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The importance of population density in broiler production Hamilton, Douglas Malcolm 1966

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THE IMPORTANCE OF POPULATION DENSITY IN BROILER PRODUCTION  by DOUGLAS MALCOLM HAMILTON, B.S.A. U n i v e r s i t y o f B r i t i s h Columbia, 1 9 6 6  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURE i n the Department of P o u l t r y Science  We accept t h i s t h e s i s as conforming t o the required standard  THE UNIVERSITY OF BRITISH COLUMBIA April, 1 9 6 6  In  presenting  requirements Columbia, for  the  c i a l  Head  gain  Department The  of  my  that shall  in  p a r t i a l  advanced  degree  at  the  the  study. t h i s  Library I  further  t h e s i s  Department  copying not  be  or  or  of  allowed  B r i t i s h  7  by  agree  without  Columbia  6\  it  that  s c h o l a r l y h i s  f u l f i l m e n t  University  make  of  of  freely  a v a i l a b l e  permission  purposes  of  t h i s  t h e s i s  my  written  the  B r i t i s h  may  representatives.  S^,^L^>  Canada 'U-  f o r  shall  p u b l i c a t i o n  Q* n * ^ £ ^  of  8,  t h e s i s  that  of  University  Vancouver Date  and  copying  understood  an  agree  reference  tensive by  I  f o r  t h i s  for be It  f o r  exgran  is f i n a n -  permission.  ii  ABSTRACT' Commercial b r o i l e r chickens were reared as combined sexes at f l o o r space areas of 0.6, 0.7, 0.8, 0.9 and 1.0 f t . per b i r d t o ten weeks of 2  age.  There was no s i g n i f i c a n t d i f f e r e n c e i n the mean body weights at nine  weeks of age„  At ten weeks of age, there was no s i g n i f i c a n t d i f f e r e n c e i n  the mean body weights of the b i r d s reared at 0,7, 0.8, 0,9 and 1.0 f t . per 2  b i r d , while the f l o o r area of 0.6 f t . per b i r d produced s i g n i f i c a n t l y 2  l i g h t e r b i r d s than d i d 1.0 f t , . 2  M o r t a l i t y was not a f f e c t e d by b i r d d e n s i t y , whereas the percentage of breast b l i s t e r s increased with i n c r e a s i n g density,. B r o i l e r production c o s t s and various combinations of feed and meat p r i c e s were used i n models t o determine the age at which maximum annual net returns per square foot of f l o o r area occurred. Assuming that the weekly mean body weights were the same f o r b i r d s grown at 0.7 and 1,0 f t . per 2  b i r d f l o o r area, maximum net r e t u r n s were obtained by marketing at nine or ten weeks of age depending on feed and meat prices« The e f f e c t on net r e t u r n s of marketing one week e a r l i e r or l a t e r than at the age of greatest net returns was examined. When i t was assumed that the number of l o t s per year was l i m i t e d to 4,33  i . e . a twelve week replacement program, annual maximum net returns were  found t o occur at a market age of at l e a s t ten weeks.  iii  When the number of l o t s marketed was not assumed t o be l i m i t e d , annual maximum returns a l s o occurred, with few exceptions, at l e a s t at t e n weeks of age.  iv TABLE OF CONTENTS CHAPTER  PAGE  I. INTRODUCTION II. REVIEW OF THE LITERATURE III. MATERIALS AND METHODS IV, RESULTS AND DISCUSSION  5 11 14  Weekly Body Weights and Feed Consumption  14.  Final Body Weights  21  Mortality  22  Marketing and Market Grades  22  V, DEVELOPMENT OF FIXED AND VARIABLE COSTS OF BROILER PRODUCTION  25  Variable Costs  26  Fixed Costs  29  Depreciation of Buildings and Equipment VI.  1  INFLUENCE OF MARKET AGE AND WEIGHT ON ANNUAL NET RETURNS  29 31  Meat Yield per 1000 Square Feet of Floor Space at 0«7 and 1,0 Square Foot per Bird Annual Net Returns Per Square Foot of Floor Area Per Year VII. SUMMARY BIBLIOGRAPHY APPENDIXES  32 32 46 49 5A  V  LIST OF TABLES TABLE I.  PAGE B r o i l e r Production E f f i c i e n c y and Marketing Trends i n Canada f o r the Period 1950-1965  II.  2  Average Body Weight and Average Cumulative Feed Consumption f o r Mixed Sexes of B r o i l e r s Raised at F l o o r Areas o f 0.6, 0.7, 0„8, 0,9 and 1.0 Square Foot per b i r d t o Ten Weeks of Age  III.  15  R e s u l t s of Duncan s Test of Weekly Mean Body Weights f o r Sexes 1  Separately and Combined from Hatch t o Ten Weeks of Age IV.  Q u a l i t y Defects Reported During Processing of B r o i l e r s at Seventy-three Days of Age  V.  23  Some Production Costs f o r 1962, 1963 and 1964, and the Three Year Average f o r B r o i l e r s reared i n B r i t i s h Columbia  VI.  16  27  Maximum Annual Net Returns per Square Foot of F l o o r Area and Associated Market Age and Weight f o r Various Feed and Meat Prices:  VII.  B i r d Density 0.7 Square Foot per B i r d  36  Maximum Annual Net Returns per Square Foot of F l o o r Area and Associated Market Age and Weight f o r Various Feed and Meat Prices:  B i r d Density 1.0 Square Foot per B i r d  37  vi TABLE VIII.  PAGE The Decrease i n Annual Net Returns per Square Foot of Floor Area Incurred by Marketing One Week E a r l i e r or One Week Later Than Optimum f o r Various Feed and Meat P r i c e s :  Bird  Density 0.7 Square Foot per B i r d IX.  39  Maximum Annual Net Returns per Square Foot of F l o o r Area and Associated Market Age and Weight f o r Various Feed and Meat Prices:  B i r d Density 1.0 Square Foot per B i r d and Number  of Lots per Year Limited t o 4-33 X.  41  Maximum Annual Net Returns per Square Foot of F l o o r Area and Associated Market Age and Weight f o r Various Feed and Meat Prices:  B i r d Density 0.7 Square Foot per B i r d and Number  of Lots per Year Limited t o 4.33  4-3  vii LIST OF FIGURES FIGURE 1.  PAGE Ranking of Weekly Mean Body Weights f o r B r o i l e r s Reared as Combined Sexes from Hatch t o Ten Weeks of Age  2.  18  R e l a t i o n s h i p Between Live Body Weights and Y i e l d of B r o i l e r Meat per 1000 Square Feet of F l o o r Area per Year at B i r d D e n s i t i e s of 0.7 and 1.0 Square Foot per B i r d  34.  viii  ACKNOWLEDGMENT  The w r i t e r wishes t o express h i s appreciation t o h i s advisor, Dr. J . F. Richards and t o the other members o f the Department o f P o u l t r y Science f o r t h e i r guidance and c r i t i c i s m throughout the course of t h i s study.  He i s also indebted t o the members o f h i s committee who c r i t i -  c a l l y read t h i s manuscript. The author i s indeed g r a t e f u l t o The Honourable Frank R i c h t e r , M i n i s t e r o f A g r i c u l t u r e , Mr. Alex H. Turner, Deputy M i n i s t e r o f A g r i c u l ture and Mr. W. H. Pope, P o u l t r y Commissioner, B r i t i s h Columbia Department of A g r i c u l t u r e , f o r the opportunity provided by them f o r him t o pursue the graduate program of which t h i s t h e s i s i s a p a r t . Appreciation i s a l s o extended t o Mr. H. E l l i s , S p e c i a l A s s i s t a n t , and t o Mr. D. Crober, f e l l o w graduate student, f o r assistance rendered. Sincere appreciation i s also expressed f o r the patience and understanding of h i s wife and f a m i l y .  CHAPTER I  INTRODUCTION  The production of broilers in Canada has developed into a multimillion dollar business involving breeder supply flocks, hatcheries, broiler farms and processing plants.  In 1964,306 million pounds (live weight) of  broilers, with a value to the growers of about 65 million dollars were delivered to processing plants in Canada. This represents an increase of 13.5 percent over the number of pounds delivered in 1961 and is reflected in the per capita consumption of broiler meat. The per capita consumption increased from 19.6 pounds (estimated) in 1961 to 21.2 pounds in 1964 . 1  British Columbia broiler prices at a l l stages of marketing have decreased steadily while production costs have increased. For example, cost other than fixed costs, feed, labour and cartage were 17.19 cents per bird in 1962, 17.79 cents in 1963 and 18.21 cents in  1964.,  Pope (1964b.) The average broiler  price declined from 25.9 cents per pound live weight in 1957 to 19.22 cents in 1964 (Appendix I). In view of decreasing prices and Increasing operating costs, broiler, growers have attempted to maintain profits by increasing the size of the production unit and the efficiency of the growing operation. Since 1950 the average age of broilers marketed, decreased from approximately 11*5 weeks to 8.5 weeks of age while the average live weight of broilers marketed increased from 3.11 to 3.75 pounds, as presented in Table I. The number of broilers ^Estimates Received by A Private Communication, 1965. Marketing Branch, Canada Department of Agriculture, Ottawa.  Production and  .2 TABLE I BROILER PRODUCTION EFFICIENCY AND MARKETING TRENDS IN CANADA FOR THE PERIOD 1950-1965  2  1950  1955  1965  11 weeks 5 days  9 weeks 5 days  8 weeks - U days to 9 weeks  Average Weight  3,11 lbs.  3.30 lbs.  3.75 lbs.  Average feed^ Efficiency-  3.31  2.57  2.39  3,000  25,000  60,000  50*  46*  Age of Broilers Sold  Size of Unit Per Man Price to Housewife^  -  63*  Estimates Received by A Private Communication, Production and Marketing Branch, Canada Department of Agriculture, Ottawa. ^Pounds of feed required per pound body weight. %etail broiler prices per pound.  3 r a i s e d per man as l i s t e d i n Table I i s estimated t o have increased from 3,000 to 60,000 b i r d s per annum while the p r i c e t o the consumer dropped from s i x t y three t o f o r t y - s i x cents per pound between 1950 and  1965.  The gains i n e f f i c i e n c y evidenced i n Table I are the r e s u l t of improvements i n the genetic p o t e n t i a l o f b r o i l e r c h i c k s a v a i l a b l e and the manifestation of that p o t e n t i a l r e s u l t i n g from improved feed formulation and manufacture. These advances have meant that during recent years more b i r d s with a weight at l e a s t equal to those produced i n 1950 could be marketed annually from f a c i l i t i e s of the same p h y s i c a l s i z e . With a view t o i n c r e a s i n g e f f i c i e n c y even more, there has r e c e n t l y been increased i n t e r e s t i n the e f f e c t s of f l o o r space per b i r d ^ on e f f i c i e n c y o f weight gains i n b r o i l e r s .  I n recent years i t has been g e n e r a l l y recommended  that a t l e a s t one square foot o f f l o o r area per b i r d i s required t o achieve maximum weight at nine or ten weeks of age.  However, some reports i n the  l i t e r a t u r e have i n d i c a t e d that l e s s space may be required f o r maximum growth. Because o f the obvious importance of e s t a b l i s h i n g the growth which may be expected from b r o i l e r s under varying f l o o r space allotments, the study reported herein was undertaken. The primary o b j e c t i v e s of t h i s study were (a) to determine the i n fluence of f l o o r space allotments from 0.6 to 1.0 square foot  per b i r d on  5Floor space per b i r d i s i n d i c a t e d by the terms "population d e n s i t y " or " b i r d density". These terms are used interchangeably throughout t h i s t h e s i s . ^Square foot per b i r d w i l l be represented by f t .  2  per b i r d .  u the average weight that b r o i l e r s achieved from one t o ten weeks o f age; (b) to determine f i x e d and v a r i a b l e costs of production f o r each treatment group; (c) to study the influence of the age at which b r o i l e r s are marketed on net returns using the body weights, feed consumption and cost data developed.  \  CHAPTER I I  REVIEW OF THE LITERATURE  I t was g e n e r a l l y accepted by e a r l y workers that f l o o r area per b i r d was a very important f a c t o r i n f l u e n c i n g the body weight of b r o i l e r s .  Brooks  (1957) reported that d i f f e r e n c e s i n body weight between b i r d s at 0.5 and 1.0 . ft?  were found t o be r e l a t i v e l y s m a l l at one week o f age but became p r o g r e s s i v e l y  greater a f t e r t h i s age, and that one could expect a steady increase i n the body  2 weights as the f l o o r area was increased from 0.5 t o 2.0 f t . b i r d s between nine and twelve weeks of age.  per b i r d  for  S i m i l a r r e s u l t s were reported by  Hansen and Becker (i960), who demonstrated that when b i r d s of f i v e  different  genotypes were provided w i t h f l o o r areas of 0.50, 0.75, 1.00 and 1.25 f t . per 2  b i r d from e i g h t t o eleven weeks of age, growth decreased as b i r d density i n creased. S i e g e l and Coles (1958), however, found no s i g n i f i c a n t d i f f e r e n c e s i n body weights of b r o i l e r s grown t o nine weeks of age a t f l o o r space ranging from 0.50 to 1.25 f t . per b i r d . 2  levels  S i e g e l (i960) b e l i e v e d that the con-  t r a d i c t o r y r e s u l t s were due t o the d i f f e r e n c e s i n genetic stock, management or other environmental causes.  