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Growth of Young Calves and Rats Fed Soy Flour Treated with Acid or Alkali1
Growth of Young Calves and Rats Fed Soy Flour Treated with Acid or Alkali Abstract Calves fed a milk replacer containing alkali-treated fully cooked soy flour as the only source of protein grew as well as calves receiving acid-treated flour and more rapidly than calves fed untreated flour. Growth in weanling rats fed either acidtreated or alkali-treated soy flour was superior to that for rats fed untreated flour. No evidence was obtained to suggest the presence of a pit-labile water-soluble growth inhibitor in the untreated flour. In a study of milk replacers containing fully cooked soy flour, Colvin and Ramsey (1) found that treatment of the flour with acid greatly improved its nutritional value for the calf. The present report represents continued exploration on the use of soy flour as a milk substitute for young animals. Experimental Procedures and Results Since calves fed acid-treated soy flour grew more rapidly than those fed untreated flour (1), the question arose as to whether treatment of soy flour with alkali would produce a similar acceleration in growth. Thus, a milk replacer was formulated in which the fully cooked soy flour~ was incubated with sodium hydroxide for five hours at 37 C. This mixture, with p i t of approximately 10.6, was subsequently neutralized with hydrochloric and phosphoric acids. The preparation and composition of this replacer was identical to the acid-treated diet (Negative Control I I ) in the previous study (1), except for reversing the addition o£ ~cid and alkali. The alkali-treated replacer was fed as the only source of nutrients for 42 days to three colostrum-fed Holstein male calves commencing at two days of age. The calves were fed twice daily from a nipple pail at the daily rate of 1 kg per 10 kg of body weight. The mean growth on this diet is compared in Fig. i with that obtained during the previous study (1) on replacers containing 1 This investigation was supported in part by research grants from the National Institute of Arthritis and Metabolic Diseases, Public Health Service (AM-02230), and the Moorman Manufacturing Company, Quincy, Illinois. Soy]ee T-15, a lecithinated fully cooked soy flour containing 44% protein, Archer Daniels Midland Company, Minneapolis, Minnesota. 270
either acid-treated or untreated soy flour. The results indicate that alkali-treated flour produced a growth response similar to the acidtreated flour and markedly superior to the untreated flour. A trial was conducted subsequently in which the young rat was used as a test animal. The soy flour was incubated as described previously (1) at p H 6.4 in a phosphate buffer or in an acidic or alkaline medium. Following neutralization of the acid- and alkali-treated material, all three preparations were lyophilized. The dry products were then used as protein sources in three experimental diets. A fourth diet containing casein was also included. The composition of these diets is presented in Table 1. All diets were formulated to contain 10% protein. Each diet was fed ad libitum to seven weanling rats for 28 days. The mean cumulative change in body weight on each diet is presented in Fig. 2. Weight gains for acidand alkali-treated flours were similar and slightly higher than that for casein, but approximately double the gain for untreated soy flour. The relative response of rats to the soy flour diets, therefore, was very similar to that of calves. Attention was focused subsequently on the question of why growth response is improved by treating soy flour with acid or alkali. One possibility is that fully cooked flour contains a growth inhibitor destroyed by exposure to a high or low p i t . To explore this possibility, fully cooked soy flour was suspended in water at 3 C and agitated constantly for 12 hours. Following centrifugation, the supernatant was TABLE 1. Composition of diets for rats. Ingredients
Casein diet
Soy diets
- - , ( % ) - Casein Lyophilized soy flour Corn starch Cellulose Wesson oil Mineral mixa Vitamins Cod liver oil
11.2 ...... 78.3 2.0 5.0 3.0 b 0.5
23.4 66.1 2.0 5.0 3.0 b 0.5
Salt Mix W, Nutritional ]Mochemicals Corporation, Cleveland, Ohio. b Milligrams per kilogram of diet: thiamine HC], 5 ; riboflavin, 5; d-Ca pantothenate, 20; pyridoxine HC1, 5; niacin, 30; p-aminobenzoie acid, 30; biotin, 0.4; folic acid, 2; inositol, 10; vitaman B12, 0.03; and choline chloride, 1,000.
