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Carbohydrate digestion in the chinchilla Smith, Diana Claire 1970

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CARBOHYDRATE DIGESTION I N THE  CHINCHILLA  by  ...  DIANA C L A I R E SMITH  B.S.A.- U n i v e r s i t y  of B r i t i s h  Columbia, 1 9 6 7  A THESIS SUBMITTED I N PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF  SCIENCE  i n t h e Department of Animal  Science  We a c c e p t t h i s t h e s i s a s c o n f o r m i n g t o t h e required  standard  THE UNIVERSITY OF B R I T I S H COLUMBIA September, 1 9 7 0  In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and Study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representatives.  It is understood that copying or publication  of this thesis for financial gain shall not be allowed without my written permission.  Department of The University of British Columbia Vancouver 8, Canada  ABSTRACT  Carbohydrase a c t i v i t y i n the c h i n c h i l l a  (Chinchilla  lanigera) was investigated from b i r t h to post-weaning.  Crude  homogenates of the small i n t e s t i n a l wall and pancreas were prepared i n order to study i n t e s t i n a l lactase, maltase and sucrase, and pancreatic amylase. assumption that, at different  The study was based on the  stages of growth, the carbohy-  drase l e v e l s r e f l e c t the a b i l i t y of the animal to u t i l i z e s p e c i f i c carbohydrates. Small i n t e s t i n a l lactase a c t i v i t y was highest from b i r t h to three weeks of age, at which time i t decreased sharply reaching the f a i r l y constant low l e v e l s found i n the post-weaned animal by four weeks. Maltase a c t i v i t y at b i r t h was appreciable, increasing s i g n i f i c a n t l y at four weeks of age and attaining maximum l e v e l s by twelve weeks of age.  The adult animal retained t h i s  high a c t i v i t y . In contrast to maltase, sucrase a c t i v i t y was n e g l i gible at b i r t h and d i d not increase s i g n i f i c a n t l y u n t i l f i v e weeks of age, at which time a steady increase was noted to the adult l e v e l s attained by the'twelve week o l d animal. Pancreatic amylase was s i m i l a r l y negligible  at b i r t h .  The highest increase i n a c t i v i t y occurred between three and  eight weeks at a time when i n t e s t i n a l lactase a c t i v i t y was decreasing.  This also corresponded to the time of most  rapid increase  i n maltase a c t i v i t y .  The digestion of more complex carbohydrates was also investigated i n the adult c h i n c h i l l a .  Cellulose, com-  p r i s i n g 18.7$ of a pelleted ration, was 54$ d i g e s t i b l e , the main s i t e s of c e l l u l o s e breakdown being the cecum and large intestine.  Total v o l a t i l e f a t t y acids (VFA) throughout the  alimentary t r a c t of animals on a normal ranch ration of p e l l e t s and hay. were quantitated, acids.  as were the i n d i v i d u a l  The cecum and large i n t e s t i n e were the only s i t e s of  VFA production, while the low l e v e l s found i n the stomach were attributed to coprophagy.  ACKNOWLEDGEMENTS  I wish to thank Dr. W. D. K i t t s , Professor of Animal Science and Chairman of the Department of Animal Science, f o r his d i r e c t i o n and support of t h i s study. I am also very grateful to my fellow students f o r t h e i r valuable assistance and c r i t i c i s m .  TABLE OF CONTENTS Page I II  . . . . . . . .  INTRODUCTION L I T E R A T U R E REVIEW A.  B.  III  IV  3  .  3  Chinchilla 1.  Growth  3  2.  Digestion  4  3.  N u t r i e n t Requirements  5 7  Digestion of Disaccharides 1.  Recent Advances  7  2.  D e v e l o p m e n t w i t h Age . . . . . . .  14  -3. C.  1  Adaptation  of Disaccharidases.  Digestion of Polysaccharides 1.  Digestion of Starch  2.  Digestion of Cellulose  Materials  B.  Methods  ... EXPERIMENTAL P a r t A.  .23 26  32 .33 . . . "  Enzyme S t u d i e s 1.  23  32  GENERAL METHODS A.  . . 19  Disaccharidases (a) Methods and M a t e r i a l s (b) R e s u l t s a n d D i s c u s s i o n  34 34 34  Page 2.  Amylase  • . . 47  .•  (a) Methods and M a t e r i a l s (b) R e s u l t s and D i s c u s s i o n P a r t B.  D i g e s t i b i l i t y Studies  1.  . . . . . . . . .  53  Time o f Passage and S i t e o f C e l l u l o s e 53 Digestion (a) Methods and M a t e r i a l s (b) R e s u l t s and D i s c u s s i o n  2.  V o l a t i l e F a t t y A c i d Production  . . . 6l  (a) Methods and M a t e r i a l s (b) R e s u l t s and D i s c u s s i o n i  V VI VII  SUMMARY  67  BIBLIOGRAPHY  69  APPENDICES  73 1.  Composition o f C h i n c h i l l a P e l l e t s  2.  Growth Curve o f C h i n c h i l l a l a n i g e r a  3.  Organ Weights as Per Cent o f L i v e Body Weight a t Various Chinchilla  .  7f  Ages i n the  •. . . .  .' . . . • & X  LIST OF TABLES  Table I II  '  4  Weights of C h i n c h i l l a  lanigera  Concentrations  i n the ceca of s e v e r a l  of VFA  31  s p e c i e s of animals III  A c t i v i t y of maltase,  sucrase and l a c t a s e i n the  a l i m e n t a r y t r a c t of the c h i n c h i l l a IV V  Amylase a c t i v i t y i n the c h i n c h i l l a Time of passage of a p e l l e t e d digestive tract  VI  Cellulose  Page  39 . . . . . . . .  f e e d through  the 57  of the c h i n c h i l l a  d i g e s t i b i l i t y and VFA  51  production i n  the a l i m e n t a r y t r a c t of c h i n c h i l l a f e d a 60  commercial c h i n c h i l l a p e l l e t VII  VFA's i n the d i g e s t i v e t r a c t s and f e c e s of f o u r a d u l t c h i n c h i l l a f e d a l f a l f a hay and cial  VIII  a commer64  chinchilla pellet  Dry matter and  cellulose  d i g e s t i b i l i t y of a  commercial c h i n c h i l l a p e l l e t w i t h and a l f a l f a hay  •  without 65  L I S T OF FIGURES  Figure 1  Page Outline of carbohydrate digestion and absorption i n man  2  Lactase a c t i v i t y i n i n t e s t i n a l mucous membranes from normal and scouring calves . . .  3  13  Optimum pH of i n t e s t i n a l lactase, sucrase and maltase i n the c h i n c h i l l a  4  9  43  I n t e s t i n a l lactase, sucrase and maltase a c t i v i t y as a function of age i n the c h i n c h i l l a . 4 6  5  Pancreatic amylase a c t i v i t y as a function of age i n the c h i n c h i l l a  6  52  Time of passage of a pelleted feed through the digestive t r a c t of the c h i n c h i l l a  5$  I  INTRODUCTION  C h i n c h i l l a have been domesticated f o r n e a r l y years and t h e i r economic importance i s now w e l l e s t a b l i s h e d .  fifty  as a l u x u r y f u r animal  D i s t i n c t i v e f e a t u r e s of the f u r  e n a b l i n g the c h i n c h i l l a t o compete s u c c e s s f u l l y w i t h o t h e r f u r b e a r e r s such as mink, s a b l e and f o x , a r e i t s extreme s o f t n e s s o f t e x t u r e and c o l o u r . to remain  However, f o r the c h i n c h i l l a  i n the c o m p e t i t i v e market, r e s e a r c h i s e s s e n t i a l  to c o n s t a n t l y improve  f u r q u a l i t y and e f f i c i e n c y o f produc-  tion. I t has been s a i d t h a t l e s s i s known about the n u t r i t i o n o f c h i n c h i l l a than any other aspect of t h e i r prod u c t i o n , and i t i s very apparent t h a t r e s e a r c h i s l a c k i n g i n t h i s area.  N u t r i e n t requirements f o r maintenance,  and p r o d u c t i o n have not been determined,  growth,  so t h a t the growing  animal, the pregnant o r l a c t a t i n g female, and the p e l t e r a r e a l l f e d t h e same d i e t , w h i l e t h e i r r e s p e c t i v e are bound t o d i f f e r .  requirements  T h i s means not only t h a t the animal's  p o t e n t i a l f o r growth and p r o d u c t i o n i s not expressed, due t o n u t r i t i o n a l d e f i c i e n c i e s , but a l s o t h a t a t r e l a t i v e l y d u c t i v e stages some animals a r e being f e d more than requirements, which i s o b v i o u s l y not economical.  unpro-  their  Before i n -  v e s t i g a t i n g the energy requirements, i t v/ould h e l p t o know more about the d i g e s t i v e p r o c e s s e s i n the c h i n c h i l l a , and the  type of feedstuffs t h i s animal can u t i l i z e most e f f i c i e n t l y f o r energy production.  With this i n mind, i t was decided  to concentrate on certain features of carbohydrate digestion. Growth of the animal i s associated with corresponding changes i n the anatomy and physiology of the digest i v e system.  These changes create l i m i t s on the amount and  type of feed that the animal can consume and u t i l i z e . the assumption testine  On  that the carbohydrase a c t i v i t i e s i n the i n -  r e f l e c t the a b i l i t y of the animal to u t i l i z e various  carbohydrates, the f i r s t experiment was  carried out to  determine the a c t i v i t i e s of s p e c i f i c carbohydrases from b i r t h to post-weaning.  These were i n t e s t i n a l sucrase,  maltase, and lactase, and pancreatic amylase. Since f i b r e has been shown to be very important i n the diet of the c h i n c h i l l a  (69),  both as a n u t r i t i v e and as  a bulk source*, the second experiment was conducted to determine the extent of f i b r e digestion of a commercial  chinchilla  ration, with and without a l f a l f a hay, and to quantitate the u t i l i z a b l e end-products, namely v o l a t i l e fatty acids. of passage of feedstuffs through the c h i n c h i l l a  Time  digestive  tract was determined before doing the d i g e s t i b i l i t y study, i t being an important factor a f f e c t i n g the e f f i c i e n c y of digestion and u t i l i z a t i o n of carbohydrates. The purpose of t h i s study was therefore twofold: f i r s t , to measure changes i n carbohydrase l e v e l s with growth of the c h i n c h i l l a ; and, second, to determine the s i t e and products of cellulose  digestion.  end-  II  LITERATURE REVIEW  A.  CHINCHILLA  C h i n c h i l l a were p r a c t i c a l l y unknown i n North America before 1923 when eleven animals were introduced by an American mining engineer returning from the Andes  (59)-  Forty years l a t e r , i n 1967, B r i t i s h Columbia alone had 140 ranches with approximately 16,000 animals (91) • the rapid increase i n numbers, there i s l i t t l e  Despite scientific  information available on the c h i n c h i l l a .  1.  Growth Young c h i n c h i l l a are born f a i r l y mature, possess-  ing hair and teeth and open eyes, and are usually weaned at sixty days (2).  Weights of Chinchilla lanigera from b i r t h  to one year of age are given by Bickel (15)•  Chinchilla  brevicaudata, a s h o r t - t a i l e d , blockier type of l e s s e r importance i n North America, are ten to f i f t e e n grams heavier than those described by Bickel  (59).  TABLE I  (Bickel (  1  5  )  )  Weights of C h i n c h i l l a Lanigera  Age (months)  Weight (g.) Maximum  Minimum  Mean  57  35  44  1  200  85  2  3 2 6  3  425  185 290  340  .4  489  312  399  5  5 2 5  340  438  650  369  556  720  397  5 5 6  at b i r t h  6  *  12  1 4 5 255  The average weight of normal adult males on a ranch diet i n the United States i s about 5 0 0 grams, with females weighing s l i g h t l y more.  Somewhat lower weights were reported  f o r 6 7 c h i n c h i l l a by Larrivee and Elvehjem ( 6 9 ) .  Most of the  animals began to l e v e l o f f i n weight at approximately nine to eleven months of age, and the range at maturity was from 3 2 0 to 4 2.  6  0 grams f o r males, and 3  5  0 to 5  0  0 grams f o r females.  Digestion The c h i n c h i l l a i s an herbivorous animal with a large  cecum.  In the wild state, c h i n c h i l l a l i v e mainly on grasses,  seeds, and the bark of trees, while most captive animals are fed a pelleted ration and hay, sometimes supplemented green feed.  with  Farmer ( 4 4 ) i n 1 9 5 7 found that commercial  p e l l e t s as the sole diet of c h i n c h i l l a during pregnancy  and  rabbi  l a c t a t i o n were s a t i s f a c t o r y , but Bickel ( 1 5 ) - i n I 9 6 2 advocated the use of hay,  cereals and fresh green feed, claim-  ing they were l e s s l i k e l y to cause digestive than p e l l e t s .  disturbances  According to K i r i s and Barantseva ( 6 6 ) i n a  report on acclimatisation of c h i n c h i l l a in the U.S.S.R., hay constitutes two-thirds  of the diet and, to a great  extent, determines the quality of the f u r . 3.  Nutrient Requirements No conclusive studies could be found on the pro-  t e i n and energy requirements of c h i n c h i l l a , but some work has been reported on vitamin and roughage requirements. Using guinea pig diets as a guide, Larrivee and Elvehjem ( 6 9 ) devised four synthetic rations varying i n roughage and s a l t content which were fed to sixty-seven c h i n c h i l l a . control r a t i o n was  a commercial c h i n c h i l l a p e l l e t .  either c e l l u l o s e (solka f l o e ) or gum was  The  Roughage,  arabic, at the 1 5 $ l e v e l  i n s u f f i c i e n t and caused constipation, but t h i s was  t i a l l y corrected at 20% l e v e l s of gum  arabic and  eliminated at 20% l e v e l s of c e l l u l o s e .  par-  completely  The ration contain-  ing 20% c e l l u l o s e supported apparently normal growth of both young and mature c h i n c h i l l a s f o r periods of f i f t e e n weeks or longer. Previously, King and Orcutt vitamin C was  ( 6 5 ) demonstrated that  not necessary f o r the growing c h i n c h i l l a , an  observation confirmed by Larrivee and Elvehjem (  6  9  ) in 1  9  5  4  Withdrav/al of v i t a m i n ordination.  caused a l o p e c i a and l a c k o f co-  The minimum d a i l y r e q u i r e m e n t f o r w e a n l i n g  c h i n c h i l l a was found t o be between 0.1  and 0.4 mg.  There  i s e v i d e n c e , t o o , t h a t the c h i n c h i l l a does not need t o be given r i b o f l a v i n  (70).  t a i n i n g 0.39  r i b o f l a v i n p e r g, showed no s i g n s o f de-  ficiency,  mg  Animals on a p u r i f i e d  diet,  con-  and grew as w e l l as t h o s e g i v e n a supplement  r a i s e the r i b o f l a v i n  c o n t e n t o f t h e d i e t t o 14.4 mg  to  per g  B. 1.  