf supplementation on voluntary feed intake, digestibility and liveweight gain of sheepgiven ad libitum access to cassava peels.73B. Materials and Methods1. Feeds and experimental dietsFresh cassava peels were obtained from ugariH processing factories in Kumasi. Fresh ficusleaves were harvested periodically from farms near the University. The fresh cassava peels andficus leaves were sun-dried on concrete floors for 4-6 d. Both the intensity and duration ofsunlight determined the duration of the drying period. The dried cassava peels and ficus leaveswere then stored in bags until required for feeding. The cassava peels and ficus leaves were usedto formulate the following dietary treatments:Ti- cassava peels ad libitum + no supplement;T2 - cassava peels adlibitum + 50g ficus leaves d’;T3 - cassava peels ad libitum + 1 OOg ficus leaves d’;T4 - cassava peels ad libitum + 1 50g ficus leaves d’;T5 - cassava peels ad libitum + 200g ficus leaves d’;T6- cassava peels ad libitum + 250g ficus leaves d’.2. Animals and experimental designFortyd-eight Djallonke wethers and ewe lambs weighing an average of 13.5 kg (SD, 1.2kg) were purchased from local producers, dewormed, vaccinated against PPR, dipped, andrandomly allocated to the six dietary treatments. The group of animals on each dietary treatmentwas balanced in terms of sex and weight. Each animal was randomly allocated to one of 48 penswith wooden slatted floors.The first 14 d of the experiment were used to adapt the animals to their experimental dietsand pens. This was followed by a 14 wk period during which daily voluntary intake of cassavapeels and liveweight gain of the sheep were determined. The daily allowance of ficus leaves wasoffered in two equal portions at 09.00 and 17.00 h. The peels and leaves were offered in separatefeeding troughs. Fresh water was provided ad libitum everyday in large plastic buckets in the74pens. The entire experiment was divided into seven 2 wk experimental periods and all animalswere weighed at the end of each fortnightly period during the entire experiment.3. Sampling and analytical proceduresA grab sample of cassava peels and ficus leaves was obtained at each feeding and pooledover every 2 wk experimental period. Refused feed from each animal was weighed separately andsubtracted from the amount offered the previous day to obtain the amount consumed. Therefused feed was then sampled for chemical analysis and the rest discarded prior to each morningfeeding. Two 5 d faecal grab samples were obtained from the rectum of each animal during thelast two experimental periods (weeks 12 and 13). The two 5 d faecal samples from each animalwere thoroughly mixed, dried at 60°C for 48 h in a forced draught oven and milled forsubsequent laboratory analyses.Samples of feed offered, feed refusals and faeces were analyzed for dry matter (DM),nitrogen and ash according to AOAC (1985) procedures. Neutral detergent fibre (NDF), aciddetergent fibre (ADF), acid detergent lignin (ADL) and acid insoluble ash were analyzed with themethods of Goering and Van Soest (1970) as modified by Van Soest et al (1991).4. Calculations and statistical analysesOrganic matter (OM) was calculated as the difference between the DM and total ash ofthe samples. Cellulose content was estimated from the difference between the ADF and the sumof lignin and acid insoluble ash. Hemicellulose was estimated as the difference between NOF andADF (Van Soest et a!., 1991). Digestibility was estimated by the use of acid insoluble ash as aninternal marker (Van Keulen and Young, 1977). A linear model was used to determine the effectsof level of ficus leaf supplementation, experimental week, and sex of animal on intake anddigestibility of nutrients and, growth rate of sheep. The model used was:75XjJk = + f3 + + (iYt + E.k where; [1]Xijk is an individual observation; t is the overall mean; tj is the effect of ficus leafsupplementation; f3, is the effect of sex; 0k is the effect of experimental week; tu is theinteraction between ficus leaf supplementation and experimental week and 6ijk is the overall errorterm. Significant differences between treatments were determined using Tukey’s studentizedrange test (HSD). The liveweight (LW) of each animal used with regard to daily intake ofnutrients was the average liveweight recorded at the beginning and end of each 2 wk period. Thestatistical programs used were all from SAS (1990).C. Results and DiscussionCassava peel refusals as a percentage of total offered, averaged 15.7% (range 10 to20%). All animals consumed their allowance of ficus leaves within 2 h. One sheep on Ti diedduring week 12. Autopsy showed generalized edema. Another sheep on T4 was removed fromthe experiment because it was found to be pregnant. Therefore data on intake, digestibility andgrowth rate for these two treatments were based on seven observations instead of the eight forthe other treatments.1. Chemical compositionThe chemical compositions of the cassava peels and ficus leaves are presented in Table6.1. Acid detergent fibre, acid insoluble ash, cellulose and nitrogen contents of ficus leaves werehigher than corresponding values in cassava peels. However, the cassava peels contained higherlevels ofNDF and ADL. The nitrogen content of the cassava peels was similar to values reportedby Ifut (1989) and Osei (1990). It is interesting to note that the level of nitrogen and NDF wassimilar to the average of the samples analyzed and reported earlier (Chapter 3). This marginallevel of nitrogen may, however, not be adequate for optimum intake and digestion of the basal76Table 5.1. Chemical composition of dry cassava peels and ficus leaves.Component Cassava peels Ficus leavesProximate composition (%DM)Organic matter 91.1 83.8Nitrogen 1.0 2.9Neutral detergent fibre 57.4 43.9Acid detergent fibre 28.4 36.5Hemicellulose 29.0 7.4Cellulose 20.8 31.1Acid insoluble ash 2.6 3.4Acid detergent lignin 5.0 2.0Macro minerals (%DM)Calcium 0.7 4.4Phosphorus 0.10 0.19Magnesium 0.15 0.55Sulphur 0.08 0.24IVlicro minerals (ppm)Copper 11 10Zinc 21 31Manganese 86 51diet. The critical level of nitrogen below which appetite is supposedly depressed is between 0.96to 1.28% of diet dry matter, (Minson, 1982; Forbes, 1986).The nitrogen content of the ficus leaves (2.9%) was higher than the values reported bySmith (1992) and Devendra (1992) for ficus leaves. The nitrogen content was also higher thanvalues reported by Reed et al. (1990) for fodder trees such as Acacia cyanophylla and A.Sieberana but it was lower than the value reported in an earlier study (Chapter 3). Except for77sulphur and phosphorus the mineral content of the cassava peels appeared to be adequate for thisclass of sheep for the elements analyzed (NRC, 1985). Although the nitrogen/sulphur ratio(12.4:1) was within the recommended range of 10-13.5:1 (Bird, 1972) it should be noted that thesulphur content of the cassava peels (0.08%) was far below the recommended level of 0.14%(NRC, 1985) for animals of this age and physiological stage.2. Feed intakeDaily intake of DM and nitrogen, and the average daily growth rate of sheep on each ofthe dietary treatments are given in Table 5.2. Supplementation significantly increased (P<0.05)total intake of DM and nitrogen. Mean daily total DM intake ranged from 44.0 g kg’ LW°75 foranimals on Ti to 81.2 g kg’ LW°75 for animals on T6. Daily nitrogen intake increased from 0.44-1 O.75 -i ,(J•75g kg Lw by animals on Ti to 1.33 g kg Lw by those on T6. The differences m DMintake between animals on the different treatments were significant (P<0.05). The only exceptionwas the difference between animals on T5 and T6. The low DM intake by sheep on Ti and T2could have been due to the low level and poor balance of certain nutrients especially nitrogen andsulphur. As suggested by Preston and Leng (1986), an imbalance or inadequacy of nutrientswould reduce rumen ammonia production and microbial growth and activity. This wouldindirectly slow down the rates of digestion and passage and subsequently reduce intake. Totaldaily DM intake by animals on T3, T4, T5 and T6 were all above the “expected intake” value of58.9 g kg’ LW°75 for this class of animals (NRC, 1985). Total DM intake increased from 2.44%of body weight for animals on Ti to 3.65% for those on T5.The influence of level of supplementation on intake of the basal ration (cassava peels) wasdetermined on the basis of OM intake (Figure 5.1). There was no significant (P>0.05) differencein consumption of the basal ration between animals on Ti and T2 or between those on T4, T5and T6. The intake of OM from the basal ration rose from 41.2 g kg’ LW°75 for animals whichreceived no supplement to a maximum of 51.8 g kg1 LW°75 for those which received 200 gldayof ficus leaves. Thereafter intake of cassava peels decreased (though not significantly, P>0.05)78Table 5.2. Daily intake of dry matter (DM) and nitrogen and growth rate of sheep fed cassavapeels-based diets with graded levels of ficus leaves.Dietary treatment’ ,Ti T2 T3 T4 T5 T6 SEM4Dry matter intake (g kg1 LW°’75)TotalDM 44.Oa 505b 63.8° 745d 78.7e 81.2° 2.44Cassava peels 44.Oa 43.6a 496b 551° 54.1° 53.8° 0.84Totalnitrogen 0.44a 063b 0.90° 111d i.25e i.i3’ 0.053Avg. DM intake (g d”) 289.6a 2814b 4060° 5076” 590.7e 672.l 24,16Dry matter intake (% LW)2Cassava peels 2.44 2.40 2.56 2.55 2.55 2.38 0.013Supplement - 0.38a 072b 0.91c 110d i.18e 0.013Total 2.44a 278b 3.29c 347d 3.65e 357° 0.073Initialliveweight(kg) 13.06 13.02 13.60 13.50 13.50 13.60 0.039Finalliveweight(kg) li.89a ii.74a 12.35a 1463b 16.18° 18.85” 0.429Liveweightgain(gd”) .i1.9a .13.1a 115b 27.5° 536d 2.53Gain:Feed