TECHNICAL
removed a n d s u b j e c t e d to one of two processes. I n the first, i t was reduced in volume b y e v a p o r a t i o n u n d e r v a c u u m a t room t e m p e r a ture. D r y i n g was completed u n d e r v a c u u m a t 48 C. This f r a c t i o n , therefore, consisted s i m p l y of the water-soluble m a t e r i a l in soy flour. I n the second, t h e s u p e r n a t a n t was a d j u s t e d to p t t 10.6 with sodium h y d r o x i d e a n d held a t 37 C f o r five hours. The p H was t h e n rea d j u s t e d to 6.4 with the same r a t i o of h y d r o chloric a n d p h o s p h o r i c acid used previously. The a l k a l i - t r e a t e d e x t r a c t was t h e n t a k e n to d r y n e s s in t h e same w a y as the u n t r e a t e d extract. E a c h of the dried e x t r a c t s was added to a diet c o n t a i n i n g ] 2 % p r o t e i n f r o m casein. Thus, three diets were f o r m u l a t e d : casein alone, casein plus u n t r e a t e d e x t r a c t of soy flour, a n d casein plus a l k a l i - t r e a t e d e x t r a c t of soy flour. The composition o£ these diets is p r e s e n t e d in Table 2. The level o£ dried soy e x t r a c t is equivalent in water-soluble soy d r y m a t t e r to the level of soy flour used in the p r e v i o u s trial. E a c h diet was f e d ad libitum to seven w e a n l i n g r a t s f o r 21 days. The m e a n cumulative change
e-----e U N T R E A T E D 2O
o
;~
271
TABLE 2. Composition of diets for rats. Casein plus dried soy
extract diets
Casein diet
Ingredients
- - ( % ) - Casein Dried soy extract Corn starch Cellulose Wesson oil Miueral mix a Vitamins Cod liver oil
13.4 ...... 76.1 2.0 5.0 3.0 b 0.5
13.4 4.2 71.9 2.0 5.0 3.0 b 0.5
Salt Mix W, Nutritional Biochemicals Corporation, Cleveland, Ohio. b See Table 1. in body w e i g h t o n each diet is p r e s e n t e d in Fig. 3. All of the diets p r o d u c e d a s i m i l a r g r o w t h response. Since t h e r e was no evidence of ~ ' o w t h s u p p r e s s i o n b y the u n t r e a t e d soy extract, it does n o t seem likely t h a t the g r o w t h r e s p o n s e f r o m alkali t r e a t m e n t i n p r e v i o u s trials can be a t t r i b u t e d t o the d e s t r u c t i o n of a water-soluble g r o w t h inhibitor. F u r t h e r observations on the p o s s i b i l i t y of a
SOY F L O U R
[]ACID-TREATED FLOUR ~ALKALI-TREATED SOY FLOUR
I-..1(.9
NOTES
SOY /
15
~ 120 ~loo I-"1" L9 m hi
>a o
80
=
= UNTREATED SOY FLOUR
[]
[] A C I D - T R E A T E D SOY FLOUR
zx
n ALKALI-TREATED SOY F L O U R
o
o CASEIN
/
/
rn
>O 0
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-10
LU (..9 Z
Z
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I.l.I (.9 Z
5
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40
t-W
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20
..1
O Z
o
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I 2
i I I I 5 4 5 6 WEEKS Fro. 1. Mean cumulative changes in body weight of calves fed milk replacers containing soy flour. T h e curves for acid-treated flour and untreated flour are a summary of previous work (1), representing mean gains for 21 and 11 calves, respectively.