DIGESTION OF DlSACCHARIDES  Recent Advances This topic and the ones following .will be d i s -  cussed with reference to work done with other animals, since no such work using c h i n c h i l l a has been reported. understanding of the physiology  An  of digestion and absorp-  t i o n of disaccharides has increased r a p i d l y i n the l a s t ten years, and some of the most s i g n i f i c a n t advances have been outlined i n several review a r t i c l e s (51, 8 6 , 3 2 ) . (a)  Site of oligosaccharide hydrolysis.  The  theory of intraluminal digestion implying that i n t e s t i n a l disaccharides, such as sucrase, maltase and lactase, are secreted into the i n t e s t i n a l lumen and hydrolyse  ingested  sugars i n the succus entericus has been disproved.  Several  workers have demonstrated that the hydrolytic a c t i v i t y measured i n i n t e s t i n a l contents was  f a r too low to account f o r  the observed rate of digestion of disaccharides Also, r e s u l t s obtained  ( 1 8 , 38, 3 1 ) .  i n animal studies, using sacs or rings  of everted small i n t e s t i n e , have shown that the disaccharidases are not released into the incubation medium, but t h e i r action i n the small i n t e s t i n a l wall ( 1 6 ) . Semenza ( 8 6 ) , evidence f o r t h i s was as 1 8 8 0 by Brown and Heron, who  exert  According  to  actually reported as early  showed that the sucrase and  maltase a c t i v i t i e s were higher i n the i n t a c t gut than i n ext r a c t s from the i n t e s t i n a l j u i c e . enzymes are apparently  The observation  that these  bound to some structures of the tissue  was  confirmed l a t e r by a number of workers at the turn of  the century.  I t has now  been established with l i t t l e  doubt that disaccharidases are located i n the brush borders of c y l i n d r i c a l c e l l s ( 8 6 ) .  M i l l e r and Crane (75)  in  1961  i s o l a t e d brush borders having 90;S of sucrase and lactase associated with them. For a time thereafter, i t was  believed that the  dietary disaccharides entered the i n t e s t i n a l c e l l prior to hydrolysis, but there i s recent evidence that hydrolysis occurs on the outside of the i n t e s t i n a l membrane at a s i t e exterior to the permeability b a r r i e r of the c e l l  (22).  No  s p e c i f i c mechanism of entry into the i n t e s t i n a l wall has been found f o r disaccharides, a requirement i f they are to be hydrolysed  intracellularly (51).  I t has been postulated  that the glycocalyx, the outer fuzzy coat of the brush border covering the m i c r o v i l l i , serves as a p a r t i a l d i f f u s i o n b a r r i e r f o r the entry and exit of sugars, so that the bulk of monosaccharides released upon hydrolysis at the brush border, rather than d i f f u s i n g back through the glycocalyx to the lumen, i s p r e f e r e n t i a l l y taken up by the i n t e s t i n a l Gray (51)  cell  concluded that the hydrolytic enzymes are located  both i n the glycocalyx and i n the m i c r o - v i l l a r membrane i t s e l f * so that they may  bind and hydrolyse  coming i n contact with the c e l l  disaccharides  surface.  Probably the most plausible answer to the sometimes discrepant theories reported, i s that provided  by Crane  (22)  He suggests an o v e r a l l digestive-absorptive function that i s not separated  p h y s i o l o g i c a l l y into the two d i f f e r e n t  functions of digestion and absorption. i s probably organized  Instead, the c e l l  so that sequential reactions of  hydrolysis and transport are physically i n close  proximity,  making i t possible f o r the products of hydrolysis to become the substrates f o r transport before there i s a chance f o r them to d i f f u s e away.  In support of t h i s theory, i t has  been shown that the membrane transport systems allow much better absorption of the monosaccharide products of brush border hydrolases  than that of free monosaccharide added to  the lumen. An outline of the intraluminal and brush border digestion of carbohydrates i n man i s given i n Figure 1 . FIGURE 1  (Gray ( 5 1 ) ) Outline of Carbohydrate Digestion and Absorption i n Man  Intraluminal  Intestinal Brush Border  Maltose Starch» Maltotrioseamylase trins..  maltase maltase _^ dextrinase^, Galactose, Cell Transport lactase Glucose  D e x  Lactose  Sucrose  G l u c o s e  <  sucrase  Glucose Fructose  (b)  Characterization of I n t e s t i n a l  Disaccharidases.  A second s i g n i f i c a n t advance i n the l a s t few years has been the characterization of several s p e c i f i c disaccharide t i n g enzymes.  split-  Evidence has been obtained f o r the existence  of four or f i v e maltases ort the basis of heat s t a b i l i t y and k i n e t i c s of mutual i n a c t i v a t i o n by various substrates ( 2 8 ) , but the techniques used have been questioned. Telenius  Dahlqvist and  ( 3 3 ) have suggested that one of the two human suc-  rases i s o l a t e d may be an a r t i f a c t produced by biochemical purification.  However, several workers have separated and  characterized at l e a s t two lactases i n human i n t e s t i n e , only one of which has the c h a r a c t e r i s t i c s of a digestive enzyme. This lactase, with a pH optimum of 6 . 0 and a s p e c i f i c i t y f o r lactose, i s markedly depressed or absent i n man with lactose intolerance.  The second lactase has a lower pH optimum and  has a s p e c i f i c i t y f o r both lactose and synthetic  substrates.  Although i t i s present at normal l e v e l s i n man with lactose intolerance, i t does not appear to be of any importance i n the digestion of dietary lactose ( 5 0 ) . There i s also an enzyme with a c t i v i t y against 1,6-CX-glucosidase l i n k s which i s usually c a l l e d isomaltase ( 5 1 ) .  Gray suggests a better  name would be ©<(-dextranase, since the only substances i t acts on are the c<-dextrins released by the action of amylase on amylopectin.  Isomaltose, the disaccharide with a 1,6-tx.  l i n k i s r e a d i l y hydrolyzed by <X-dextranase,- but i s not a p h y s i o l o g i c a l substrate present i n the i n t e s t i n e .  (c)  D e f i c i e n c y of S p e c i f i c  Disaccharidases.  C l i n i c a l c o n d i t i o n s have r e c e n t l y been recognized  i n which  the l e v e l s of a c t i v i t y of a s p e c i f i c d i s a c c h a r i d a s e  are i n -  adequate to d i g e s t the u s u a l d i e t a r y i n t a k e of t h a t d i s a c charide.  These c o n d i t i o n s can e i t h e r be  or a c q u i r e d  congenital  defects,  c o n d i t i o n s r e s u l t i n g from an u n d e r l y i n g  disorder  with l o s s or damage of i n t e s t i n a l t i s s u e ( i ) Acquired  forms.  I n t e s t i n a l l a c t a s e i s absent i n a d u l t s  of most mammals except man, l e v e l s of a c t i v i t y .  (32).  who  u s u a l l y r e t a i n s measurable  But some do l o s e t h e i r l a c t a s e  t h e r e f o r e cannot t o l e r a t e l a c t o s e or m i l k . Dahlqvist  According  i n f a n c y , and  develop the c o n d i t i o n as a  sequel t o some k i n d of damage t o the mucosa.  Lactase  a tendency to be more s e v e r e l y a f f e c t e d by  i n a l disease  describing this i n 5-10%  S t a t e s and  c o n d i t i o n i n man  intest-  70-100$ of Negroes and  Many r e p o r t s  i n the  O r i e n t a l s (13).  Cuatre-  microvilli  d e f i c i e n c y i s found i n d i s e a s e s  cystic fibrosis,  (24)•  sub-  unable to change l a c t a s e  l e v e l s i n e i t h e r normal or l a c t a s e d e f i c i e n t persons.  other malabsorption  United  grams of l a c t o s e per day to f o u r t e e n  j e c t s f o r three months and was  e r a l disaccharidase  and  have appeared, i t being  of the a d u l t white p o p u l a t i o n  casas (24) f e d 150  giardiasis,  acti-  c o n d i t i o n s than the o t h e r d i s a c c h a r i d a s e s ,  a l s o to r e t u r n more s l o w l y to normal v a l u e s .  present  to  (32), these people have a h i s t o r y of normal milk  tolerance during  v i t y has  and  c o e l i a c disease,  Gen-  such as  enteritis,  s t a t e s a s s o c i a t e d with, b l u n t i n g of  and  the  In animal studies, calves dying a f t e r scouring (seven days of age) had lower lactase a c t i v i t y i n the upper small i n t e s t i n e than did healthy calves ( 1 9 ) ' ence i n a c t i v i t y can be seen i n Figure 2 .  This d i f f e r -  Radotstits (7$)  i n 1965 noted a f l a t t e n e d appearance of i n t e s t i n a l epithel i a l c e l l s from scouring calves and suggested that these may be impaired i n t h e i r a b i l i t y to digest and absorb nutrients. When the lactase i n the i n t e s t i n e i s inadequate to cope with the lactose i n the d i e t , undigested lactose i s fermented by micro-organisms i n the lower part of .the i n t e s t i n e , r e s u l t ing i n fermentative diarrhoea which aggravates any existing diarrhoea ( 1 9 ) .  This i s i n keeping with the findings of  Blaxter and Wood (17) who showed that scouring animals had a lowered f e c a l pH and a raised l e v e l of f e c a l f a t t y acids t y p i c a l of an abnormal carbohydrate ( i i ) Congenital forms.  fermentation,  In t h i s condition the small i n t e s -  t i n a l mucosa i s normal and the symptoms rapidly disappear on a lactose free d i e t .  The disease i s believed to be heredi-  tary, the deficiency remaining throughout l i f e but the symptoms growing milder with time.  Durand (42) found the  condition to start i n infancy with severe diarrhoea, malnut r i t i o n , f l a t lactose tolerance curve but normal galactose plus glucose tolerance, and acid feces containing large amounts of lactose and l a c t i c acid after ingestion of l a c t o s e . Newborn human babies sometimes have d i f f i c u l t y digesting the large amounts of lactose ingested, but t h i s should not be  mistaken f o r a deficient condition (32).  Aurrichio and co-  workers (8) report that lactase a c t i v i t y i n man.and other animals develops l a t e i n f o e t a l l i f e and seems to increase somewhat a f t e r b i r t h .  FIGURE 2  (Bywater (19)) Lactase A c t i v i t y i n I n t e s t i n a l Mucous Membrane from Normal and Scouring Calves V e r t i c a l bars represent S.E.M.  normal  10  scouring 8  -p  •H  > •H •P O  <:  <D CO  as  •P o CO  i-3  0 duodenum  20  40  60  80  100  i.c.v.  Distance from duodenum to i l e o - c e c a l valve {%)  Congenital sucrpse-isomaltose  intolerance i s  another i n h e r i t a b l e condition, the two enzymes always being absent or inactive simultaneously.  Maltase a c t i v i t y i s  also reduced but lactase remains the same.  Symptoms appear  only when sucrose, isomaltose and related oligosaccharides containing the same °<-l,6 bonds as form the branch l i n k s of starch are i n the d i e t .  Although the condition has been  found i n only a very few people, i t has i n c i t e d considerable i n t e r e s t since i t i s transmitted by a single recessive autosomic genetic f a c t o r .  According to. Semenza ( S 6 ) t h i s i s one  of the f i r s t examples, i f not the f i r s t , i n human genetics of a single genetic f a c t o r c o n t r o l l i n g more than one enzyme. 2.  Development With Age Disaccharidase a c t i v i t y during the pre-weaning  stage of growth has been studied i n recent years to a considerable extent.  Although factors c o n t r o l l i n g the develop-  ment of enzyme a c t i v i t y are not c l e a r l y understood, i t appears that the disaccharidases develop i n a way that allows u t i l i zation of the carbohydrates  that the animal i s l i k e l y to  encounter under normal feeding conditions  Thus, i n  most young suckling mammals, ^-galactosidase a c t i v i t i e s i n the small i n t e s t i n e are high, allowing e f f i c i e n t u t i l i z a t i o n of the lactose i n the dam's milk.  One major exception to  t h i s i s the C a l i f o r n i a n seal, the small i n t e s t i n e of which does not contain l a c t a s e . tains no lactose ( 6 8 ) . increases.  Correspondingly,  seal milk con-  After weaning, the lactase a c t i v i t y  This i s consistent with the change i n carbohydrate  i n the diet, although i t i s not indicative of dietary cont r o l of disaccharidase a c t i v i t y .  Attempts to induce  activity  by feeding s p e c i f i c disaccharides have generally been inconclusive  (88). Studies with rats, rabbits, calves, and humans  have shown that the small i n t e s t i n a l disaccharidases are formed long before they are normally required f o r the digest i o n of disaccharides (88,  8,  37).  Lactase and sucrase have  been demonstrated i n two to three month old human foetuses by Auricchio and co-workers (8),  but i n the chick, marked  increases i n a c t i v i t y occurred only during the l a s t few days of embryonic development (88).  This i s the time of elonga-  t i o n and increase i n number of the s m a l l - i n t e s t i n a l  villi.  S i m i l a r l y i n the r a t , ^ - g a l a c t o s i d a s e a c t i v i t y i s present at day eighteen of gestation, the period of rapid d i f f e r e n t i a t i o n of i n t e s t i n a l c e l l s (37).  Siddons (88)  therefore  suggests that the development of enzyme a c t i v i t y r e f l e c t s morphological  changes i n the developing i n t e s t i n e .  The i n -  crease i n lactase a c t i v i t y before b i r t h i n rats and rabbits xvas also correlated with a r i s e i n the l e v e l of lactose i n the blood.  Doell and Kretchmer (37)  s u r g i c a l l y removed the  mammary glands of pregnant rabbits, but were unable to prevent the r i s e i n lactase a c t i v i t y . Koldovsky et a l . (67)  studied extensively the post-  natal changes of @-galactosidase a c t i v i t i e s i n the mouse, rat, guinea pig and rabbit.  They had previously i d e n t i f i e d  two  ^-galactosidases which d i f f e r e d i n t h e i r a f f i n i t y f o r lactose and a r t i f i c i a l substrates, and also in their d i s t r i b u t i o n along the digestive t r a c t .  The r a t i o of these two enzymes  during development changed i n the ileum and jejunum i n the rat, mouse, and rabbit, but a c t i v i t y developed s i m i l a r l y i n both parts of the small intestine in the guinea p i g . et a l . (6l)  Huber  also found a changing relationship i n the c a l f ;  lactase a c t i v i t y in the ileum decreasing twenty times postn a t a l l y while the decrease i n the jejunum w a s only by  10$.  