ratio 005b -0.03° 0.02” o.ose 0.08” 0.003Ti=cassava peels + no supplement; T2=cassava peels + 50g of ficus per day; T3=cassavapeels + bOg of ficus per day; T4cassava peels + 150g of ficus per day; T5=cassava peels+200g of ficus per day; and T6=cassava peels + 250g of ficus per day.2LW live weight‘Means within rows with different letters are significantly different (P<0.05).4Standard error of the pooled means.790)a)CuiiE0CCu0)0Total intake intake from peels 1Figure 5.1. Effect of level of ficus leaf supplementation on daily voluntary intake (kg°75)oforganic matter by sheep.0 50 100 150 200 250Ficus leaf supplementation level (gid)80even though the total OM intake continued to increase. It is pertinent to note that about 26% ofthe total DM consumed by the animals on T4 was from the supplement (ficus leaves), while thoseon T5 and T6 consumed the supplement in excess of 30% of their total DM intake. Generally,asupplement consumed in excess of 30% of the dietary DM may not be an ideal supplement, itcould be regarded as part of the basal diet.When intake of the basal ration (DM intake) was expressed in relation to live weight therewere no differences due to the level of supplementation. According to Veira et al. (1994) this is abetter comparative measure of intake because it removes the variability caused by differences inlive weight which result from increased gain due to treatment.3. Apparent digestibility coefficientsApparent digestion coefficients of nutrients are presented in Table 5.3. Increases in thelevel of ficus leaves supplementation significantly (P<0.05) depressed digestibilities of DM, OMand ADF of the diets. The apparent dry matter digestibility (DMD) and organic matterdigestibility (OMD) coefficients of Ti and T2 were not significantly different (P>0.05). Theywere, however, significantly higher (P<0.05) than the coefficients for the other dietarytreatments. The lower D]VID and OMD coefficients for diets containing ficus leaves could havebeen due to either low digestibility of ficus leaves and/or the effect of higher intake and higherrumen rate of passage (Van Soest, 1982). The DMD and OMD coefficients observed in thepresent study are comparable to the 72.0 and 77.4 % reported by Iflit (i989) for goats fedcassava peels.Supplementation increased (P<0.05) the coefficient of neutral detergent fibre digestibility(NDFD) from 48.7% (Ti) to 5 5.3% (T4) and declined thereafter; probably the result of theinteraction between intake and rumen clearance rate (Van Soest, 1982). Iflit (i 989) alsoobserved an improvement in digestibility of the NDF fraction of cassava peels as a result ofsupplementation. Supplementation apparently depressed (P<0.05) the digestibility of the aciddetergent fibre (ADFD) fraction of the whole diet.81Nitrogen digestibility coefficients improved as a result of supplementation. The greatesteffect of supplementation on nitrogen digestibility was observed in animals on T6. However, thedifference between T6 and those on T4 and T5 were not significant (P>0.05).A major limitation to the use of cassava peels and other low quality agricultural byproducts is the low nitrogen content. Supplementary nitrogen has been shown to improveutilization in many experiments (Devendra, 1992; Reed et al., 1990; Adegbola et al., 1989; Mosiand Butterworth, 1985), but what constitutes an optimum level of supplementation is still amatter of conjecture. Horton and Holmes (1976) did not observe any responses by sheep on alow nitrogen diet to nitrogen supplementation. This may reflect the fact that even if feedstuffs arelow in nitrogen there may be sufficient present for optimum utilization of the amount of energyTable 5.3. Apparent digestion coefficients of cassava peels-based diets (%).Component TiDietary treatment’ ,2T2 T3 T4 T5 T6 SEM’Dry matter 78.la 773a 748b 7501) 739b 7391) 0.27Organic matter 81.4a 81.3a 791k 79i 77•9b 775b 0.25Nitrogen 50.7a 568b 58l 687bc 69.2° 71.6° 1.28Neutral detergent fibre 48.7a 508k 56.4° 553° 535d 525d 0.43Aciddetergentfibre 50.9a 48.7a 445b 46413 468ab 442 0.39T1=cassava peels + no supplement; T2cassava peels + 50g of ficusper day; T3=cassava peels + lOOg of ficus per day; T4=cassava peels + 150g of ficus per day;T5=cassava peels +200g of ficus per day; and T6=cassava peels + 250g of ficus per day.2Means within rows with different superscripts are significantly different (P<0.05).3Standard error of the pooled means.82available (Orskov and Grubb, 1975). The amount of nitrogen available to support rumenfermentation depends, among other things, on the total quantity of nitrogen in the diet, thedegradation of the nitrogen source in the rumen, the outflow rate from the rumen and nitrogenrecycling.In production trials it has been suggested that the maximum overall digestibiities of lowquality feedstuffs can be achieved by supplementation with nitrogen to obtain a crude proteinlevel of 7 to 8% of total diet dry matter (Allden, 1982). Broster et al. (1979) stated that intakeand digestibility of dry matter of low quality diets was not affected when crude protein levelsexceeded 8.5% of the dry matter of the diet. Other researchers have found that maximum fibredigestion in the rumen occurs with about 12% crude protein in the diet (Kropp et al. 1977;Pritchard and Males, 1985). McAllan et al. (1982) found that maximum digestion of dietarycrude fibre in the rumen occurred when dietary crude protein was between 12 and 16%. Itappears that the optimum level of dietary crude protein required depends on the basal diet. Basedon the nitrogen intake in the present study, it appears that for sheep given ad libitum access tocassava peels the minimum daily intake of protein required for optimum OM and fibre (NDF)-1 0.75 -1digestion is 5.6 g kg LW d4. Weight gainThe level of ficus leaf supplementation significantly (P<O.05) improved live weight gain(Figure 5.2). Animals on Ti, T2 and T3 lost weight throughout the experiment while those onT4, T5 and T6 steadily gained weight (Table 6.2). The mean growth rate of 53.6 g d4 for sheepon T6 was the highest, followed by those on T5 (27.5 g d4) and T4 (11.5 g d’). The differenceswere significant (P<O.05). The highest growth rate observed in the present study was comparableto the 59 g d’ reported for the same breed of sheep fed cassava peels supplemented with 20%gliricidia leaves (Adegbola et al., 1989). The growth rates of animals on T4, T5 and T6 reflectedthe higher intake of these diets and the balance of essential nutrients provided by the higher levelof ficus leaves supplementation. Once animals started gaining weight every gram of ficus leaf DM8319181716I:ii.Weeks—W- No ficus leaf —1-— 50 g/d officus —*— 100 g/d of ficus-a-- 150 g/d of ilcus—— 200 g/d officus -*250 gld officusFigure 5.2. Effect of level of ficus leaf supplementation on liveweight changes in sheep.84intake resulted in approximately 0.48 g d1 additional gain in weight. It appears that thesupplementation of cassava peels with 1 50g of ficus leaves per day may be sufficient to preventthis class of sheep from losing weight.Generally, the Djallonke breed has a low growth rate. Pre-weaning growth rate is about60 g d’ (Tuah and Baah, 1985). The average daily gain for the breed, at a comparable age (6-12months) has been reported to be 25 g (Wilson, 1991). Therefore the average daily gains observedin animals on T5 and T6 are quite remarkable.5. Prediction of nutritive valueThe quest for a reliable and inexpensive technique to evaluate ruminant feedstuffs andalso to predict animal performance has been a long one. The in vitro digestion procedure (Tilleyand Terry, 1963); the number of chews required per unit of feed (Balch, 1969); the detergentfibre analysis system (Van Soest, 1982;) the in vitro gas production technique of Menke andSteingass (1988); grinding resistance (Minson, 1990) and particle density (Lechner-Doll et a!.,1990) are all recent examples of attempts to predict animal performance from feedstuffs. Even ifall these methods were reliable, the laboratory conditions required would put them beyond thereach of most laboratories in the developing countries because of technical and economicdifficulties. The nylon bag (in sacco) estimation of degradability has been suggested as aninexpensive and reliable method of estimating the feeding value of ruminant feedstuffs (Orskovand Reid, 1989). An attempt was therefore made to evaluate this method in terms of its ability topredict animal performance on the feedstuffs used in this study.Data acquired in the present study on total dry matter intake, dry matter digestibility,organic matter digestibility and growth rate of animals on the different dietary treatments wereindividually regressed on degradation characteristics (i.e., A, the rapidly disappearing fraction inthe feed; B=a+b, the potential degradation or disappearance; C, the rate constant and; the lagdetermined for cassava peels in the different rumen environments created by the different dietary85Table 5.4. Prediction of dry matter intake, dry matter digestibility, organic matter digestibility andgrowth rate in sheep from degradation characteristics’Factorsa Y variableb Prediction equation r2 P leveleB DM1 Y=-1328.6+28.9B 0.981 0.0001B+lag DM1 Y= -1262.1 + 30.7B - 118.6lag 0.993 0.001A DMD Y= 87.3 - 0.73A 0.9 14 0.002A+C DMD Y 84.8 - 0.77A +32.3C 0.932 0.02B OlviD Y= 97.3 - 0.29B 0.928 0.002B+C OMD Y=95.2-0.31B+32.8C 0.950 0.01B GR Y= -275.3 + 4.6B 0.854 0.009A+B OR Y=-381.9- 11.8A+9.4B 0.929 0.019‘The equation was; p a + b( 1-e’) for t > lag; where p is the disappearance (%) after thours, a is the fraction which disappears rapidly, b