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Influence of Zinc Deficiency on Dry Matter Digestibility in Ruminants1
1012
J O U R N A L OF D A I R Y S C I E N C E
Influence of Zinc Deficiency on Dry Matter Digestibility in Ruminants The growth, health, and welt-being of cattle and goats are severely affected by a zinc deficiency (1-5). One of the effects is a reduced voluntary intake of feed. Recently, it was established that when fed at the same level of intake as normal animals, zinc-deficient calves grew at a much slower rate and required considerably more feed per unit of weight gain (5). The purpose of the two experiments herein presented was to determine whether the zinc deficiency affected dry matter digestibility of calves and goats. Experimental Procedure
Two male goats and two Holstein calves were fed a zinc-deficient diet for several weeks while comparable animals were fed the same diet except for addition of zinc. Prior to the experiment the animals were fed practical-type diets including milk replacer and calf starter until 3 or 4 months old. The zinc-deficient basal diet was similar to that used when the effects of a zinc deficiency on feed efllciency were established (5). I t consisted of the following per 100 kg: glucose monohydrate, 19.5 kg; corn starch, 25.0 kg; dried whole whey (spray process), 20.0 kg; cellulose, ]0.0 kg; gelatin (flake, 50-bloom), 10.0 kg; egg albumen (autoclaved), 3.0 kg; urea (feed grade, 42% N), 0.5 kg; KHCO:,, 1.5 kg; NaItCO.~, 2.5 kg; dicalcium phosphate (anhydrous, food grade), 2.0 kg; CaCO.~ (marble dust), 1.0 kg; lard (stabilized), 3.0 kg; Na~SO,~ (anhydrous), 350 g; KC1, 550 g; NaC1, 484 g; MgO (56% Mg), 165 g; Fe,_,(SO,,):~XH._,O (72% Fe by assay), 22 g; MnSO,'H,_,O, 4.4 g; CuSO, 3.1 g; CoCO.~ (45-50% Co by assay), 22 rag; KI, 18 rag; thianfine HC1, 0.9 gl riboflavin (USP), 2.0 g; nicotinic acid (USP), 2.2 g; calcium pantothenate, 3.3 g; pyridoxine HC1, 1.1 g; folic acid (USP), 0.22 g; cyanocobalamin (1 mg B,,., activity/gram), 2.2 g; menadione sodium bisulfite (63%), 0.33 g; d-biotin, 26 rag; all-alpha tocopherol acetate (220 I.U. vitandn E activity/gram), 2.2 g; vitamin A paImitate (250,000 I.U./gram), ]7.6 g; vitamin I)~, (200,000 I.U./gram), 2.2 g; choline C1 (70%), 264 g; and oxytetracycline (25%), 88 g. The basal diet contained 6 ppm zinc on a dry matter basis. The control diet was identical, except for the addition of 40 ppm of supplemental zinc as ZnO. After those animals fed the deficient diet Journal Paper no. 480, College Experiment Station, University of Georgia, Athens. Supported in part by Public Health Service Research Grant no. AM 07367 NTN from the National Institute of Arthritis and Metabolic Diseases.
developed typical clinical symptoms of a zinc deficiency (1, 2), they and comparable controls were accustomed to metabolism crates for 1 wk prior to fecal collections. Thereafter, all the animals within an experiment received the same level of feed intake. They were fed once per day and given water ad libitum. Frequent clinical examinations were made by personnel of the School of Veterinary Medicine, to be certain that the zinc-deficient animals maintained typical symptoms of the defiicieney and that the controls were normal throughout the study. Dry matter digestibility was determined by the total collection procedure. Four consecutive seven-day collection periods were employed for the goats and three nine-day periods for the calves. At the beginning of the first collection period the calves had an average weight of 133 kg and were four or five months of age. The goats weighed 22 kg and were five and one-half months old. Their average weight gain during the period was 36 g/day. The calves were fed 2,975 g of dry matter per day and the goats 450 g. Results and Discussion
Data for the goats and calves are presented in Tables 1 and 2. Zinc deficiency did not affect the dry matter digestibility in either species. Averages for zinc-deficient and control goats were 84.4 and 83.4%, respectively. For calves, the corresponding values were 86.5 and 87.6%. Thus, the over-all aw~rage was 85.4% for the zinc-deficient animals and 85.5% for the controls. Zinc-deficient animals have a slower growth rate than control animals fed at the same level (5). Since dry matter digestibilities were not different, the digested nutrients nmst be utilized less efficiently in zinc-deficient animals than in normal animals. Determining the mechanism which is impaired and responsible for the reduced efficiency in converting digested nutrients to weight gains should be of considerable benefit in understanding the function of zinc in the metabolism of ruminants. Abstract
Previously it was established that when fed at the same level of intake as normal animals, zinc-deficient calves grew at a much slower rate and required more feed per unit of weight gain (5). This research was conducted to determine whether a zinc deficiency affected digestibility in goats and calves. Dry matter digestibility of a purified diet was determined with two zincdeficient and two control goats in four sevenday total collection periods. A comparable experiment was conducted with calves using three
TECHNICAL NOTES
1013
TABLE 1 Dry m a t t e r digestibility of zinc-deficlent and control goats as determined by four seven-day total fecal collectlon periods Period no. Goat no.