Higher lactase l e v e l s i n the anterior than i n the posterior areas of the small i n t e s t i n e of calves have also been reported by Heilskov (55).  Kidder et a l . (64)  measuring the absorption  of various sugars by the p i g l e t as a means of determining n u t r i t i v e value, found that most of the sugar disappeared i n •the f i r s t h a l f of the small i n t e s t i n e .  Since i t i s established  that disaccharides are mainly s p l i t by enzymes located within or on the surface of the mucosa (75),  the absorption of sugars  might be expected to correspond to mucosal enzyme concentrations  (64). In the four species studied by Koldovsky  (67),  galactosidase a c t i v i t y decreased during postnatal development as expected.  In rats, the decrease was f a i r l y sudden between  the fourteenth and tv/enty-first days.  However, the decrease  was almost n e g l i g i b l e i n guinea pigs, which i s i n agreement with the findings of De Groot and Hoogedoorn (34). (67),  Koldovsky  r e l a t e s the l e v e l of postnatal a c t i v i t y to the degree  of maturity of the animal at b i r t h .  Mice, r a t s ,  and r a b b i t s a r e b o r n i m m a t u r e and w e a n i n g o c c u r s  between t h e second  and t h i r d  -galactosidase a c t i v i t y  decreases.  changes i n l a c t a s e a c t i v i t y f o r e be due and  The  insignificant  i n the guinea p i g might t h e r e -  t o the c o m p a r a t i v e l y lower consumption  thus of l a c t o s e .  relatively  p o s t n a t a l week a t a t i m e when  S i m i l a r l y i n the c a l f ,  an a n i m a l  m a t u r e , Huber ( 6 l ) f o u n d i n t e s t i n a l  h i g h e s t a t one  day o f age  of milk, born  lactase to  and t o d e c r e a s e t h e r e a f t e r .  Lac-  t a s e a c t i v i t i e s i n y o u n g p i g s have a l s o b e e n o b s e r v e d t o c r e a s e w i t h age, mately f i v e one  but a t b i r t h ,  intestinal  54).  Siddons  as t h o s e  ( 8 8 ) , i n 1968,  d i s a c c h a r i d a s e s i n the c h i c k .  The  days o f age,  activities  but the l a c t a s e a c t i v i t y  s i d e r a b l y lower than t h a t of maltase or sucrase. hatched  c h i c k may  con-  The  newly  «X-glycosidases.  both maltose  and  to  be due  t o non-  These enzymes a r e c a p a b l e o f s u c r o s e t o some e x t e n t ( 7 ) .  d o g , l a c t a s e a c t i v i t y was decreased to the l e v e l  of  e x p l a i n the h i g h  m a l t a s e a c t i v i t y , w h i l e t h e h i g h s u c r a s e may  lyzing  to  be l i k e n e d t o t h e weaned mammal i n t h a t  T h i s , a c c o r d i n g t o Siddons, would  specific  of  was  most o f t h e c a r b o h y d r a t e i n i t s d i e t i s i n t h e f o r m starch.  of  studied  m a l t a s e , s u c r a s e , a n d l a c t a s e a l l i n c r e a s e d f r o m one forty-three  de-  t h e a c t i v i t i e s were a p p r o x i -  t i m e s as h i g h p e r u n i t body w e i g h t  o l d calves (55,  day  be  h i g h e s t i n the young a n i m a l  f o u n d i n t h e a d u l t dog by  s i x t y - o n e days o f age.  were l o w e r i n young t h a n  S u c r a s e and m a l t a s e adult animals  (95).  hydro-  In the and  twenty-nine  activities Rubino  et a l .  (84),  reporting on i n t e s t i n a l disaccharidases i n adult  suckling rats, noted that sucrase was  and  absent at b i r t h but  - a c t i v i t y appeared at f i f t e e n or sixteen days and developed rapidly to adult l e v e l s around the twentieth day. was  Maltase  present at very low levels at b i r t h , increasing with  the appearance of sucrase at sixteen days. high at b i r t h and diminished reports had indicated (67)  Lactase was  more gradually than  to adult l e v e l s .  very  previous  Siddons (6*7)  found lactase a c t i v i t i e s to be highest i n the four day old c a l f , decreasing up to forty-three days but changing l i t t l e between forty-three and 1 4 4 days.  A further decrease bet-  ween the 1 1 4 day old calves and the adults was  noted.  Again  the decrease was more marked i n the d i s t a l sections of the small i n t e s t i n e .  Maltase was  very much lower than the l a c -  tase a c t i v i t y and did not change with age.  Sucrase was  detected i n any of the calves or i n the adults. (61)  Huber et a l .  also found that i n t e s t i n a l maltase of the c a l f was i n -  dependent of age.  According  to Siddons ( 8 7 ) ,  reports of other workers i n d i c a t i n g age,  not  conflicting  increasing a c t i v i t y with  could be due to an increase i n the t o t a l i n t e s t i n a l  size.  The absence of sucrase i n the c a l f as well as the adult cow and sheep has been reported by several workers. Calves are unable to u t i l i z e fructose without getting severe diarrhoea  (93).  This i s i n sharp contrast to  results  reported f o r pigs, where high levels of sucrase were present after two weeks of age ten days of age  (41).  (9), and sucrose was  well u t i l i z e d at  •*-y  3.  Adaptation of  Disaccharidases  The observed change i n lactase a c t i v i t y corresponding to a decreased lactose intake at weaning, has l e d many workers to investigate the causal r e l a t i o n s h i p .  Wein-  land (94) i n 1899 reported that lactase remained high even after weaning i f lactose v/as added to the d i e t .  PIiminer  (77) reviewed early experiments on lactase adaptability i n 1906  and concluded that the i n t e s t i n e was incapable of  adapting to feedstuffs.  More recently several workers have  f a i l e d to prevent the decrease i n lactase at weaning by feeding lactose ( 5 ) .  Doell and Kretchmer (37) i n 1962 were  unable to prevent the lactase decrease i n infant rats by i n t r a p e r i t o n e a l administrations  of lactose.  However, the  experiments of Koldovsky (67) have shov/n that the diet can have some e f f e c t on lactase l e v e l s , although i t i s not the only decisive f a c t o r .  Rats were weaned to a standard diet  or to an experimental diet containing either lactose or glucose plus galactose  as the only carbohydrate source.  The  rats fed the lactose d i e t had a higher i n t e s t i n a l lactase a c t i v i t y at nineteen or twenty days of age than the rats fed the glucose galactose mixture.  In both control and experi-  mental animals, there was a f a l l i n a c t i v i t y between the f i f t e e n t h and nineteenth day, but the f a l l v/as l e s s pronounced i n the lactose fed group than i n the group fed glucose plus galactose, which showed similar a c t i v i t y to the normally fed animals.  Koldovsky therefore concluded  that under certain conditions the diet could have an effect on the usually occurring changes i n lactase a c t i v i t y , but that other factors must be involved since the f a l l i n a c t i v i t y also occurs i f the lactose diet i s fed. Siddons (6*7) reported no marked differences i n the carbohydrase a c t i v i t i e s of the i n t e s t i n a l mucosa of four month old calves that had been fed s o l e l y on milk, and  calves  of the same age that had been given a concentrate-hay diet from s i x weeks of  age.  Although Fischer (45)  reported large amounts of  lactase a c t i v i t y i n lactose fed rats, t h i s was  due to an i n -  crease i n weight of the i n t e s t i n a l mucosa; the s p e c i f i c a c t i v i t y did not  increase.  Recent work i n both rat and man  has shown that  dietary carbohydrate can play a role i n the regulation of sucrase and maltase a c t i v i t i e s , and t h i s i s reflected by chan ges i n rates of sucrose hydrolysis i n vivo.  Both sucrose and  1 fructose feeding produced an increase in i n t e s t i n a l sucrase a c t i v i t y within two to f i v e days, a time comparable to that required for crypt c e l l s to migrate up to the v i l l u s t i p (82) This suggested that change i n disaccharidase a c t i v i t i e s  was  due primarily to an effect on the crypt c e l l . Feeding of glucose did not produce an increase i n the enzymes and since sucrose i s hydrolyzed fructose, i t was  suggested that fructose was  to glucose and the only sugar  i n the diet that could increase sucrase or maltase a c t i v i ties  (51).  Reddy et a l . ( B l ) , i n 1968, d i e t a r y carbohydrates conventional r a t s .  s t u d i e d the e f f e c t o f  on c e r t a i n enzymes i n germ-free and  In a l l treatments,  germ-free r a t s  showed h i g h e r d i s a c c h a r i d a s e l e v e l s than c o n v e n t i o n a l r a t s , and  changes i n maltase  and•sucrase  l e v e l s r e s u l t i n g from  f e e d i n g t h e r e s p e c t i v e d i s a c c h a r i d e s , were shown t o occur independently  o f the i n t e s t i n a l m i c r o f l o r a .  Since d i e t alone was not able t o account  f o r the  normal changes seen i n i n t e s t i n a l enzyme a c t i v i t i e s , f a c t o r s were i n v e s t i g a t e d .  C o r t i s o n e caused  other  precocious  development of s u c r a s e i n developing r a t i n t e s t i n e when administered  t o three and nine day o l d r a t s , but i t d i d not  appear t o i n f l u e n c e the a c t i v i t y o f l a c t a s e .  This  suggested  t h a t c o r t i s o n e d i d not a c t s o l e l y by h a s t e n i n g the normal maturation  process. Deren et a l • (36)  found sucrase and maltase trols.  adrenalectomized  a d u l t r a t s and  l e v e l s comparable t o those of con-  S t e r o i d a d m i n i s t r a t i o n d i d not s i g n i f i c a n t l y i n c r e a s e  their activities.  The response  t o sucrose f e e d i n g was  l a r i n both c o n t r o l and adrenalectomized  simi-  r a t s , i n d i c a t i n g the  absence o f s t e r o i d a l c o n t r o l on sucrase and maltase  activity  i n the a d u l t animal. In c o n t r a s t to the experiments of D o e l l and K r e t c h mer (39),  who found no e f f e c t of c o r t i s o n e on l a c t a s e a c t i v i t y ,  Koldovsky  (67)  was a b l e t o demonstrate a d e f i n i t e e f f e c t .  e x p l a i n e d the d i s c r e p a n c y on t h e b a s i s o f e a r l i e r work i n  He  12-  which he showed that adrenalectomy and the application of cortisone both had had very i r r e g u l a r effects on rats aged f i v e to nine days, the approximate age of Doell's r a t s . • I t i s generally accepted now that adrenalectomy  of  the young developing animal r e s u l t s i n the maintenance of enzymatic a c t i v i t y at a l e v e l that corresponds to a younger developmental stage.  In other words, i t prevents the usual  r i s e i n sucrase and maltase, and i n h i b i t s the decrease i n lactase a c t i v i t y  (67).  C.  1.  DIGESTION OF POLYSACCHARIDES  Digestion of Starch Ingested.starch i s composed of two types of glu-  cose polymers,  amylose and amylopectin.  Salivary and pan-  creatic 0<-arnylases attack the i n t e r i o r 1 , 4 - < X g l u c c s i d i c bonds, apparently at random, but have l i t t l e or no specif i c i t y f o r the outermost digested amylose.  l i n k s of native or p a r t i a l l y  Therefore, the end products of amylase  action on amylose are maltose and maltotriose. Maltotetrose, having a single i n t e r i o r l , ^ . - ^ l i n k , i s the smallest substrate which can be rapidly hydrolyzed by ©(-amylase. Amylopectin has a 1 , 6 - c * branching point approximately every twenty-five glucose units along the chain, i n addition to the l , 4 - ° < l i n k e d straight chain of glucose molecules.  Again, the ©t-amylases are capable of hydrolyzing  only the i n t e r i o r 1 , 4 - ° < -glucose bonds, show no s p e c i f i c i t y f o r the 1 , 6 - c x . branching points and possess markedly decreased a c t i v i t y against the 1 , 4 bonds adjacent to these branching points ( 5 1 ) . Therefore, the f i n a l products of amylopectin digestion are maltose, maltotriose and a mixture of l i m i t dextrins.  The smallest <x-dextrin i s a pentasaccharide. Because of the low or absent s p e c i f i c i t y of CK-amy-  lase. f o r the outermost  1 , 4 l i n k s , no glucose i s formed under  physiological conditions of r e l a t i v e l y short exposure of substrate to enzyme in the i n t e s t i n e .  Also, contrary to the  previous view, isomaltose i s not formed at a l l ( 8 6 ) .  The biosynthesis of pancreatic amylase i s under alimentary  and hormonal control (86).  Fasting reduces the  l e v e l s of amylase a c t i v i t y , while animals on a high glucose or starch diet produce much more pancreatic amylase than controls on a protein r i c h diet (74) •  Semenza (8"6) suggests  that the stimulus f o r amylase synthesis i s i n s u l i n , a theory supported by the fact that alloxan-diabetic animals produce l e s s amylase than normal u n t i l treated with i n s u l i n . chain of events i n t h i s case would be:  The  Absorption of  glucose—>hyperglycemia—& i n s u l i n secretion —> increased amylase synthesis (80). The fact that pancreatic amylase i s secreted into the i n t e s t i n a l lumen and that i t s a c t i v i t y i s high i n i n t e s t i n a l f l u i d s has long been accepted as evidence that the enzyme acts on starch while both are free i n the i n t e s t i n a l cavity.  However, Ugolev and co-workers (92) found that pan-  creatic amylase can be adsorbed onto the i n t e s t i n a l mucosal surface and act at t h i s s i t e .  As a r e s u l t of the work of  Dahlqvist and Thompson (29), i t i s known that i n t r i n s i c and adsorbed pancreatic amylase are present i n i n t e s t i n a l mucosal homogenates.  Dahlqvist  (29) separated  two amylases from the  mucosa, one that could not be distinguished from pancreatic amylase and was probably adsorbed amylase, and the other having quite d i f f e r e n t properties.  The l a t t e r  attacked  maltose as well as starch, with glucose as the end product, and was s i m i l a r to an amylase found i n other organs such as the l i v e r and kidney.  The results indicated that although  i n t e s t i n a l mucosa does possess amylase a c t i v i t y , the of d i g e s t i o n probably  bulk  occurs by the a c t i o n of enzyme f r e e (27).  w i t h i n the i n t e s t i n a l f l u i d  I t i s dubious whether  mucosal membrane d i g e s t i o n of s t a r c h i s ever of p h y s i o l o g i c a l importance  (51)..  