is the slowly disappearing fraction, c is thefractional rate of disappearance (%/h), and t is time (h) of incubation.a A=rapidly soluble or disappearing fraction of the feed determined by soaking the feed in water(39°C) for 1 h; B=insoluble but fermentable substrate (a+b)-A i.e. asymptote less the rapidlysoluble fraction; C=rate constant of the degradation of B i.e. the same as c in the above equation.b DMI=dry matter intake; DMD=in vivo dry matter digestibility; OMD=in vivo organic matterdigestibility; GR=growth rate (g d’).Level of significance.86treatments determined in an earlier study) (Chapter 4). The regression procedures of the SAS(1990) were used.The single most important degradation characteristic which was significantly correlatedwith all the variables measured (intake, digestibility and growth rate) was B, the potentiallydegradable fraction (Table 5.4). The predictive ability of B was improved in the case of drymatterintake by adding the factor lag (from an r2 of 0.98 to 0.99; P<0.001); in the case of organicmatter digestibility by adding the factor C (from an r2 of 0.93 to 0.95; P<0.01) and; in the case ofgrowth rate by adding the factor A (from an r2 of 0.85 to 0.93; P<0.02). Orskov and Ryle(1990) in experiments using the same principle reported r2 values of 0.83, 0.70 and 0.84 usingfactor B alone to predict dry matter intake, dry matter digestibility and growth rate respectively.These r2 values were improved to 0.89, 0.85 and 0.91 respectively by adding the factor C. Inanother study, Kibon and Orskov (1993) fed six browse species to goats in Nigeria and reportedthat adding the factor C improved the ability of B to predict dry matter intake (r2=0.99), drymatter digestibility(r2=0.88) and, growth rate(r2=0.99). Characteristics of feedstuffs such as thesolubility, the potential digestibility and the rate at which the insoluble part of the feed isfermented all contribute to the feeding value of the feedstuff in one way or the other. It istherefore not surprising that the contribution of each of these factors varied in importance in thepredictive equations depending on what aspect of feeding value was being measured. Forexample the B fraction appears to feature prominently in all the predictive equations because it isthe amount of the feedstuff digested and from which the animal would ultimately derive the bulkof it nutrients for its requirements if the A fraction was small.The fact that each factor (A, B, C, or lag) included in the regression equations developedin the present study was statistically significant does not necessarily mean that they are the causalfactors in the responses which were measured i.e. intake, digestibility and growth rate. Thus thereis no direct evidence that B (the potentially degradable fraction in a feedstufi) for example,determines the total dry matter intake, organic matter digestibility and growth rate of sheep.87is no direct evidence that B (the potentially degradable fraction in a feedstuff) for example,determines the total dry matter intake, organic matter digestibility and growth rate of sheep.Voluntary intake, digestibility and growth are complex physiological processes which areinfluenced by combinations of factors in feedstuffs and in animals. Therefore, the significance ofthese statistical relationships lie in their ability to identify some of these factors which could thenbe utilized in the development of models to explain and predict the physiological processes.D. ConclusionsThe results of the study indicated that feeding 1 50g d’ of ficus leaves to sheep will elicitoptimum response in terms of dry matter intake of a basal diet of cassava peels, and digestibilityof the nutrient fractions in the total ration. Moderate growth rates were achieved with this levelof ficus leaf supplementation, however, the results flirther indicated that higher growth rates werepossible with higher levels (200-250 g d’) of ficus leaf supplementation. These higher levels ofsupplementation are recommended in areas where the cost of obtaining the leaves can bejustified. However, in cases where it may be difficult to obtain ficus leaves it would be necessaryto provide other sources of supplemental nitrogen and minerals.88CHAPTER 6 MICROBIAL COLONIZATION OF FEED PARTICLESAND ENUMERATION OF BACTERIA IN THE RUMEN OF SHEEP FEDCASSAVA PEELS AND GRADED LEVELS OF FICUS LEAVESA. IntroductionIn an earlier study (Chapter 3), the potential disappearance/degradability of the dry matterfraction in cassava peels and ficus leaves was estimated to be 71 and 80%, respectively. The rateof degradation of the dry matter of cassava peels was 0.020% h1 and ficus leaves 0.026% W1. At48 h only 43.1% and 44.6% of the dry matter of cassava peels and ficus leaves respectively, hadbeen effectively degraded. In another in vivo study (Chapter 5) reductions in total dry matterdigestibilities with increasing levels of ficus leaf supplementation were observed in sheep fedcassava peels ad libitum. With such high potential degradabilities and slow rates of degradation itwas necessary to investigate the causes for these slow rates in order to develop appropriatemeasures to increase the degradation rates and ensure the efficient utilization of these valuablefeed resources.The unique ability of ruminant animals to utilize low quality feedstuffs derives primarilyfrom the microbial population (especially the cellulolytic bacteria) in their rumen. Currentunderstanding of microbial digestion of feed particles which enter the rumen is that microbialadhesion to ingested feed particles is of pivotal importance in digestion because all cellulolyticand most amylolytic micro-organisms must attach themselves to their insoluble substrates inorder to effect their digestion (Kudo et at., 1986; McAllister et at., 1990a).Many rumen bacteria operate optimally within complex adherent consortia (Kudo et al.1990). Also the type of microbial populations which develop within the rumen, though complex,is highly dependent on the chemical micro-environments provided by nutrients in the ingestedfeed. Once established they are very stable and only change when the nutrients are changed(Cheng and Costerton, 1980). An ecological analysis of the rumen population, including thetypes, and relative proportions of the microbes, is necessary for a complete understanding of themicrobial digestion of feedstuffs. The purpose of this chapter is to report two experiments89conducted to determine the extent of microbial colonization and digestion of cassava peels andficus leaves and, the effect of level of ficus leaf supplementation on the total and cellulolyticbacterial populations in the rumen of sheep. A brief overview of studies on microbialcolonization and digestion of feedstuffs and factors affecting microbial populations in the rumenare presented first.1. Microbial colonization and digestion of feedstuffsMost bacteria in the rumen are associated with feed particles and the digestion of thesefeed particles depends on the adhesion of the bacteria to their specific insoluble nutrientsubstrates (Cheng et at., 1984; Kudo et at., 1987; McAllister et al., 1990a. B). The colonizationand digestion of feed particles in the rumen follow a sequential pattern. Microscopic examinationof forage tissues undergoing digestion in the rumen has shown that cell wall types vary in theirsusceptibility to microbial attack. Generally, phloem contains highly digestible cell walls, theparenchyma cells are only slightly digested. The remaining vascular bundles (with a compositionand structure that depends on its maturity and location in the plant) as well as the epidermis are,almost non digestible ( Akin, 1980; Van de Meer et at., 1987). Extensive studies on thesequential colonization and digestion of fresh legumes (Cheng et at., 1980), hay (Stewart eta!.,1979); straw (Akin, 1980) and grains (McAllister et a!., 1 990b, c) by rumen bacteria have beenconducted.Specific histological staining techniques have revealed that the digestion rates of specifictissues relate to the cell wall composition, particularly, to the extent of lignification. However,similar tissues in different forage species, or even cultivars within species, with apparently similarlignin content are often degraded at different rates (Gordon eta!., 1985). This suggests that otherstructural constraints and not the content of lignin per se may be responsible for the differences inrates of microbial digestion.902. The rumen bacterial populationTwo methods have generally been used to estimate bacterial numbers in the rumen. Theseare direct counts and viable (culture) counts. Appropriate dilution of rumen contents andinoculation of known quantities into culture media yield a value called the culture or viable count.While this is not necessarily identical with the number of cells in the rumen contents, itnevertheless provides a means of detecting relative differences in numbers between samples.Generally, the bacterial population in the rumen is in the order of 1 to 1010 m1’ of rumen fluid.The most reliable method for determining the total number of bacteria in the rumen is by directmicroscopic counts. The major limitation of this method is that it may not reflect accurately thebacteria attached to digesta particles.A number of factors are known to affect the population and activities of rumen microbes.These include: the type and quantity of feed; factors such as species, age and size of animal;individual animal differences; frequency of feeding; and, season. In general, bacterialconcentrations are higher in those animals consuming a high-concentrate diet (Flungate, 1966;Grubb and Dehority, 1980; Leedle and Hespell, 1980). However, there have also been severalresearchers who have found that bacterial numbers are equal or higher in animals fed high-roughage diets (Bryant and Robinson, 1968; Latham et a!., 1971; Van der Linden et a!., 1984;Leedle et a!., 1986). The culture count per millilitre is usually higher just before feeding,diminishes during feeding because of high dilution rates, and ultimately increases after feeding(Hungate, 1966).Thorley et a!. (1968) compared bacterial concentrations in two cows fed ad libitum oneither long grass or the same grass ground and pelleted. Mean colony counts were significantlyhigher when the animals were given ground grass (15.7 x i0 mf’) rather than long grass (10.5 x1 mij. Differences between such factors as percentage of concentrate in the diet, feedingfrequency, feeding level and sampling time, all appear to influence bacterial concentrations and inturn make comparisons difficult. However, the available data seem to indicate that bacterialconcentrations do tend to increase with an increased intake of available energy.913. The ciliate protozoa and fungiThe majority of rumen protozoa are ciliates. They are the most active and most obviousmicro-organisms when rumen contents are observed in a light microscope. The ciliates maycontain up to 40% of the microbial nitrogen under favourable conditions and account for up to60% of the total fermentation products (Hungate, 1966). For this reason, they were consideredessential to the host animal, but some experiments indicated that ruminants could survive andgrow without a rumen ciliate population (Abou Akkada and El Shazly, 1964; Williams andDinussen, 1973). Bacteria are engulfed by ciliates and digested. Some of the digestion productsare used for protozoal growth while the remainder, principally amino acids, are released backinto the rumen where they are fermented by bacteria. Part of the fermentation products are usedfor bacterial growth but the remainder circulate in the rumen (Williams and Coleman, 1992). Thisrecycling of bacterial carbon and nitrogen represents an energy and nitrogen loss as far as thehost animal is concerned and may be of crucial importance in animals fed diets low in nitrogen.The ciliates have been divided into the holotrichs (Family Isotrichidae) and theentodiniomorphs (Family Ophryoscolecidae of the order Entodiniomorphida). Their populationdensity is normally in the range 104106 ml’, of which the majority are members of theOphryoscolecidae. Factors such as type of diet (Wedekind et at. ,1986), level of feed intake(Dehority, 1986), and frequency of feeding (Kaufman et at., 1980; Bragg et at., 1986) have beenshown to affect their population in the rumen. Seasonal changes also affect their numbers.Protozoan species and populations have also been found to vary from one geographic location toanother (Dehority and 0rpm, 1988).The holotrichs in the rumen include Isotricha prostoma, I. intestinalis, and Dasytricharuminantium. Holotrichs have complete body ciliation, move quickly, and rapidly assimilatesoluble sugars. The entodiiomorphs lack complete body ciliation but have bands of syncilia formovement and feed ingestion. They are a more diverse group than the holotrichs and are92represented in the rumen by many genera including Ophryoscolex, Epidinium, Diplodinium andPolyplastron (Williams and Coleman, 1992).The phycomycete fungi are a recently discovered group of rumen micro-organisms. Theirlife cycles consist of an alternation of generations between a motile zoospore stage free in rumenliquor, and a non-motile, vegetative reproductive stage which occurs on digesta particles (0rpm,1975, 1977a, b; Bauchop, 1979). Because of the intimate association of rumen phycomyceteswith the digesta particles, it has not yet been possible to arrive at accurate figures for theirbiomass in the rumen. However, it is estimated that under favourable conditions, up to 8% of themicrobial biomass may consist of phycomycete fungi (0rpm, 1981).Previous knowledge of the chemical composition of cassava peels and ficus leaves,coupled with the current understanding of microbial digestion of feedstuffs, indicate thatstructural constraints in both cassava peels and ficus leaves could be responsible for the slow rateat which they are digested in the rumen. Combining scanning electron microscopy (SEM) withelectron dispersive X-ray analysis (EDXA) offers a combination of visual inspection with semi-quantitative information on the distribution of tissues and certain elements in cell walls and theirphysical relationship with rumen micro-organisms. A combination of this technique withdegradability estimates would be particularly useful in the evaluation of novel feedstuffs likecassava peels and ficus leaves and help identify any features in the feedstuffs which could impedetheir digestion. In EDXA a specimen is bombarded with electrons which then emit X-rays whoseenergies are characteristic for each element present. A detector is used to capture and measurethe intensity of the emitted X-rays (Van der Meer et at., 1987).The digestion of ficus leaves and cassava peels has never been examined by SEM. Neitheris there any information on the relative proportion of cellulolytic bacteria to the total bacteriapopulation in the rumen of sheep in Ghana. Such knowledge may be essential in identification ofconstraints associated with the digestion of feedstuffs and the development of processingtechniques which could aid in their digestion.Therefore the main objectives of the experiment described here were;931) to study the microbial colonization and digestion of cassava peels and ficus leaves byelectron microscopy.2) to identif’ the features of cassava peels and ficus leaves which could impede theirdigestion in vivo, and3) to determine the effect of level of ficus leaf supplementation on the total andcellulolyticbacteria populations in the rumen of sheep fed a cassava peel-based diet.B. Materials and MethodsThe extent of microbial colonization and digestion of cassava peels and ficus leaves wasexamined with the aid of scanning electron microscope (SEM) to which was attached an electrondispersive X-ray analyzer (EDXA). The anaerobic culture technique of Hungate (1950) was usedto obtain the total and cellulolytic bacteria populations in the rumen.1. Animals and feedingSix rumen fistulated Djallonke wethers (average body weight was 33.6 ± 2.7 kg) andfitted with permanent rumen cannulae were used in a completely randomized design. Animalswere kept in individual pens with wooden slatted floors. Each animal had ad libitum access tosun-dried cassava peels and water. In addition each animal was given one of the following levelsof sun-dried ficus leaves; 50, 100, 150, 200, and 250 g day4. One animal did not receive anysupplement and this was used as the control animal. The daily allowances of ficus leaves wereoffered in two equal portions at 08.30 and 16.30 h.2. Incubation and sample preparation for SEMSamples of either cassava peels or ficus leaves were cut into approximately 5 x 5 mmpieces, placed in nylon bags and incubated in the rumens of the six wethers. The bags were made94of monofilament nylon mesh (53 jim pore size, 5 cm x 20 cm; Ankom, Fairport, New York). Thebags were withdrawn from the rumen after 2, 4, 6, 9, 12, 24, 48, 72 and 96 h of incubation. Thebags and contents were immediately rinsed under cold running tap water and the contents fixedfor 3 h in 5% glutaraldehyde in 0.1 M sodium cacodylate acid buffer (pH 7.2). After the 3 h offixation, the fixative solution was pipetted off and a wash solution consisting of 0.1 M cacodylatebuffer was added to the samples and allowed to stand for 20 mm. The wash solution wasremoved after this and a fresh wash solution added. The washing was repeated (three washes inall). The samples were then stored in the final wash solution at 4°C.Samples were later dehydrated at room temperature in a graduated ethanol series (30 mmeach in 10, 20, 30, 50, 70, 90, 95 and 100% ethanol). The samples were then critical point dried(Cohen et a!., 1968). Samples were then mounted on aluminium stubs with silver paste, viewedwith a Hitachi S-570 scanning electron microscope at an accelerating voltage of 15 KeV andphotographed with Kodak film. After mounting on aluminium stubs some specimens werevacuum coated with evaporated carbon and viewed with an SEM equipped with a Kevex 8000energy dispersive X-ray analyzer (Kevex Instruments, Inc. San Carlos, California).3. Sampling, media and cultural methods for bacterial countsRumen contents were sampled 2.5 h after the morning feeding. The sample of rumencontents was immediately strained through two layers of cheese cloth into a beaker and taken tothe laboratory within 30 mm for subsequent dilution. The pH of the ruminal fluid was determinedat this time with an Omega pH meter (Model PHH-63; Omega Engineering Inc. Stamford,Connecticut, USA) and at five other times after the morning feeding i.e. 2, 3, 7, 15 and 17 hafter feeding.Methods for obtaining total viable counts of “total culturable” bacteria and cellulolyticbacteria were those of Hungate (1950) as modified by Bryant and Burkey (1953 a). Bacteria werecultured anaerobically in Scott and Dehority (1965) artificial medium with rumen fluid and thefollowing modifications. For the total count, glucose was decreased from 0.5% to 0.025% w/v;95and cellobiose and starch were included at 0.025% and 0.05% w/v respectively. For cellulosedigestion, the glucose in the medium was replaced with 1 cm x 1 cm Whatman No.1 filter paper.Roll tubes