0
Z
tlJ I
I I
I I I 2 5 4 WEEKS Fm. 2. M e a n c u m u l a t i v e c h a n g e s i n b o d y weight of ra£s fed diets containing casein, untreated soy flour, acid-treated soy flour, or alkali-treated soy flour. J . DAIRY SCIENCE ~OL. 52, NO. 2
272
JOURNAL OF DAIRY SCIENCE
growth inhibitor were made in a fourth trial with calves. Soy flour was suspended in water (1:9) at 3 C for 12 hours. This mixture was stirred frequently during the first six to eight hours and allowed to settle during the latter portion of the extraction period. The supernatant portion was removed by siphon and used to reconstitute a commercial milk replacer containing only milk protein, 24%. The ratio of replacer to liquid soy extract was 15:85. I n its content of water-soluble soy dry matter, this diet was approximately equivalent to the soy flour replacers used in previous trials. The control diet in this study was the commercial milk replacer reconstituted in water, 15:85. Each diet was fed to two calves f o r four weeks. Care and feeding was the same as in the previous calf trial. The mean gains in body weight were similar f o r both diets (Fig. 4). Since there was no evidence of growth suppression in the soy extract diet, these results are in accord with those of the previous trial with rats.
value o£ fully cooked soy flour for the young calf and the young rat is improved by treatment with either acid or alkali. Though the cause-and-effect relationship between treatment and animal response is unknown, the improvement in growth does not appear to result from the destruction of a water-soluble growth inhibitor in the flour. The possibility of a waterinsoluble inhibitor to which the young animal is particularly sensitive still exists. I t is also possible that growth improvement by treatment with acid or alkali is mediated through the chemical alteration of some nutrient in soy flour, thereby making it more available to t h e animal. B. M. C O L V I N * and H. A. RAMSEY, Department of Animal Science, North Carolina State University, Raleigh
8 Present address: Department of Biochemistry, Oklahoma State University, Stil]water. Acknowledgments
Discussion
Though animal numbers were small, this study provided evidence that the nutritional
120 n," ~.100 T
o
oCASEIN
¢
= C A S E I N + UNTREATED
20t
/
H
80
)Q om
60
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~lo
hi (.9
Z
z
-r L) W
~ 4o
L) hi
>_5 I--._1
~ 2o _J
u
Z
OMILK REPLACER IN WATER ; M I L K REPLACER IN EXTRACT OF UNTREATED SOY FLOUR
TREATED E X T R A C T / / /
LIJ
z
o
=
EXTRACT OF SOY FLOUR / OASE,N + A L K A L , -
(9
The authors are particularly grateful to the Moorman Manufacturing Company, Quincy, Illinois, for financial support. Gratitude is ex-
0
z
0
.
.
.
.
.
m
w I I
I 2
I 5
WEEKS Fm. 3. Mean cumul~ivechangesin body weight of rats fed diets containlng casein alone or casein plus an untreated or alkali-treated extract of soy flour. J . DAIRY SCIENCE VOL, 52, NO. 2
I I
I 2
I 3
I 4
WEEKS FIe. 4. Mean cumulative changes in body weight of calves fed a commercial milk replacer reconstituted in water alone or in a water extract of untreated soy flour.
T E C H N I C A L NOTES
pressed also to the following companies for contributing various products used in some of the experimental diets: Foremost Dairies, Inc., San Francisco, California, lactose; Procter and Gamble Company, Cincinnati, Ohio, hydrogenated vegetable oil; Nopco Chemical Company, Newark, New Jersey, methionlne and vitamin mix; a~ld
273
American Cyanamid Company, New York, New York, chlortctraeycline. Reference
(1) Colvin, B. M., and tI. A. l~amsey. 1968. Soy flour in milk replacer for young calves. J. Dairy Sci., 51: 898.