Amylase a c t i v i t y  i n s a l i v a and  i n the  i s low i n s u c k l i n g animals during the f i r s t days (67).  In the young dog,  week and. then again occurs.  the second and  The  i n c r e a s e s between  percentage i n c r e a s e i n  a c t i v i t y v a r i e s with d i f f e r e n t r e p o r t s and bably  due  to c o n s i d e r a b l e  second  s i x t h week when weaning  rat, activity  t h i r d week.  post-natal  i t decreases about the  at about the  S i m i l a r l y i n the  few  pancreas  t h i s i s pro-  amylase a d a p t a t i o n  to the amount  (95).  of amylose i n the d i e t Cunningham (25)  showed t h a t the newborn p i g l e t  can  d e a l w e l l with d i s s o l v e d s t a r c h , but not with rough s t a r c h . By f i v e days of age,  d i g e s t i o n of e i t h e r was  equally  c i e n t , although a d d i t i o n of amylase d i d not a f f e c t  effi-  the  d i g e s t i o n of rough s t a r c h i n newborn p i g l e t s . De Laey (35) washings of the in  r e p o r t e d t h a t the amylase a c t i v i t y i n  small i n t e s t i n e i n c r e a s e s l i n e a r l y with  the r a t , while the s o - c a l l e d contact  by Ugolev  (92) The  decreases somewhat with a p p l i c a t i o n o f 1 mg  digestion  age  described  age.  of c o r t i s o n e per 1 0 0 g  body weight per day f o r f o u r days i n c r e a s e d p a n c r e a t i c amyl a s e a c t i v i t y i n s u c k l i n g r a t s , but d i d not have an  effect  on r a t s during the weaning p e r i o d . Low amylase a c t i v i t i e s i n most s u c k l i n g mammals are understandable from the p o i n t o f view o f the food sumed d u r i n g t h i s p e r i o d .  con-  Cunningham's experiments (25)  i n d i c a t e t h a t the change i n amylase a c t i v i t y  occurring  d u r i n g weaning might not only be q u a n t i t a t i v e but a l s o qualitative. 2.  Digestion of C e l l u l o s e . The  d i g e s t i b i l i t y o f c e l l u l o s e and h e m i c e l l u l o s e  by nonruminant h e r b i v o r e s attention.  has r e c e i v e d r e l a t i v e l y  little  There are, however, s e v e r a l r e c e n t r e p o r t s i n -  d i c a t i n g that c e l l u l o s e i s p a r t i a l l y animals p o s s e s s i n g  digested by those  ceca and l a r g e i n t e s t i n e s capable o f  b a c t e r i a l fermentation.  Conrad et a l . (20), i n 1958, found  as much as 50$ of the c e l l u l o s e from v a r i o u s sources f e d t o r a t s was d i g e s t e d and the products were absorbed and metabolized.  T h i s was based on t h e o b s e r v a t i o n  t h a t about 50$  o f the r a d i o a c t i v i t y o f the d i e t a r y c e l l u l o s e appeared as . r a d i o a c t i v e carbon d i o x i d e i n the e x p i r e d a i r . t h a t the degradation  Evidence  of c e l l u l o s e i s by i n t e s t i n a l micro-  organisms came from the a d d i t i o n o f s u l f a t h a l i d i n e i n p i g rations  (47).  The s u l f a drug decreased the d i g e s t i b i l i t y o f  c e l l u l o s e from about 50$ to 38"$. pigs  In work with both guinea  (76) and r a b b i t s (60), gum a r a b i c , a h e m i c e l l u l o s e , was  at l e a s t 90$ d i g e s t e d when f e d a t 15$ and 20$ l e v e l s tively.  respec-  However, c e l l u f l o u r was e s s e n t i a l l y undigested  by  guinea p i g s .  The d i g e s t i b i l i t y o f c e l l u l o s e  f i e d or d e - l i g n i f i e d feedstuffs that  f e d t o p i g s was s i m i l a r t o  found i n sheep, i . e . 7^-90$ (23),  feedstuffs  in non-ligni-  whereas i n l i g n i f i e d  c e l l u l o s e d i g e s t i b i l i t y was much lower.  there i s a c o n s i d e r a b l e v a r i a t i o n i n the f i b r e  dige'stibilitie:  r e p o r t e d by d i f f e r e n t workers, and much i n d i v i d u a l especially lar  i n rabbits  weight t o d i g e s t  and p i g s .  variation,  The a b i l i t y o f p i g s o f s i m i -  p u r i f i e d forms o f c e l l u l o s e o f t e n  with a standard d e v i a t i o n little  However,  o f ± 5$.  varies  The l e v e l o f f i b r e has  e f f e c t on i t s d i g e s t i b i l i t y when composing up t o 30$  of the r a t i o n , but i t has a s i g n i f i c a n t e f f e c t on the d i g e s tibility  of other nutrients,  t h e i r . d i g e s t i b i l i t y decreasing  as the f i b r e i n c r e a s e s , the more d i g e s t i b l e  the f i b r e the  l e s s the decrease. To  determine the r o l e o f the cecum i n c e l l u l o s e  breakdown, the d i g e s t i b i l i t y o f v a r i o u s n u t r i e n t s pared i n whole and cecectomizad p i g s eight weeks o l d (71).  v/as com-  t o twenty-eight  Crude f i b r e was,in some cases, more e f f i -  c i e n t l y d i g e s t e d by the i n t a c t p i g , but the l a r g e  intestine  seemed t o be a more important s i t e o f b a c t e r i a l f e r m e n t a t i o n than the cecum.  Cellulose  was p a r t i a l l y d i g e s t e d by r a t s  whether the cecum was present o r - n o t , although cecectomy decreased the d i g e s t i o n  o f c e l l u l o s e from 37$ to 24$ ( 9 6 ) .  In d i g e s t i b i l i t y s t u d i e s w i t h most rodents, coprophagy i s an important c o n s i d e r a t i o n .  The r e c y c l i n g o f  f e c e s permits the remaining unabsorbed products from degraded c e l l u l o s e t o be absorbed i n the upper s e c t i o n s o f  the t r a c t (96).  Rabbits have been reported to excrete both  hard and soft feces, the soft feces being almost completely consumed and being r i c h i n nitrogen, B vitamins and most of the dietary minerals (90).  Yoshida et a l . (9$) reported  that germ-free rabbits did not consume any feces, and he suggested that coprophagy depended on b a c t e r i a l products i n the feces, such as v o l a t i l e f a t t y acids or amines, giving o f f a c h a r a c t e r i s t i c odour.  He also concluded that i n t e s -  t i n a l microbes, even without the enhancing effect of coprophagy, a i d i n the digestion of carbohydrates by the rabbit, and that reingestion of f e c a l carbohydrates, crude f a t and protein might improve the quality of the t o t a l nutrient i n take. The absorbed products of cellulose digestion i n most herbivores appear to be the lower v o l a t i l e f a t t y acids. Elsden and co-workers (43), i n 1946, found large quantities of v o l a t i l e f a t t y acids present i n the cecum and colon of seven ruminant and non-ruminant species, and Barcroft et a l . (11) showed that these acids were absorbed from the organs i n which they were produced.  Alexander (4) found that the  v o l a t i l e f a t t y acid content of the cecum and colon of the rabbit was considerable, while only a trace was found i n the stomach. (57).  A similar situation was reported i n the guinea p i g  Evidence of some microbial a c t i v i t y i n the stomach  was obtained from the production of l a c t i c acid when food homogenate was incubated with gastric contents.  This i n  v i t r o production was prevented by p e n i c i l l i n and  chloram-  phenicol, and also when, g a s t r i c mucosa was used instead of the contents ( 4 ) .  V o l a t i l e f a t t y acid production of a  pony fed hay was only s l i g h t l y less than when the same pony was fed grass and oats; whereas a sheep fed grass produced nearly twice the amount of f a t t y acid than when fed hay alone ( 3 ) .  This might be due to the more soluble  carbohydrate being digested and absorbed i n the ileum of the horse, while i n the sheep, a l l the food was in the rumen.  fermented  Annison et a l . ( 6 ) , i n 1 9 6 7 , found a c e t i c ,  propionic, and butyric acids to be the major end products of fermentation i n the digestive t r a c t of fowl, and the ceaca were the main s i t e s of t h e i r formation.  Johnson and  McBee ( 6 3 ) found the average proportion of these acids i n •the porcupine cecum to be 7 4 $ acetic, 1 2 $ propionic, and 1 4 $ butyric.  88$ of the acids absorbed were from the cecum,  and 1 2 $ from the large i n t e s t i n e .  Similar concentrations  of v o l a t i l e f a t t y acids were found i n the kangaroo fore stomach and the guinea pig cecum ( 5 7 ) . Although l i t t l e information i s available concerning the n u t r i t i o n a l contribution of v o l a t i l e f a t t y acids i n monogastric animals, at least nine d i f f e r e n t species have been reported to contain v o l a t i l e f a t t y acids i n t h e i r cecum ( 9 7 ) .  These are l i s t e d i n Table I I .  In langur mon-  keys, g a s t r i c VFA reportedly contributed energy i n excess of that required f o r maintenance, and i n porcupines the cecal VFA supplied 1  6  $ to 3  3  $ of their requirements (  6  3  Yang et a l . ( 9 7 ) measured the rate of disappearance of VFA from the cecum of rats k i l l e d at various i n t e r v a l s a f t e r feeding, and concluded that the contribution of the acids to the rat's energy metabolism was 4 . 7 $ of the c a l o r i c i n take.  This amounted to 9*4$ of the energy required f o r  maintenance.  Further support i n d i c a t i n g that VFA are  energy sources f o r r a t s , came from the appearance of radioactive carbon dioxide i n the expired a i r when radioactive VFA were placed i n the cecum ( 9 7 ) .  TABLE I I CONCENTRATIONS OF VFA IN THE CECA OF SEVERAL SPECIES OF MONOGASTRIC ANIMALS (YANG, Approximate Age o r Weight  Species  Diet  Acetic  Propionic  me q/g  0.21  17 weeks  Standard l a y e r feed  0.42  Guinea p i g  Adult (?)  S t a n d a r d comm e r c i a l (?)  -0.38 a c e t i c  Hamster  Adult (?)  S t a n d a r d commercial (?) Grass, straw, mangolds  Horse  530 Kg  Pig  9 weeks  Pig  84 Kg  Pig  6 weeks  Porcupine  10 Kg  Rabbit  Adult (?)  Rat  Adult (?)  Rat  487 g  Butyric  References  dry content  Chicken  .  (97))  0.007 equivalent-  —present—  Annison e t a l . (6) (5) Hagen and Robinson  (52)  Hoover e t aL(5#)  0.75  0.17  0.05  Elsden  e t al.(43)  Bran  0.40  0.15  0.04  Elsden  e t al.(43)  B a r l e y , whey, bran Casein, soy, cerelose, cellulose, f a t Natural wild vegetation Bran, o a t s , mangolds Bran, o a t s , hay  0.72  0.51  0.10  F r i e n d e t al.(48)  0.31  0.41  0.04  Hendricks et a l . (56)  0.38  0.06  0.07  0.26  0.03  0.03  Johnson and McBee (63) Elsden et al.(43)  0.37  0.15  0.14  Elsden  0.50  0.07  0.15  Yang e t a l . (96)  Natural grain mix  et- a l . (43)  Ill  A.  MATERIALS  1.  Experimental Animals  GENERAL METHODS  The c h i n c h i l l a used f o r a l l studies were Chinc h i l l a lanigera from the University of B r i t i s h herd.  Columbia  They were obtained from various ranches, but had  been kept under the same conditions of feeding and housing f o r nine months p r i o r to experimentation. 2.  Feeding A l l animals were fed ad l i b , once a day a com-  mercial pelleted c h i n c h i l l a ration (National Feeds, ford, B.C.), and a l f a l f a hay.  Abbots-  The p e l l e t s provided 1 5 $  protein on analysis and 8 2 0 K c a l . per pound of metabolizable energy.  The p e l l e t ingredients are l i s t e d i n Appendix  1.  3.  Housing The c h i n c h i l l a were kept i n 1 " x h galvanized n  wire mesh cages, 1 1 " x 1 5 " x 1 8 " , shavings.  which were suspended  over  A dust bath, Blue Cloud C h i n c h i l l a Dust, was pro-  vided twice weekly, and small wooden blocks f o r the animals to gnaw on were placed i n a l l the cages.  4.  Records A polygamous breeding system was used whereby one  male had access to eight females.  Breeding records were  kept on a l l animals and d a i l y weights from b i r t h to' weaning were recorded.  After weaning at eight weeks, the animals  were weighed weekly.  The average growth of ten animals i s  tabulated and graphed i n Appendix 2.  B.  METHODS  1.  Organ Weights After an animal v/as k i l l e d , the l i v e r , heart,  lungs, spleen, kidneys, adrenal glands, and pancreas, were removed and rinsed free from adhering tissue and blood, blotted gently and weighed.  The weights were recorded as  per cent of l i v e body weight i n Appendix 3. 2.  pH of Digesta The pH of the contents of the stomach, small i n -  t e s t i n e , cecum and large i n t e s t i n e was measured a f t e r death.  immediately  The digesta were rinsed out with d i s t i l l e d  water and the pH was read on a Radiometer, type PHM  & Large and small colons  28.  IV.  EXPERIMENTAL  PART A- - ENZYME STUDIES 1.  Disaccharidases A s t u d y was made o f t h e c h a n g e i n a c t i v i t y o f i n -  testinal  s u c r a s e , m a l t a s e , and l a c t a s e , from b i r t h  to adult-  hood i n t h e c h i n c h i l l a , (a)  Methods and M a t e r i a l s The  g l u c o s e - o x i d a s e method o f D a h l q v i s t  used t o determine g l u c o s e l i b e r a t e d from  ( 3 0 ) was  disaccharides.  This i s a m o d i f i e d procedure i n which t r i s  (hydroxymethyl)  aminomethane ( T r i s ) i s i n c o r p o r a t e d t o i n h i b i t  contaminant  d i s a c c h a r i d a s e s present i n commercial g l u c o s e - o x i d a s e r e agents . (i)  Materials:  S u b s t r a t e s o l u t i o n s - The s u b s t r a t e s u s e d w e r e r e agent grade m a l t o s e , s u c r o s e , and l a c t o s e . of  A  O.O56M s o l u t i o n  e a c h d i s a c c h a r i d e was p r e p a r e d i n O.IM m a l e a t e b u f f e r o f  o p t i m u m pH. pH5«0,  The o p t i m u m pH o f l a c t a s e a c t i v i t y was b e l o w  so a s o d i u m a c e t a t e b u f f e r was u s e d i n s t e a d .  about 1 ml  p e r 1 0 0 ml  Toluene,  s u b s t r a t e s o l u t i o n , was a d d e d a s a  p r e s e r v a t i v e and t h e s o l u t i o n s were t h e n s t o r e d i n t h e r e frigerator.  .  T r i s - g l u c o s e oxidase glucose oxidase reagent,  (TGQ) reagent - A  3  5  commercial  " G l u c o s t a t " , from Vforthington B i o -  chemical Co. was used i n the f o l l o w i n g way.  A 0.5M  Tris-HCl  b u f f e r o f pH7.0 and a detergent s o l u t i o n , c o n s i s t i n g of 10ml of  t r i t o n - X 100 (Sigma Chemical  were prepared.  