inoculated with ruminal fluid samples for the total “culturable counts” wereincubated at 39°C for 7 d after which colonies were counted. Tubes containing filter paper wereexamined after 2 wk for turbidity and the most probable number method used to estimate thecellulolytic bacteria population (Jones, 1979).C. Results and Discussion1. Colonization and digestion of feed particlesThere were no discernable differences in the extent of microbial colonization anddigestion of either the cassava peels or the ficus leaves which could be attributed to the differentrumen environments which resulted from feeding the graded levels of ficus leaves. Examinationof samples of micrographs of cassava peels and ficus leaves incubated in the rumen of the animalsappeared to indicate that irrespective of level of supplementation, 4 h post incubation wasrepresentative of the initiation of digestion. The plateau in digestion appeared to be 24 h in mostof the samples examined.The micrographs revealed that a tremendous diversity of micro-organisms were involvedwith the digestion of cassava peels and ficus leaves. Even though the microbial digestion offeedstuffs in the rumen usually involves morphologically different bacteria and protozoa (Chenget al. 1984; McAllister et al., 1990c), the morphological diversity of the micro-organismsobserved in the present study was much greater than have previously been observed during SEMstudies on the digestion of other feedstuffs (T.A. McAllister, personal communication).Numerous morphological types of bacteria (rods, ovals and cocci; Plate la), protozoa(Entodinium caudatum; Plate lb and dividing Entodinium sp.; Plate lc) and fungi (Plate id)could be seen to be involved in the digestion of cassava peels and ficus leaves in most of themicrographs examined.96Plate 1 a, 1 b, 1 c and 1 d. Micrographs depicting the morphological diversity of the microbialpopulation in sheep fed cassava peels and ficus leaves.97Plate 2a. Micrograph of the cortex of cassava peel incubated in sheep rumen (4 h). Note colonization ofthe peel by bacteria, protozoa, fungi and the distinctive digestive colonies.Plate 2b. Micrograph of the outer epidermis of cassava peel incubated in sheep rumen (24 h). Note sparsecolonization.Plate 2c. Micrograph of parenchyma cells of the cortex of cassava peel in sheep runien (24 h). Noteresistance to digestion.Plate 2d. Microgaph of starch grains of cassava peel in sheep rumen (4 h). Note few pit formations.98One of the most striking observations was the numerous micrographs showing rumenfungi to be involved in the digestion of these feedstuffs (Plates id and 2a). A lot of themicrographs indicated that feed particles had been penetrated by rhizoids. This association ofrumen fungi with feed particles is a phenomenon relatively easy to observe in in vitro studies ofthe digestion of feed particles by fungi. The ubiquity of this phenomenon in the present in vivostudy probably indicates the special role of rumen fungi in the digestion of low quality feedstuffsin these tropical animals. The major species of fungi produce a wide range of predominantlyextracellular enzymes that degrade the plant cell wall. According to Fonty and Joblin (1991),even though the fungi are unable to use pectin or lignin as carbon sources, they can solubilizelignin. Akin et at., (1989) have, however, postulated that the most important function of thefungi is to weaken plant tissues by the penetration of the rhizoids. lVlicroscopic examination ofthe cassava peels prior to incubation in the rumen revealed that most parts of the phellodermwere colonized by fungal mycelia but after 4 h of incubation only certain portions of the peelswere colonized. It is most likely that fungi found on the pre-incubated phelloderm were aerobicand were therefore destroyed upon introduction into the rumen and their place taken over by theanaerobic ones in the rumen. As with both bacteria and protozoa, initial colonization of feedparticles by fungi can occur within 15 minutes (Ho et at., 1988).The cell walls of the outer epidermis and parenchymatous cells of the sub-epidermis ofcassava peels were sparsely colonized by bacteria even after 24 h of incubation in the rumenexcept for damaged spots (Plates 2b, and 2c). Cell walls of the sub-epidermis and cortex werecomposed of parenchymatous cells which contained starch granules that were similar to those ofbarley, (French, 1984; McAllister et al., 1990a). Although microbial colonization of thesegranules had occurred by 2 h, it appeared that 4 h was close to the initiation of digestion (Plate2d). At 4 h of incubation, starch granules in the sub-epidermis of the cortex were heavilycolonized by bacteria (Plate 3a) and digestive microcolonies could be seen by this time (Plate 2a).At 24 h most of the cell walls holding the starch grains had been digested to expose thestarch grains and distinctive bacterial microcolonies of one or two morphotypes were observed99Plate 3a. Micrograph of the cortex of cassava peel in sheep rumen (4 h) showing heavy microbialcolonization of starch grains.Plate 3b. Micrograph of starch grains of cassava peel in sheep rumen showing distinct pit formations (24h).Plate 3c. Micrograph of starch grains in parenchyma cells of cassava peel exposed in sheep rumen (24 h).Plate 3d. Micrograph of starch grains in sheep rumen (24 h) with deep cavitations.100Plate 4a. Micrograph of the upper surface of Ficus exasperata leaf showing trichomes and silica bodies.Plate 4b. Silicon elemental dispersion map of the surface of Ficus exasperata leaf.Plate 4c. Micrograph of the damaged leaf surface of Ficus exasperata in the rumen of sheep (4 h).Plate 4d. Micrograph of damaged regions of Ficus exasperata leaf.101Plate 5. Micrograph of the surface of Ficus exasperata leaf with silicon body broken off. Note theabsence of microbes on the surface.102adhering to and effecting the digestion of starch grains as evidenced by the formation of pits andcavitations on the grains (Plate 3b, 3 c, and 3d). A similar pattern of colonization has beenreported in studies of cereal grains by McAllister et at., (1990d). However, the starch grains incassava peels appeared to be packed individually in the parenchymatous cells (similar to starchfound in wheat) and not held together by a protein matrix as found in the starch of maize grains(Plates 2c and 3b). Even if a protein matrix was present it was easily digested and did notconstitute a barrier to digestion as observed in the digestion of maize starch by selected speciesof rumen bacteria by McAllister et at., (1 990b).Microscopic examination of both the upper and lower epidermis of the ficus leafindicated that both surfaces were covered with numerous hairs, bristles and solid projectionswhich are referred to as phytoliths in this paper (Plates 4a). Measurements made by EDXA onspecimens of ficus leaves indicated that the phytoliths and the entire cuticularized epidermisexcept damaged sites contained silicon (Plate 4b). All these protuberances could have given ficusleaves the rough ‘sand paper-like” feel. Further examination of these phytoliths indicatedlocalized concentrations of silicon far higher than the background level found on the entire leaf.The relative concentrations of the major elements in the phytoliths were Si (76.8%), Ca (11.4%),Na (5.8%) and Al (4.1%) (Figure 6.1).Both the lower and upper leaf surfaces appeared to be extremely resistant to microbialcolonization and digestion, although there were damaged regions in the leaf on which rumenmicrobes concentrated their attack. The undamaged parts of the lower and upper epidermis ofthe ficus leaves were sparsely colonized, even after 24 h very little evidence existed to indicatethat any digestion had occurred. It appeared that the epidermis was highly resistant to digestion.However, damaged areas were heavily colonized by 4 h (Plate 4c). Upon gaining entry into theleaf, digestion of mesophyll cells was evident at 4 h (Plate 4d). Continued digestion led tocuticular breakage either by physical action or by microbial action underneath the cuticle. Evenafter 24 h the only visible effect of the continued digestion on the cuticle and vascular tissues wasthe physical disruption of the cuticle. (Plate 5).103Yerts 13751 counts Disp2 I Elapsed2 21G secs:::::::::::::::::::::::::::::::::::::::::::::::::::::;:::Ma:::::::::::::::::jj::4— Range’. 