He suggested that these f a c t o r s may be important  i n determining the body weights of b i r d s grown under v a r i o u s f l o o r space a l l o t ments. In order t o determine the influence of time of the year and f l o o r space per b i r d on b r o i l e r weights, Moreng et a l (i960) reared commercial type b r o i l e r chicks during the four seasons of the year at area d e n s i t i e s of 0.50, 0.75,  1.00  6 p  and 1.25 f t .  per b i r d .  In general they found that b i r d s given 1.00 f t .  2  of  f l o o r area t o eleven weeks grew w e l l during f a l l , winter and spring months however, during the summer months 1.25 f t .  per b i r d was required t o obtain  comparable growth r a t e s .  There was very l i t t l e d i f f e r e n c e i n body weights 2 between 0.75 and 1.00 f t . of f l o o r space. Depressed growth was observed at 2 the 0.5 f t . f l o o r area p a r t i c u l a r l y during the nine t o eleven week p e r i o d . Krueger (196l) reported t h a t b r o i l e r growth a t eight weeks was p o s i t i v e l y c o r r e l a t e d with f l o o r space.  In t h i s study the b i r d s averaged 3.12 pounds a t  0.60 f t . and 3.29 pounds at 1.20 f t . per b i r d . 2  2  S i e g e l (i960) and Moreng et a l (1961) concluded that body weight as a f u n c t i o n of b r o i l e r s t r a i n was more important than age i n determining f l o o r space requirements  f o r optimum growth and development.  Nurse and co-workers  (i960) recommended t h a t a three pound b r o i l e r be allowed 0.70 f t . ; a 3.5 pound (1964b)  b i r d 0.85 f t . and a four pound b i r d 1.0 f t . . Noles and Padgett 2  2  recommended s l i g h t l y more f l o o r area per b i r d ; 0.86 f t .  f o r each three pound  ? 2 b r o i l e r ; 1.0 f t . f o r a 3.5 pound b r o i l e r and 1.1 f t . per b i r d at four pounds body weight. Some recent reports have i n d i c a t e d t h a t population d e n s i t y has no s i g n i f i c a n t e f f e c t on body weights.  B i e l y e t a l (1963) pointed out that where 2  commercial b r o i l e r s were reared at d e n s i t i e s o f 0.75 and 1.45 f t .  per b i r d ,  b i r d s at the lower d e n s i t y (1.45 f t . per b i r d ) had higher average body weights 2  at 3, 5, 7, and 8 weeks of age.  These d i f f e r e n c e s increased with age.  The  d i f f e r e n c e however, between the two d e n s i t i e s at eight weeks was not s t a t i s t i c a l l y significant.  7 Recent reports of the Arkansas Meat Performance Test (1965) indicated no significant differences in broiler body weights among densities of 0.6, 0.9, and 1.0 f t .  0.8,  per bird for fourteen different broiler strains raised to  eight weeks of age.  In a second test using thirteen strains of broilers at  floor areas of 0.4, 0.5, 0.6, 0.7 and 0.8 f t . per bird to eight weeks, i t 2  was found that there was no significant difference among the floor areas of 0.5, 0.6, 0.7 and 0.8 f t . per bird. However, birds reared at floor areas of 0.5, 2  0,6, 0.7 and 0.8 f t . had significantly greater body weights than those reared 2  at the 0.4 f t .  2  level*  Merritt et al (i960) reported that when sexes were reared separately there was greater variation in body weight than when they were reared together. This difference disappeared at eight weeks of age.  In order to determine i f  growing the sexes separately or combined had any effect on the overall body weights and profits Wiseman et al (1961) grew broilers separately and combined at two different floor allotments of 0.8 and 1,0 f t . per bird to thirteen 2  weeks of age.  They found that the males grew faster when reared with the fe-  males than when they were reared separately. The females, when grown separately, were heavier than when reared with males at 0.8 ft« . At 1,0 f t . 2  2  per  bird the reverse of, this relationship was true, Wiseman et al (1961) also compared the effect of floor areas of 0,8 and 1.0 f t . per bird on thirteen 2  week body weights for broilers reared as combined sexes. They reported that at 0.8 and 1.0 f t .  2  per bird floor areas, the males weighed 5.40 and 5.67  pounds respectively and the females 4*03 and 4.22 pounds respectively. These differences in body weights favouring the greater floor area were significant.  8 To determine optimum production conditions on the b a s i s of the weight o f the b i r d s alone, i s not p o s s i b l e .  When values are applied t o the input-output"*"  f a c t o r s of production, p r o f i t or l o s s c a l c u l a t i o n s may then be put t o p r a c t i c a l use through the adoption of monetary values as a common b a s i s f o r study.  Several  studies have been undertaken t o determine at what age or weight b r o i l e r s should be marketed i n order that maximum net returns are r e a l i z e d on a per l o t b a s i s . Smith et a l (194-9) conducted a study of the Del-Mar-Va b r o i l e r i n d u s t r y , and found t h a t the marketing of a three pound b i r d at t h i r t e e n weeks of age r e s u l t e d i n greatest returns.  Baum and Walkup (1950) found that a 3.5 b r o i l e r  marketed at twelve weeks of age provided highest t o t a l r e t u r n s .  Baum and Walkup  (1956) reported p o s i t i v e net returns t o management occurring when the b r o i l e r body weights ranged from 2.37 t o 3.43 pounds, while Berg (1958) reported that b i r d s marketed at 10.5 weeks averaging 3.5 pounds were the most p r o f i t a b l e . Sanz-Arias and Paz-Saez (1963) pointed out t h a t due t o the growth pattern of b r o i l e r s , net p r o f i t s decrease  r a p i d l y a f t e r the desired market weights have  been obtained and t h i s r e s u l t s i n a net l o s s i f b i r d s are not marketed close t o optimum weight.  He found t h a t p r o f i t s began when the b i r d s reached 2.84 pounds  and were greatest a t 4.35 pounds l i v e weight. When c a l c u l a t i n g p r o f i t s from a b r o i l e r growing operation w i t h i n a s p e c i f i e d time period the point o f maximum p r o f i t i s where marginal cost and marginal revenue c o i n c i d e .  E a r l y i n v e s t i g a t o r s f i r s t determined net returns on a per b i r d  i l n p u t - any item that contributes to the production of the product; output - the product produced.  9 per l o t b a s i s as indicated by the work of Baum and Walkup (1952), M e r r i t t e t a l (i960) and Smith (1949)«  This approach i s not v a l i d f o r any continuous b r o i l e r  operation as i t does not consider the time f a c t o r , Trent and Winder (1961), Nurse e t a l (i960) and Noles and Padgett (1964b) i n d i c a t e d that the cost o f feeding a f l o c k of b r o i l e r s f o r an a d d i t i o n a l day o r week must include the opportunity c o s t .  2  The question which must be asked i s could the a d d i t i o n a l  day or week have been used more p r o f i t a b l y (on the b a s i s of annual net returns per u n i t area) by a subsequent f l o c k . Noles and Padgett (1964b) i n d i c a t e d that marketing b r o i l e r s e a r l i e r than ten or twelve weeks o f age may maximize net returns by spreading the  deprecia-  t i o n over more b i r d s per year* Nurse e t a l (i960) i n v e s t i g a t e d the marketing of b r o i l e r s a t l i v e weights of 2.6 t o 4.0 pounds l i v e weight with v a r i a b l e feed and chick costs and l i v e broiler prices.  They assumed that the body weight achieved by b r o i l e r s i n a  given time i s a f u n c t i o n of f l o o r area allowed per b i r d .  The model they used  assumed that the l i g h t e r the weight at which b r o i l e r s were marketed, the lower the f l o o r area required per b i r d .  By the use of t h i s model they concluded that  under a continuous operation net returns per year ..are maximized i f b r o i l e r s are marketed younger ( i . e . l i g h t e r b i r d s and more b i r d s per year) when: 1. Feed and chick p r i c e s are constant and meat p r i c e s increase. 2. Feed and meat p r i c e s are constant and chick p r i c e decreases, 3.  Chick and meat p r i c e s are constant and feed p r i c e decreases.  Opportunity cost: the r e t u r n that the occupied f l o o r area would contribute t o the annual net r e t u r n i f used by a new l o t of b r o i l e r s .  10 When the reverse of these r e l a t i o n s hold true net returns are maximized when b i r d s were reared to heavier weights. Smith ( l % 5 ) concluded that the f a s t e r and cheaper b r o i l e r weight gains obtained by growers i n 1963 as compared t o 1952 were due t o improved technology i n b r o i l e r production.  With p r i c e mapping he showed that t e c h n o l o g i c a l  changes have m a t e r i a l l y lessened the r e l a t i v e cost disadvantage broilers. started.  of heavier  Costs such as c h i c k , f u e l and medicines are constant per chick On a per pound b a s i s they decrease as body weight increases.  comparing the most p r o f i t a b l e marketing weight of b r o i l e r s between 1952  In and  1963, Smith (1965) showed t h a t (a) the e n t i r e cost structure of b r o i l e r production has been lowered hence maximization of p r o f i t s are possible at lower meat p r i c e s , (b) increases i n the b r o i l e r - f e e d p r i c e r a t i o have favoured  a  l i g h t e r b i r d since t h i s i s the only way that output from a given f l o o r area can be expanded, (c) the penalty f o r producing a b i r d somewhat heavier or l i g h t e r than the desired marketing weight was considerably l e s s i n 1963 than i n 1952,  i . e . The weight of b r o i l e r s marketed has increased with these  heavier b i r d s becoming more competitive due to improved feed conversion.  CHAPTER III MATERIALS AND METHODS An experiment was designed t o determine the e f f e c t s of varying f l o o r space on the body weight of b r o i l e r s from one t o ten weeks of age.  Sixteen  hundred and twenty-four one-day o l d commercial b r o i l e r chicks of a single s t r a i n were sexed by the vent method, i n j e c t e d with T y l o s i n and randomly assigned by sex to treatment groups so that each group contained an equal number of males and females. A l l chicks were wing-banded and i n d i v i d u a l l y weighed t o the nearest gram. The treatments consisted of f i v e population d e n s i t i e s : 0.7 and 0.6 f t .  of f l o o r space per b i r d .  1.0, 0.9,  0.8,  The b r o i l e r s were r a i s e d i n a  p r e s s u r e - v e n t i l a t e d , windowless house c o n s i s t i n g of sixteen pens.  Ten pens,  f i v e i n s i m i l a r p o s i t i o n s i n each end of the house were chosen t o form r e p l i cates i n space.  Within each block (end of the house) the treatment groups  were randomly assigned to pens.  Each pen consisted of 126 f t .  of f l o o r  space so the number of b i r d s per treatment group was as i n d i c a t e d below: Number of Square Feet Per B i r d  Number of B i r d s Males Females  1.0  63  63  0.9  70  70  0.8  78  78  0.7  90  90  0.6  105  105  Each pen had 3 inches of k i l n - d r i e d shavings on the f l o o r and heat was provided by e l e c t r i c heat lamps.  12  During the f i r s t week the c h i c k s had access t o chick feeders then gradua l l y they were changed to f o r t y pound c a p a c i t y hanging feeders, two per 1 0 0 b i r d s , supplying 104. inches of feeding space per 1 0 0 b i r d s .  Equal feed space  per b i r d was maintained i n each pen by i n s t a l l i n g , wooden blocks as required r e s t r i c t feed space (Appendix 3 ). pen depending on the requirements.  to  Each pen contained three or four feeders per The feed was a regular commercial r a t i o n and  feeding p r a c t i c e s recommended by the feed manufacturer were followed.  One-half  pound of s t a r t e r mash per b i r d was f e d , followed by medicated grower crumbles u n t i l the b i r d s were 4 2 days o l d . removed.  Any feed l e f t at t h i s date was weighed and  A medicated, crumbled f i n i s h e r was then fed t o the b i r d s u n t i l they  were 70 days o l d at which time the experiment was  terminated.  The c h i c k s had access t o four one-gallon water founts per pen  (except  f o r the lowest d e n s i t y pen which had t h r e e ) . These were used f o r fourteen days then gradually replaced by one f o u r - g a l l o n waterer and two automatic f o u n t a i n cups per pen.  This r e s u l t e d i n a minimum water space of approximately 0 . 3 3  inches per b i r d . F l o x a i d , an a n t i b i o t i c - v i t a m i n mixture was administered i n the d r i n k i n g water at one teaspoon per g a l l o n f o r 0 - 3 days.  A r e g u l a r c o c c i d i o s t a t was  provided i n the feed throughout the t e s t period.  