Arteriosclerosis in Forestomach-Bypass Calves I Abstract
The occurrence of arteriosclerosis in two forestomach-bypass calves (esophagealabomasal anastomosis) of 8.5 and 11 months of age is reported. Lesions were seen on the endocardial surfaces of the atrial and ventricular walls of the heart and in the pulmonary artery. Of two surgically unaltered calves, '11 months old, one displayed slight arter[dsclerotic changes, located in the pulmonary artery. All calves were fed commercial milk replacer as their only feed. The fore-stomach-bypass calves had poor appetites for several months before death. The surgically unaltered calves appeared healthy, whereas the forestomach-bypass calves were underweight and appeared unthrifty. Numerous degenerative lesions were found in various organs of the forestomach-bypass calves. The original work on this project dealt with techniques for esophageal-abomasal anastomosis (forestomach-bypass surgery) and the nutrient needs of forestomach-bypass calves. The occurrence of arteriosclerosis in young ruminants, as found in these calves, is uncommon (1). Elucidation of the pathogenesis of arteriosclerosis in experimental animals may lead to an understanding of this disorder in man. New ways to produce this disease in animals are of importance. The occurrence of arteriosclerosis in forestomach-bypass calves under one year of age is reported. F o u r Holstein calves were examined at postmortem. Data pertinent to these animals are as follows: A, female, 8.5 months old; B, male, 11 months old; C, male, 11 months old; D, male, 11 months old. Calves C and D were euthanatized by injecting saturated magnesium sulfate solution into the jugular vein; Calves A and B died from a p p a r e n t toxemia and were examined within one to three hours after death, l%restomach-bypass surgery (esophageal-abomasal anastomosis) had been
performed on Calves A and B at three months and three weeks of age, respectively (6). All calves were given milk replacer beginning at about three days of age as their only feed. The forestomach-bypass calves, A and B, appeared unthrifty and often had bloat, while the surgically unaltered calves, C and D, appeared healthy. Body weights of the calves at termination were A, 122 kg; B, 146 kg; C, 343 kg; D, 272 kg. During the last several months of life feed consumption of the forestomach-bypass calves was very poor. Arteriosclerotic lesions were noted in the forestomach-bypass calves, A and B, but not in the surgically unaltered calves, C and D, with the exception of an arterioseIerotic lesion in the pulmonary artery of Calf D. Irregular outlines of raised whitish material were seen on the endocardial surface of the left atrial and ventricular walls of Calf A. Calf B showed similar but more extensive lesions. Atrial lesions were seen. Prominent and rough plaques were seen on the medial and lateral walls of the left ventricle from the aortic valve to the apex. Plaques also occurred in the pulmonary arteries (Fig. 1). The myocardium was irregularly mottled. I n addition to arteriosclerosis, numerous gross pathologic changes were seen in the forestomach-bypass calves. The digestive tract in both animals was atonic, displayed little muscular development, and contained gravel, sawdust, and large amounts of gas and some hairballs. The ruminal and omasal mucosa of Calf A was yellow and easily peeled away and the abomasal mucosa was inflamed. These changes were absent in Calf B; however, the duodenum revealed inflammation of mueosal and serosal surfaces. The gall bladder in both calves was greatly distended, with pale yellow bile. The lungs from Calf A appeared mottled on the surface and areas of atelectasis were present. The lungs from Calf B displayed patchy reddening and small fibrotie nodules about 3 mm in diameter. On gross examination the adrenal glands from Calf A had pin-point red areas J. DAIRY SCIEI~'OE ~rOL. 52, NO. 2
either acid-treated or untreated soy flour. The results indicate that alkali-treated flour produced a growth response similar to the acidtreated flour and markedly superior to the untreated flour. A trial was conducted subsequently in which the young rat was used as a test animal. The soy flour was incubated as described previously (1) at p H 6.4 in a phosphate buffer or in an acidic or alkaline medium. Following neutralization of the acid- and alkali-treated material, all three preparations were lyophilized. The dry products were then used as protein sources in three experimental diets. A fourth diet containing casein was also included. The composition of these diets is presented in Table 1. All diets were formulated to contain 10% protein. Each diet was fed ad libitum to seven weanling rats for 28 days. The mean cumulative change in body weight on each diet is presented in Fig. 2. Weight gains for acidand alkali-treated flours were similar and slightly higher than that for casein, but approximately double the gain for untreated soy flour. The relative response of rats to the soy flour diets, therefore, was very similar to that of calves. Attention was focused subsequently on the question of why growth response is improved by treating soy flour with acid or alkali. One possibility is that fully cooked flour contains a growth inhibitor destroyed by exposure to a high or low p i t . To explore this possibility, fully cooked soy flour was suspended in water at 3 C and agitated constantly for 12 hours. Following centrifugation, the supernatant was TABLE 1. Composition of diets for rats. Ingredients
Casein diet
Soy diets
- - , ( % ) - Casein Lyophilized soy flour Corn starch Cellulose Wesson oil Mineral mixa Vitamins Cod liver oil
11.2 ...... 78.3 2.0 5.0 3.0 b 0.5
23.4 66.1 2.0 5.0 3.0 b 0.5
Salt Mix W, Nutritional ]Mochemicals Corporation, Cleveland, Ohio. b Milligrams per kilogram of diet: thiamine HC], 5 ; riboflavin, 5; d-Ca pantothenate, 20; pyridoxine HC1, 5; niacin, 30; p-aminobenzoie acid, 30; biotin, 0.4; folic acid, 2; inositol, 10; vitaman B12, 0.03; and choline chloride, 1,000.