Co.) i n 40ml o f 95$ ethanol  The contents o f the chromagen and G l u c o s t a t  v i a l s were d i s s o l v e d i n detergent s o l u t i o n and T r i s  buffer  r e s p e c t i v e l y , combined and d i l u t e d w i t h T r i s b u f f e r t o 100ml. The reagent was kept a t 5°C and used w i t h i n f o r t y - e i g h t of  hours  i t s preparation. Standard glucose s o l u t i o n - A 10$ s o l u t i o n o f g l u -  cose i n d i s t i l l e d v/ater was prepared, and 0.27$ benzoic a c i d was added as a p r e s e r v a t i v e .  A standard curve was prepared  u s i n g 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5 rnl o f t h e g l u c o s e solution.  These tubes  contained 0, 10, 20, 30, 40 and 50 mg  r e s p e c t i v e l y of glucose. ( i i ) Methods: P r e p a r a t i o n o f homogenates - The animals were killed  w i t h ether and the stomach, s m a l l i n t e s t i n e , cecum and  l a r g e i n t e s t i n e were immediately  cut out and kept i n i c e .  The d i g e s t a were r i n s e d out v/ith d i s t i l l e d water and saved for  pH d e t e r m i n a t i o n s .  The small i n t e s t i n e was then  again w i t h i c e - c o l d p h y s i o l o g i c a l three equal l e n g t h s .  s a l i n e , and d i v i d e d  rinsed into  The f a t and mesentery were removed from  the o u t s i d e and the i n t e s t i n e was weighed and homogenized  with p u r i f i e d  sand u s i n g a mortar and  pestle.  The  disac-  c h a r i d a s e s were e x t r a c t e d with f o u r volumbes of 0.15M and  NaCl  c e n t r i f u g e d f o r ten minutes a t 4,000 r.p.m. i n a  S o r v a l l RC2-B c e n t r i f u g e . assayed.  The  Homogenates from the  t e s t i n e were prepared  supernatant  was  froz.en u n t i l  stomach, cecum and  large i n -  i n a s i m i l a r manner.  To determine a c t i v i t y i n the  contents  o f the  d i g e s t i v e t r a c t , as much as p o s s i b l e of the d i g e s t a removed without of s a l i n e was  d i s t u r b i n g the mucosa, and  added.  Homogenation and  was  an equal volume  c e n t r i f u g a t i o n were  as f o r the t i s s u e p r e p a r a t i o n s . Enzyme assay  - 0.1ml  of the d i l u t e d enzyme s o l u t i o n  p l u s an equal volume of the a p p r o p r i a t e were i n c u b a t e d  i n a water bath at 37°C f o r one  drop of t o l u e n e was  added as a p r e s e r v a t i v e .  t i o n , 0.3ml of d i s t i l l e d water was i n b o i l i n g water f o r two  again  f o r one  i n a S p e c t r o n i c 20 mu,  The l y z e d was  of g l u c o s e ,  hour a t 37°C.  (Bausch and  a g a i n s t a reagent  A small  After incuba-  added and the tube immersed  mixed with'3.0ml of the TG0  incubated  hour.  minutes to stop the r e a c t i o n .  F o r the d e t e r m i n a t i o n t i o n was  substrate s o l u t i o n  0.5ml of the s o l u -  reagent. The  The  tube  c o l o u r was  was  measured  Lomb) spectrophotometer a t  420  blank.  d i s a c c h a r i d a s e a c t i v i t y o f the p r e p a r a t i o n ana-  obtained  by the f o l l o w i n g formula  (Dahlqvist, I 9 6 4 ) .  Disaccharidase a c t i v i t y =• a x d  units/rnl  n x 540  1  where a = )xg glucose l i b e r a t e d i n sixty minutes; d = d i l u t i o n f a c t o r of the enzyme solution used f o r mixing with the substrate; n = number of glucose molecules per molecule of disaccharide (for maltose, n-2; unit d e f i n i t i o n :  f o r sucrose and lactose, n = 1 ) ; 1 unit'of disaccharidase hydro-  lyses 1 ^irnole disaccharide per minute under the incubation conditions used. To evaluate the a c t i v i t y of the i n t e s t i n a l homogenates, the disaccharidase units were then calculated per g protein. Protein determination  - Protein was  determined  using the method of Lowry et a l . ( 7 2 ) . The standard was  curve  prepared using bovine serum albumen. Optimum pH determination  a c t i v i t y of each enzyme was pH 3.6 to pH 9.0.  - The pH f o r optimum  determined over the range of  The buffers used were:  pH 3»6 - 4.8 sodium acetate, pH 5.0 - 7.0 t r i s maleate, pH 8.0 - 9.0 sodium b a r b i t a l .  (b)  Results and Discussion In preliminary experiments, i t was found that homo-  genates of the small i n t e s t i n e from adult c h i n c h i l l a r e a d i l y hydrolyzed maltose and sucrose, and hydrolyzed lactose slowly. Homogenates of the walls of the stomach, cecum and large i n testine did not have any disaccharidase a c t i v i t y , and neither did the stomach contents.  This was  as expected, since the  disaccharidases are known to be secreted from the crypts of Lieberkuhn  which are found only i n the small i n t e s t i n a l  mucosa (53).  However, digesta from the small i n t e s t i n e con-  tained very active maltase and sucrase, as i s shown i n Table III.  This high a c t i v i t y i n the i n t e s t i n a l contents does not  coincide with results reported i n other animals (86) nor with the presently held theories concerning the s i t e of d i s a c c h a r i dase a c t i v i t y (75).  The enzymes act i n t r a c e l l u l a r l y ,  and  there i s l i t t l e d i f f u s i o n into the lumen of the small i n t e s tine.  The preparative technique  of gently squeezing out the  contents could have removed some of the mucosa as well, which v/ould increase the apparent a c t i v i t y of the  contents.  Maltase and sucrase a c t i v i t y i n the cecal contents was  3$.5$ and 10.5$  respectively of that i n the small i n t e s -  t i n a l contents, and i n the large intestine a c t i v i t y of maltase and sucrase was  57.2  and 3.5$.  Although present i n low levels  in the small i n t e s t i n a l mucosa of adult animals, lactase could not be detected i n contents of the small i n t e s t i n e , cecum or large i n t e s t i n e .  3 9  TABLE I I I A c t i v i t y o f Maltase, Sucrase and L a c t a s e in  the Alimentary T r a c t o f the C h i n c h i l l a  Enzyme a c t i v i t y t r a c t assayed &  „ S.l3.M. f o r 3 a n ima Is Maltase  Small wall to  -middle -distal  to -p  Small i n t e s t i n a l contents Cecal  c o o  Lactase  • Sucrase  intestinal  -proximal CD  (units/mg p r o t e i n )  contents  Large i n t e s t i n a l contents  3  5  . 77.27  . 5 .4 7  5 _1 3 . 9 1  D  - 17.3°  22.02 _ 2.6D 127-91 - 15.5 49.25  - 6 . 7  73.23  - 10.4  b  - 1.7  27.40 _ 9 . 5  a  01  6  1  39.95 - 14.2  3  .  9 1.1°" 9 _  .  5 . 2 8 _ 1.6*  7 . 1 6 _ 0.81  4.17 - 4 . 2  a  5 . 1 5 _ 1.7  1  b  a  — —  3 3 . 84 _ a  *  No a c t i v i t y o f maltase, sucrase or l a c t a s e was found i n the stomach, c e c a l o r l a r g e i n t e s t i n a l w a l l s , o r i n t h e stomach c o n t e n t s .  ^  Means f o r each enzyme w i t h i n r e g i o n or contents having common s u p e r s c r i p t s a r e not s i g n i f i c a n t l y d i f f e r e n t (P<.05).  40  Since starch and simple sugar fermenting organisms have been found i n the cecum of the horse (62), an animal similar i n i t s digestive anatomy to the c h i n c h i l l a , and also since the magnitude of.disaccharidase a c t i v i t y attributed to the small i n t e s t i n a l contents has been questioned, i t seemed possible that the maltase a c t i v i t y i n the cecum and large i n testine might be of b a c t e r i a l o r i g i n , and not necessarily due to indigenous enzymes washed through with digesta from the small i n t e s t i n e . Having found that the disaccharidases exerted most of t h e i r a c t i v i t y i n the small i n t e s t i n e , the d i s t r i b u t i o n of the enzymes was noted i n the proximal, middle and d i s t a l sections of the small i n t e s t i n a l wall.  These areas would roughly  correspond to the duodenum and upper jejunum, the lower j e j u num and upper ileum, and the lower ileum.  Three adult animals  were used and the results i n Table I I I indicate a c t i v i t y of a l l three enzymes i s highest i n the middle section, i . e . the lower jejunum and upper ileum.  A non-uniform d i s t r i b u t i o n of  disaccharidases was observed i n other animals by Malhotra and P h i l l i p (73)• In the dog, guinea pig and pig, the enzymes were concentrated i n the jejunum and to some extent i n the upper ileum, while the lower ileum always had less than 15$ of the enzyme a c t i v i t y .  A c t i v i t i e s of lactase, sucrase, and  maltase i n dogs, studied by Welsh et a l . (96), were highest i n the proximal and middle sections of the small i n t e s t i n e .  As the disaccharidases exert t h e i r a c t i v i t y i n t r a c e l l u l a r l y (75),  i t has been suggested by Siddons (8$) that the l o c a -  tion of optimum a c t i v i t y along the small i n t e s t i n e may  re-  f l e c t the s i t e of absorption of the disaccharides. The average pH of the i n t e s t i n a l contents of animals of a l l ages was  7.1,  a higher pH than that of  optimum a c t i v i t y of the disaccharidases studied.  This i s  not too surprising since i t i s known that the optimum pH of a p a r t i c u l a r enzyme i n v i t r o i s not necessarily the same pH at which i t functions p h y s i o l o g i c a l l y .  The pH did not  change s i g n i f i c a n t l y with age i n the stomach, small i n t e s t i n e , cecum or large i n t e s t i n e , and was  3 * 4 , 7*1,  7«9> and  7.9 respectively. The pH optima f o r sucrase, maltase and lactase i n homogenates of the small i n t e s t i n a l wall were 6.4> 6 . 0 , and 4.6 respectively.  The a c t i v i t y of each enzyme r e l a t i v e to  the maximum a c t i v i t y at 100$ has been plotted versus pH i n Figure 3 .  The values f o r sucrase and maltase are i n agree-  ment with the range found i n other animals, but the lactase pH optimum i s comparatively  low.  In the dog, sucrase  and  maltase are optimum at pH 6 . 0 ( 9 6 ) , i n pigs, pH 6.5 ( 2 6 ) , and i n man,  pH 6 . 0 ( 7 ) .  zymes i s pH 5-3 ( 3 4 ) .  In rats the optimum f o r both enThe optimum pH f o r lactase has been  reported from pH 5 . 0 in dogs (96) to pH 6 . 0 i n pigs and rats (26).  The 4 . 6 value obtained v/ith c h i n c h i l l a i s therefore  lower than most others reported i n the l i t e r a t u r e , although Siddons, i n 1969, i n the chick.  (88)  found an i n t e s t i n a l lactase of pH 3*6  Of the 3 @-galactosidases separated by Gray  and Santiago (49),  one had a pH optimum at 4.5,  found only i n lysosomes.  but i t was  I t would therefore have a dubious  role i n the digestion of dietary lactose, since i n t a c t disaccharide i s considered incapable of quantitively entering the absorptive c e l l , a requirement i f i t i s to come i n contact with lysosomal enzymes.  Gray suggested the enzyme of  importance i n the mucosal digestion of dietary lactose had a pH optimum of 6.0.  The i n v i t r o a c t i v i t y at pH 4.6  found  i n the c h i n c h i l l a would appear to be i n d i c a t i v e of a lack of the pH 6.0  enzyme i n the adult animal.  However, assays of  i n t e s t i n a l homogenates of animals two hours, one week and -two weeks of age also resulted i n an active lactase with a pH optimum at 4.6,  i n d i c a t i n g lack of the pH 6.0  the young animal as well.  enzyme i n  Since lactose was being hydro-  lyzed by small i n t e s t i n a l homogenates of the young c h i n c h i l l i t seems reasonable to conclude that the lactase of physiol o g i c a l importance i n t h i s animal does have optimum a c t i v i t y at pH  4.6. Changes i n lactase, sucrase, and maltase l e v e l s  were observed from b i r t h to maturity i n the c h i n c h i l l a , animals nine months and older being c l a s s i f i e d as mature. The results are plotted i n Figure 4.  Sucrase was absent at  b i r t h and remained n e g l i g i b l e u n t i l two weeks of age, at  x o o  4.0  0 FIGURE 3  -  5.0  6.0 PH  7.0  x Lactase o Maltase o Sucrase  8.0  Optimum pH of Intestinal Lactase, Sucrase and Maltase In Chinchilla  9.0 the  which time i t i n c r e a s e d started  to increase  weeks, r e a c h i n g weeks o f a g e .  low  fairly  Lactase  was  The  and i n c r e a s e d  there teen  i n the adult  'in  days, t h e r e  size  five  fold  p o r t i o n of the gut.  weeks o f a g e .  this  chilla  as  being  Also  at f i v e  a considerable  f e e d was f o u n d  but sucrase  does i n c r e a s e mains f a i r l y  was  At  days,  and s a c c u l a -  The cecum i s c o m p a r a b l e chinchilla  weeks, t h e s t o m a c h  contents  over the r e l a -  and c o i n c i d i n g w i t h time.  Young  a t two o r t h r e e  i n t h e stomach i n s m a l l M a l t a s e was  negligible.  by  and t h e r e m a i n d e r  increase  at this  were o b s e r v e d t o e a t p e l l e t s  time,  nature  and by f o u r -  i n size  90$ green f e e d  e a r l y a s one v/eek a f t e r b i r t h .  this  t h e cecum.  to that o f the a d u l t  i n lactase activity  and g r e e n  i n the  s u c h ; by s e v e n  amounts i n a two week o l d a n i m a l ,  the.decrease  age  especially  i s a marked i n c r e a s e  were composed o f a t l e a s t  tive  are r e f l e c t e d  i n the large i n t e s t i n e ;  and c o m p l e x i t y  was m i l k ,  weeks t o t h e  animal.  t h e cecum i s n o n - e x i s t e n t ' a s  in this  at three  i n t h e s t o m a c h , and c h a n g e s i n t h e r e l a t i v e  i s a fused  tions  t o a peak o f a c t i v i t y a t  sharply  s i z e s o f the d i g e s t i v e organs, birth,  five  between t w e l v e and s i x t e e n  changes i n a c t i v i t y  of the digesta  and  and  t h e most a c t i v e o f t h e t h r e e  I t then dropped  l e v e l s found  adult levels  r a p i d l y between t h r e e  adult levels  enzymes a t b i r t h , two weeks.  s l o w l y , and r e a c h e d  chin-  days o f amounts  present  Although  at  sucrase  between s i x and t w e l v e weeks o f a g e , i t r e low when compared t o m a l t a s e ,  even i n a d u l t  FIGURE 4 - I n t e s t i n a l Lactase, Sucrase  and  Maltase A c t i v i t y as a Function of Age i n the C h i n c h i l l a .  46  Specific activity  animals.  Since the  enzyme i s n o t  present  i n l a r g e amounts  i n t h e a d u l t c h i n c h i l l a w h i l e t h e d i e t o f p e l l e t s and c o n t a i n s c o n s i d e r a b l e sucrose, i t would suggest bial  fermentation  tine.  I t was  of sucrose  v e r i f i e d i n the  that active fermentation  sugars,  as w e l l  of indigenous 2.  sucrase  micro-  large  intes-  study  does t a k e p l a c e i n t h e s e  areas  as  m e n t e d i n t h e r u m e n , and  cecum and  some  second p a r t o f t h i s  the p r o d u c t i o n of v o l a t i l e simple  i n the  hay  fatty  acids.  