A l l b i r d s were vaccinated  at fourteen days of age using Modified Combined Newcastle-Bronchitis water type vaccine i n the d r i n k i n g water. The b i r d s were i n d i v i d u a l l y weighed t o the nearest gram each week from 1 t o 10 weeks.  The feed assigned to each pen and the feed remaining i n each  pen was weighed weekly to the nearest one-quarter of a pound.  Feed conversion  13 was corrected f o r m o r t a l i t y .  At the end of the t e n week period the b i r d s were  commercially processed and plant graded. From each pen, 62 males and 62 females were randomly selected and the weekly weights o f these b i r d s were subjected t o a n a l y s i s of variance.  The  data f o r each sex were analyzed separately as w e l l as on the combined sex data. Treatment means were subjected t o Duncan's New M u l t i p l e Range Test^ (1955) t o determine the s i g n i f i c a n c e of d i f f e r e n c e s .  Duncan,  A l l tests of significance  were performed a t the 5 percent l e v e l .  "^Duncan's New M u l t i p l e Range Test w i l l be r e f e r r e d t o as Duncan's Test.  CHAPTER IV RESULTS AND DISCUSSION Weekly Body Weights and Feed Consumption.  Mean weekly body weights and  average cumulative feed consumption f o r the b i r d s i n each population  density  are presented i n Table I I . The data were subjected t o a n a l y s i s o f variance (Appendix 4- - 6) .  The.; s i g n i f i c a n c e o f d i f f e r e n c e s among the means was deter-  mined by Duncan's Test and the weekly r e s u l t s are summarized i n Table I I I . I t was found (Table I I I ) that f o r the mean body weights o f the combinedsex data there was a s i g n i f i c a n t d i f f e r e n c e among the density means a t 1, 2, 3, 4 and 5 weeks o f age. During t h i s period b i r d s at the 0.6 f t . allotment were generally l i g h t e r than those a t lower d e n s i t i e s and at 3 and 4 weeks s i g n i o f i c a n t l y l i g h t e r than a l l other density groups.  B i r d s at 0.7 f t .  were  generally heaviest but were not s i g n i f i c a n t l y heavier than b i r d s at 0.8 or 0.9 f t . . 2  No s i g n i f i c a n t d i f f e r e n c e s were found at 6 weeks but a t 7 and 8 weeks of age b i r d s at 0.7 f t .  2  were the l i g h t e s t and were s i g n i f i c a n t l y l i g h t e r than  the heaviest b i r d s - those at 1.0 f t .  2  per b i r d .  The d i f f e r e n c e s were 40 and  35 grams a t 7 and 8 weeks r e s p e c t i v e l y . At 9 weeks of age no s i g n i f i c a n t d i f f e r e n c e s were evident.  At 10 weeks  of age the average weight o f b i r d s a t 0.6 f t . was s i g n i f i c a n t l y lower than that o f b i r d s at 0.9 or 1.0 f t . . No s i g n i f i c a n t d i f f e r e n c e s i n average body 2  weight were found among 0.7, 0.8, 0.9 or 1.0 f t . per b i r d at 10 weeks.  TABLE I I AVERAGE BODY WEIGHT AND AVERAGE CUMULATIVE FEED CONSUMPTION FOR MIXED SEXES OF BROILERS RAISED AT FLOOR AREAS OF 0.6, 0.7, 0.8, 0.9 and 1.0 SQUARE FOOT PER BIRD TO TEN WEEKS OF AGE  FLOOR AREA PER BIRD IN FT. 1.0  0.8  0.9  Cumulative Feed Pounds  Average Body Weight Grams  2  0.6  Age Weeks  Average Body Weight Grams  0  38  0  37  0  37  0  37  0  37  0  1  107  0.2  109  0.2  110  0.2  111  0.2  108  0.2  2  235  0.7  241  0.7  241  0.7  246  0.7  230  0.6  3  407  1.3  408  1.3  408  1.3  414  1.3  394  1.2  A  584  2.1  605  2.1  594  2.1  609  2.1  571  2.0  5  808  3.1  816  3.1  786  3.1  798  3.1  773  3.0  6  1036  A, 3  1019  4.2  1027  4.3  1011  4.2  1011  4.2  7  1294  5.7  1274  5.6  1285  5.6  1254  5.5  1273  5.5  8  1550  7.1  1529  7.1  1534  7.1  1515  7.0  1526  7.0  9  1789  8.7  1787  8.7  1776  8.6  1759  8.5  1762  8.5  10  2035  10.5  2027  10.4  1993  10.2  1991  10.2  1972  10.1  Cumulative Feed Pounds  Average Body Weight Grams  0.7  Cumulative Feed Pounds  Average Body Weight Grams  Cumulative Feed Pounds  Average Body Weight Grams  Cumulative Feed Pounds  Facing page 1 6  NOTE: The mean body weight of birds from treatments underlined by the same line were not significantly different. lBirds were reared as combined sexes. 2  Floor area per bird (0.7 - seven tenths of one square foot).  TABLE I I I RESULTS OF DUNCAN'S TEST OF WEEKLY MEAN BODY WEIGHTS FOR SEXES SEPARATELY AND COMBINED FROM HATCH TO TEN WEEKS OF AGE MALES  FEMALES Age Weeks  Lighte st Weight  Hatch  0.7  1  Heavie st Weight  Lightest Weight DENSITIES  1,0  0.6  0.9  0.8  0 8 T  1,0  0.6  1.0  0.9  0 8  0.7  1.0  0.6  2  0.6  1.0  0,8  o,9  0.7  0.6  1.0  3  0.6  0,8  1,0  O? t  0.7  0.6  A  0.6  1.0  0.8  0.9  0.7  5  0.6  0.8  0.7  1.0  6  o,9 0,7  0 8 f  7  0,7  Of?  8  0 8  9 10  0,7  1  COMBINED SEXES Heaviest Weight  Lightest Weight  Heaviest Weight  0,9  0.6  1,0  0.7  0.9  0.6  0 8  0,8  0,7  1.0  0.6  o,9  0.8  0 7  0 8 t  0,9  0,7  0,6  1,0  0.8  o,9  0,7  1,0  o,9  0.8  0,7  0.6  1,0  0,8  0,9  0,7  0.6  1.0  O 8 t  0.9  0.7  0.6  1.0  0.8  0.9  0.7  0.9  0.6  0.8  0.7  1.0  0.9  0,6  0.8  0.7  1.0  0.9  0,6  1,0  0.6  0.7  o,9  1,0  0,8  0.7  0.6  0.9  0.8  1.0  0,8  0.6  1,0  0.7  0,6  o„9  1,0  0,8  0,7  0,6  o,9  0,8  1,0  0,7  0.9  0.6  1,0  0.7  0.6  0.9  1.0  0.8  0.7  0.6  0.9  0.8  1.0  0.8  0.6  0.7  0.9  1,0  0.6  0.7  1.0  0.9  0.8  0.6  0.7  0.8  1.0  0.9  0.8  0.6  0.7  0.9  1.0  0.6  0.7  0.8  1.0  0.9  0.6  0.7  0.8  0.9  1.0  t  2  f  t  t  17  When the mean body weights of the sexes were analyzed separately, Duncan's Test indicated that s i g n i f i c a n t d i f f e r e n c e s e x i s t e d among the d e n s i t y treatments each week f o r the males and each week except 6, 7, 8, and 9 f o r the females.  During the f i r s t U weeks i t was noted that f o r e i t h e r sex the  b i r d s reared at 0.7 f t .  2  per b i r d were the heaviest and i n most cases s i g n i -  f i c a n t l y heavier than those reared at e i t h e r 0.6 or 1.0 f t .  2  per b i r d .  However,  during subsequent weeks an apparent density e f f e c t began to appear as the rank p of the 0.7 f t . t i c u l a r l y 1.0  treatment decreased and that o f the lower density pens, parft.  , increased. This e f f e c t i s i l l u s t r a t e d i n Figure 1  2  (page 18) f o r both the separate and combined sex data. I t can be seen from Figure 1 and Table I I I that there was considerable v a r i a t i o n i n the order o f rank beyond U weeks of age and i t should be noted that d i f f e r e n c e s i n rank were not always based on s i g n i f i c a n t body weight differences. I t can a l s o be seen that the order of rank i s not p r e c i s e l y i n accordance w i t h density at 10 weeks o f age but there d i d appear t o be a tendency f o r the 2 low density pens, i . e . , 0.9 and 1.0 f t .  per b i r d , t o be the heaviest.  A s i m i l a r v a r i a b i l i t y i n the e f f e c t of density on body weights throughout the experiment was observed by Moreng e t a l (1961).  They noticed that  b r o i l e r s a t f i v e weeks of age were s i g n i f i c a n t l y heavier when the population density was 0.5 f t .  0  per b i r d than when 1.00 or 1.25 f t .  2  were allowed.  I t i s d i f f i c u l t t o e x p l a i n why the b i r d s reared on the f l o o r area of 0.7 f t .  2  i n the present work and at 0.5 f t .  2  i n the t e s t as reported by  18 Ortlev of He  COMBINED SEXES  aviest  I  2  x-  3 H Lightest: rlatck  of  OrAo-V  Rahk.  7  if  /  8  ?  fo  weeks o f age  FEMALES  Da«  Hea\i~<Q.s t  s It  y  . 5"  Hah test  7  2  weeks o f age Orciev  MALES  of  «dnlt.  <7  JO  £><2 rs 5 lZy  Hcavi&sL I 2 3 ¥• LiyhLest h-  L  7  8  weeks o f  FIGURE 1 RANKING OF WEEKLY MEAN BODY WEIGHTS FOR BROILERS REARED AS COMBINED SEXES FROM HATCH TO TEN WEEKS OF AGE  IO  Moreng et a l ( 1 9 6 1 ) , were superior and i n some cases s i g n i f i c a n t l y superior i n body weight during the f i r s t four or f i v e weeks and no b e t t e r than equal to b i r d s at the low density pens at e i g h t and nine weeks of age.  Any  ex-  planation advanced must take i n t o account the f a c t that i n the work reported h e r e i n , the 0 . 6 f t . treatment was generally i n f e r i o r to 0 . 7 f t . 2  2  during the  f i r s t f i v e weeks-. Moreng et a l (1961) suggested that the s u p e r i o r i t y of the b i r d s from the more crowded pens might be explained by the f a c t that the b i r d s were c l o s e r to the feeders i n the pens.  In the present experiment feeder space  per b i r d was kept constant at one inch per b i r d f o r a l l pens.  This i s more  than an adequate amount of feed space to ten weeks of age according to the work of Hansen and Becker ( I 9 6 0 ) .  The denser pens, then, have more feed  2  space per f t . of f l o o r area which may have made i t e a s i e r f o r the b i r d s i n the crowded pens to f i n d the feed as they d i d not have to t r a v e l as f a r as i n the l e s s populated pens.  This explanation, however, cannot account f o r 2  the f a c t that the b i r d s at 0 . 7 f t . per b i r d were s i g n i f i c a n t l y superior to those at 0 . 6 f t . during t h e i r e a r l y growing period unless i t Is assumed ,  2  that the a d d i t i o n a l t h i r t y b i r d s present i n the 0.6 f t . treatment pens caused the crowding about the feeders to become so severe as to a c t u a l l y . discourage some b i r d s from attempting t o eat. Another f a c t o r which may be involved i n the changing pattern of the density e f f e c t i s s o c i a l pressure.  Guhl (1953) reported that p r i o r to eight  weeks of age there does not appear to be any s o c i a l dominance among chickens. C o l l i a s (1950) concluded from h i s studies of chick ;• a c t i v i t i e s " ,  that the  20 need f o r companionship i n chick behaviour f a c i l i t a t e s aggregation and ation.  A f l o o r allowance of 0.7 f t .  2  socializ-  produced the heaviest b r o i l e r s during  the f i r s t four weeks i n the present experiment.  I t i s p o s s i b l e that t h i s  degree of crowding a l s o f a c i l i t a t e d aggregation and s o c i a l i z a t i o n which through some mechanism not yet elucidated contributed to the well-being of the chicks during the f i r s t four weeks.  During the l a t e r weeks t h i s crowding may have  been detrimental as the b i r d s became more aggressive. As outlined by Guhl (1953$ aggressiveness  develops slowly and begins to  express i t s e l f around eight weeks of age f o r the males and ten weeks f o r the females.  This could also p a r t l y account f o r the males responding to density  pressure e a r l i e r than the females.  I t must be recognized that the a p p l i c a -  b i l i t y of t h i s explanation t o the present experiment depends upon c e r t a i n premises.  I t must be assumed that there are l i m i t s to the b e n e f i t s to be  gained by crowding during the f i r s t few weeks and that overcrowding can be a c t u a l l y detrimental to growth during the f i r s t four weeks as w e l l as during the l a t e r weeks.  In the present experiment i t would appear that 0.6  square  foot per b i r d c o n s t i t u t e d an overcrowded c o n d i t i o n during the f i r s t four weeks, 2  2  0.7 f t . was optimum and the 0.8 and 0.9 f t . f i c a n t l y d i f f e r e n t to the 0.7 density pens.  per b i r d pens were not s i g n i -  The preceding t h e o r i e s are attempts t o e x p l a i n d i f f e r e n c e s of a r e l a t i v e l y small magnitude - i n most cases d i f f e r e n c e s of no more than 45 grams (0.1 l b . ) and during the e a r l y weeks considerably l e s s .  There i s  the p o s s i b i l i t y that the changing order of rank was the r e s u l t of pen e f f e c t s during the e a r l y weeks.  The s i m i l a r i t y of the r e s u l t s reported by Moreng e t a l  21 (1961) concerning increased density favouring e a r l y chick growth however, lend credence to the f i n d i n g s i n the present experiment.  Nevertheless, much  more supporting evidence i s required t o e s t a b l i s h the v a l i d i t y of the f i n d ings and t o f u l l y e x p l a i n them. F i n a l Body Weights.  I t i s w e l l e s t a b l i s h e d t h a t environmental tempera-  tures i n f l u e n c e growth and feed e f f i c i e n c y .  Recently, Prince et a l (1965)  demonstrated that an ambient temperature of 55° F. was superior to one of 75° F. f o r growth and feed e f f i c i e n c y of b r o i l e r s from four to eight weeks of age. Average weekly maximum temperatures during the experiment reported herein ranged from a high of 79° F. during the f o u r t h week to a low of 62° during the tenth week.  (Appendix 7 ) ,  F.  These temperatures are somewhat above  the i d e a l and probably had a depressing e f f e c t i n the average body weight achieved.  