10.230 keY 10.110 4Integral 8 = 293345Figure 6.1. Electron dispersive x-ray analysis (EDXA) of a silicon body on the upper surface of aFicus exasperata leaf showing elemental composition.104Bauchop (1980) and Cheng et al. (1984) also observed that intact outer plant surfaceswere not colonized by microbes and that the major route of invasion and colonization of plantwas by epidermal lesions.Silicon appeared to be part of each epidermal cell in ficus leaves and could be acting as astructural inhibitor to digestion as described by Habers and Thouvenelle (1980). Habers et aL(1981) also found that the cuticle per se could act as a structural inhibitor to colonization anddigestion even in the absence of silicon. Denium (1974) noted that silicon acts as a structuralinhibitor during digestion by preventing microbial penetration into the leaves. It does not hindermesophyll digestion once microbes gain access through exposed surfaces (edges, and maceratedparts). Two structural components in forages; silica and lignin, have been known to beresponsible for the incomplete digestion of forages by ruminants (Van Soest and Jones, 1968).This silica includes silicon deposits in the epidermal tissue, silicon associated with cellulose as asecond layer in the epidermis and silicon linked to organic compounds in other cells (Yoshida etaL, 1962). As observed in the present study, silica deposited in the epidermal tissue could haveprevented rumen microbial attachment and penetration through that tissue but, it apparently hadno effect on degradation of the inner tissues once micro-organisms were exposed to them (innertissues). That could account for the appreciably high potential degradability value observed in thenylon bag studies on ficus leaves reported in Chapter 3 and the depression in digestibility withincreasing levels of ficus leaf supplementation of the diets in Chapter 5. Van Soest and Jones(1968) observed a 3% decrease in digestible dry matter for every unit of silica in a wide range ofgrasses. However, Smith et al. (1971) observed only a 1% decrease in organic matterdigestibilities of grasses in the South-western part of the United States.2. Viable counts of total and cellulolytic bacteria populationsThe mean values of rumen pH, total viable counts and cellulolytic bacteria in the rumen ofsheep fed the different levels of ficus leaves are presented in Table 6.1. Supplementation had nosignificant effect (P>0.05) on the pH of the rumen. The total culturable bacteria population105ranged from 2.05 to 2.13 x The cellulolytic bacteria population in the different rumenenvironments ranged from 5.07 to 5.10 x Supplementation again had no significant (P>0.05)effect on the number of total culturable and cellulolytic bacteria populations. Similar observationshave been made by Burroughs et at. (1950) who fed corn cobs and alfalfa hay and Bryant andBurkey (1 953b) who fed wheat straw to cattle. Burroughs et al. (1950) demonstrated thatroughage digestion and total counts of ruminal bacteria in cattle were not affected by addingalfalfa to a low protein basal ration of corn cobs. Adding starch and protein to a wheat straw dietdid not affect the total counts of bacteria in the experiment of Bryant and Burkey (1953b).Table 6.1. Effect of different dietary treatments on total culturable and cellulolytic bacteriapopulations and pH in ruminal fluid of sheep.Variable2 T 1Dietary treatment1T2 T3 T4 T5 T6 SEM4Total viable bacteria (x10 m1’) 2.08 2.08 2.08 2.13 2.05 2.08 0.010Cellulolytics (x107mt’) 5.07 5.07 5.08 5.08 5.07 5.10 0.005Ratio of Cellulolytics:Totalbacteria 1:4.1 1:4.1 1:4.1 1:4.2 1:4.0 1:4.1 0.025pH3 6.68 6.77 6.72 6.69 6.76 6.65 0.019Ti cassava peels + no supplement; T2=cassava peels + 5 Og of ficus per day; T3=cassava peels+ iOOg of ficus per day; T4=cassava peels + 150g of ficus per day; T5cassava peels +200g officus per day; and T6=cassava peels + 250g of ficus per day.2 of three determinations from the same animal.of six determinations from six animals.4Standard error of the mean.106Bryant and Burkey (1953b) found that the cellulolytic bacteria accounted for 5.2% of thebacteria cultured from the rumen when a concentrate diet was fed; and 28% when a wheat strawration was fed. However, in a study of the effect of different protein supplements on the numbersand types of cellulolytic bacteria in the rumen of sheep fed a low protein teff hay, van Gylswyk(1970) found that the cellulolytic bacteria constituted about 1-3% of the total culturable bacteria.While the total culturable counts ranged between 1-4 x 1 , the cellulolytic population was in the7.order of 2-14 x 10 . Wrnsryg et a!. (1991), however reported that 3-6/s of the total viablebacteria (10 x 1010) in the rumen of cattle were cellulolytic. The lack of dietary response in thepresent study could be due to the fact that the diets were not markedly different especially interms of the total amount of cellulose.D. General DiscussionSEM observations of the breakdown of cassava peels and ficus leaves undergoingdigestion in the rumen have demonstrated that many bacteria, protozoa and sporangia ofanaerobic fungi are involved in the digestion of these feedstuffs. The rumen bacteria (especiallythe cellulolytic ones) are the most important degraders of cellulolytic materials (Bryant, 1973). Ingeneral, the feeding of diets which provide readily available forms of fermentable carbohydratesresults in higher numbers of bacteria in the rumen (Latham et a!., 1971). In some feedstuffs, sucheasily available energy (e.g., sugars and starches) may be scarce. The total numbers of cellulolyticbacteria have been reported to decline with the feeding of grain but numbers of certaincellulolytic types, notably the cocci, are relatively constant during concentrate and roughagefeeding (Henning et a!., 1980). Moreover, when meals are separated by long intervals, microbesmay decrease in number because of lack of nitrogen and/or energy and, the microbial populationmay change. The feeding of cassava peels ad libitum in this study ensured a continuous supply ofan energy source, while the twice daily feeding of ficus leaves provided essential nutrients to themicrobes throughout the day. The lack of response to the different levels of ficus leafsupplementation could therefore be due to the fact that the diets were not significantly different107in terms of digestible energy and the supply of essential nutrients from the feedstuffs, thoughsmall, could have been adequate for microbial growth.The role of protozoa in fibre digestion appears to depend on the type of diet (0rpm,1983, 1985; Coleman, 1985). Enhanced cellulose digestion in the presence of Entodinium wasobserved whenever readily fermentable carbohydrates were fed, Jouany et al. (1988). 0rpm(1985) reported that Entodinium spp. are not directly involved in the digestion of fibre but theirrole lies in their ability to decrease the numbers of amylolytic bacteria notably S. bovis, therebypreventing the lowering of rumen pH which could decrease the number of cellulolytic bacteria.This moderating effect of protozoa on rumen pH probably accounts for the relatively high pHvalues even in the rumen of the animals which consumed only cassava peels (Table 6.1).The attachment of cellulolytic microbes to feed particles requires both time and a readilyavailable energy source (Engels, 1986). In the rumen, insoluble nutrients such as cellulose,(Minato and Suto, 1978) and starch (Minato and Suto, 1979) are rapidly colonized by sub-populations of bacteria, protozoa and fungal zoospores that use them as substrates. Consortiadevelop in which substrates are efficiently passed from one microbial population to the other. Avariety of soluble nutrients are produced which support the growth of a rich diversity of bacterialspecies (Cheng et al., 1977; McAllister et al., 1990b, c). Cassava peels and ficus leaves arestructurally and chemically complex and the process of microbial attack is similar to thatdescribed in whole cereal grains (McAllister et al., 1 990d); smooth brome and tall fescue (Haberset a!., 1981) and whole legume leaves (Cheng et a!., 1980). Entry of microbes into plantmaterials is by preference via damaged surfaces, cut edges and natural openings such as stomata(Chesson and Orskov, 1984). As in both whole cereal grains and forages, the most readilydigestible tissues in cassava peels and ficus leaves were located inside the plant and the microbesgain access to these digestible tissues only through damaged sites. Rumen fungi could play animportant role in this regard by penetrating parts of the plant unattainable by bacteria andthereby creating more avenues for the bacteria to enter through later. The existence of a morefavourable nutrient melieu inside the plant promoted bacterial proliferation and digestion of the108carbohydrates and the proteinaceous substrates and the subsequent development of thickbacterial bioflim which when passed from the rumen into the lower gut could be an importantsource of metabolizable energy to the host animal (Rode et al., 1986; McAllister et al., 1990c).The ecological niches which developed inside the cassava peels and ficus leaves wereheavily colonized by 4 h and the climax population consisted of different bacterial morphotypes;some attached to the digestible tissues while others were embedded in large amounts ofexopolysaccharide products. The cuticularized layers of both cassava peels and ficus leaves wereavoided by rumen micro-organisms. In the case of cassava peels the parenchymatous cellscontaining starch granules were penetrated and digested to expose the starch granules whichwere then penetrated and cavitated. This whole process of digestion of the peel and the starchgranules was consistent with the ‘Inside-out” process of digestion of feedstuffs by rumen microorganisms described by Cheng et a!. (1991). This process of digestion of feedstuffs by rumenmicro-organisms implies that the nutritionally poor outer plant tissues (are barriers to digestion);and these have to be penetrated first by micro-organisms before digestion proper begins with themore digestible internal tissues. The outer less digestible tissues are the last to be attacked.E. ConclusionsThe results of the present study indicate that two types of cells found in cassava peels(outer corky epidermis and parenchymatous cell walls which hold starch grains) are resistant todigestion in varying degrees (compared to the rest of the cells in the peels). Microbialcolonization and digestion of the inner tissues were possible only after these tissues had beenbreached. Both the upper and lower epidermis of ficus leaves were covered with silica depositsand silica bodies (phytoliths). These epidermal layers were extremely resistant to microbialcolonization and digestion. The coating of silica could be partly responsible for the long lag