Treatment
1
2
3
4
Avg
1 2
Deficient Deficient
81.7 82.8
82.1 84.8
84.9 86.5
86.2 86.6
83.7 85.2
Avg
82.2
83.4
85.7
86.4
84.4
Control Control Avg
82.2 84.7 83.4
83.6 84.4 84.0
83.9 82.9 83.4
82.2 83.5 82.8
83.0 83.9 83.4
3 4
TABLE 2 Dry m a t t e r digestibility of zinc-deficient and control calves as determined by nine-day total fecal collection periods Period no. Calf no.
Treatment
1
2
11 14
Deficient Deficient
83.7 88.7
84.3 87.2
87.0 88.2
85.0 88.0
Avg
86.2
85.8
87.6
86.5
CoNtrol Control
85.6 91.9
84.9 85.6
88.8 88.8
86.4 88.8
Avg
88.8
85.2
88.8
87.6
........................................
12 13
n i n e - d a y collection p e r i o d s . D r y m a t t e r digestibilities were n o t affected b y the zinc deficiency. T h u s , the r e d u c e d f e e d efficiency in zinc-deficient a n i m a l s (5) is c a u s e d by a r e d u c e d u t i l i z a t i o n of digested nutrients.
W. J. MILLER G. W. POWELL and J. M. HIERS, JR. Department of Dairy Science University of Georgia Athens, Georgia Acknowledgments
The authors appreciate the assistance of R. P. Gentl~y, ~V. J. Pitts, P. R. Fowler, and Dr. C. M. Clifton with certain aspects of the work. They thank Dr. D. M. Blaekmon for m a k i n g the clinical examinations of the animals. Appreciation is extended to the K r a f t Foods Company, Garland, Texas, for dried whole whey; to the Chas. Pfizer Company, Terre t i a u t e , Indiana, for antibiotics and vitanfins; to I-Ioffmann-La Roche, Inc., Nutley, STew Jersey, for the biotin; to the Commercial Solvents Conlpany, New York, New York, for cho-
3 (%)
Avg
........................................
line; to Basic Incorporated, Cleveland, Ohio, for m a g p e s i u m oxide; and to the Allied Chemical Company, Atlanta, Georgia, for urea.
References (1) Miller, J. K., and Miller, W. J. 1960. Development of Zinc Deficiency in Holstein Calves F e d a Purified Diet. J. Dairy Sci., 43 : 1854. (2) Miller, J. K., al~d M~ller, W. J. 1962. Experimental Zinc Deficiency and Recovery of Calves. J. Nutrition, 76: 467. (3) Miller, W. J., and Miller, J. K. 1963. Photomicrographs of Skin from Zinc-Deficient Calves. J. Dairy Sci., 46: 1285. (4) Miller, W. J., Morton, J. D., Pitts, W. J., and Clifton, C. M. 1965. Effect of Zinc Deficiency and Restricted Feeding on Wound Healing in the Bovine. Proc. Soc. Exptl. Biol. Med., 118: 427. (5) Miller, W. J., Pitts, W. J., Clifton, C. M., and Morton, J. D. 1965. Effects of Zinc Deficiency per se on Feed Efficiency, Serum Alkaline Phosphatase, Zinc in Skin, Behavior, Greying, and Other Measurements in the Holstein Calf. J. Dairy Sci., 48: 1329.