TECHNICAL
removed a n d s u b j e c t e d to one of two processes. I n the first, i t was reduced in volume b y e v a p o r a t i o n u n d e r v a c u u m a t room t e m p e r a ture. D r y i n g was completed u n d e r v a c u u m a t 48 C. This f r a c t i o n , therefore, consisted s i m p l y of the water-soluble m a t e r i a l in soy flour. I n the second, t h e s u p e r n a t a n t was a d j u s t e d to p t t 10.6 with sodium h y d r o x i d e a n d held a t 37 C f o r five hours. The p H was t h e n rea d j u s t e d to 6.4 with the same r a t i o of h y d r o chloric a n d p h o s p h o r i c acid used previously. The a l k a l i - t r e a t e d e x t r a c t was t h e n t a k e n to d r y n e s s in t h e same w a y as the u n t r e a t e d extract. E a c h of the dried e x t r a c t s was added to a diet c o n t a i n i n g ] 2 % p r o t e i n f r o m casein. Thus, three diets were f o r m u l a t e d : casein alone, casein plus u n t r e a t e d e x t r a c t of soy flour, a n d casein plus a l k a l i - t r e a t e d e x t r a c t of soy flour. The composition o£ these diets is p r e s e n t e d in Table 2. The level o£ dried soy e x t r a c t is equivalent in water-soluble soy d r y m a t t e r to the level of soy flour used in the p r e v i o u s trial. E a c h diet was f e d ad libitum to seven w e a n l i n g r a t s f o r 21 days. The m e a n cumulative change
e-----e U N T R E A T E D 2O
o
;~
271
TABLE 2. Composition of diets for rats. Casein plus dried soy
extract diets
Casein diet
Ingredients
- - ( % ) - Casein Dried soy extract Corn starch Cellulose Wesson oil Miueral mix a Vitamins Cod liver oil
13.4 ...... 76.1 2.0 5.0 3.0 b 0.5
13.4 4.2 71.9 2.0 5.0 3.0 b 0.5
Salt Mix W, Nutritional Biochemicals Corporation, Cleveland, Ohio. b See Table 1. in body w e i g h t o n each diet is p r e s e n t e d in Fig. 3. All of the diets p r o d u c e d a s i m i l a r g r o w t h response. Since t h e r e was no evidence of ~ ' o w t h s u p p r e s s i o n b y the u n t r e a t e d soy extract, it does n o t seem likely t h a t the g r o w t h r e s p o n s e f r o m alkali t r e a t m e n t i n p r e v i o u s trials can be a t t r i b u t e d t o the d e s t r u c t i o n of a water-soluble g r o w t h inhibitor. F u r t h e r observations on the p o s s i b i l i t y of a
SOY F L O U R
[]ACID-TREATED FLOUR ~ALKALI-TREATED SOY FLOUR
I-..1(.9
NOTES
SOY /
15
~ 120 ~loo I-"1" L9 m hi
>a o
80
=
= UNTREATED SOY FLOUR
[]
[] A C I D - T R E A T E D SOY FLOUR
zx
n ALKALI-TREATED SOY F L O U R
o
o CASEIN
/
/
rn
>O 0
z
-10
LU (..9 Z
Z
"r" h.I >
I.l.I (.9 Z
5
"I-
6O
40
t-W
._1
>
~
D ,O
20
..1
O Z
o
w
I
I i
I 2
i I I I 5 4 5 6 WEEKS Fro. 1. Mean cumulative changes in body weight of calves fed milk replacers containing soy flour. T h e curves for acid-treated flour and untreated flour are a summary of previous work (1), representing mean gains for 21 and 11 calves, respectively.