A l s o , i n the  cow,  complex p o l y s a c c h a r i d e s , are Huber ( 6 1 ) has  r e p o r t e d an  with  fer-  absence  i n the a d u l t i n t e s t i n e of these  animals.  Amylase The oc-amylase a c t i v i t y  t i n e was  measured a t d i f f e r e n t  of the  stages  p a n c r e a s and  intes-  of growth i n the  chin-  chilla. (a)  M e t h o d s and  Materials  A c t i v i t y was  m e a s u r e d by  colorimetric  of the r e d u c i n g groups produced from s t a r c h . c e d u r e was 46)  determination  The  assay  a m o d i f i c a t i o n o f s e v e r a l r e p o r t e d methods 3,5-dinitrosalicylate  using the  reagent  o f Sumner  pro(14, (89).  (i) Materials: A 1%  solution  o f s o l u b l e s t a r c h ( J . T.  a g e n t ) was  made i n 0.04M T r i s m a l e a t e b u f f e r , pH  s t a r c h was  d i s s o l v e d by An  prepared  alkaline  b o i l i n g f o r ten  Baker, r e 6.9*  minutes.  s o l u t i o n of d i n i t r o s a l i c y l i c  a c c o r d i n g t o F i s c h e r and  Stein  The  (46).  acid  was  ( i i ) Methods: Preparation  of.homogenates - The animals were  euthanized with ether and the entire digestive tract pancreas were removed. nine volumes 0.01M  homogenized with  calcium chloride i n a mortar and  and the homogenate was minutes.  The pancreas was  and  pestle,  centrifuged at 15,000 r.p.m. f o r ten  The uppermost clear layer of the supernatant  was  frozen and assayed f o r amylase within forty-eight hours. The  contents of the stomach, small i n t e s t i n e ,  cecum and large i n t e s t i n e were each well mixed with one volume of 0.15M  sodium chloride, and centrifuged at 4,000  r.p.m. for ten minutes.  The  stomach, cecal and large i n -  t e s t i n a l walls were rinsed free of any remaining digesta and homogenized with four volumes 0.15M  sodium chloride.  They were centrifuged at 4,000 r.p.m. for ten minutes and the supernatants were assayed. was  The small i n t e s t i n a l wall  i n i t i a l l y prepared in the same way,  but the u n l i k e l y  high values f o r amylase a c t i v i t y suggested contamination with pancreatic  amylase.  Therefore, before homogenizing  the.small i n t e s t i n e , i t was  rinsed well with a cold Ifo  starch solution followed by 0.15M  sodium chloride to remove  as much as possible of any intraluminal amylase. Enzyme assay -1.0 ml of starch and were incubated at 37°G for f i f t e e n minutes.  1.0 ml of enzyme The  enzyme  diluted so as not to cause the l i b e r a t i o n of more than  was1.5  mg of maltose per ml under the above conditions.  This  implied a d i l u t i o n of 1:200 to 1:500 f o r the pancreatichomogenate, and 1:20 f o r the homogenates of digesta and i n t e s t i n a l wall.  The reaction was stopped by the addition  of 2ml d i n i t r o s a l i c y l a t e f o r f i v e minutes.  reagent, and the tubes were boiled,  They were then diluted s i x times and the  concentration of 3-amino, 5 - n i t r o s a l i c y l i c acid formed was determined  on a Spectronic 20 at 570mu.  was prepared using maltose  A standard curve  (range 0.1 - 1.5rng/ml).  One unit of amylase a c t i v i t y was defined as that amount of enzyme releasing reducing groups corresponding to lmg of maltose per minute at 37°G.  The s p e c i f i c a c t i v i t y i s  expressed as units per rng protein. Protein determination - Protein v/as again determined by the method of Lowry et a l . (72) using bovine serum albumen as standard. (b)  Results and Discussion Pancreatic amylase v/as n e g l i g i b l e at b i r t h , but  increased f a i r l y rapidly with age and remained at a r e l a t i v e l y constant l e v e l a f t e r twelve weeks (Figure 7).  L'ucosal amy-  lase v/as present i n very low l e v e l s , but considerable a c t i v i t y was found i n i n t e s t i n a l contents.  This i s i n agreement with  the intraluminal breakdown of starch.  When the i n t e s t i n e was  prepared f o r assay by gently squeezing out the contents and  r i n s i n g with physiological saline, considerable a c t i v i t y was found i n the i n t e s t i n a l wall.  Since i t has been  demonstrated  that pancreatic amylase although active on starch i n the lumen i t s e l f , also adheres to the i n t e s t i n a l c e l l wall, i t was thought that much of the a c t i v i t y attributed to the mucosa of the intestine was probably pancreatic amylase.  To  v e r i f y t h i s and also to see i f the i n t e s t i n e i t s e l f was a s i t e of amylase production, the intestine was rinsed several times with a 1 $ starch solution and then again with physiol o g i c a l saline before i t was homogenized and assayed. resulted i n a marked decrease i n amylase a c t i v i t y .  This  At the  present time, the importance of t h i s mucosal amylase i n the breakdown of dietary starch i s not known ( 2 9 ) . The a c t i v i t y recovered from the pancreas was ten to twenty times greater than that of the i n t e s t i n a l contents.  Homogenates of the  stomach, cecal, and large i n t e s t i n a l walls had no amylase a c t i v i t y , but both the cecal and large i n t e s t i n a l contents had almost 5 0 $ of the a c t i v i t y of the contents of the small i n t e s t i n e (Table IV).  This suggested a b a c t e r i a l amylase i n  these areas, although i t could also be pancreatic amylase remaining i n the digesta.  Starch fermenting organisms have  been found i n the feces of horses and pigs, and i n the cecum of the horse ( 6 2 ) .  TABLE IV  Amylase A c t i v i t y i n the Chinchilla  Homogenate assayed  Specific  14.59± 3.15  Pancreas  0.94 - 0.01  Small i n t e s t i n a l contents Cecal contents  .  Large i n t e s t i n a l contents *Means it 3.E.M. f o r three adult Specific  activity  0.52 ± 0.05 0.57 i0.11 chinchilla.  a c t i v i t y = units/rug protein  Age in weeks  FIGURE 5 - Pancreatic Amylase as a Function of Age in the  Chinchilla  PART B - DIGESTIBILITY STUDIES 1.  Time of Passage and Site of Cellulose Digestion This study was conducted f i r s t , to determine the  time of passage of feedstuffs through the digestive tract of the c h i n c h i l l a ; and second, to determine the c e l l u l o s e digest i b i l i t y of a commercial c h i n c h i l l a p e l l e t and the dominant s i t e s of cellulose digestion, i . e . the stomach, cecum or large i n t e s t i n e , (a)  Methods and Materials: ( i ) Time of passage - Feed was removed, from four  adult female c h i n c h i l l a f o r twenty-four hours before the start of the experiment.  They were then given the basal  pelleted ration to which 2% chromic oxide had been added. After twenty-four hours, the intake of marked feed was recorded and the regular ration of p e l l e t s and hay was resumed. Fecal samples were collected at i n t e r v a l s of 1 8 , 24, 3 0 . 5 , 3 5 , 4 3 , and 56 hours after feeding and were analyzed f o r chromic oxide by the method of Schurch et a l . ( 8 5 ) . ( i i ) Cellulose digestion - The same four adult females that were used for the time of passage determination were used again f o r t h i s experiment.  They were fed the p e l -  l e t s " containing 2$ chromic oxide f o r a two-week preliminary period.  No hay was fed and water was f r e e l y a v a i l a b l e .  Daily feed intake was recorded and a representative of feces was c o l l e c t e d d a i l y f o r s i x days.  sample  Pooled f e c a l  samples from each animal were then assayed f o r cellulose by the method of Crampton and Maynard (21)  and chromic oxide  by the method of Schiirch et a l . ( 8 5 ) . At the end of the c o l l e c t i o n period, the animals were k i l l e d with ether and the contents of the stomach, cecum, and large i n t e s t i n e were removed quantitatively and weighed.  Saturated mercuric chloride was added to prevent  further microbial a c t i v i t y and sodium hydroxide prevent v o l a t i l i z a t i o n of the short chain acids.  (l.ON)  to  Distilled  water was added to double the o r i g i n a l volume of digesta and the contents were centrifuged at 7 , 0 0 0 r.p.m. f o r twenty minutes.  Total v o l a t i l e f a t t y acids were measured i n the  supernatants and c e l l u l o s e and chromic oxide were determined i n the dried p r e c i p i t a t e s .  For the determination of v o l a t i l  f a t t y acids, 5ml of the supernatant plus 2ml of ION  sulfuric  acid were steam d i s t i l l e d and t i t r a t e d against standardized sodium hydroxide to the phenolphthalein endpoint. By comparing the r a t i o s of cellulose to chromic oxide in the feed, stomach, cecum, large i n t e s t i n e , and fece the c e l l u l o s e d i g e s t i b i l i t i e s i n the various organs were determined. (b)  Results and Discussion (1) Time of passage - Time of passage of feedstuff  through the digestive t r a c t i s related to the a b i l i t y of the animal to u t i l i z e carbohydrates, microbial breakdown of corn-  plex polysaccharides taking longer than i n t e s t i n a l enzyme breakdown of those more readily a v a i l a b l e .  Since the chin-  c h i l l a has a large functioning cecum and she can digest c e l l u l o s e (69),  i t was  expected to have a r e l a t i v e l y long  time of passage. The results are indicated i n Table V and Figure 6.  Chromic oxide was f i r s t noted i n the feces eighteen  hours a f t e r feeding the marked feed, and trace amounts were found at f i f t y - f i v e hours. expressed was  The bulk of the chromic oxide,  as a per cent of the total'chromic oxide ingested,  excreted t h i r t y to f o r t y - f i v e hours after feeding with  an average time of t h i r t y - f i v e hours. The early appearance of chromic oxide i n the feces was  probably due to the animal's having been starved f o r a  day p r i o r to the feeding of the marked ration.  The above  average feed consumption at t h i s time could have caused an i n i t i a l increase i n the rate of passage.  I t was  necessary  to starve the animals to guarantee they would a l l s t a r t eating as soon as the marked feed was  put before them.  Chin-  c h i l l a are b a s i c a l l y nocturnal, n i b b l i n g at t h e i r feed i n t e r m i t t e n t l y during the day but eating mainly i n the early evening and at night.  Also, they defecate l i t t l e or not at  a l l i n the day time which made i n i t i a l attempts to v i s u a l l y record the f i r s t appearance of marked feces unsuccessful. As expected, the time of passage in the c h i n c h i l l a i s comparable to that of the horse and guinea pig, both  these animals also possessing large ceca and the a b i l i t y to digest c e l l u l o s e .  Vander Koot et al'. (93) found the rate  of passage i n horses on a chopped a l f a l f a hay diet to be greatest at t h i r t y - s i x hours and forty-eight hours, with 83/0 of the chromic oxide fed being excreted after the f i r s t forty-eight hours.  Individual animal variation was quite  large and they therefore recommended a c o l l e c t i o n period of at least four days i n digestion t r i a l s with horses. From the results obtained i n t h i s study with chinc h i l l a , i t was  concluded that the c o l l e c t i o n period i n the  following d i g e s t i b i l i t y t r i a l s should also be at l e a s t four days.  A somewhat longer period would probably be necessary  when hay was included i n the r a t i o n . Any further comparisons  of the time of jjassage i n  c h i n c h i l l a with that of other animals i s complicated by d i f ferences i n the rations fed, the age of the animals used, the feeding l e v e l s applied and the experimental technique. ( i i ) Site of cellulose digestion - The per cent cellulose digestion i n the stomach, cecum and large i n t e s t i n e and the v o l a t i l e fatty acids i n these areas are reported i n Table VI.  The results indicate that most c e l l u l o s  digestion i n the c h i n c h i l l a takes place i n the cecum and large i n t e s t i n e , while the t o t a l c e l l u l o s e d i g e s t i b i l i t y of a commercial 53.9$.  c h i n c h i l l a p e l l e t containing 18.7$ cellulose i s  Evidence from studies with other monogastric  herbi-  vores indicates that the products of cellulose fermentation  TABLE V Time of Passage of a Pelleted Feed Through The Digestive Tract of the C h i n c h i l l a  24 hr. feed Animal No. Consumption (g) 1  2 1  Cr 0  3  Cr 0  3  Cr 0  3  Cr 0  3  Cr 0  3  Cr 0  3  2  2  23  2  2  16  Time after feeding (hrs) 18 3 0 . 5 3 5 4  2  2  (mg) % (mg)  9  2 6  1/43  4.13  15  2  2 6  1 6  4.13 2 . 5 4 6  35  2  4  0 0 0  2.17  3.77  5.07  3-48  0  (mg)  0  16  21  12  0  fo  0  3.33  4.38  2.50  0  %  3  5  10  20  30  40  50  Time after feeding (hours)  FIGURE 6  _  Time of Passage of a Pelleted Feed through the Chinchilla Digestive T r a c t  60  are v o l a t i l e organic acids (43)•  The r e l a t i v e l y high vola-  t i l e f a t t y acid l e v e l s i n the same areas where c e l l u l o s e digestion occurred were therefore to be expected, and support the observation that the cecum and large i n t e s t i n e are the main s i t e s of c e l l u l o s e breakdown. The v a l i d i t y of the values f o r cellulose d i g e s t i b i l i t y found i n the stomach i s doubtful.  Not only i s there  considerable v a r i a t i o n between animals, but also the low pH of the stomach contents i s well below the optimum f o r surv i v a l of c e l l u l o s e fermenting  bacteria ( 6 2 ) .  The apparent  digestion of cellulose as well as the presence of v o l a t i l e f a t t y acids i n the stomach could have been due to coprophagy. C h i n c h i l l a practise coprophagy to a considerable extent, as do most rodents, and measurable amounts of v o l a t i l e f a t t y acids have been found i n the feces.  Germ-free rabbits do  not consume any feces, and i t has therefore been suggested that coprophagy depends on b a c t e r i a l products  such as vola-  t i l e f a t t y acids giving o f f a c h a r a c t e r i s t i c odour i n the feces.  The practise of coprophagy i s important  i n allowing  the breakdown and absorption of some products of cellulose digestion which would otherwise  be wasted.  The c h i n c h i l l a  large i n t e s t i n e has a greater volume than does the cecum and yet contains less t o t a l v o l a t i l e f a t t y acid.  