J O U R N A L OF D A I R Y S C I E N C E
Influence of Zinc Deficiency on Dry Matter Digestibility in Ruminants The growth, health, and welt-being of cattle and goats are severely affected by a zinc deficiency (1-5). One of the effects is a reduced voluntary intake of feed. Recently, it was established that when fed at the same level of intake as normal animals, zinc-deficient calves grew at a much slower rate and required considerably more feed per unit of weight gain (5). The purpose of the two experiments herein presented was to determine whether the zinc deficiency affected dry matter digestibility of calves and goats. Experimental Procedure
Two male goats and two Holstein calves were fed a zinc-deficient diet for several weeks while comparable animals were fed the same diet except for addition of zinc. Prior to the experiment the animals were fed practical-type diets including milk replacer and calf starter until 3 or 4 months old. The zinc-deficient basal diet was similar to that used when the effects of a zinc deficiency on feed efllciency were established (5). I t consisted of the following per 100 kg: glucose monohydrate, 19.5 kg; corn starch, 25.0 kg; dried whole whey (spray process), 20.0 kg; cellulose, ]0.0 kg; gelatin (flake, 50-bloom), 10.0 kg; egg albumen (autoclaved), 3.0 kg; urea (feed grade, 42% N), 0.5 kg; KHCO:,, 1.5 kg; NaItCO.~, 2.5 kg; dicalcium phosphate (anhydrous, food grade), 2.0 kg; CaCO.~ (marble dust), 1.0 kg; lard (stabilized), 3.0 kg; Na~SO,~ (anhydrous), 350 g; KC1, 550 g; NaC1, 484 g; MgO (56% Mg), 165 g; Fe,_,(SO,,):~XH._,O (72% Fe by assay), 22 g; MnSO,'H,_,O, 4.4 g; CuSO, 3.1 g; CoCO.~ (45-50% Co by assay), 22 rag; KI, 18 rag; thianfine HC1, 0.9 gl riboflavin (USP), 2.0 g; nicotinic acid (USP), 2.2 g; calcium pantothenate, 3.3 g; pyridoxine HC1, 1.1 g; folic acid (USP), 0.22 g; cyanocobalamin (1 mg B,,., activity/gram), 2.2 g; menadione sodium bisulfite (63%), 0.33 g; d-biotin, 26 rag; all-alpha tocopherol acetate (220 I.U. vitandn E activity/gram), 2.2 g; vitamin A paImitate (250,000 I.U./gram), ]7.6 g; vitamin I)~, (200,000 I.U./gram), 2.2 g; choline C1 (70%), 264 g; and oxytetracycline (25%), 88 g. The basal diet contained 6 ppm zinc on a dry matter basis. The control diet was identical, except for the addition of 40 ppm of supplemental zinc as ZnO. After those animals fed the deficient diet Journal Paper no. 480, College Experiment Station, University of Georgia, Athens. Supported in part by Public Health Service Research Grant no. AM 07367 NTN from the National Institute of Arthritis and Metabolic Diseases.
developed typical clinical symptoms of a zinc deficiency (1, 2), they and comparable controls were accustomed to metabolism crates for 1 wk prior to fecal collections. Thereafter, all the animals within an experiment received the same level of feed intake. They were fed once per day and given water ad libitum. Frequent clinical examinations were made by personnel of the School of Veterinary Medicine, to be certain that the zinc-deficient animals maintained typical symptoms of the defiicieney and that the controls were normal throughout the study. Dry matter digestibility was determined by the total collection procedure. Four consecutive seven-day collection periods were employed for the goats and three nine-day periods for the calves. At the beginning of the first collection period the calves had an average weight of 133 kg and were four or five months of age. The goats weighed 22 kg and were five and one-half months old. Their average weight gain during the period was 36 g/day. The calves were fed 2,975 g of dry matter per day and the goats 450 g. Results and Discussion
Data for the goats and calves are presented in Tables 1 and 2. Zinc deficiency did not affect the dry matter digestibility in either species. Averages for zinc-deficient and control goats were 84.4 and 83.4%, respectively. For calves, the corresponding values were 86.5 and 87.6%. Thus, the over-all aw~rage was 85.4% for the zinc-deficient animals and 85.5% for the controls. Zinc-deficient animals have a slower growth rate than control animals fed at the same level (5). Since dry matter digestibilities were not different, the digested nutrients nmst be utilized less efficiently in zinc-deficient animals than in normal animals. Determining the mechanism which is impaired and responsible for the reduced efficiency in converting digested nutrients to weight gains should be of considerable benefit in understanding the function of zinc in the metabolism of ruminants. Abstract
Previously it was established that when fed at the same level of intake as normal animals, zinc-deficient calves grew at a much slower rate and required more feed per unit of weight gain (5). This research was conducted to determine whether a zinc deficiency affected digestibility in goats and calves. Dry matter digestibility of a purified diet was determined with two zincdeficient and two control goats in four sevenday total collection periods. A comparable experiment was conducted with calves using three
TECHNICAL NOTES
1013
TABLE 1 Dry m a t t e r digestibility of zinc-deficlent and control goats as determined by four seven-day total fecal collectlon periods Period no. Goat no.