0
Z
tlJ I
I I
I I I 2 5 4 WEEKS Fm. 2. M e a n c u m u l a t i v e c h a n g e s i n b o d y weight of ra£s fed diets containing casein, untreated soy flour, acid-treated soy flour, or alkali-treated soy flour. J . DAIRY SCIENCE ~OL. 52, NO. 2
272
JOURNAL OF DAIRY SCIENCE
growth inhibitor were made in a fourth trial with calves. Soy flour was suspended in water (1:9) at 3 C for 12 hours. This mixture was stirred frequently during the first six to eight hours and allowed to settle during the latter portion of the extraction period. The supernatant portion was removed by siphon and used to reconstitute a commercial milk replacer containing only milk protein, 24%. The ratio of replacer to liquid soy extract was 15:85. I n its content of water-soluble soy dry matter, this diet was approximately equivalent to the soy flour replacers used in previous trials. The control diet in this study was the commercial milk replacer reconstituted in water, 15:85. Each diet was fed to two calves f o r four weeks. Care and feeding was the same as in the previous calf trial. The mean gains in body weight were similar f o r both diets (Fig. 4). Since there was no evidence of growth suppression in the soy extract diet, these results are in accord with those of the previous trial with rats.
value o£ fully cooked soy flour for the young calf and the young rat is improved by treatment with either acid or alkali. Though the cause-and-effect relationship between treatment and animal response is unknown, the improvement in growth does not appear to result from the destruction of a water-soluble growth inhibitor in the flour. The possibility of a waterinsoluble inhibitor to which the young animal is particularly sensitive still exists. I t is also possible that growth improvement by treatment with acid or alkali is mediated through the chemical alteration of some nutrient in soy flour, thereby making it more available to t h e animal. B. M. C O L V I N * and H. A. RAMSEY, Department of Animal Science, North Carolina State University, Raleigh
8 Present address: Department of Biochemistry, Oklahoma State University, Stil]water. Acknowledgments
Discussion
Though animal numbers were small, this study provided evidence that the nutritional
120 n," ~.100 T
o
oCASEIN
¢
= C A S E I N + UNTREATED
20t
/
H
80
)Q om
60
z
o om
~lo
hi (.9
Z
z
-r L) W
~ 4o
L) hi
>_5 I--._1
~ 2o _J
u
Z
OMILK REPLACER IN WATER ; M I L K REPLACER IN EXTRACT OF UNTREATED SOY FLOUR
TREATED E X T R A C T / / /
LIJ
z
o
=
EXTRACT OF SOY FLOUR / OASE,N + A L K A L , -
(9
The authors are particularly grateful to the Moorman Manufacturing Company, Quincy, Illinois, for financial support. Gratitude is ex-
0
z
0
.
.
.
.
.
m
w I I
I 2
I 5
WEEKS Fm. 3. Mean cumul~ivechangesin body weight of rats fed diets containlng casein alone or casein plus an untreated or alkali-treated extract of soy flour. J . DAIRY SCIENCE VOL, 52, NO. 2
I I
I 2
I 3
I 4
WEEKS FIe. 4. Mean cumulative changes in body weight of calves fed a commercial milk replacer reconstituted in water alone or in a water extract of untreated soy flour.