This could be  due to an increased absorption of acids i n t h i s area.  TABLE VI Cellulose D i g e s t i b i l i t y and V o l a t i l e Fatty Acid Production i n the Alimentary Tract of C h i n c h i l l a Fed a Commercial Chinchilla Pellet Figures f o r cellulose are expressed as per cellulose digestion,  Animal No.  2 4  2 6  1 1  and VFA i s i n t o t a l  Stomach cellulose  8.03  VFA  0 . 0 1 2  cellulose VFA  VFA  milli-equivalents.  Large Intestine  4 8 . 6  1 7 . 5 0 . 0 2 4  Total**  4 8 . 8  0.272  5 9 . 1  0 . 1 5 3  4 0 . 0 0 . 0 0 7  cellulose  Cecum  cent of the t o t a l  4 3 . 5  5 3 . 5  0 . 2 9 0  0 . 3 5 3  4 5 . 9  4 2 . 5  4 9 . 1  0 . 2 5 0  0 . 3 2 3  Mean _ S.E.M. Z 6.1_0.83 5 3 . 9 - 1 . 6 7  cellulose 8 . 5 2 - 2 . 1 2  4 3 - 7 - 1 . 4 7  VFA  0 . 3 1 6 - . 0 1 4 0 . 2 3 1 - . 0 2 4  0  ^ c e l l u l o s e digestion  .0 1 4 - . 0 0 3  k  = cellulose cone, i n feces x CrgO^ i n feed x cellulose cone, i n feed C 2°3 i" r  i  n  e c e s  2.  Production of V o l a t i l e Fatty Acids This experiment was conducted to extend the results  obtained i n the previous t r i a l , and also to determine the effect on d i g e s t i b i l i t y of adding a l f a l f a hay to the ration. Having found that v o l a t i l e f a t t y acids are present i n s i g n i f i c a n t amounts, i t v/as decided to determine the r e l a t i v e d i s t r i b u t i o n of the major acids throughout the c h i n c h i l l a digestive t r a c t , (a) Methods and Materials: Four adult animals were placed i n metabolism cages f o r a ten day adjustment period.  They v/ere fed a l f a l f a hay  and c h i n c h i l l a p e l l e t s ad libitum.  They v/ere. then fed pel-  l e t s only f o r a preliminary period of seven days and a c o l l e c tion period of s i x days. recorded d a i l y .  Fecal output and feed intake was  Total dry matter d i g e s t i b i l i t y and cellulose  d i g e s t i b i l i t y v/ere then determined. Ad libitum feeding of hay and p e l l e t s was resumed f o r a second preliminary period of seven days, after which daily consumption of hay and p e l l e t s was recorded and t o t a l feces collected.  The animals were k i l l e d after the six-day  c o l l e c t i o n period and the contents of the stomach, cecum, large i n t e s t i n e , and rectum were removed and analysed as before f o r cellulose and t o t a l v o l a t i l e f a t t y acids.  The d i s -  t i l l a t e from the t o t a l VFA determination was made alkaline with l.ON  NaOH and dried over low heat.  The VFA s a l t s were  removed and p u r i f i e d by the method of Ross ( 8 3 ) in preparation f o r gas chromatographic  analysis.  A Hicrotec (Model  2 , 0 0 0 MF) gas chromatograph f i t t e d with a hydrogen flame ionization detector was used.  The columns used and the  operation of the machine are described by Ranta ( 7 9 ) '  The  peak areas and t h e i r r e l a t i o n to the concentration of the i n d i v i d u a l acids were analyzed by the method of Baumgardt (12). (b)  Results and Discussion Again, the bulk of cellulose digestion, as r e f l e c t e d  by the v o l a t i l e f a t t y acid content, takes place i n the cecum and large i n t e s t i n e (Table VII).  Acetic, propionic and  buty-  r i c acids expressed per gram of dry matter are higher i n the cecum, although the large intestine has been demonstrated by other workers to be of equal importance i n the digestion of cellulose.  Yang et a l . ( 9 7 ) found that rats could digest  cellulose whether the cecum was present or not, although cecectomy decreased the cellulose digestion from 3 7 $ to 25$. Considerable absorption of v o l a t i l e f a t t y acid took place i n the large i n t e s t i n e as was indicated by a marked decrease i n concentration of a l l the acids i n the rectum as compared with those i n the cecum.  Absorption was also appa-  rent i n the rectum, there being very low levels of VFA excreted i n the feces.  However, the f e c a l values might be  s l i g h t l y low,- since some VFA w i l l have been v o l a t i l i z e d  be-  fore the feces v/ere analyzed.  Also, the "rectum" i n t h i s  experiment consisted of the pelvic colon as well as the true rectum, so that part of the VFA  contributed to t h i s  area should r e a l l y be included with that of the large i n testine. There was no measurable t i t r a t a b l e a c i d i t y i n the stomach, ( t i t r a t i o n against 0.0243N NaOH), although there were trace amounts of acids present which showed up on the gas chromatogram and are included i n Table VII. The apparent dry matter and c e l l u l o s e d i g e s t i b i l i t i e s of a commercial c h i n c h i l l a pellet, with and without a l f a l f a hay are recorded i n Table VIII.  There v/ere no  sig-  n i f i c a n t changes In body weight on either ration f o r the four week duration of the experiment, and nor were there  any  outward, signs of digestive upsets as determined by e r r a t i c feed intake and appearance and quantity of feces.  The  s l i g h t increase i n dry matter d i g e s t i b i l i t y of p e l l e t s alone would therefore suggest that hay i s not necessary in the ration.  However, there are many other factors to consider  when the feeding regime i s continued f o r more than a short time.  Impaction i s very common i n c h i n c h i l l a v/ith i n s u f f i -  cient bulk ( 6 9 ) ,  and n i b b l i n g at the hay also provides a  d i s t r a c t i o n from f u r chewing.  This i s one of the main pro-  blems facing the c h i n c h i l l a rancher and i s generally believed to be caused by stress factors such as boredom.  TABLE VII VOLATILE FATTY ACID (VFA) IN THE DIGESTIVE TRACTS AND FECES OF FOUR ADULT CHINCHILLA FED ALFALFA HAY AND A COMMERCIAL CHINCHILLA PELLET  Stomach .  Acid ;aequiv^ Acetic  molar %  Cecum  Large Intestine  Rectum  182.4  121.7  44.9  72.2  72.2  67.0  87.2  27.5  20.5  11.3  . 0.45  11.3 .  12.1  16.0  10.7  84.6  /lequiv Propionic  Iso-butyric  Butyric  Iso-valeric  Valeric ±  molar %  9.62  ;aequiv molar fo  5.81  3.66  2.16 .  4.61 •  1.07  0.01  1.02  2.73  1.58  0.25  8.30  0.07  ^iequiv  35.8  22.1  molar %  14.1  13.1  12.1  ;aequiv  . 1.77  3.55  molar fo  0.51  2.11  1.36  ;aequiv  1.59  1.28  0.99  molar fo  O.69  0.76  1.49  micro-equivalents per gram dry matter.  Feces  . 1.20  1.88  TABLE VIII DRY MATTER AND CELLULOSE DIGESTIBILITY OF A COMMERCIAL CHINCHILLA PELLET WITH AND WITHOUT ALFALFA HAY  Pellets Aver, daily feed consumption  consumption  fo  18.7  3*2  fo dry matter digestion  15«2  6.85 4.2  (g)  c e l l u l o s e digestion  27.1 11.9  (g)^  Aver, d a i l y cellulose  Hay and Pellets  2.6  47.5  4$«9  63.4  57.9  •average of four adult females.  It  i s apparent t h a t f o r the purposes of most  diges-  t i o n t r i a l s w i t h c h i n c h i l l a , the removal of hay from the ration the  does not have a d e t r i m e n t a l p h y s i c a l e f f e c t ,  although  n u t r i t i o n a l e f f e c t would be dependent on the remaining  ration  components.  SUMMARY  The conclusions that can be drav/n from t h i s study are summarized below. 1.  Maltase, sucrase and lactase a c t i v i t y were found  i n homogenates of the small i n t e s t i n a l wall and contents of adult c h i n c h i l l a , while-only sucrase and maltase a c t i v i t y were found i n the cecal and large i n t e s t i n a l contents.  Ko  disaccharidase a c t i v i t y was found i n the walls of the stomach, cecum or large i n t e s t i n e . 2.  Assuming that the disaccharidase a c t i v i t i e s i n  i n t e s t i n a l homogenates r e f l e c t the a b i l i t y of the animal to u t i l i z e various sugars, the young preweaned c h i n c h i l l a i s readily able to u t i l i z e lactose, can u t i l i z e maltose to a l e s s e r extent, and possesses limited a b i l i t y to u t i l i z e sucrose.  Between four and s i x weeks of age, there i s a  marked decrease i n lactase a c t i v i t y and an increase i n the a c t i v i t i e s of sucrase and maltase.  By twelve weeks of age,  maltase has attained l e v e l s found i n the adult animal, having increased to f i v e times the l e v e l s measured i n the newborn animal.  Sucrase also has reached l e v e l s found i n the  adult by twelve weeks of age, but the increase from b i r t h i s f a r less than that noted i n maltase.  Lactase i s present  i n very low l e v e l s from s i x weeks of age onwards.  3.  The disaccharidases v:ere non-uhiformly.'distributed  along the small, i n t e s t i n e . A c t i v i t y of maltase was s i g n i f i cantly greater i n the lower jejunum and upper ileum than i n the remainder of the small i n t e s t i n e . A similar trend was observed with sucrase and lactase a c t i v i t i e s . 4.  The optimum pH for i n v i t r o a c t i v i t y of i n t e s t i n a l  lactase, sucrase and maltase v/as pH 4 . 6 , 6 . 4 and 6 . 0 , respectively. The optimum pH for lactase a c t i v i t y was lower than that reported i n most other 5.  animals.  Levels of pancreatic amylase indicate that u n t i l  four weeks of age, the young c h i n c h i l l a has a very limited a b i l i t y to u t i l i z e starch. Amylase increases f a i r l y steadily with age from negligible l e v e l s at b i r t h . 6.  The time of passage of a pelleted ration through  the digestive tract of c h i n c h i l l a , as indicated by the time of excretion of the highest concentration of chromic."oxide was 3 5 to 4 0 hours after feeding. Traces of marker remained 5 5 hours a f t e r feeding. Four days was suggested as the minimum c o l l e c t i o n period i n a d i g e s t i b i l i t y t r i a l when hay or other roughage v/as included i n the ration. 7.  Percent cellulose digestion of a commercial chin-  c h i l l a p e l l e t containing 1 8 . 7 % cellulose was 53.9%, the main s i t e s of cellulose breakdown and v o l a t i l e fatty acid production being the cecum and large i n t e s t i n e . It was suggested that the low l e v e l s of v o l a t i l e fatty acid found i n the stomach v/ere due to coprophagy.  BIBLIOGRAPHY Aherne, F., V. W. Hays, R. C. Ewan and V. C. Speer. I 9 6 9 . Absorption and u t i l i z a t i o n of sugars by the baby p i g . J . Anim. S c i . 29:444. Aitken, F.C., 1963. C h i n c h i l l a , In Feeding of fur-bearing animals. P. 86. Tech. Com. No. 23, C.A.B., Farnham Royal, Bucks, Scotland. Alexander, F. 1952. Some functions of the large i n t e s t i n e of the horse. Quart.' J . Exp. Physiol. 37:205. Alexander, F. and A. K. Chowdhury. 1958. Digestion i n the rabbit's stomach. B r i t . J . Nutr. 12:65. Alvarez, A. and J . Sas. I96I. ^-galactosidase changes in the developing i n t e s t i n a l tract of the r a t . Nature, Lond. 190:826. Arrison, E. F., K. J . H i l l and R. Kenworthy. 1968. V o l a t i l e f a t t y acids i n the digestive tract of the fowl. B r i t . J . Nutr. 22:207. Auricchio, S., A. Rubino, R. Tosi, G. Semenza, M. Landolt, H. K i s t l e r and A. Prader. 1963. Disaccharidase a c t i v i t i e s i n human i n t e s t i n a l mucosa. Enzymol. B i o l . C l i n . 3:193. Auricchio, S., S. Rubino and G. Miirset. 1965. Intestinal glycosidase a c t i v i t i e s i n the human embryo, fetus and newborn. Pediatrics, S p r i n g f i e l d , 35:944* Bailey, C. B., V/. D. K i t t s and A. J . Wood. 1956. The development of the digestive enzyme system of the pig during i t s pre-weaning phase of growth. B. I n t e s t i n a l lactase, sucrase and maltase. Can. J . Agric. S c i . 36:51. Ballard, F. J . and I. T. Oliver. 1 9 6 5 . Carbohydrate metabolism i n l i v e r from f o e t a l and neonatal sheep. Biochem. J . 95:191.  11. Barcroft, J . , R. A. McAnally and A. T. P h i l l i p s o n . 1944. Absorption of v o l a t i l e acids from the alimentary t r a c t of the sheep and other animals. J . Exp. B i o l . 20:120.  12.  Baumgardt, B. R. I 9 6 4 . P r a c t i c a l observations on the quantitative analysis of free v o l a t i l e f a t t y acids (VFA) i n aqueous solutions by gas chromatography. Dept. B u l l . 1 , Dept. Dairy S c i . , Univ. Wisconsin, Madison.  13. Bayless, T. M. and Huang, S. 19^9• Inadequate i n t e s t i n a l digestion of lactose. Amer. J . C l i n . Nutr. 22:250.  14. B e r r f i e l d , P. 1 9 5 5 . P. 1 4 9 . In Methods i n Enzymology, v o l . 1 , eds., S. P. Colovdck and N. 0 . Kaplan. Acad. Press, New York. 15. Bickel, E. I 9 6 2 . (The subject of c h i n c h i l l a feeding.) Deutsch. Pelztierzlichter, 36:66. 16. Blankenhorn, D. H., J . Hirsch and. E. H. Ahrens, J r . 1 9 5 5 . T i r a n s i n t e s t i n a l intubation: technique f o r measurement of gut length and physiological sampling at known l o c i . Proc. Soc. Exp. B i o l . Med. 68:356. 17. Blaxter, K. L. and V/. L. Wood. 1 9 5 3 . Some observations on the biochemical and physiological events associated with diarrhoea i n calves. Vet. Rec. 65:889. 18. Borgstrom, B., A. Dahlqvist, G. Lundh and J . S j o v a l l . 1957. Studies of i n t e s t i n a l digestion and absorpt i o n i n the human. J . C l i n . Invest. 3 6 : 1 5 2 1 . 19. Bywater, R. J . and W. J . Penhale. 1 9 6 9 . Depressed . lactase a c t i v i t y i n the i n t e s t i n a l mucous membrane of calves after neonatal diarrhoea. Res. Vet. S c i . 10:591.  20.  Conrad, H. E., and T. E. uniformly the r a t .  W. R. watts, J . M. Iacono, H. F. K r a y b i l l Friedemann. 1 9 5 8 . D i g e s t i b i l i t y of l a b e l l e d carbon 14 soybean cellulose i n Science 1 2 7 : . 1 2 9 3 .  2 1 . ' Crampton, E. V/. and L. W. Maynard. 1 9 3 8 . The r e l a t i o n of cellulose and l i g n i n content to the n u t r i t i v e value of animal feeds. J . Nutr. 1 5 : 3 8 3 .  Crane, R. K. 1969. t i v e function.  A perspective of digestive-absorpAmer.'J. C l i n . Nutr. 22:242.  Cranwell, P. D. 1968. Microbial fermentation i n the alimentary t r a c t of the pig. Nutr. Abstr. Rev. 33:721. Cuatrecacas, P., D. H. Lock-wood and J . R. Caldwell. •I965. Lactase deficiency i n the adult. Lancet, 1:14. Cunningham, H. M. and G. J . Brisson. 1 9 5 7 . The effect of amylases on the d i g e s t i b i l i t y of starch by baby pigs. J . Anim. S c i . 16:370. Dahlqvist, A. . 1961. The location of carbohydrases i n the digestive t r a c t of the pig. Biochem. J . 78: 232. Dahlqv.ist, A. and 3. Borgstrom. 1961. Digestion and absorotion of disaccharides i n man. Biochem. J . 