phasein the digestion of ficus leaves.Observations in this study also indicate that the effect of silica on the digestion of ficusleaves could be moderated by processing of the leaves to open up more avenues for microbial109penetration. The presence of the numerous phytoliths on the ficus leaves could in some cases aidthe digestion of the leaf in that it appears to be easier for physical action either outside or withinthe rumen to break off the phytoliths and create more damaged avenues through which themicrobes could enter the leaf.The large morphological diversity of microbes found to be associated with feed particlesundergoing digestion in the rumen of animals used in this study calls for further studies in rumenecology, especially the contribution of protozoa and ftmgi in digestion. The role of thesemicrobes may have been previously underestimated.110CHAPTER 7 GENERAL CONCLUSIONS AND RECOMMENDATIONSProducers of small ruminants in the urban and pen-urban areas of Ghana have and willcontinue to play an important role in the provision of animal protein in the diets of the everincreasing urban population in the country. The animals raised also play important roles in thelives of producers; most importantly apart from the fact that they are used to supplementhousehold income they also provide a ready source of cash to meet both expected andunexpected expenditures. The need for extra income in Ghanaian households is universal andprobably explains the popularity of small ruminant production among the different ethnic, social,educational, age and economic groups encountered in this study. The low feed requirements ofsmall ruminants and their resourcefulness in terms of their ability to forage and thrive onrelatively low quality feedstuffs, coupled with the low management level required to make aneconomic profit make small ruminant production in these areas the preferred agricultural activity.The rapid increases in urban population which has a positive effect in terms of ensuring acontinual demand for meat has, however, meant that animals have to be confined in most cases.Confinement has led to the demand for greater management input especially in terms of provisionof adequate and nutritious diets to the animals.Fortunately considerable amount of browses and by-products from food processingindustries exist in and around the urban areas. This study has successfully identified and evaluatedcassava peels and the leaves of Ficus exasperata as feedstuffs which could be utilized to meetthis demand for nutritious feed. In this study the evaluation of the feeding value of cassava peelsand ficus leaves involved chemical, microbiological, nylon bag degradation, in vivo digestibility,feed intake and growth studies. The methodology and equipment required in some of thesestudies are cumbersome and expensive and may not be appropriate for most developingcountries. It appears that the potential degradation and the degradation constants generated fromthe mathematical description of degradation with time of feedstuffs incubated in the rumen ofanimals (in sacco method), may be an easy and reliable technique to evaluate feedstuffs and therumen environment.111From the results of the study of small ruminant production systems and the nutritionalevaluation of the selected feedstuffs (cassava peels and ficus leaves), it was concluded that:1. The potential exists in the urban and pen-urban centres of Ghana for a viable smallruminant production industry. There is, however, the need to strengthen traditional andlocal institutions by organizing producers into co-operatives and associations so that theycan address their concerns collectively. A major advantage of this would be theestablishment of better communication channels between the producers and thegovernment agencies so that concerns of producers can be better articulated. It wouldalso make it easier for the delivery of veterinary services and could also open up avenuesfor individual producers to secure small loans for stock improvement.2. A successfiul small ruminant feeding system can be based on cassava peels and ficusleaves. Respectable liveweight gains (25 and to 54 g d”) can be achieved in Djallonlcewethers and ewe lambs raised solely on a combination of cassava peels and 200 to 250 gd’ of air-dried ficus leaves. There are also indications that higher levels ofsupplementation (in areas where they can be provided) would result in faster growth ratesand, feeding as little as 100 -150 g d’ of ficus leaves would be sufficient to prevent sheepraised solely on cassava peels from loosing weight.3. The outer layer of cassava peel is extremely resistant to microbial colonization anddegradation. Before techniques are identified to improve the colonization and degradationof this layer (which constitutes about 15% of the dry matter of the peel), its removal (apopular practice among producers who feed cassava peels) should be encouraged. Thiscould lead to an increase in the rate of digestion of the peels and a reduction in its ‘fillingeffect” which could ultimately increase total dry matter intake by the animals.1124. The lower and upper epidermis of ficus leaves are covered with silicon deposits.Microbial colonization and/or penetration of the leaves occurs only in damaged spots.There are indications that the detachment of the silicon bodies (one of the group ofstructures on the surface of the leaves) from the leaf surface creates avenues for rumenmicrobes to invade the more digestible inner parts. Any processing or treatment whichwould lead to detachment of more of these silicon bodies could be an effective way ofcreating avenues for microbes to invade the more digestible internal tissues of the leaf.5. Studies are required to ascertain the exact influence of silicon on bacterialattachment and on processing techniques which would lead to a more efficient utilizationof both cassava peels and ficus leaves.6. The rumen ecology of these animals needs to be investigated fijrther. 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Major constraints.130Appendix 2.2.Sample questionnaire used to gather information on the small ruminant productionsystems in the urban and pen-urban households in GhanaSCHEDULE 1.HOUSEHOLD IKFORMAT[ON SHEET/CHECK LISTThis hiformation was gathered from each selected household.Interviewer Date ofvisit Suburb House No.Name ofHousehold head Name of respondent(001) Location 01 Kumasi 02 Effiduasi(002) Sex of respondent 01 Male 02 Female(003) Religion 01 Christian 02 Moslem 03 Others(004) Age of respondent (years)01 <20 02 20-29 03 30-39 04 40-4905 50-59 06 60+(005) Education 01 No formal education 02 Below Sch. Certificate.03 Below diploma 04 Diploma 05 Up to University(006) Major occupation 01 Farmer 02 Civil servant03 Technician/artisan 04 Trader 05 Student06 Pensioner 07 Unemployed/Homemaker 08 Other(007) Household Ownership 01 Owned 02 Rented 03 Caretaker(008) Family size (009) No. of men (010) No. of women01 1-4 01 1-4 01 1-4025-8 025-8 025-803 9-12 03 9-12 03 9-1204 >12 04 >12 04 >1205 Zero 05 Zero(011) No. of children01 1-402 5 - 803 9-1213104 >1205 ZeroLAND(012) Access to land 01 Owned 02 Share Cropping03 Family 04 Others 05 N/A(013) Farm/land size in terms of:01 excess 02 adequate 03 inadequate 04 N/A(014) Major crops grown 01 Food Crops (Maize, Plantain, Cassava, cocoyam, etc.)02 Cash Crops (Cocoa, Oil Palm etc.)03 01 and 02 04 Others 05 N/A(015) Yield (Current/Previous year)01 Excess 02 Adequate 03 Shortage 04 N/A(016) Site of farm (distance from home)01 <1 km 02 1 -2 km 03 >2 km 04 N/A(017) Access to labour for rearing (both family and hired - indicate numbers and seasonality)01 Family 02 Hired 03 Respondent alone 04 Others05 01 and 02 0601 and 04 0702 and 03 08 02 and 0409 03 and 04 10 More than two sources(018) Assets (very broad items like houses, machines, etc.)01 House 02 Machines 03 Vehicle 04 Others 05 None06 01 & 02 07 02 & 03 08 01 & 03 09 01, 02 & 03(019) Other employment opportunities (apart from major occupation and farming, i.e. part-time jobs,trading, etc.)01 Trading 02 Artisan 03 Others 04 None(020) Major items sold - last year (rank in order of income)01 Farm produce (Crops) only 02 Livestock only 03 None Agric. Items 04 None05 01>02 06 02>01(021) Major items purchased - last year (rank in order of expenditure)01 Vehicle only 02 House/Building materials only03 Household Appliances only 04 Other Items 05 None06 01 > Other Items 07 02 > Other Items 08 03 > Others(022) Rank major staples in order of consumption01 Root Crops > Plantains> Cereals13202 Plantains > Root Crops> Cereals03 Cereals > Root Crops > Plantains04 Cereals > Plantains > Root Crops05 Plantains> Cereals > Root Crops06 Root Crops> Cereals> Plantains07 Other Combinations(023) Any plants in the vicinity of household? 01 Yes 02 No(024) Name or type ofplant 01 Terminalia spp. 02 Ficus spp.03 Fruit plants 04 Others 05 N/ASCHEDULE 2UVESTOCK REARING ACTIVITIESLiVESTOCK STRUCTURE(025) Which ofthese animals do you keep?01 Goats 02 Sheep 03 01 and 02 04 Others 05 01 and 040602 and 04 0703 and 04(026) How many goats do you have?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(027) How many of these are adult males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(028) How many ofthese are adult females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(029) How many ofthese are young males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(030) How many ofthese are young females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(031) How many sheep do you have?