T E C H N I C A L NOTES
pressed also to the following companies for contributing various products used in some of the experimental diets: Foremost Dairies, Inc., San Francisco, California, lactose; Procter and Gamble Company, Cincinnati, Ohio, hydrogenated vegetable oil; Nopco Chemical Company, Newark, New Jersey, methionlne and vitamin mix; a~ld
273
American Cyanamid Company, New York, New York, chlortctraeycline. Reference
(1) Colvin, B. M., and tI. A. l~amsey. 1968. Soy flour in milk replacer for young calves. J. Dairy Sci., 51: 898.
Arteriosclerosis in Forestomach-Bypass Calves I Abstract
The occurrence of arteriosclerosis in two forestomach-bypass calves (esophagealabomasal anastomosis) of 8.5 and 11 months of age is reported. Lesions were seen on the endocardial surfaces of the atrial and ventricular walls of the heart and in the pulmonary artery. Of two surgically unaltered calves, '11 months old, one displayed slight arter[dsclerotic changes, located in the pulmonary artery. All calves were fed commercial milk replacer as their only feed. The fore-stomach-bypass calves had poor appetites for several months before death. The surgically unaltered calves appeared healthy, whereas the forestomach-bypass calves were underweight and appeared unthrifty. Numerous degenerative lesions were found in various organs of the forestomach-bypass calves. The original work on this project dealt with techniques for esophageal-abomasal anastomosis (forestomach-bypass surgery) and the nutrient needs of forestomach-bypass calves. The occurrence of arteriosclerosis in young ruminants, as found in these calves, is uncommon (1). Elucidation of the pathogenesis of arteriosclerosis in experimental animals may lead to an understanding of this disorder in man. New ways to produce this disease in animals are of importance. The occurrence of arteriosclerosis in forestomach-bypass calves under one year of age is reported. F o u r Holstein calves were examined at postmortem. Data pertinent to these animals are as follows: A, female, 8.5 months old; B, male, 11 months old; C, male, 11 months old; D, male, 11 months old. Calves C and D were euthanatized by injecting saturated magnesium sulfate solution into the jugular vein; Calves A and B died from a p p a r e n t toxemia and were examined within one to three hours after death, l%restomach-bypass surgery (esophageal-abomasal anastomosis) had been
performed on Calves A and B at three months and three weeks of age, respectively (6). All calves were given milk replacer beginning at about three days of age as their only feed. The forestomach-bypass calves, A and B, appeared unthrifty and often had bloat, while the surgically unaltered calves, C and D, appeared healthy. Body weights of the calves at termination were A, 122 kg; B, 146 kg; C, 343 kg; D, 272 kg. During the last several months of life feed consumption of the forestomach-bypass calves was very poor. Arteriosclerotic lesions were noted in the forestomach-bypass calves, A and B, but not in the surgically unaltered calves, C and D, with the exception of an arterioseIerotic lesion in the pulmonary artery of Calf D. Irregular outlines of raised whitish material were seen on the endocardial surface of the left atrial and ventricular walls of Calf A. Calf B showed similar but more extensive lesions. Atrial lesions were seen. Prominent and rough plaques were seen on the medial and lateral walls of the left ventricle from the aortic valve to the apex. Plaques also occurred in the pulmonary arteries (Fig. 1). The myocardium was irregularly mottled. I n addition to arteriosclerosis, numerous gross pathologic changes were seen in the forestomach-bypass calves. The digestive tract in both animals was atonic, displayed little muscular development, and contained gravel, sawdust, and large amounts of gas and some hairballs. The ruminal and omasal mucosa of Calf A was yellow and easily peeled away and the abomasal mucosa was inflamed. These changes were absent in Calf B; however, the duodenum revealed inflammation of mueosal and serosal surfaces. The gall bladder in both calves was greatly distended, with pale yellow bile. The lungs from Calf A appeared mottled on the surface and areas of atelectasis were present. The lungs from Calf B displayed patchy reddening and small fibrotie nodules about 3 mm in diameter. On gross examination the adrenal glands from Calf A had pin-point red areas J. DAIRY SCIEI~'OE ~rOL. 52, NO. 2