81:411. . • Dahlqvist, A. 1962. S p e c i f i c i t y of the human i n t e s t i n a l disaccharidases and implications f o r hereditary disaccharide intolerance. J . C l i n . Invest. 41:463.' Dahlqv.ist, A. and D. L. Thompson. 1963. Separation and characterization of 2 r a t - i n t e s t i n a l amylases. Biochem. J . 3 9 : 2 7 2 . Dahlqvist, A. 1964. Method f o r assay of i n t e s t i n a l disaccharidases. Anal. Biochem. 7:18. Dahlqvist, A. 1967. L o c a l i z a t i o n of the small i n t e s t i n a l disaccharidases. Amer. J . C l i n . Nutr. 20:81 Dahlqvist, A., 3. Lindquist and. G. Meeuwisse. 1968. Disturbances of the digestion and absorption of carbohydrates. In Carbohydrate Metabolism and i t s Disorders, v o l . 2, ed. Dickens, Randle and Whelan, Acad. Pres. London. Dahlqvist, A. and U. Telenius. 1969. Column chromatography of human s m a l l - i n t e s t i n a l maltase, isomaltas and invertase a c t i v i t i e s . Biochem. J . 111:139.  De Groot, A. P. and. P. Hoogedoorn. 1957. The d e t r i mental effect of lactose. I I . Quantitative l a c tase determinations i n various mammals. Netherland . Milk and Dairy J . 11:290. De Laey, P. I 9 6 6 . Development of the i n t e s t i n a l digestion mechanism of starch as a function of age in r a t s . Nature,. Lond. 212:78. Deren, J . J . , S. A. Broitman and N. Zamchek, 1967E f f e c t of diet upon i n t e s t i n a l disaccharidases and disaccharide absorption. J . C l i n . Invest. 46:186. Doell, R. G. and N. Kretchmer. 1962. Studies of the small intestine during development. I. D i s t r i b u t i o n and a c t i v i t y of ^-galactosidase. Biochim. Biophys. Acta. 62:353. Doell, R. G. and N. Kretchmer. 1963• The i n t r a c e l l u l a r location of i n t e s t i n a l ^-gaiactosidase. Biochim. Biophys. Acta. 67:516. Doell, R. G. and N. Kretchmer. I964. I n t e s t i n a l invertase: precocious development of a c t i v i t y a f t e r i n j e c t i o n of hydrocortisone. Science 143:42. Doell,.R. G., G. Rosen and N. Kretchmer. 1965. Immunochemical studies of i n t e s t i n a l disaccharidases during normal and precocious development. Proc. Nat. Acad. S c i . U.S. 54:1268. Dollar, A. M., K. G. M i t c h e l l and J . W. G. Porter. 1957. The u t i l i z a t i o n of carbohydrates i n the young pig. Proc. Nutr. Soc. 16:12. Durand, P.. 1964. P. 107. In Disorders Due to I n t e s t i n a l Defective Carbohydrate Digestion and Absorption, ed. P. Durand, Rome. Elsden, S. R., M. W. S. Hitchcock, R. A. Marshall and A. T. P h i l l i p s o n . 1946. V o l a t i l e acid i n the digesta of ruminants and other animals. J . Exp. B i o l . 22:191. Farmer, F. S. 1957. A study of protein i n the diet of c h i n c h i l l a s . Fur Trade J . Can. 35:35. Fischer, J . S. 1957. Effects of feeding a diet containing lactose upon $-D-galactosidase a c t i v i t y and organ development i n the rat digestive t r a c t . Amer. J . Physiol. 188:49. '  46.  F i s c h e r , S . H. and E. A. S t e i n . I 9 6 4 . oc-amylase from human s a l i v a . Biochem. prep. 8:27.  47.  F o r b e s , R. M. and T. S. H a m i l t o n . 1952. The u t i l i z a t i o n o f c e r t a i n c e l l u l o s i c m a t e r i a l s by swine. J . Anim. Sci. 11:480.  48.  F r i e n d , D. W. , H. M. Cunningham and J . V/. G. N i c h o l s o n . 1963. The p r o d u c t i o n o f o r g a n i c a c i d s i n t h e p i g . II. The e f f e c t o f d i e t on t h e l e v e l s o f v o l a t i l e f a t t y a c i d s and l a c t i c a c i d i n s e c t i o n s o f t h e alimentary t r a c t . Can. J . Anim. S c i . 43:156.  49.  Gray, G.. M. and N. A. S a n t i a g o . 1969. I n t e s t i n a l g a l a c t o s i d a s e s . I . S e p a r a t i o n and c h a r a c t e r i z a t i o n o f t h r e e enzymes i n normal human i n t e s t i n e . J . C l i n . I n v e s t . 48:716.  50.  Gray, G. M., N. A. S a n t i a g o , E. H. C o l v e r and M. Genel. 1969. I n t e s t i n a l B-galactosidases. I I . Biochemical a l t e r a t i o n i n human l a c t a s e d e f i c i e n c y . J . C l i n . I n v e s t . 43:729.  51.  Gray, G. M. 1970. Carbohydrate d i g e s t i o n and a b s o r p t i o n . G a s t r o e n t e r o l o g y 58:96.  52.  Hagen, P. and K. W. Robinson. 1953. The p r o d u c t i o n and absorption of v o l a t i l e f a t t y acids i n the i n t e s t i n e o f t h e g u i n e a p i g . Aust. J . Exp. B i o l . Med,. S c i . 31:99.  53*  Ham, A. w. and T. S. Leeson. I 9 6 I . H i s t o l o g y , p. 6 2 2 . 4th. ed., J . P. L i p p i n c o t t , M o n t r e a l .  54. Hartman, P. A., V. W. Hays, R. 0. Baker, L. H. Meagle and D. V. C a t r o n . 19'6l. D i g e s t i v e enzyme development i n t h e young p i g . J . Anim. S c i . 20:114. 55.  H e i l s k o v , N. S. 0. 1951. S t u d i e s on animal l a c t a s e . I I . D i s t r i b u t i o n i n some o f t h e glands o f t h e d i g e s t i v e tract. A c t a P h y s i o l . Scand. 24:84-  56.  H e n d r i c k s , D., E. R. M i l l e r , D. E. U l l r e y and M. G. Young, (unpublished data).  57.  Henning, S. J . and F. J . R. H i r d . 1970. Concentrations and metabolism o f v o l a t i l e f a t t y a c i d s i n t h e f e r m e n t a t i v e organs o f 2 s p e c i e s o f kangaroo and t h e guinea p i g . B r i t . J . Nutr. 24:145-  58.  Hoover, W. H., C. L. Mannings and H. .E. S h e e r i n . 1968. O b s e r v a t i o n s p e r t a i n i n g t o d i g e s t i o n i n t h e golden hamster. J . Anim. S c i . 27:1512 ( a b s t r a c t ) .  5 9 . Houston, J . '[•}. and J . P. Prestwich. 1962. Care, 4th. ed. , Borden Pub'l. Co.  Chinchilla  6 0 . Hove, E. L . and J . F. Herndon. 1957. Growth of rabbits on p u r i f i e d diets. J . Nutr. 63:19361.  Huber, J . T., N. L. Jacobson, R. S. Allen and P. A. Hartman. 1961. Digestive enzyme a c t i v i t i e s i n the young c a l f . J . Dairy S c i . 44:1494.  6 2 . Hungate, R. S. I966. Acad. Pres.  The Rumen and i t s Microbes.  P. 6 0 .  6 3 . Johnson, J . L . and R. H. McBee. 1967. The porcupine cecal fermentation. J . Nutr. 91:540. 64. Kidder, D. E., M. J . Manners and M. R. McCrea. 1963. The digestion of sucrose by the p i g l e t . Res. Vet. Sci.  -4:131.  6 5 . King, K. VJ. and F. S. Orcutt. 1952. N u t r i t i o n a l studies of the c h i n c h i l l a , with s p e c i a l reference to ascorbic, acid and thiamine. J . Nutr. 48:31. 66. K i r i s , I . B. and E. D. 3arantseva. 1963. F i r s t experiment i n acclimatization of c h i n c h i l l a i n the U.S.S.R. p. 70. In Acclimatization of Animals i n the U.S.S.R. ed. A. I . Yanushevich, Oldbourne Pres, London. 67.  Koldovsky, 0. 1969. Digestion and absorption of carbohydrates, p. 25. In Development of the Functions of the Small Intestine i n Mammals and Man, Karger, N.Y.  68.  Kretchmer, N. and P. Sunshine. 1967- I n t e s t i n a l disaccharidase deficiency i n the sea l i o n . Gastroenterology 53:123.  6 9 . Larrivee, G. P. and C. A. Elvehjem. 1954- Studies on the n u t r i t i o n a l requirements of c h i n c h i l l a . J . Nutr. 52:427. 70.  Leoschke, W. L . and. C. A. Elvehjem. 1959. Riboflavin i n the n u t r i t i o n of the c h i n c h i l l a . J . Nutr. 69:214.  71.  Lloyd, L. E., D.' G. Dale and E. W. Crampton. 1953. The role of the caecum i n nutrient u t i l i z a t i o n by the pig. J . Anim. S c i . 17:684-  72.  Lowry, 0. H., N. J . Rosebrough, A. L. Farr and R. J . Randall. 1951- Protein measurement with the F o l i n phenol reagent. J . B i o l . Chem. 193:265.  7 3 . Malhotra, 0 . P. and G. P h i l l i p . 1965. Hydrolytic enzymes of mammalian i n t e s t i n e s . Part I I . Distribution of hydrolytic enzymes i n dog, guinea » pig, s q u i r r e l , albino rat and rabbit i n t e s t i n e s . Ind.  J . Med.  Res.  53:410.  74. McGeachin, R. L. and N. K. Ford J r . 1 9 5 9 . Distribution of amylase i n the g a s t r o i n t e s t i n a l tract of the r a t . Amer. J . Physiol. 1 9 6 : 9 7 2 . 75« M i l l e r , D. and R. K. Crane. 1961. The digestive funct i o n of the epithelium of the small i n t e s t i n e . I I . Localization of disaccharide hydrolysis i n the i s o l a t e d brush border portion of i n t e s t i n a l e p i t h e l i a l c e l l s . Biochim. Biophys. Acta. 5 2 : 2 9 3 . 7 6 . O'Dell, 3. L., E. R. Morris, E. E. Pickett and A. G. Hogan. 1957. Diet composition and mineral balance i n guinea pigs. J . Nutr. 63:193. 77.  Plimmer, R. H. A. 1906. On the presence of lactase i n the i n t e s t i n e s of animals and on the adaptation of the i n t e s t i n e to lactose. J . Physiol. 35:20.  78. Radotstits, 0 . M. 1965. C l i n i c a l management of neonatal diarrhoea i n calves, with s p e c i a l reference to patho genesis and diagnosis. J . Amer. Vet. Med. Ass. 147:1367.  7 9 . Ranta, J . L. 1967. The effect of the l e v e l of roughage, d i e t h y l s t i l b e s t r o l , and iron on certain blood components i n growing beef c a t t l e . M.S.A. Thesis U.B.C Library, U.B.C. SO. Reboud, J . P., G. Marchis-Mouren, A. Cozzone and P. Desnuelle. I 9 6 6 . Variations i n the biosynthesis rate of pancreatic amylase and chyrnotrypsinogen i n response to a starch-rich or a protein-rich d i e t . Biochim. Biophys. Res. Com. 22:94. 8 1 . Reddy, B. S., J . R. Pleasants and B. S. Wostrnann. I968. Effect of dietary carbohydrates on i n t e s t i n a l disaccharidases in germ-free and conventional r a t s . J . Nutr. 95:413. 82. Rosenweig, -N. S. and R. H. Herman. I969. Time response of jejunal sucrase and maltase a c t i v i t y to a high sucrose diet i n normal man. Gastroenterologv 5 o : 5 0 0 83.  Ross, J . P. 1970. An improved method f o r the determinat i o n of v o l a t i l e f a t t y acids (VFA) from ruminant blood plasma. (unpublished r e s u l t s ) .  IS  84.  Rubino, A., F. Zimbalatti and S. Auricchio. I 9 6 4 . I n t e s t i n a l disaccharidase a c t i v i t i e s i n adult and „ suckling rats. Biochim. Biophys. Acta. 9 2 : 3 0 $ .  85.  Schiirch, A. F., L. E. Lloyd and E. if. Crampton. 1 9 5 0 . The use of chromic oxide an index f o r determining d i g e s t i b i l i t y of a d i e t . J . Nutr. 4 1 : 6 2 9 .  06. Semenza, G. 1 9 6 7 . Selected topics i n carbohydrate biochemistry: Digestion and absorption of sugars i n the i n t e s t i n a l t r a c t . Caries Res. 1:187-. 87.  Siddons, R. C. 1 9 6 8 . Carbohydrase a c t i v i t i e s i n the bovine digestive t r a c t . Biochem. J . 1 0 8 : 8 3 9 . -  88.  Siddons, R. C. 1 9 6 9 . I n t e s t i n a l disaccharidase a c t i v i t i e s i n the chick. Biochem. J . 112:51.  89.  Sumner, J . B. 1 9 2 4 . The estimation of sugar i n diabetic urine, using- d i n i t r o s a l i c y l i c acid. J . B i o l . Chem. 62:287.  90.  Thacker, E. J . and C. S. Brandt. the  rabbit.  J . Nutr.  1955... 55:375.  Coprophagy i n  91.  The Fur Farm Industry i n B.C. Province of B.C. Dept. Agric. Livestock Branch publ. I967.  92.  Ugolev, A. M. , K. N. Jesuitova, II. M. Timofeeva, and I. N. Fediushina. I 9 6 4 . Location of hydrolysis of certain disaccharides and peptides i n the small i n t e s t i n e . Nature, London. 2 0 2 : 8 0 7 .  93-  Vander Moot, G. W. , L. D. Symons, R. K. Lydraan and P. V. Fonnesbeck. 1 9 6 7 . Rate of passage of various feeds t u f f s through the digestive t r a c t of horses. J . Anim. S c i . 2 6 : 1 3 0 9 .  94.  Velu, J . G., K. A. Kendall and K. E. Gardner, i 9 6 0 . U t i l i z a t i o n of various sugars by the young dairy c a l f . J'. Dairy S c i . 4 3 : 5 4 6 .  95-  V/einland, E. 1 8 9 9 . Biol., 38:16. cited by Koldovsky, 0. 1 9 6 9 . In Development of the Functions of the Small Intestine i n Mammals and Man. p. 2 5 . Karger, N.Y.  9 6 . Welsh, J . D. and A. Walker. 1 9 6 5 . I n t e s t i n a l disaccharidase and-alkaline'phosphatase a c t i v i t y in'the dog. Proc. Soc. Exp. B i o l . Med. N.Y. 1 2 0 : 5 2 5 .  Yang, M. G., K. Manoharan and A. K. Young. I969. Influence and degradation of dietary cellulose i n cecum of r a t s . J . Nutr. 97:260. Yang, K. G., K. Manoharan and 0. Michelsen. 1970. N u t r i t i o n a l contribution of v o l a t i l e f a t t y acids from the cecum of rats. J . Nutr. 100:545Yoshida, T., J . R. Pleasants, 3. S. Reddy and B. S. Wostrnann. 1966*. E f f i c i e n c y of digestion i n germfree and conventional rabbits. B r i t . J . Nutr. 22:723.  VII  -  APPENDICES  Appendix 1  CHINCHILLA PELLETS Amounts (lbs)  Ingredients Ground Wheat  3 0 0  Ground Corn  100  Ground Barley  100  Soybean Heal  (4$.5$)  268  Sun-cured A l f a l f a  6 0 0  Ground Beet Pulp  100  D i s t i l l e r ' s Solubles  200  Defluorinated Phosphate  50  Dried Whey  17  Iodized Salt  10  Molasses  200  Durabond  50 5  Vitamin Mix^  2,000 ^Vitamin Mix Vitamin A Vitamin D3 Vitamin E Riboflavin Calcium Pantothenate Niacin Vitamin B-12 Choline Chloride DL. Methionine Vitamin K. Oleandomycin Zinc oxide Potassium Iodide Manganese oxide Made up to 5 l b s . v/ith v/he  4,000,000 units. 1,000,000 units 5,000 units 4 grams 8 grams 18 grams 6 milligrams 227 grams 5 5 4 grams 1 gram 2 grams 60 grams 0 . 4 5 grams 80 grams middlings.  APPENDIX 2 -  Growth  Curve of 6 Female and 8 Male Chinchilla lanigera  Appendix 2  Age (days)  -  GROWTH OF CHINCHILLA LANIGERA  Average 'Weight ± S.E.l-i.  No. of Animals*  1  49.6  +  0.9  10  14  86.5  +  2.2  9  128.0 +  ...28  +  3.6.  10  4.3  10  4.1  10  42  186.3  56  233.6  +  70  275.0  +  3.8  10  84  307.5  +  4.3  10  98  329.0  +  5.7  10  112  359.0  +  9.6  6  126  378.0  +  3.6  10  140  393.2  +  9.2  8  154  415.6  +  12.7  10  168  426.6  + 12.2  10  182  •  196  252  (adult)  439.4  +  472.0  +  524.4  +  10.4  8  15.1  4  7.9  7  •When 1 0 animals were used, they consisted of 6 females and. 4 males.  Appendix 3  Age (weeks)  liver  -  ORGAN WEIGHTS A3 PER CENT OF LIVE -BODY WEIGHT AT VARIOUS AGES IM THE CHINCHILLA  Organ Weight {% of body wt.) kidneys lungs heart spleen adrenals  1  3.63  0.88  1.21  0.47  2  4.86  1.21  0.77  0.40  3  4.41  0.94  3.83 6  pancreas  0.03 0.21  0.02  0.63  0.18  0.02  1.11  0.63  . 0.20  3.20  0.95  0.43  6  4.56  0.90  0.67  0  6  3.67  •1.06  0 . 5 2  7  4.10  1.03  7.  3.55  8  0.16  0 . 5 2  0 . 1 5  0.03  0 3. 1 •7  0.03  0.41  0 . 1 5  0.02  0.28  0.49  0.34  0.18  0.02  0 . 3 0  0.93  0.51  0.37  0.12  0.04  3.94  1.0  O.48  0 . 3 1  0 . 1 3  0.04  11  3.71  0.92  0.53  0.31  0.12  0.02  0.32  12  4.08  0.95  0.42  0.34  0.10  0.03  0.20  adult  3.35  0.77.  0.42  0 . 3 3  0.10  0.02  0.41  (aver, of 5 animals)  .  3  

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