The average body weight at e i g h t and nine weeks were somewhat  below those normally achieved i n experimental work and more c l o s e l y approximate what could be expected under commercial c o n d i t i o n s * There was some evidence to suggest that the a i r movement w i t h i n the b u i l d i n g was not adequate p a r t i c u l a r l y from the seventh week on.  A notice-  able amount of ammonia was present, at times, i n the b u i l d i n g . Although the l e v e l of ammonia was not l i k e l y high enough to have an e f f e c t on the b i r d s per se, (Smith et a l , 1962)  i t was an i n d i c a t i o n that a i r movement through  the b u i l d i n g was not at as high a r a t e as required t o adequately remove the moisture developed from the increased b i r d population.  22 Mortality.  The l o s s e s incurred t o ten weeks of age amounted to 1.37  percent of the 1624. b i r d s s t a r t e d . 0.8 percent f o r the 1.0 f t . areas.  (Appendix 8).  2  This m o r t a l i t y rate ranged from a low of  allowances t o 2.9 percent f o r the 0.9 f t .  2  floor  Losses due t o starveouts and smothering amounted t o  ten b i r d s out of a t o t a l m o r t a l i t y of twenty-five.  Another f i v e b i r d s died  from perosis and the remaining ten died from unknown causes. . The o r i g i n a l d e n s i t i e s of 0.6, 0.7, 0.8, 0.9 and 1.0 f t . very l i t t l e by subsequent m o r t a l i t y .  2  were modified  At f i v e weeks of age the d e n s i t i e s ,  corrected f o r m o r t a l i t y were 0.61, 0.71, 0.82, 0.94 and 1.02 f t . per b i r d . 2  At t e n weeks of age the corresponding f i g u r e s were 0.62, 0.72, 0.82, 0.95 and 1.02.  The d i f f e r e n c e between these values and the d e n s i t i e s at the  i n i t i a t i o n o f the experiment were deemed t o be inconsequential. Marketing and Market Grades.  The b i r d s were marketed a t seventy-three  days of age through a l o c a l i n s p e c t e d  1  processing plant.  was processed separately according t o pen density.  Each treatment group  The b i r d s were l i n e graded  according to standard plant p r a c t i c e s and the r e s u l t s of the grading are shown i n Table IV. I t i s g e n e r a l l y believed that l i t t e r c o n d i t i o n i s a primary cause of breast b l i s t e r s .  Wiseman and Bean (1965), found that l i t t e r moisture was  the major cause of breast b l i s t e r s i n male b r o i l e r s .  They reported that the  number o f b l i s t e r s doubled with each two week age i n t e r v a l a f t e r eight or nine weeks of age, at d e n s i t i e s of 1.0 square f o o t per b i r d .  -^-Inspected by Health o f Animals D i v i s i o n , Production and Marketing Branch, Canada Department o f A g r i c u l t u r e , Ottawa.  23  TABLE IV QUALITY DEFECTS REPORTED DURING PROCESSING OF BROILERS -AT SEVENTY-THREE DAYS OF AGE F l o o r Space Number F t . per of Bird Birds  Number of B i r d s Breast with Blisters Breast B l i s t e r s %  Number of B i r d s with (Condemned Lack of F l e s h i n g Birds  1.0  250  25  10.0$  0.9  272  3U  12.5%  0.8  307  a  0.7  354  58  16.4$  -  1 (P.)  0.6  412  77  18.7$  3  0  1  -  5  0 1 (P.) 0  P. P e r o s i s In the present experiment the percentage of breast b l i s t e r s increased according t o density from ten percent a t 1.0 f t . per b i r d t o 18.7 percent 2  at 0,6 f t , f l o o r space allotments as presented i n Table IV. This pattern 2  reflected  the c o n d i t i o n of the l i t t e r which was worse i n the high density  than i n the low density pens.  The l i t t e r remained quite dry t o s i x and one  h a l f weeks of age f o r a l l d e n s i t i e s but then became i n c r e a s i n g l y damp and caked as the b i r d density was increased. Krueger e t a l (1961) showed that crowding per se had only a s l i g h t i n fluence on the number of condemnations and breast b l i s t e r s t o eight weeks of age and that adjustments i n v e n t i l a t i o n rateucould c o n t r o l l i t t e r dampness a r i s i n g from high density operation. Under normal commercial conditions the b i r d s would have been marketed  24 no l a t e r than 9 weeks of age.  T h i s would have undoubtedly reduced the number  of breast b l i s t e r s and might even have e l i m i n a t e d the d i f f e r e n c e s between densities.  I t should be noted f u r t h e r that under present marketing arrange-  ments i n B r i t i s h Columbia the producer r e c e i v e s the same p r i c e f o r b i r d s w i t h b l i s t e r s as f o r those without; even when the b l i s t e r may be severe enough t o cause the b i r d t o be c l a s s i f i e d as Grade B or lower.  Thus,from an economic  standpoint the f a c t t h a t the higher d e n s i t i e s r e s u l t e d i n a higher proportion of b l i s t e r s i s of questionable importance t o B r i t i s h Columbia producers.  CHAPTER V DEVELOPMENT OF FIXED AND VARIABLE COSTS OF BROILER PRODUCTION Any short-run feeding e n t e r p r i s e , such as the production of b r o i l e r s , hogs or beef i n feed l o t s , begins with the purchase of the young animal and terminates when the animal i s marketed.  E a r l i e r i n v e s t i g a t o r s , such as  Baum and Walkup (1952), described b r o i l e r farming as a comparatively v e h i c l e f o r studying some techniques f o r determining appropriate values.  simple  input-output  B r o i l e r production i n v o l v e s or concerns both f i x e d and v a r i a b l e re-  sources each of which v a r i e s i n importance with environmental p h y s i o l o g i c a l age of the b i r d .  conditions and  Baum and Walkup (1952) described f i x e d resources  as those that do not change during the growing period whereas v a r i a b l e resources do change as the b i r d s grow older. Baum and Walkup (1956) and Noles and Padgett (1964a) stated that when a s i n g l e l o t of b r o i l e r s i s considered, a l l production c o s t s , except feed c o s t s , are f i x e d ; feed cost then i s the only v a r i a b l e cost. l a t i o n density i s s p e c i f i e d .  This assumes that popu-  However when considering a continuous b r o i l e r  production operation, many of the costs which are considered f i x e d on a s i n g l e l o t b a s i s must be classed as v a r i a b l e costs even though population density i s s p e c i f i e d , because on the b a s i s of cost per square foot per year these  items  vary with the number of l o t s produced, which i s determined by the age at which each l o t i s marketed.  Noles and Padgett (1964b) i n d i c a t e d that f o r a continu-  ous operation, the cost of feed, c h i c k s , medication, brooding, f u e l , l i t t e r , e l e c t r i c i t y , labour and miscellaneous items are v a r i a b l e costs.  Fixed costs  c o n s i s t of d e p r e c i a t i o n on b u i l d i n g s and equipment, r e p a i r s , taxes, insurance  26 and interest on investment. Variable Costs.  A broiler cost survey conducted by Pope (1964b) pro-  vided information on some of the variable production costs (continuous basis) during 1962-1964. The total number of birds involved in this report represented 4.5 percent of a l l broiler chicks hatched in British Columbia from 19621964.  The results of this survey are summarized in Table V.  For the purpose  of this thesis the three year average for each of these costs was used for the development of an input cost structure. The variable costs included chick cost, which changed very l i t t l e during the period. Vaccination and medication costs increased each year, probably because of greater use of vaccines followed by medication for a few days to reduce the effect of the vaccine.  Litter and brooding costs rose slightly  each year, while electricity costs showed very l i t t l e change. It was expected that increased mechanization would be reflected in increased electricity costs but this was not the case.  It was thought advisable, therefore, to compute  the electricity demands in order to compare the value of 0.38 cents per bird with an expected cost for 1964.  In applying 1964 electricity costs to a model  farm as outlined in Appendix 9, the costs were estimated to be 0.37 cents per bird.. The close agreement between this estimate and the 0.38 cents reported seemed to justify the use of this latter value.  l l f the number of lots produced annually by a continuous operation as well as the population density is specified and remains constant, then the situation is similar to the single lot operation; a l l costs except feed are fixed. This is normally the situation when the industry is governed by a marketing board.  TABLE V SOME PRODUCTION COSTS FOR 1962,  1963 AND 1964,  AND THE THREE YEAR  AVERAGE FOR BROILERS REARED IN BRITISH COLUMBIA THREE YEAR SUMMARY  No. o f f l o c k s r e p o r t i n g T o t a l number o f b i r d s sold Average number o f b i r d s Percent v i a b i l i t y Days t o market Percent Grades - A's - B's - Rejects Average body weight i n pounds Feed e f f i c i e n c y 3  Costs:  per b i r d started ( c e n t s ) ^  Chicks Vaccination and Medication Litter Brooding Electricity Marketing Board  1962  1963  1964.  124 804,300 6,486 96.3 64.3  442,958 5,679 97.9  78  33 323,635  91.1  6.6 2.3 3.62 2.52  1962  62.9  92.4 7.0 0.6 3.75 2.48  1963  14.36  .27  .50 1.25 .44 ,56 17.19  14.08  .58 .58 1.40 .44 ,71  17.79  9,807  98.8  62.3  92.1 7.1 0.8 3.84 2.49 (Average  1964 14.30 .72  .68 1.48 .38  M  18.21  14.25 .52 .59 1.38 .43 .64 17.81  2The t o t a l number of b i r d s sold accounted f o r 4.5 percent o f a l l b r o i l e r chicks hatched during the 3 year period. 3pounds of feed required t o produce one pound o f l i v e b r o i l e r . .^Does not include i n t e r e s t on investment, d e p r e c i a t i o n , cartage, or feed.  labour  28 In British Columbia, a l l broilers are marketed through a marketing board at a cost of 0.75 cents for each Grade A or Grade B bird processed. This amounted to 0.64 per bird started over the three year period. Mortality of broilers during rearing has decreased considerably in recent years. Nurse et al. (i960) assumed a 7 percent mortality rate. Data from the broiler cost survey of Pope (1964b) indicate a range of from 1 to 4 percent.  It is common practice for hatcheries to provide four extra chicks  per one hundred delivered and the chick cost figure of #14..25 per hundred is actually overstated. However, based on the figures of the cost survey (1964) a mortality rate of 4 percent was assumed and the chick price of  #14.25 per  hundred was considered to be adjusted for mortality. Because of the variability of labour costs among broiler operations, these costs were not included in the cost calculations. Broiler feed costs were charged at the average commercial feed prices of feed delivered in bulk to broiler establishments in the Fraser Valley during the year 1964- by a local feed cooperative.^  The costs were: #105.00 per ton for starter, l/2 pound of  which was fed per bird; #93.90 per ton for grower which was fed until the birds were six weeks old; and #87.4-5 per ton for finisher. 2 It is normal for broiler production costs to be expressed on a per f t . per year basis as is done with fixed costs in the following section. In order 2  to convert variable costs expressed on a per bird basis, to an annual per f t . basis these costs must be multiplied by two factors. Surrey Cooperative Association  One factor adjusts for the  number of b i r d s r a i s e d per f t .  per l o t (density) and the other adjusts f o r the  number of l o t s marketed per year (market age and c l e a r p e r i o d ^ ) . For example, i f b r o i l e r s are r a i s e d at 0.7 f t .  per b i r d , marketed at eight weeks and a two  week c l e a r period i s allowed between l o t s the v a r i a b l e costs are m u l t i p l i e d by 1.43  and 5.20.  The conversion f a c t o r s f o r other d e n s i t i e s and market ages are  presented i n Appendix 13. Fixed Costs Depreciation of b u i l d i n g s and equipment.  Appendix 10 contains b u i l d i n g  and equipment s p e c i f i c a t i o n s and costs which are estimated t o be t y p i c a l f o r B r i t i s h Columbia.  The cost of the two-storey 10,000 square f o o t , c o n t r o l l e d  environment house described i s estimated at $1.00 per f t .  of f l o o r area.  Depreciation of the b u i l d i n g over twenty years ( s t r a i g h t l i n e method) r e s u l t s i n an estimated annual cost of f i v e cents per f t . . 2  Automatic equipment f o r the b u i l d i n g i s estimated at #5,000. or #500. 2 per year.  The estimated annual cost then would be f i v e cents per f t . 7 on s t r a i g h t - l i n e d e p r e c i a t i o n over ten years.  based  2 Insurance costs were estimated at 2.248 cents per f t . f u l l coverage of b u i l d i n g s , equipment and b i r d s (Appendix 11).  