Treatment
1
2
3
4
Avg
1 2
Deficient Deficient
81.7 82.8
82.1 84.8
84.9 86.5
86.2 86.6
83.7 85.2
Avg
82.2
83.4
85.7
86.4
84.4
Control Control Avg
82.2 84.7 83.4
83.6 84.4 84.0
83.9 82.9 83.4
82.2 83.5 82.8
83.0 83.9 83.4
3 4
TABLE 2 Dry m a t t e r digestibility of zinc-deficient and control calves as determined by nine-day total fecal collection periods Period no. Calf no.
Treatment
1
2
11 14
Deficient Deficient
83.7 88.7
84.3 87.2
87.0 88.2
85.0 88.0
Avg
86.2
85.8
87.6
86.5
CoNtrol Control
85.6 91.9
84.9 85.6
88.8 88.8
86.4 88.8
Avg
88.8
85.2
88.8
87.6
........................................
12 13
n i n e - d a y collection p e r i o d s . D r y m a t t e r digestibilities were n o t affected b y the zinc deficiency. T h u s , the r e d u c e d f e e d efficiency in zinc-deficient a n i m a l s (5) is c a u s e d by a r e d u c e d u t i l i z a t i o n of digested nutrients.
W. J. MILLER G. W. POWELL and J. M. HIERS, JR. Department of Dairy Science University of Georgia Athens, Georgia Acknowledgments
The authors appreciate the assistance of R. P. Gentl~y, ~V. J. Pitts, P. R. Fowler, and Dr. C. M. Clifton with certain aspects of the work. They thank Dr. D. M. Blaekmon for m a k i n g the clinical examinations of the animals. Appreciation is extended to the K r a f t Foods Company, Garland, Texas, for dried whole whey; to the Chas. Pfizer Company, Terre t i a u t e , Indiana, for antibiotics and vitanfins; to I-Ioffmann-La Roche, Inc., Nutley, STew Jersey, for the biotin; to the Commercial Solvents Conlpany, New York, New York, for cho-
3 (%)
Avg
........................................
line; to Basic Incorporated, Cleveland, Ohio, for m a g p e s i u m oxide; and to the Allied Chemical Company, Atlanta, Georgia, for urea.
References (1) Miller, J. K., and Miller, W. J. 1960. Development of Zinc Deficiency in Holstein Calves F e d a Purified Diet. J. Dairy Sci., 43 : 1854. (2) Miller, J. K., al~d M~ller, W. J. 1962. Experimental Zinc Deficiency and Recovery of Calves. J. Nutrition, 76: 467. (3) Miller, W. J., and Miller, J. K. 1963. Photomicrographs of Skin from Zinc-Deficient Calves. J. Dairy Sci., 46: 1285. (4) Miller, W. J., Morton, J. D., Pitts, W. J., and Clifton, C. M. 1965. Effect of Zinc Deficiency and Restricted Feeding on Wound Healing in the Bovine. Proc. Soc. Exptl. Biol. Med., 118: 427. (5) Miller, W. J., Pitts, W. J., Clifton, C. M., and Morton, J. D. 1965. Effects of Zinc Deficiency per se on Feed Efficiency, Serum Alkaline Phosphatase, Zinc in Skin, Behavior, Greying, and Other Measurements in the Holstein Calf. J. Dairy Sci., 48: 1329.