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(032) How many of these are adult males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(033) How many ofthese are adult females?13301 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(034) How many ofthese are young males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(035) How many ofthese are young females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(036) How many goats did you have last year?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(037) How many ofthese were adult males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(038) How many ofthese were adult females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(039) How many ofthese were young males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(040) How many ofthese were young females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None (041) How many sheep did youhave last year?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(042) How many of these were adult males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(043) How many of these were adult females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(044) How many ofthese were young males?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 None(045) How many of these were young females?01 1-5 02 6-10 03 11-15 04 16-20 05 >20 06 NoneACQUISITION AND DISPOSALWhat are your main reasons for keeping these animals? (Prioritize reasons for each species)(046) Goats:01 Financial Only 02 Meat Only 03 Recreational/Hobby Only04 Religious/Social Only05 01 > Other Reasons13406 02 > Other Reasons07 03 > Other Reasons08 04> Other reasons09 Other Reasons10 N/A(047) Sheep:01 Financial Only 02 Meat Only 03 Recreational/Hobby Only04 Religious/Social Only05 01 > Other Reasons06 02> Other Reasons07 03 > Other Reasons08 04 > Other reasons09 Other Reasons10 N/AHow long since rearing activities started (by species)?(048) Goats: 01 lyr 02 2yrs 03 3yrs 04 >3yrs 05 N/A(049) Sheep: 01 lyr 02 2yrs 03 3yrs 04 >3yrs 05 N/A(050) How did you acquire your first animals?0]. Gift 02 Purchased 03 Caretaker 04 OthersAge of disposal(051) Goats: 01 lyr 02 2yrs 03 3yrs 04 >3yrs 05 N/A(052) Sheep: 01 lyr 02 2yrs 03 3yrs 04 >3yrs 05 N/ATime of disposal(053) Goats: 01 Religious/Social occasions 02 Financial need03 No specific time 04 N/A(054) Sheep: 01 Religious/Social occasions 02 Financial need03 No specific time 04 N/APreferred sex(055) Goats: 01 Male 02 Female 03 Both 04 N/A(056) Sheep: 01 Male 02 Female 03 Both 04 N/A135(057) Method of disposal 01 Direct sale (farm gate) 02 Middlemen 03 Market 04 Meat 05Gifts 06 Batter 07 Other 08 N/A 09 01 and 02 10 01 and 03 11 01 and 04 12 02 and 0313 02 and 04 14 Other combinationsPrices(058) Goats: 01 <5,000 02 5-10,000 03 >10,000 04 N/A(059) Sheep: 01 <5,000 02 5-10,000 03 >10,000 04 N/ANumber born last year(060) Goats: 01 1-3 02 4-6 03 7-10 04 >10 05 N/A(061) Sheep: 01 1-3 02 4-6 03 7-10 04 >10 05 N/ANumber disposed offlast year (sold, consumed, given away etc.).(062) Goats: 01 1-3 02 4-6 03 7-10 04 >10 05 N/A(063) Sheep: 01 1-3 02 4-6 03 7-10 04 >10 05 N/AMANAGEMENT PRACTICESDoes the farmer carry out any ofthese practices?Culling(064) Goats: 01 Yes 02 No 03 N/A Why(065) Sheep: 01 Yes 02 No 03 N/A WhyCastration(066) Goats: 01 Yes 02 No 03 N/A Why(067) Sheep: 01 Yes 02 No 03 N/A WhyVaccinations(068) Goats: 01 Yes 02 No 03 N/A Why(069) Sheep: 01 Yes 02 No 03 N/A WhyDeworming136(070) Goats: 01 Yes 02 No 03 N/A Why(071) Sheep: 01 Yes 02 No 03 N/A Why(072) Which ofthe following does the fanner practice?01 Selective mating 02 Random mating 03 Both(073) Does the farmer breed during a particular season?01 Yes 02 No Why(074) Who makes management decisions concerning animals?01 Farmer/Respondent 02 Household head 03 Collective 04 Any member of household05 Spouse 06 Children0701 and 02 08 01 and 05 09 02 and 05Numbers in breeding herd(075) Female goats:01 1-3 02 4-6 03 7-9 04 10+ 05 N/A(076) Male goats:01 1-3 02 4-6 03 7-9 04 10+ 05 N/A(077) Female sheep:01 1-3 02 4-6 03 7-9 04 10+ 05 N/A(078) Male sheep:01 1-3 02 4-6 03 7-9 04 10+ 05 N/AMortalities last year (both adults and young ones)(079) Goats: 01 1-3 02 4-6 03 7-9 04 >10 05 N/A(080) Sheep: 01 1-3 02 4-6 03 7-9 04 >10 05 N/A(081) What were the main causes ofmortalities/losses? List in order of importance.01 Diarrhoea!PPR(Diseases) 02 Accidents 03 Poisoning/Theft 04 Cause not known 05Miscellaneous Factors 06 None07 01 and Other Causes 08 02 and Other Causes09 03 and Other Causes(082) Have you taken any measures to reduce mortalities or losses?01 Yes 02 No 03 N/A Explain(083) How effective have these measures been?13701 Improvement/Reduction in mortalities02 Same/No improvement 03 Worse 04 N/AFEEDING(084) Method offeeding:01 Roadside herding/grazing - please indicate time(s) of day and the duration ofgrazing activity.02 Free range grazinglbrowsing or scavenging03 Hand feeding04 Anyother O5OlandO2 O6OlandO3 0702and0308 01, 02 and03N.B. For each method of feeding record distance between current source of feed and point ofutilization.(085) Person responsible for feeding animals.01 Farmer/Respondent 02 Children/Family member03 Hired labour 04 Others 05 01 and 02 06 01 and 0307 01 and 04 08 02 and 03 09 02 and 04 10 03 and 0411 More than two categories from 01 -04(086) Cost per unit of feed ifpurchased (does this vary with season? If so record prices by seasons)01 <1,000/yr 02 1-4,000/yr 03 >4,000but<10,000/yr04 >10,000/yr 05 N/A 06 Negligible(087) Cost oftransporting each type of feed.01 <1,000/yr 02 1-4,000/yr 03 >4,000 but <10,000/yr04 >10,000/yr 05 N/A 06 Negligible(088) Physical form in which each feed type is obtained01 Dry 02 Wet 03 Other(089) Any physical processing before feeding? Ifyes pleasedescribe briefly.01 Yes 02 No 03 N/A(090) Which ofthese feed sources are commonly used?01 Pastures, forages, hay etc.(specify, species, source and quantity)02 Grains, root and grain by-products, (types, sources and quantities)03 Protein concentrates, commercial feed mix (types, sources and quantities)04 Household garbage/reflise (types, sources and quantities)0501and02 0601and03 07 OlandO4 08 01,O2andO3 0901,O2andO4 1001,O3andO41102 and 03 1202 and 0413 02, 03 and 04 14 03 and 04 15 All sourcesPlease indicate the importance of each method/kind offeeding by138(091) Season 01 Yes 02 No Why?(092) Sex of animal 01 Yes 02 No Why?(093) Age of animal 01 Yes 02 No Why?(094) Condition of animal 01 Yes 02 No Why?FEED STORAGE FACILITIES(095) Does the farmer have any feed storage facilities?01 Yes 02 No(096) Type of storage/container01 Silos/Rooms 02 Barrels/Drums 03 Baskets04 Bags 05 Others 06 N/A 07 More than one type(097) Storage capacity01 Adequate 02 Inadequate 03 N/A(098) Duration of storage01 <1 month 02 1-3 months 03 >3 but <6 months04 >6 months 05 N/A(099) Any processing before storage? 01 Yes 02 No 03 N/A(100) Direct cost of storage01 <1,000/yr 02 1-4,000/yr 03 >4,000but<10,000/yr04 >10,000/yr 05 N/A 06 NegligibleSANITATION(101) Animal sanitation 01 Yes 02 No Explain(102) Housing sanitation 01 Yes 02 No Explain (e.g. methods of cleaning and disinfecting).(103) Water and Feed sanitation 01 Yes 02 No Explain(104) Person responsible for sanitation related duties01 Farmer/Respondent 02 Children/Family member03 Hired labour 04 Others 05 01 and 03 06 01 and 0407 O2andO3 08 O2andO4 09 O3andO410 More than two categories from 01 -04(105) Sanitation related problems 01 Yes 02 None Explain139SCHEDULE 3EXPANSION POTENTIAL AND WILLINGNESS TO INVEST(106) Is the farmer willing to increase his flock numbers?01 Yes 02 No Why?(107) Constraints as seen by farmer (prioritize/rank)01 Labour only 02 Marketing only 03 Health only04 Credit only 05 Feeding only 06 Theft only07 Space only 08 Others 09 01 and 03 10 01 and 0411 01 and 05 12 01 and 07 13 03 and 04 14 03 and 0513 03 and 07 14 04 and 05 15 04 and 06 16 04 and 0717 05 and 06 18 05 and 07 19 01 and 0620 More than two ofthe above.(108) Possible solutions (fanner’s views)(109) Constraints as seen by interviewer - prioritize(110) Are there any current compensating strategies? Prioritize.(111) Options and opportunities for improvement (through research, and policy changes, i.e. identi1,’researchable problems)(112) If farmer had access to credit or excess liquidity how would he/she invest or utilize it?140Appendix 3.1.Sample of SAS program used to solve the modified version of Orskov and McDonald (1979)equation with a lag phase. Program was written by Dr. John Hall of Agriculture Canada, Vancouver,BC. Canada.*ORSKOV EQUATIONS WITH LAG PHASE SOLUTION;OPTIONS PAGESIZE=90;TITLE Dry matter degradation’;FILENAME SASDATA ‘DMDEG’;DATA DMD;INFILE SASDATA MIS SOVER;INPUTT]MEFEED$anTRTDMD;RUN;PROC SORT;BY FEED an;PROC NLIN ITER5O METHOD=MARQUARDT;BY FEED an;PARMS A=15 B=40 C=.04 LAG=0,3,6;BOUNDS LAG>=O;IF LAG<0.0 THEN DO;LAG 0.0;END;IF T<LAG THEN DO;MODEL DMD = A;DER.A= 1.;DER.B=0.;DER.C=0.;DER.LAG = 0,;END;ELSE DO;MODEL DMD = A + B*(1.EXP(C*(TLAG)));DER.A= 1.;DER.B = (1.EXP(C*(TLAG)));DER.C = B*(TLAG)*EXP(C*(TLAG));DER.LAG = B*C*EXP(C*(TLAG));END;OUTPUT OUT=B PREDICTEDYHAT RESIDUALYRES PARMS=A B C LAG;PROC PRINT DATA=B;PROC PLOT;BY FEED an;OPTIONS PAGESIZE=25;PLOT DMD*T0! YHAT*TPI / OVERLAY;RUN;DATA SUM(DROP= YHAT YRES);141OPTIONS PAGESIZE9O;*CALCULATJG EFFECTIVE DEGRADABILITY;SET B;IFT<48 THENDELETE;IF T >48 THEN DELETE;*THE CALCULATED CONSTANTS ARE THE SAME FOR EACH iNCUBATIONTIMETHIS STATEMENT DELETES ALL BUT ONE TIME;TO=LAG;Kf=.06;*Kf IS THE FRACTIONAL RATE OF PASSAGE;EFFDGRDA+(((B*C)*E(C*TO))/(C+JJ))*EXp(...(C+J)*TO);PUT FEED an A B C LAG KfEFFDGRD;RUN;PROC PRINT;RUN;


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