per year f o r Some b r o i l e r  producers do not insure the b i r d s and others do not c a r r y f u l l coverage on b u i l d i n g s and equipment.  In a d d i t i o n , insurance r a t e s d i f f e r between companies  ^The age at which the b i r d s are t o be marketed plus a two week c l e a r period. ^Department of N a t i o n a l Revenue, Farmer's and Fisherman's Guide 1964. (Ottawa, Queen's P r i n t e r ) , p. 5. :  30 and between d i s t r i c t s depending upon f i r e p r o t e c t i o n .  8  Therefore the estimated  insurance cost may be d i f f e r e n t than that a c t u a l l y incurred by many growers. I n t e r e s t on investment was c a l c u l a t e d on the b a s i s of 6„0( annum.  I n t e r e s t on a $15,000. investment amounts to 4.4V  year (Appendix  percent per  cents per f t .  per  12). 2  16.72  These f i x e d costs were c a l c u l a t e d on a f t . 2 io cents per f t . per year.  per year b a s i s and t o t a l e d  ^Dudley Blaschek, 1965, A p r i v a t e communication, Royal Exchange Assurance Corporation, V i c t o r i a . 9Daryl T. Thompson, 1965, A p r i v a t e communication, Accounting Corporation of America, Vancouver. i^Due t o v a r i a b i l i t y of tax r a t e s between areas, the d i f f e r e n c e due to s i z e of operation, the d i s t r i b u t i o n of taxes between business and d w e l l i n g , a charge f o r taxes was not included i n the t o t a l f i x e d costs. A s i m i l a r s i t u a t i o n was encountered f o r r e p a i r s . In the f o l l o w i n g chapter Net Returns i s returns to labour, taxes and r e p a i r s .  CHAPTER V I INFLUENCE OF MARKET AGE AND WEIGHT ON ANNUAL NET RETURNS The study reported herein i n d i c a t e s that changing b i r d density from 0.7 to 1.0 f t .  per b i r d has no s i g n i f i c a n t e f f e c t on body weight a t nine or t e n  weeks of age. A t seven and e i g h t weeks of age b i r d s reared at 0.7 f t .  2  per  2  b i r d were s i g n i f i c a n t l y l i g h t e r than those at 1.0 f t . . The f a c t that t h i s s i g n i f i c a n t d i f f e r e n c e d i d not e x i s t a t nine or ten weeks of age and was not present at s i x weeks of age suggests t h i s d i f f e r e n c e may be the results of f a c t o r s other than density. In I960, S i e g e l concluded that the c o n t r a d i c t o r y r e s u l t s obtained from b r o i l e r density studies may be due t o the d i f f e r e n c e i n genetic stock, or other environmental f a c t o r s .  Krueger e t a l (1961) reported that there was  l i t t l e e f f e c t on growth, l i v a b i l i t y , and market q u a l i t y and number of condemnations f o r b r o i l e r s reared t o eight weeks at f l o o r areas of from 0.6 t o 1.2 f t .  per b i r d .  B i e l y e t a l (1963) was unable t o demonstrate any s i g n i -  f i c a n t d i f f e r e n c e i n body weight f o r b r o i l e r s reared t o eight weeks a t 0.75 and 1.45 f t . per b i r d .  The Arkansas Meat Productions Tests (1965) showed  no s i g n i f i c a n t d i f f e r e n c e a t eight weeks of age f o r b r o i l e r s reared at 0.5, 0.6, 0.7, 0.8 and 1.0 f t .  2  allotments.  In view of these reports and the r e s u l t s of the present experiment i t was concluded that 0.7 f t . of f l o o r area per b i r d would produce average body 2  weights comparable t o those achieved at 0.8, 0.9 and 1.0 f t .  per b i r d a t ages  of from s i x t o ten weeks. This would be a p p l i c a b l e t o commercial b r o i l e r production assuming that the b r o i l e r s were reared i n an i n s u l a t e d ,  mechanically  32 v e n t i l a t e d b u i l d i n g , with adequate feed and water space and good management. Meat Y i e l d per 1000 Square Feet of F l o o r Space at 0/7 and JLO Square Fobt per B i r d .  The t o t a l y i e l d i n pounds of meat per 1000 f t .  per year f o r b i r d s reared at 0.7 and 1.0 f t .  2  2  o f f l o o r space  per b i r d f l o o r areas and marketed  w i t h i n the period of s i x t o ten weeks of age i s o u t l i n e d i n Figure 2.  It is  obvious that annual y i e l d increases as the b i r d s are marketed at heavier weights.  Nurse et a l (I960) p l o t t e d annual y i e l d per f t .  2  versus average mar-  ket weight and presented a curve w i t h a negative slope. T h i s was due t o t h e i r assumption that as the b r o i l e r s grew older they required more f l o o r space per b i r d with an average of about one f t . lighter birds.  2  f o r a f o u r pound b i r d and l e s s f o r  By marketing l i g h t e r b i r d s (younger), density (number o f b i r d s  per l o t ) as w e l l as the number of l o t s per year could be increased. Thus, a decrease i n the market age r e s u l t e d i n an increase i n the pounds produced per year.  Such a model however, w i l l not accommodate the f i n d i n g s of the present  work, t h e r e f o r e , i t was decided t o determine the influence of market age and 2 weight on net returns per year when b i r d density was constant at 0.7 f t .  per  b i r d , regardless of market age and weight. Annual Net Returns Per Square Foot of F l o o r Area Per Year. 2 t a i n the annual net returns per f t .  To ascer-  o  using 0,7 f t .  the f o l l o w i n g c a l c u l a t i o n s were performed.  of f l o o r area per b i r d  T o t a l Revenue per ft.* T.R. = AW x P T o t a l Costs per f t .  2  m  per year (T.R.) x L x 1.43  1  per year (T.C.)  T.C. = F.C. + (V.C.nf x L x 1.43) 4 ( F x P p  Net Return per f t .  2  f  x L x 1.4-3)  per year (N.R.)  N.R. = T.R. - T.C.  -  AW  - Price  L  1.43 F.C. V.C.nf F  Average b i r d weight i n pounds  P  Pf  -  per pound of l i v e b r o i l e r  Number of l o t s of b r o i l e r s produced per year Number of b i r d s produced per f t .  2  p Fixed Costs per f t .  per year  Non-feed v a r i a b l e costs per b i r d Pounds of feed per b i r d P r i c e per pound of feed  In Table VI the age and weight at which b r o i l e r s must be marketed t o p  maximize annual net r e t u r n s per f t .  of f l o o r area i s presented f o r each com-  b i n a t i o n of several feed and meat p r i c e s .  These data, based on allowing 0.7  2 ft.  per b i r d , were selected from Appendix 14 which l i s t s the net r e t u r n s c a l -  culated f o r market ages of s i x t o t e n weeks f o r each combination of feed and meat p r i c e . In t h i s model (Table VI) p r o f i t s are maximized by marketing at nine or ten weeks of age depending upon feed and meat p r i c e s . At 0.7 f t . birds.  As i n d i c a t e d , when the  per b i r d each square foot of f l o o r area accommodates 1.43  34  FIGURE 2 RELATIONSHIP BETWEEN LIVE BODY WEIGHTS AND YIELD OF BROILER MEAT PER 1000 SQUARE FEET OF FLOOR AREA PER YEAR AT BIRD DENSITIES OF 0.7 AND 1.0 SQUARE FOOT PER BIRD  A c l e a r period of two weeks between successive l o t s i s assumed.  feed p r i c e was four cents per pound b i r d s should be marketed at l e a s t at ten weeks of age to maximize net returns w i t h i n a meat p r i c e range of 15-23 per pound.  cents  Using a f i v e cent per pound feed p r i c e , b i r d s should be marketed  at nine weeks on a 17-19 cent meat p r i c e and at l e a s t at ten weeks of age w i t h a 21-23 cent meat p r i c e .  Thus, as meat p r i c e increases f o r any constant feed  p r i c e (4.0-5.5 cents per pound), net returns are maximized when b i r d s are marketed at heavier weights.  Nurse et a l (i960) stated that when meat p r i c e s  increased, b r o i l e r s should be marketed younger ( l i g h t e r b i r d s ) . f o r the production of more b i r d s per f t . returns.  2  This allows  per year r e s u l t i n g i n increased net  S i m i l a r l y , Nurse et a l (i960) recommended keeping the b i r d s longer  and marketing them as heavier b r o i l e r s , when meat p r i c e was constant and feed p r i c e increased.  This r e s u l t e d i n decreasing the t o t a l feed consumption per  year f o r b i r d s grown i n a given f l o o r area.  The data i n Table VI however,  i n d i c a t e t h a t b r o i l e r s should be marketed younger (at l i g h t e r weights) under constant meat p r i c e and i n c r e a s i n g feed p r i c e c o n d i t i o n s . The f a c t that Nurse et a l (i960) assumed that the number of b i r d s per f t .  2  could be i n -  creased as the market age and weight was decreased, accounts f o r these d i s crepancies. Table V I I (taken from Appendix 15) i n d i c a t e s the maximum net returns o  obtainable per f t . " ' per year when b r o i l e r s are r a i s e d at 1.0 f t . fourteen day c l e a r period.  with a  P r o f i t s were maximized when b i r d s were marketed  at nine or ten weeks of age depending upon feed and meat p r i c e . maximizingjmarket  2  The  profit  age was e x a c t l y the same as that f o r b r o i l e r s reared at  0.7 f t . . The increase i n annual net r e t u r n a t t a i n e d by r a i s i n g b r o i l e r s  TABLE VI MAXIMUM ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA AND ASSOCIATED MARKET AGE AND WEIGHT FOR VARIOUS FEED AND MEAT PRICES: BIRD DENSITY 0.7 SQUARE FOOT PER BIRD  Feed Cost In Cents Per Pound  3  Live B r o i l e r Meat P r i c e (cents per pound) 15  17  19  21  23  4.0  28.419 " 10 4.42  83.155 10 4.42  137.892 10 4.42  192.628 10 4.42  247.365 10 4.42  4.5  -2.245 9 3.91  51.267 10 4.42  106.003 10 4.42  160.740 10  4.42  215.476 10 4.42  5.0  -31.330 9 3.91  21.564 9 3.91  74.457 9 3.91  128.852 10 4.42  183.588 10 4.42  5.5  -60.415 9 3.91  -7.521 9 3.91  45.373 9 3.91  98.266 9 3.91  151.700 10 4.42  4  3  A two week c l e a r period between successive l o t s i s assumed.  4For each combination of feed and meat p r i c e , the upper f i g u r e r e f e r s t o the maximum annual net returns per square foot (cents). The second and t h i r d f i g u r e s are the associated market age (weeks) and weight (pounds), r e s p e c t i v e l y .  TABLE V I I MAXIMUM ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA AND ASSOCIATED MARKET AGE AND WEIGHT FOR VARIOUS FEED AND MEAT PRICES:  Feed Cost In Cents Per Pound  BIRD DENSITY 1.0 SQUARE FOOT PER BIRD  5  L i v e B r o i l e r Meat P r i c e (cents per pound) 15  17  19  21  23  6 14.846 10 4.42  53.123 10 4.42  91.400 10 4.42  129.677 10 4.42  167.955 110 4.42  4.5  -6.598 9 3.91  30.823 10 4.42  69.101 10 4.42  107.378 10 4.42  145.655 10 4.42  , 5.0  -26.937 9 3.91  10.052 9 3.91  47.040 9 3.91  85.078 10 4.42  123.356 10 4.42  5.5  -47.276 9 3.91  -10.287 9 3.91  26.701 9 3.91  63.690 9 3.91  101.056 10 4.42  4.0  5A two week c l e a r period between successive l o t s I s assumed. ^For each combination of feed and meat p r i c e , the upper f i g u r e r e f e r s t o the maximum annual net return per f t . i n cents. The second and t h i r d f i g u r e s are the associated market age (weeks) and weight (pounds), r e s p e c t i v e l y .  38 at 0.7 f t . and V I I .  2  as compared t o that of 1.0 f t .  ?  can be seen by comparing Tables VI  For example, when the feed p r i c e was 5.0 cents per pound the net r e -  t u r n f o r 0.7 f t .  2  allotments was greater than that f o r the 1.0 f t .  5  allotments  by 11.51, 27.42, 43.77 and 60.23 cents f o r meat p r i c e s of 17, 19, 21, and 23 cents per pound,respectively. Sometimes f o r reasons beyond t h e i r c o n t r o l producers are unable t o ship b r o i l e r s to market at the desired age.  The e f f e c t that t h i s would have on  annual net returns can be seen i n Table V I I I (taken from Appendix 14.).  When  feed costs were 4.0 or 4.5 cents per pound maximum net returns were obtained by marketing at ten weeks of age.  Under these conditions as the meat p r i c e i n -  creased the penalty f o r marketing one week e a r l i e r a l s o increased.  When feed  p r i c e s were 5.0 or 5.5 cents per pound and the desired market weight was nine weeks at meat p r i c e s of 17 and 19, and 19 and 21, r e s p e c t i v e l y , marketing week e a r l y caused a much l a r g e r reduction i n net returns than marketing week l a t e .  one  one  Thus, the s e v e r i t y of the e f f e c t of marketing before or a f t e r the  desired age i s dependent upon the body weight and the meat and feed p r i c e s prevailing.  Smith (1965) i n d i c a t e d that the e f f i c i e n c y of feed conversion with  present day commercial b r o i l e r stock i s now b e t t e r maintained i n t o the heavier weights.  For t h i s reason present day b r o i l e r growers incur a smaller penalty  than d i d growers i n the e a r l y 1950's by marketing e a r l i e r or l a t e r than the desired market age. The data i n Table IX (taken from Appendix 16) i n d i c a t e the age and weight at which b r o i l e r s should be marketed to maximize net returns when the number of l o t s of b i r d s marketed y e a r l y was l i m i t e d to 4.33  (twelve week  TABLE V I I I THE DECREASE IN ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA INCURRED BY MARKETING ONE WEEK EARLIER OR ONE WEEK LATER THAN OPTIMUM FOR VARIOUS FEED AND MEAT PRICES: BIRD DENSITY 0.7 SQUARE FOOT PER BIRD  Feed Cost In Cents Per Pound  L i v e B r o i l e r Meat P r i c e (cents per pound)  5.0  5.5  19  21  23  3.4 (10)  5.3 (10)  7.1 (10)  9.0 (10)  ••  ••  ••  *•  -8.6 (9) -1.2  0.6 (10)  2.5 (10)  4.3 (10)  6.1 (10)  ••  ••  ••  ••  -5.9 (9) -4.0  8.7 (9) 2.2  11.5 (9) 0.3  1.5 (10)  3.3 (10)  ••  • •  -3.2 (9) -6.8  -6.0 (9) -5.0  8.8 (9) 3.1  » •  4.5  17  15 1.62 (10)  4.0  7  8  A two week c l e a r period between successive  11.5 (9) 1.3  0.5 (10) • •  l o t s i s assumed.  % o r each combination of feed and meat price the upper and the lower f i g u r e s i n d i c a t e the respective decrease (cents) i n net return per f t . per year incurred by marketing one week e a r l i e r or one week l a t e r than optimum, . The middle f i g u r e i s the market age i n weeks at which net returns per f t . per year are maximized, i . e . , the optimum market weight. 2  2  replacement cycle) and the density at which they were reared was s p e c i f i e d at 2 9 1.0 f t . per b i r d .  For each combination of feed and meat p r i c e s where p o s i -  t i v e maximum net returns were found, the magnitude of net returns was maximized by marketing at ten weeks of age.  Under t h i s production-controlled system, the  market tvould receive b i r d s of maximum body weight (4.42 age.  pounds) a t ten weeks of  The market, however, requires some l i g h t e r b i r d s f o r i n s t i t u t i o n a l trade.  In order to obtain such b i r d s i t then would be necessary f o r the buyer to pay a premium f o r the l i g h t e r b i r d s .  This premium would need to be of such magnitude  that f o r each combination of feed and meat p r i c e s the net returns would be at l e a s t equal to those obtained by r a i s i n g the b i r d s to ten weeks of age (Append i x 16). The  same s i t u a t i o n e x i s t s when there i s no r e s t r i c t i o n on the number of  l o t s that can be marketed per year.  Again a premium would be required to b r i n g  f o r t h l i g h t e r b i r d s and I t s magnitude can be e a s i l y obtained from Appendix 15. In many cases the minimum premium necessary to maintain net,returns i s very small.  In p r a c t i c e the premium o f f e r e d would probably need to be  considerably  more than the minimum to entice growers to market b i r d s at l i g h t e r weights. The data i n Table X i n d i c a t e maximum net returns per square foot of f l o o r space w i t h a twelve-week replacement cycle and a 0.7 f t . per b i r d f l o o r  •'When c o n t r o l s are placed on the number of l o t s of b i r d s reared per year at a given f l o o r area per b i r d as may occur under a Marketing Board, such c o n t r o l s are r e f e r r e d t o i n t h i s t h e s i s as production-controlled or c o n t r o l l e d replacement. When these conditions e x i s t c a l c u l a t i n g net r e turns becomes analogous to determining the market age and weight required to maximize net returns per l o t .  TABLE IX MAXIMUM ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA AND ASSOCIATED MARKET AGE AND WEIGHT FOR VARIOUS FEED AND MEAT PRICES:  BIRD DENSITY 1.0 SQUARE FOOT  PER BIRD AND NUMBER OF LOTS PER YEAR LIMITED TO 4.33  Feed Cost In Cents Per Pound  10  Live B r o i l e r Meat P r i c e (cents per pound) 15  17  19  21  23  53.123 10 4.42  91.400 10 4.42  129.677 10 4.42  167.955 10 4.42  4.0  14.846 10 4.42  4.5  -7.454 9.5 4.16  30.823 10 4.42  69.101 10 4.42  107.378 10 4.42  145.655 10 4.42  5.0  -26.073 9 3^91  8.524 10 4.42  46.801 10 4.42  85.078 10 4.42  123.356 10 4.42  5.5  -44.042 8 3.37  -10.831 9 3.91  24.502 10 4.42  62.779 10 4.42  101.056 10 4.42  11  10A two week c l e a r period between successive l o t s i s assumed. H F o r each combination of feed and meat p r i c e the upper f i g u r e r e f e r s t o the maximum annual net returns per f t . (cents). The second and t h i r d f i g u r e s are the associated market age (weeks) and body weights (pounds), r e s p e c t i v e l y .  space allotment.  Net returns were maximized by marketing at ten weeks of age.  The obvious increase i n net returns per f t .  2  per year over a 1.0 f t .  2  allot-  ment (Table IX) was due t o the increased number of b i r d s produced. I f the density allotment were changed from 1.0 t o 0.7 f t .  2  per b i r d  there would be an increase i n the number of b r o i l e r s coming onto the market (1.43 b i r d s per f t .  2  i n place o f 1 b i r d per f t . ) . 2  This could cause meat  p r i c e t o d e c l i n e and p o s s i b l y lower the net returns per f t . per year.  For  example, i f the p r i c e d e c l i n e d two cents per pound (from 21^ t o 19<£) at a feed p r i c e o f f i v e cents per pound the net returns per f t . * o f f l o o r area f o r b i r d s reared at 0.7 f t .  2  per b i r d would be 74.115 cents (Table X ) .  This  i s 10.963 cents (85.078^ - 74.115<£) l e s s than net returns received when b i r d s 2 were grown at the 1.0 f t . allotments a t the 21 cent meat p r i c e p r i o r to the increase i n density.  An increase i n output by increasing b i r d population  density can be achieved without a concomitant drop i n p r i c e only i f i t i s assumed that a market i s a v a i l a b l e f o r the a d d i t i o n a l product. The i n f l u e n c e of a c o n t r o l l e d replacement program on net returns can be seen from a comparison o f Tables V I and X and Tables V I I and IX. In most cases maximum net returns occurred a t ten weeks o f age and, with few except i o n s , net returns were i d e n t i c a l regardless of whether the number of l o t s were c o n t r o l l e d or not c o n t r o l l e d . There were four combinations of feed and meat p r i c e s a t which s l i g h t l y greater returns r e s u l t e d from nine week mark e t i n g under the uncontrolled system.  When the b i r d s were reared a t 0.7 f t .  (Tables V I and X) and when the feed p r i c e was 5.0 cents per pound and meat p r i c e s 17 and 19 cents the d i f f e r e n c e s i n net returns i n favour of the open  2  TABLE X MAXIMUM ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA AND ASSOCIATED MARKET AGE AND WEIGHT FOR VARIOUS FEED AND MEAT PRICES:  BIRD DENSITY 0.7 SQUARE FOOT 12  PER BIRD AND NUMBER OF LOTS PER YEAR LIMITED TO 4.33  Feed Cost In Cents Per Pound 4.0  Live B r o i l e r Meat P r i c e (cents per pound) 17  28.419 10  83.155 10  137.892 10  -3.469 9.5 4.16  51.267 10  106.003 10  4.42  4.42  4.42  -30.095 9 3.91  19.379 10  74.115 10  128.852 10  4.42  4.42  -55.791 8 3.37  -8.299 9 3.91  42.227  96.963 10  4.42  4.5  5.0  5.5  21  15  4.42  4.42  19  4.42  192.628 10  4.42 160.740 10  10  4.42  4.42  23  247.365 10  4.42  215.476 10  4.42 183.588 10  4.42 151.700 10  4.42  12A two week c l e a r period between successive l o t s i s assumed. l ^ F o r each combination of feed and meat p r i c e the upper f i g u r e r e f e r s t o the maximum annual net returns per f t . (cents). The second and t h i r d f i g u r e s are the associated market age (weeks) and bodyweights (pounds), r e s p e c t i v e l y . 2  44 system were 2.195 cents and 0.342 cents r e s p e c t i v e l y per f t .  2  per year. When  feed p r i c e was 5.5 cents per pound and meat p r i c e s 19 and 21 cents the d i f f e r ences i n favour of the open system were 3.146 and 1.303 cents r e s p e c t i v e l y per  2 ft.  per year. Removal of production c o n t r o l (assuming a two week c l e a r period was  maintained) t h e o r e t i c a l l y would have no e f f e c t on the number or weight of b i r d s marketed except under the four combinations of feed and b r o i l e r p r i c e s mentioned above.  I f any o f these four b r o i l e r and feed p r i c e combinations  existed i t would be expected that a greater number of b i r d s of l i g h t e r weight would be marketed.  The increase expected would be approximately 9.2%.  The  depression i n p r i c e which could r e s u l t from such an increase could e a s i l y eliminate the advantage o f the open market s i t u a t i o n which was i n i t i a l l y superior t o c o n t r o l l e d production by only a f r a c t i o n o f a cent per f t .  per  year a t comparable b r o i l e r p r i c e s .  2 I f the c o n t r o l l e d density and replacement c y c l e of 1.0 f t .  per b i r d  and twelve weeks r e s p e c t i v e l y (Table IX) was removed, a large increase i n net returns would occur. T h i s assumes that the increased numbers o f b i r d s which could be expected on the market by r e a r i n g a t greater density t o as low as 0.7 f t .  per b i r d would not depress market price (Table IX and Table V I ) .  That t h i s assumption i s u n r e a l i s t i c i s obvious when i t i s seen that.the -  U  (1.43H 4.73) - (1.43 U4.33) x (1.43)(4.33)  100 = 9.2J6  increase i n number of b i r d s marketed could be expected t o be between 4 3 $ and 15  56$.  Even i f t h i s increase i n supply was assumed t o depress b r o i l e r p r i c e  by only two cents per pound the i n i t i a l apparent advantage of the open market s i t u a t i o n would be l o s t .  1  5  ( 1 . 4 3 ) ( 4 . 3 3 )  -  ( l . 0 0 ) ( 4 . 3 3 )  x  1  0  0  =  4 3 $  (l.OO)(4.33) ( l  r  4 3 ) ( 4 . 7 3 )  -  ( l o p ) ( 4 t 3 3 ) t  ( 1 . 0 0 ) ( 4 . 3 3 )  x  ioo  =  5 6 . 2 $  CHAPTER V I I SUMMARY Sixteen hundred and twenty-four commercial b r o i l e r chickens were reared as mixed sexes under f i v e d i f f e r e n t f l o o r space areas (0.6, 0.7, 0.8, 0,9, and 1.0 f t . per b i r d ) t o study the e f f e c t of density on produc2  t i o n e f f i c i e n c y and annual net returns per f t . of f l o o r area*  The c h i c k -  2  ens were f e d a commercial b r o i l e r r a t i o n according t o the manufacturer s l  recommendations.  I n d i v i d u a l body weights and feed consumption per pen  were taken at weekly i n t e r v a l s u n t i l the b i r d s reached t e n weeks of age. The b i r d s reared a t 0,7 f t . f l o o r area were the heaviest 2  the one t o four week period.  during  This d i f f e r e n c e i n body weight may have been  due t o d i f f e r e n c e s i n feed space per f t . o f f l o o r area, the s o c i a l behav2  i o r of the b i r d s or merely a pen e f f e c t .  On a combined-»sex b a s i s , no s i g -  n i f i c a n t d i f f e r e n c e s among d e n s i t i e s were observed i n nine week mean body p  weight. At ten weeks of age the mean body weight of the b i r d s at 1,0 f t . density was s i g n i f i c a n t l y superior t o that of b i r d s w i t h 0,6 f t . per b i r d . There were no s i g n i f i c a n t d i f f e r e n c e s among the mean body weights of b r o i l p  ers reared at 0.7, 0.8, 0.9 and 1.0 f t , per b i r d at t e n weeks of age. M o r t a l i t y was not a f f e c t e d by b i r d d e n s i t y .  The percentage of  breast b l i s t e r s a t slaughter (73 days) was d i r e c t l y r e l a t e d t o the f l o o r area per b i r d . B r o i l e r production costs were developed and used i n models t o determine at what age maximum net returns per f t ,  2  of f l o o r area per year  occurred, f o r various combinations o f feed and meat p r i c e s .  I t was assumed p  that weekly mean body weights of b i r d s grown a t 0.7 and 1.0 f t .  per b i r d  were equal and that a two week c l e a r period was provided between successive l o t s .  Under these assumptions, the market age a t which annual net  returns were maximized was nine or ten weeks, depending upon feed and meat priees. When i t was assumed that b r o i l e r s were reared a t a f i x e d d e n s i t y , that d i d not change w i t h market age, and a two week c l e a r period was allowed between l o t s , the f o l l o w i n g observations were made: (a) f o r any given feed p r i c e , as meat p r i c e increased annual net returns per f t ,  2  could be maximized by marketing  l a t e r (heavier and older b i r d s ) , (b) f o r any given meat p r i c e as feed p r i c e increased annual net returns per f t ,  2  could be maximized by marketing  e a r l i e r ( l i g h t e r and younger b i r d s ) . The magnitude of the e f f e c t on annual net returns per f t ,  2  of f l o o r  area of marketing one week e a r l i e r or l a t e r than the age o f greatest net returns v a r i e d w i t h feed and meat p r i c e s . As meat p r i c e s increased the l o s s i n c u r r e d by marketing one week e a r l i e r a l s o increased. When production c o n t r o l s , c o n s i s t i n g of a twelve week replacement program ( i . e . no more than 4*33 l o t s per year) were a l s o assumed, maximum net returns per f t ,  2  were found t o occur by marketing no younger than t e n  weeks o f age f o r any feed and meat p r i c e combination  considered.  Under these  conditions the market would receive l i g h t e r weight b i r d s , i . e . younger than ten weeks, only by the payment of a premium p r i c e s u f f i c i e n t t o r e s u l t i n an annual net r e t u r n equal t o that which would have been received by mark e t i n g a t ten weeks.  4-8 A comparison of models w i t h and without the assumption of production c o n t r o l s i n d i c a t e d that w i t h few exceptions, maximum annual net returns occurred at the same market age, i . e . ten weeks* The influence of population density on annual production per f t . and i t s i m p l i c a t i o n s w i t h regard t o b r o i l e r p r i c e s and net returns under s e v e r a l model systems was discussed.  2  49 BIBLIOGRAPHY Adams, J . L., W. J . Owings. 1964. The performance of l a y i n g chickens housed at various d e n s i t i e s on l i t t e r f l o o r . P o u l t r y S c i . , 43: 1298. (Abstract) Arkansas Meat Performance Test No. 9-B. 1965. 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Annual Meeting of the American S o c i e t y A g r i c u l t u r e Engineers, Minneapolis, Minnesota. Pope, W. H. 1964a. Annual report of p o u l t r y branch, B r i t i s h Columbia. ment o f A g r i c u l t u r e , V i c t o r i a . Mimeographed r e p o r t , 39 pp.  Depart-  1964b. B r o i l e r cost comparison 3 year summary. B r i t i s h Columbia Department of A g r i c u l t u r e , V i c t o r i a . Mimeographed report.  52 P r i n c e , R. P., W. C. Wheeler, W. A. J u n i l a , L. M. P o t t e r and S. P. Singsen. 1958. E f f e c t of temperature on feed consumption and weight gains i n b r o i l e r production. U n i v e r s i t y of Connecticut, Progress Report 33. P r i n c e , R. P., J . H. Whitaker, L. D. Matterson and R. E. Luginbuhl. 1965. Response of chickens to temperature and r e l a t i v e humidity. P o u l t r y S c i . , 44: 73-78. Proudfoot, F. G., R. S. Gowe and B. F. Cheney. 1957. Studies on the design of comparative p o u l t r y t e s t s . A comparison of three s t r a i n s of white leghorns housed i n r e p l i c a t e d f i f t y - b i r d pens and intermingled i n a large pen. Canadian Journal of Animal S c i . , 37: 168-178. Roy, E w e l l P. 1965. Baton Rouge.  A P r i v a t e Communication.  Louisiana State U n i v e r s i t y ,  Sanz-Arias, R., and A. Paz-Saez. 1963. Determination of the best sale weight of heavy breed b r o i l e r s . World's P o u l t r y S c i . Journal, 19: 231. S i e g e l , H. S. I960. E f f e c t of population density on the p i t u i t a r y - a d r e n a l c o r t i c a l a x i s of cockerels. P o u l t r y S c i . , 39: 500-509. S i e g e l , P. B., and R. H. Coles. 1958. E f f e c t s of f l o o r space on b r o i l e r performance. P o u l t r y S c i . , 37: 1243. S i e g e l , P. B., W. L. Beane and C. Y. Kramer. 1963. The measurement of feeding a c t i v i t y i n chickens from 0 to 8 weeks of age. World's P o u l t r y S c i . J o u r n a l , 19: 594-608. Smith, E. J . 1965. Technology i n b r o i l e r production. Economic Research S e r v i c e , United States Department of A g r i c u l t u r e , C i r c u l a r 246. U.S. Government P r i n t i n g O f f i c e . Smith, H. D., P. R. Poffenberger and S. H. De V a u l t . 1949. R e l a t i o n s h i p of production f a c t o r s to out-of-pocket b r o i l e r costs and p r o f i t s . Maryland A g r i c u l t u r a l Experimental S t a t i o n , P u b l i c a t i o n 91. U n i v e r s i t y of Maryland. Smith, R..M., J . Kan and T. R. C. Rokeby. 1962. The e f f e c t s of poultry housing on b r o i l e r weight, feed conversion, and m o r t a l i t y . P o u l t r y  S c i . , 41: 594-608.  Stephenson, E. L., J . M. Bezanson and C. F. H a l l . I960. Factors a f f e c t i n g the incidence and s e v e r i t y of a breast b l i s t e r c o n d i t i o n i n b r o i l e r s . P o u l t r y S c i . , 39: 1520-1524. Thompson, Daryl T. 1965. A P r i v a t e Communication. of America, Vancouver, B. C.  Accounting  Corporation  53 Trant, G. I . , and J . W. L. Winder. 1961. Time opportunity costs i n b r o i l e r production. Journal o f Farm Economics, A3: 939-957. Wiseman, E. L., W. L. Beane, W. R. Luckman and E. 0. Essary. 1961. E f f i c i e n c y of growing b r o i l e r s t o a heavier weight. P o u l t r y S c i . , AO: 1705-1712. Wiseman, E. L . , and W. L. Beane. 1965. E f f e c t of some management f a c t o r s on the incidence of breast b l i s t e r s i n heavy b r o i l e r s . P o u l t r y S c i . , A4: 737-7A1.  54  -APPENDIXES  APPENDIX I PRODUCER, WHOLESALE, RETAIL PRICE IN CENTS AND THE PRODUCERS SHARE IN PERCENT OF EACH DOLLAR. SPENT BY THE CONSUMER IN BRITISH COLUMBIA FOR BROILERS DURING THE PERIOD 1957 - 1965  1  1957  I960  1964  1965 (Jan./June)  Price to producers for live broilers.  25.9*'  21.5*  19.22*  20.8*  Wholesale to retail prices.  49.0*  39.2*  33.9*  37.0*  Retail to consumer price  63.0*  52.0*  45.0*  49.0*  Producer s share of consumer dollar  41.1$  41.3$  42.7%  42.4$  l  1 Canada Department of Agriculture, Poultry Market Report, (Ottawa, Queen's Printer), Weekly Reports, 1957-1965.  APPENDIX 2 BROILER PRODUCTION. IN CANADA AND IN BRITISH COLUMBIA INCLUDING NUMBER OF BIRDS AND THEIR WEIGHT AND THE AVERAGE SIZE OF THE LIVE BIRDS WHEN MARKETED  2  Average S i z e o f B i r d i n Pounds. Year  No.of B i r d s 'OOO  Weight  '000  Eviscerated Weight  L i v e Weight^  CANADA  1961  82,071  226,523  2.76  3.78  1962  81,506  227,276  2.79  3.82  1963  96,335  276,979  2.88  3.94  1964  105,800  305,608  2.89  3.95  BRITISH COLUMBIA  1961  8,082  20,607  2.55  3.49  1962  7,666  19,813  2.58  3.53  1963  8,939  24,330  2.72  3.73  1964  8,776  24,122  2.75  3.77  NOTEs Canadian production and the B r i t i s h Columbia production of b r o i l e r s has not Increased i n the same proportion. I n 1961 B r i t i s h C o l umbia produced approximately 9.8$ o f a l l b r o i l e r s produced i n Canada while i n 1964 i t was 8.3$. T h i s was due t o c o n t r o l l e d production as enforced by the B r i t i s h Columbia B r o i l e r Marketing Board. ^ C a l c u l a t e d from eviscerated weight column on a b a s i s of 73$ y i e l d .  Canada Department of A g r i c u l t u r e , P o u l t r y Market Report, (0ttawa Queen*s P r i n t e r ) Weekly Report, 1961 - 1964.  :  ^APPENDIX 3 FORTY POUND HANGING FEEDER  3  ^Each feeder supplied 52" o f feed space. Based on supplying one inch of feed space per b i r d (2 feeders per 100 b i r d s ) s t a r t e d , three or four feeders were supplied t o each pen as r e q u i r e d . Wooden b l o c k s were i n s t a l l e d i n the feed trough t o r e s t r i c t the a c t u a l feeding space t o the r e quired equivalent feeding area. These blocks were cut t o shape from §• i n c h plywood and i n s t a l l e d i n the feeding t r a y . When the b l o c k s were i n p l a c e , the chicks had access to feed only i n the exposed areas of the feed trough.  APPENDIX 4 ANALYSIS OF VARIANCE OF WEEKLY MEAN BODY WEIGHTS OF MALE BROILERS HATCH TO TEN WEEKS OF AGE  MEAN SQUARES FOR DIFFERENT PERIODS (Weeks) Source of Variation.  Degrees of Freedom.  HATCH Mean Squares  Replication Density R e p l i c a t e s x Den. Error  1 4 4 610  166.2* 2.8 3.3 9.7 4  Replication 1 Density 4 R e p l i c a t e s x Dens. 4 Error 610  86.0 41853.0 * 5884.0 3659.2  Mean Squares 1146.2* 353.3 * 412.7* 109.9 5 8544.0 37837.0 * 8068.0 6204.4  Mean Squares 271.0 6389.6 5013.9 573.2 6 26400.0 39610.0 * 26600.0 11508,0  8  9  10 60800.0  Replication  1  9424.0  22016.0  Density  4  5850.0  98376.0 *  190420,0 *  R e p l i c a t e s x Dens.  4  139550.0 *  111960.0 *  52120.0  Error  *  610  P<0.05  25810,0  34744.0  45538.0  Mean Squares 4248.O 8503.0 7193.7 1436,7 7 10832,0 64592.0*" 69308.0 *" 17682.0  APPENDIX 5 ANALYSIS OF VARIANCE OF WEEKLY MEAN BODY WEIGHTS OF FEMALE BROILERS, HATCH TO TEN WEEKS OF AGE  MEAN SQUARES FOR DIFFERENT PERIODS (Weeks) Source of Variation,  Degrees of Freedom,  1 Replication Density 4 Replicate x Dens, u Error 610  HATCH Mean Squares 196.4* 14.5 13.8 7.72  1  2  3  Mean Squares  'Mean Squares  Mean Squares  20.2 4217.1 * 1834*1 * 389.1  7174*0 * 6405.7 * 3306.7* 988.8  2037,7 3563.7 * 244.5 * 81,4  6  4  5  Replication 1 Density 4 Replicate x Dens, 4 610 Error  6634.0 28117.0 * 3015*5 2296.8  628.0 34055.0 * 26658,0 * 3839.1  28148,0 * 8470,0 20190.0 * 6385.1  1 Replication Density 4 Replicate x Dens, 4 Error 610  8 42400.0 16312.0 30940.0 13408,0  9 98464,0 * 16812,0 18864,0 16903.0  10 44032,0 71776,0 * 23136,0 21332,0  * P<0.05  7 31648.0 10562.0 13048.0 9802.9  APPENDIX 6 ANNALYSIS OF VARIANCE OF WEEKLY MEAN BODY WEIGHTS OF COMBINED SEXES, HATCH TO TEN WEEKS OF AGE  Source of Variation  MEAN SQUARES AND F-VALUES FOR DIFFERENT PERIODS (Weeks) of Freedom  HATCH Mean Squares  1 Mean Squares  2 Mean Squares  3 Mean Squares  4 Mean Squares  5 Mean Squares  Replication(Rp.)  1  Density(D.)  A  362.0 * 5,2  3120.2 * 661.2 *  219.0 10095.0 *  11232,0 * 14056.0 *  64696.O *  6904.0 66074.0 *  Sex(S.)  1  26,1  3593.9 *  88674.0*  609610.0 *"  2027300.0 *  5146100.0 *  Replicate x Density 4  10.4  454.5 *  5723.7 *  7847.5 *  5769.0  30196.0 *  4120.0  Replicate x Sex  1  0,6  63 6  72,0  188,0  2600,0  2264.0  Density x Sex  A A  12.1  48.3  512.0  851.5  5274.0  5814.0  6.7  203.0  1124.0  2653.5  3129.0  4530.0  1220  8.7  95.7  481.1  1212.5  2977.8  5021.3  8.  9 106850.0^  10 640.0  50944.0  189260.0 *  D. x Rp» x S, Error  6 Replication  8  7  •1  54528.0 *  39744.0  Density  A  30964.0 *  51756,0 *  Sex  1  11155000,0 *  20255000,0 *  33539000.0 *  50853000.0 *  Replicate x Density A  33272,0*  57688.0 *  141620.0 *  97392.0*  45888,0 • 35904.0  31888.0 104190.0  R e p l i c a t e x Sex  1  16.0  2736.0  5952.0  Density x Sex  A A  17112.0  23396.0  38904.0  64240,0 *  72928.0  13516.0  24656.O  28864.0  25819.0  43360,0  1220  8945.4  13741.0  19606.0  25809.2  33429.0  D, x Rp, x Sex Error * P 0.05  13632.0  71052000.0 *  APPENDIX 7 DAILY TEMPERATURE AND RELATIVE HUMIDITIES AS RECORDED BY THE UNIVERSITY OF BRITISH COLUMBIA METEOROLOGICAL STATION SITUATED IN THE CLOSE PROXIMITY OF THE POULTRY FARM - JULY 6 TO SEPTEMBER 16, 1965  'JULY 1965 D A T E  / Temperature*High  Low  AUGUST 1965  ; Mean Relative Humidity  .1  2 3 4 5 6 7 8 9 10 11 12 13  14 15 16 17 18  19 20 21 22 23 24 25 26 27 28  29 30 31  Temperature High 80  74  60  76 74  60  60 63  61  68  71  74 73  72 71  66 64 65 64 67 71  77 77  80 70  74 83 86 86  57 58 52 51  50 52  51  51 59 59 54 53 54 52 55 54 55 53 54  61 62  57 58 56 58 61  53 53  78 81  77  82  56 74 68 63 74  76 60  65 73 75 76 73 60 73 46  81  59  60  37 39  SEPTEMBER 1965  57 66 72  76 64 73 73 71  64 69 69 70 71  57  80  66 67  70 70  58 60 67 67 63 61  61  64 70  Mean Relative Low Humidity  66 62 58 56 55 54 59  60  56 60 59 60  56 52 54 55 68  52 71  97 R  98 R. 90 72  74 96 R 76 68  80 R 84 R 72  83  81 78  61  62  59  75 R  58  55 57 57 57 57 59 56 51 54 55 58  Temperature High  65 59  61 62 62  69 64 63 64 64 60 61  57 63 58 58  Mean Relative Low Humidity  57 54 54 53 55 58  56 55 55 57 53 54 53 54 52 49  74  78  73  81  79  51 62  69  81  74 79 74 88 87  69 41  90 R 87  86 97 R 92 R 80  66 62 65 68  72  55  R - Rain. ^Temperatures are taken i n a Stevenson Screen which simulates temperature i n s i d e a shaded b u i l d i n g * R e l a t i v e humidity was read a t 4:15 P.M. Peak d a i l y temperatures are normally obtained on or about 4:00 P.M. during summer months, hence, the taking of humidities when peak d a i l y temperatures are t o be expected.  APPENDIX 8 WEEKLY MORTALITY FOR BROILERS RAISED AT DENSITIES 0.6, 0.7, 0.8, 0.9 AND 1.0 SQUARE FOOT PER BIRD TO TEN WEEKS  WEEKS  Percent M o r t a l i t y to  Density  1  2  1.0  u.u.  0.9  u.u. u.u.  0.8  u.  3  4  u.  u.  5  u. u.  0.7  u.  0.6  u.u.  u.  7  6  8  9  p.  10  0.8$  0.8$  2.5$  2.9$  1.3$  1.3$  s.  1.1$  1.4$  u.  1.2$  1.4$  P. s.  P.  s.  u.  Unknown causes: and starveouts  p,  Perosis  s.  Smothering  p.s.  p.  9 weeks 10 weeks  APPENDIX 9 E l e c t r i c i t y Costs per B i r d In 1962 and 1963 e l e c t r i c i t y costs per b i r d were 0.44 cents, however, i n 1964. they declined t o 0.38 cents.  (Table V)  Generally  costs have been i n c r e a s i n g therefore average e l e c t r i c i t y costs were app l i e d t o a model b r o i l e r farm using 1964- e l e c t r i c i t y r a t e s t o check t h i s rate of 0,38 cents. Model S p e c i f i c a t i o n s : - 10,000 square foot house o f 10,000 b i r d c a p a c i t y . - L i g h t i n g - continuous, 72/4-0 watt bulbs weekly cost $2.02. - V e n t i l a t i o n by fans ( c a l c u l a t i o n s on next page). A fans 1500 c.f.m. with -J- hp motors 11 fans 3000 c.f.m. with 1/3 hp motors Calculated e l e c t r i c i t y requirements t o 63 days o f age. L i g h t 9 x $2.02 = #18.18 f o r 63 days. Approximate 63 day e l e c t r i c i t y cost per b i r d * Minimum Usage Lights Fans Total Cost per b i r d b a s i s 10,000 b i r d s Average  Maximum Usage  #18.180  #18.180  14.092  27.258  #32.272  #41.350 0.413*  0.32* 0.37*  9 "continued" MINIMUM AIR MOVEMENT - BASIS 0.5 CUBIC FEET PER MINUTE  Age i n Estimated-* B i r d Wt. Weeks  c.f.m. No. Fans Volume  Minimum  .Required  Horse iof Fans .Power  Total Cost Additive - Per Week Cost 6  f  ( i n pounds)  1 2 3 4 5 6  0.26 0.56 0.95 1.39 2.01 2.64  1,300 2,800 4,750 6,950 10,000 13,200  7  3.27  16,350  8  3.84  19,200  9 10  4.33 4.79  21,650 23,950  1500 1500 1500 3000 3000 1500 3000 1500 3000 1500 3000 3000 3000  1 2 3 2 3 (1 (4 (1 (5 (1 (6 7 8  3/4  iA iA  1/3  iA)  3/3)  IA) V3)  0.314 0.628 0.942 0.836 1.250 1.984  .314 .942 1.884 2.720 3.970 5.954  2.404  8.358 •  1/4)  2.814  11.172  1/3 1/3  2,920 3.340 17.432  14.092 17.432  0.625 0,836 1.250 1.984  0.628 1.464 2.714 4.698  2.920 3.760 4.600 5.430 5.850 6.270  7.618 11.378 15.978 21.408 27.258 33.528  V3)  MAXIMUM AIR MOVEMENT - BASIS 1 CUBIC FOOT PER MINUTE c.f.m. Maximum  1 2 3 4  0,26 0.56 0.95 1.39  2,600 5,600 9,500 13,900  5 6 7 8 9 10  2.01 2.64 3.27 3.84 4.33 4.79  20,100 26,400 32,700 38,400 43,300 47,900  " -" ,J  1  •! II  • i i II. . .  M.  I I  1500 3000 3000 1500 3000 3000 3000 3000 3000 3000 3000  2 2 3 (1 (4 7 9 11 13 14 15  i  i  i i • i  i  iA  1/3  iA)  1/3) v; 1/3 1/3 1/3 1/3  V3  33.528  i  •  i  Fan usage - three f i f t e e n hundred c.f.m. set at f i v e minute a i r change, a l l others c a l c u l a t e d t o run as r e q u i r e d . ^Selected optimum body weight growth, as obtained from the 10th B r o i l e r Tests, B. C. Random Sample Testing S t a t i o n , 1964. %S. C. Power Commission r a t e s .  APPENDIX 10 DESCRIPTION OF BROILER REARING BUILDING, ITS EQUIPMENT AND ESTIMATED COST  7  1. B u i l d i n g Costs. - two-storied — 31 f e e t x 161 f e e t . - w a l l s and c e i l i n g of top f l o o r l i n e d w i t h vapour b a r r i e r , plywood and i n sulation, - Fan v e n t i l a t e d . - E x t e r i o r - s h i p l a p , t a r paper and s i d i n g . Cedar shingle r o o f . - Concrete f l o o r down, plywood f l o o r up. - Concrete foundations. Estimated cost f o r 10,000 square f e e t - $10,000.00  #10,000.00  2. Equipment Costs. Brooding Equipment Fans 14- @ 140.00 each Bulk Tanks and Augers Waterers, feeders, conveyors T o t a l Cost  1,800.00 560.00 500.00 2,14-0.00 # 5,000.00  T o t a l Cost B u i l d i n g and Equipment  5.000.00 115,000.00  Annual C a p i t a l Cost Allowance.  Per Square Foot  B u i l d i n g s 20 years @ #10,000.00  #500.00  #0.05  Equipment 10 years @ # 5,000.00  #500.00  #0.05  T o t a l Cost Per Square Foot Per Year as a C a p i t a l Cost Allowance ).10 ^Estimated by Author.  APPENDIX 11 INSURANCE RATES AS APPLIED TO A BROILER-FRYER HOUSE 8  CONTAINING 10,000 SQUARE FEET OF FLOOR AREA AS DESCRIBED IN APPENDIX TABLE TEN Annual Insurance cost f o r b u i l d i n g #10,000,00 and equipment #5,000.00 at a rate of #1,33 per #100.00 B i r d insurance (10,000 b i r d s ) housed at one square foot per b i r d Insurance cost per square f o o t o f f l o o r area  #199.50 25.27 #224.77 2.248*  B i r d insurance was c a l c u l a t e d on a 19 cent per b i r d value which would be the cost of s t a r t i n g a new l o t of c h i c k s .  Insurance r a t e s on the b i r d s  was estimated a t #1.33 per #100.00 b i r d value per year.  T h i s can vary  according t o how i n s u r e d , type of b u i l d i n g , f i r e p r o t e c t i o n and the company.  I f the b i r d s were insured a t a market value of a four pound b i r d  at 19 cents per pound then the insurance would increase from #25.27 t o #101.56 per 10,000 b i r d capacity per year.  Insurance r a t e s estimated by Insurance Agent, Exact r a t e s unobtainable due t o v a r i a t i o n s between companies, f i r e p r o t e c t i o n d i s t r i c t s and o v e r - a l l coverage r e q u i r e d . ^Dudley Blaschek, 1965, A p r i v a t e communication, Royal Exchange Assurance Corporation, V i c t o r i a .  APPENDIX 12 From correspondence w i t h recognized a u t h o r i t i e s i n accounting, i t was thought that 0.06 was a f a i r value t o use i n c a l c u l a t i n g i n t e r e s t on investment f o r b r o i l e r production. *^ The procedure as outlined by Roy 1  1  was used t o c a l c u l a t e i n t e r e s t charges. Value of property the f i r s t of the year i s added t o the depreci a t e d value at the end of the year and averaged. The same procedure i s followed f o r equipment.  I n order t h a t the  average i n t e r e s t on investment may be used f o r the purpose of t h i s study the t o t a l investment payments f o r a twenty year period were added and divided by twenty which r e s u l t e d i n $7,4-50,00 as the average investment. Using 0,06 as the rate of i n t e r e s t the annual cost of i n t e r e s t i n i n v e s t 2 ment was 4-»47 cents per f t per year.  D a r y l T. Thompson, 1965. A p r i v a t e communication. Corporation of America, Vancouver, 1 0  Accounting  E w e l l P. Roy, 1965, A p r i v a t e communication, L o u i s i a n a State U n i v e r s i t y , Department of A g r i c u l t u r a l Economics and Agribusiness, i:L  12 "continued"  Year  Value of Build- Average ing as of Yearly January 1st Value  Value of Equipment as of January 1st  Average Yearly Value  Average Yearly Value of Equipment and Buildings.  1  10,000  9,750  5,000  4,750  14,500  2  9,500  9,250  4,500  4,250  13,500  3  9,000  8,750  4,000  3,750  12,500  4  8,500  8,250  3,500  3,250  11,500  5  8,000  7,750  3,000  2,750  10,500  6  7,500  7,250  2,500  2,250  9,500  7  7,000  6,750  2,000  1,750  8,500  8  6,500  6,250  1,500  1,250  7,500  9  6,000  5,750.  1,000  750  6,500  10  5,500  5,250  500  250  5,500  11  5,000  4,750  * 5,000  4,750  9,500  12  4,500  4,250  4,500  4,250  8,500  13  4,000  3,750  4,000  3,750  7,500  14  3,500  3,250  3,500  3,250  6,500  15  3,000  2,750  3,000  2,750  5,500  16  2,500  2,250  2,500  2,250  4,500  17  2,000  1,750  2,000  1,750  3,500  18  1,500  1,250  1,500  1,250  2,500  19  1,000  750  1,000  750  1,500  20  500  250  500  250  500  21  0  0 149,000 20 17,450  New Equipment  APPENDIX 13 NUMBER OF LOTS OF BROILERS PER YEAR WHEN REPLACEMENT TIME IS TWO WEEKS AFTER MARKETING Marketing Age Weeks  Replacement Period Weeks  Lots per Year  11  13  4.00  10  12  4.33  9  11  4.73  8  10  5.26  7  9  5.78  6  8  6.50  •  CORRECTION FACTORS FOR CHANGING VALUES  FOR DENSITIES BELOW ONE SQUARE FOOT TO ONE SQUARE FOOT Square Foot Allotment  C o r r e c t i o n Factor  1.0  1.00  0.9  1.11  0,8  1.25  0.7  1.43  0.6  1.67  APPENDIX 14 ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA WHEN BIRDS ARE MARKETED AT 6, 7, 8, 9 OR 10 WEEKS OF AGE FOR VARIOUS FEED AND MEAT PRICES: BIRD DENSITY 0*7 SQUARE FOOT PER BIRD Feed Cost In Cents Per Pound  Age o f Bird i n Weeks  Live B r o i l e r Meat P r i c e (cents per pound)  17  15 4.0  4.5  5.0  5.5  6 7 8 9 10  -24.714 - 0.685 15.552 26.840 28.419  6 7 8 9 10  -44.233 - 2.406 -23.828 22,623 -10,846 39.273 - 2.245 50.648 - 3.469 51.267  6 7 8 9 10  -63.753 -21.925 -46.971 - 0.520 -37.243 12.875 -31.330 21.564 -35.358 19.379  6 7 8 9 10  -83.272 -70.114 -63.641 -60.415 -67.246  +  17.114 45.766 65.671 79.733 83.155  +  +  +  - a . 445 -23.663 -13.523 - 7.521 -12.510  +  23  58.941 92.218 115.790 132.627 137.892  100.769 138.670 165.908 185.521 192.628  39.422 69.075 89.392 103.542 106.003  81.249 115.526 139.510 156.436 160,740  +  4  +  +  21  19  19.902> 45.932 62.994 74.457 74.115 0.383 22.789 36.596 45.373 42.227  +  +  4  4  +  61.730 92.383 113.113 127.351 . 128.852+-H 42.210 69.240 86.715 98.266 96.963  +  142.596 185.121 216.027 238.414 247.365  +  123.077 161.978 189.629 209.330 215.476 103.557 138.835 163.231 180.245 183.588  +  +  84,038, 115.692 136.833 151.160 151.700  +  Maximum annual net returns per f t . ^ f o r each combination of feed and meat p r i c e , ^•9A two week c l e a r period between successive l o t s i s assumed. USample c a l c u l a t i o n : Marketed a t ten weeks w i t h a l i v e body weight of 4.42 pounds, two week c l e a r p e r i o d , feed cost of 5.0* per pound and a 21 cent per pound l i v e b r o i l e r meat p r i c e .  14 "continued" T.R.=- 4.42 21.0 x 4.33 x 1.43= T.C.r 16.72+(17.8 x 1.43 x 4.33) + (10.3 x 5.0 x 1.43 x 4.33) = x  Net return per square foot per year  =  574.732* 445.880* 128.852*  APPENDIX 15 ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA WHEN BIRDS ARE MARKETED AT 6, 7, 8, 9 OR 10 WEEKS OF AGE FOR VARIOUS FEED AND MEAT PRICES: BIRD DENSITY 1.0 SQUARE FOOT PER BIRD Feed Cost i n Cents Per Pound  Age of Bird i n Weeks  L i v e B r o i l e r Meat P r i c e (cents per pound)  15 4.0  4.5  5.0  5.5  17  19  6.940 26.977 40.896 50.730^ 53.123  36.190 59.460 75.944 87.718 91.400  6 7 8 9 10  -22.310 - 5.507 5.848 13.741+ 14.846  6 7 8 9 10  -35.960 - 6.710 22.540 43.276 -21.691 10.793 -12.612 22.436 57.484 - 6.598 " 30.391 67.379 30.823 ' 69.101 - 7.454  6 7 8 9 10  -49.610 -20.360 -37.875 - 5.391 -31.072 3.976 -26.937 * 10.052 -29.753 8.524  6 7 8 9 10  -63.260 -54.059 -49.532 -47.276 -52.053  +  .21  f  1  4  +  +  8.890 27.092 39.024 47.040 46.801  +  +  -34.010 - 4.760 10.908 -21.575 20.564 -14.484 -10.287+ 26.701^ -13.776 24.502  23  65.440 91.944 110.992 124.707 129.677  +  94.690 124.428 146.040 161.696 167.955  4  51.790 75.760 92.532 104.368 107.378" "  81.040 108.244 127.580 141.357 145.655  38.140 59.576 74.072 84.029 85.078  67.390 92.060 109.120 121.018 123.356 +  1  24.490 43.392 55.612 63.690 62.779  +  +  +  53.740 75.876 90.660 100.679 101.056+"  +" Maximum annual net returns per f t . f o r each combination of feed and meal p r i c e . 2  'A two week c l e a r period between successive l o t s i s assumed.  APPENDIX 16 'ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA WHEN 'BIBBS ARE MARKETED AT 6, 7, 8, 9 OR 10 WEEKS OF AGE FOR VARIOUS FEED AND MEAT PRICES: BIRD DENSITY 1.0 SQUARE FOOT PER BIRD AND NUMBER OF LOTS PER YEAR LIMITED TO £.33  Feed Cost i n Cents Per Pound  Age o f Bird i n Weeks  L i v e B r o i l e r Meat P r i c e (cents per pound) .  15 4.0  4.5  5.0  5.5  13  .17  19  .21  6 7 8 9 10  -20.444 - 8.320 2.072 11.165, 14.846  - 0.959 16.015 31.256 45.026 53.123  6 7 8 9 10  -29.537 -20.444 -13.299 - 7.454 - 7.454""  -10.052 3.891 15.885 26.407 30.823 *  9.433 28.225 45.069 60.267 69.101  6 7 8 9 10  -38.630 -32.568 -28.671 -26.073 -29.753  -19.145 - 8.233 0.513 7.788 8.524  0.340 16.101 29.698 41.648 46.801^  6 7 8 9 10  -47.723 -44.692 -44.042 -44.692 -52.053  +  +  18.526 40.349 60.441 78.886 91.400  +  +  +  -28.238 - 8.753 -20.357 3.977 -14.858 14.326 -10.831^ 23.029 -13.776 24.502  38.011 64.684 89.625 112.747 129.677 28.918 52.560 74.253 94.128 107.378  +  +  23 57.496 89.019 118.809 146.608 167*955  +  48.403 76.895 103.437 127.989 145.655 +  +  19.825 40.436 58.882 75.509 85.078^"  39.310 64.771 88.066 109.370 123.356  10.732 28.312 43.510 56.890 62.779  30.217 52.647 72.694 90.751 101.056 +  +  +  Maximum annual net returns per f t . f o r each combination of feed and meat p r i c e ,  13A two week c l e a r period between successive l o t s i s assumed.  APPENDIX 17 ANNUAL NET RETURNS PER SQUARE FOOT OF FLOOR AREA WHEN BIRDS ARE MARKETED AT 6, 7, 8, 9 OR 10 WEEKS OF AGE FOR VARIOUS FEED AND MEAT PRICES: BIRD DENSITY 0.7 SQUARE FOOT PER BIRD AND NUMBER OF LOTS PER YEAR LIMITED TO  Feed Cost i n Cents Per Pound  Age of Bird i n Weeks  Live B r o i l e r Meat P r i c e (cents per pound)  17  15 4.0  4.5  5.0  5.5  19  6 7 8 9 10  -22.045 - 4.708 10.153 23.156 28.419  6 7 8 9 10  -35.048 -22.045 -11.828 - 3.469* - 3.469  - 7.184 12.753 29.905 44.951 51.267  6 7 8 9 10  -48.051 -39.382 -33.810 -30.095 -35.358  -20.187 - 4.584 7.924 18.326 19,379^  6 7 8 9 10  -61,054 -56.720 -55.791 -56.720 -67.246  +  +  +  33.682 64*889 93.620 119.997 137.892  5.819 30.091 51.886 71.576 83.155  +  +  -33.190 -21.921 -14.057 - 8.299 -12.510  4  23  61.546 99.688 135.353 168.418 192.628*  89.409 134.486 177.086 216.838 247.365  20.679 47.552 71.638 93.372 106.003+  48.543 76.406 82.350 117.149 113.372 155.105 141.793 190.213 160.740^ 215.476"  7.676 30.215 49.657 66.747 74.115  35.540 63.403 65.013 99.812 91.391 133.124 115.167 163.588 128.852 183.588+  - 5.327 12.877 27.676 40.122 42.227  +  21  +  +  +  22.537 47.676 69.409 88.542 96.963*-  50.400 82.474 111.143 136.963 151.700^  * Maximum annual net returns per f t . f o r each combination of feed and meat p r i c e . 2  *4A two week c l e a r period between successive l o t s i s assumed.  

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