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Performance of Calves Fed Combinations of Whole Milk and Reconstituted Skim Milk Powder
Performance of Calves Fed Combinations of Whole Milk and Reconstituted Skim Milk Powder K. J. J E N K I N S and A . B O N A 1 Animal Research Centre 2 Research Branch Agriculture Canada Ottawa, Ontario K1A 0C6 ABSTRACT
A 52-d study with 24 3-d-old calves compared the effect of feeding whole milk (controls) or milk diluted 1:1 or 1:3 with reconstituted skim milk powder (10%, wt/wt) on calf performance to weaning at 38 d. Skim powder diets were supplemented with vitamins and trace minerals. Liquid diet was fed at 5% body weight twice daily for 24 d, then once daily for 14 d followed by abrupt weaning. Starter was provided for ad libitum intake from 14 to 52 d. F o r the first 13 d, controls had the greatest weight gains, but at 38 and 52 d, gains were similar for all groups. Threequarters of the whole milk diet could be replaced with reconstituted skim milk powder (10% wt/wt) without any reduction in calf gain to weaning because starter intake increased 23%. INTRODUCTION
Many dairy producers feed whole milk to calves up to weaning despite its high cost. Some reasons include convenience, lack of confidence in commercial milk replacers, and a need to utilize milk produced over quota. One useful m e t h o d of reducing cost of feeding whole milk to calves would be to replace part of it with reconstituted skim milk powder. G o o d quality skim milk powder can be obtained relatively cheaply since there is a large surplus on world markets. When reconstituted, skim milk powder contains virtually all the nutritional value of whole milk except energy
Received February 9, 1987. Accepted April 17, 1987. I IAPAR, (Agriculture Research Institute of the State of Parana) CAIXA POSTAL 2301. 80.000, Curitibia-pr., Brazil. Contribution Number 1459. 1987 J Dairy Sci 70:2091-2094
content is lower. When mixed with milk, the fat concentration is reduced, but even at high proportions of skim milk with milk, sufficient fat remains to support good calf growth. A distinct advantage of skim milk powder over commercial milk replacers is that the quality of the product can be assured more easily. Most skim powders are of high quality, whereas there are no simple tests to determine milk replacer quality, which can vary depending or the content of poorly utilizable ingredients and the manufacturing procedures used. Also, skim powders tend be more resistant than milk replacer to deterioration during storage due to low fat content. This study compared the performance of calves fed whole milk and calves fed milk diluted 1:1 (1 part milk: 1 part skim) or 1:3 (1 part milk: 3 parts skim) with reconstituted skim milk powder (10%, wt/wt) to weaning at 38 d and then fed starter ration to 52 d. Early weaning minimized costs for feed and labor and minimized digestive upsets, which are more c o m m o n during milk feeding (3).
MATERIALS
AND METHODS
Calves and Diets
The Animal Research Centre dairy cattle breeding herd provided male calves. After receiving colostrum for the first 3 d, 24 calves were assigned in equal numbers to the three dietary treatments in a manner that provided a similar starting weight and the same number of purebreds, Holstein (H) or Ayrshire (A), and crossbreds (HA) for each lot. Calves were housed in individual pens with expanded metal floors in a heated, insulated, forced-air ventilated room. Water was provided for ad libitum consumption. When there was indication of respiratory infection (rectal temperatures exceeding 39.5°C), calves were treated with Reverin (pyrrolidinomethylte-
2091
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JENKINS AND BONA
TABLE 1. Composition of liquid diets (g/100 g).
Ingredient 1 Whole milk Reconstituted skim milk powder 2 Vitamin premix Micromineral premix Dry matter content, % Dry matter composition, % Protein (N × 6.38) Lactose 3 Lipid
Whole milk control
Whole milk + skim, 2 1 : 1
Whole milk + skim, a 1:3
100.0 ... . . . 12.6
49.72 49.72 28 .28 11.0
24.87 74.61 .26 .26 10.2
30.5 45.0 16.4
32.3 49.2 9.5
.
.
27.8 38.1 28.6
I Skim milk powder, low temperature (94.3% dry matter, 34.0% protein, .09% lipid), Gay Lea Foods Co-op Ltd., Guelph, Ont. Micromineral premix to supply (mg/kg diet dry matter):Kl, 1;FeSO,'7HaO, 500; ZnO, 60; CuSO4.5H20, 40; MnSO4.H~O, 120; Na2SeO4.10H20, .5; and Na2MoO,.2HaO, 2.5. Vitamin premix to supply (mg/kg diet dry matter): pyridoxine, 30; nicotinic acid, 20; riboflavin, 2; vitamin Bla, .04; pantothenic acid, 10; folic acid, 1; thiamine, 5; d-biotin, .5; and per kilogram of diet dry matter, vitamin A, 10,000 IU; vitamin D~, 2000 IU; vitamin E, 50 IU. 2 Reconstituted skim milk powder, 10% (wt/wt). 3 Lactose values were calculated from Atlas o f Nutritional Data on United States and Canadian Feeds (2).
t r a c y c l i n e ; C a n a d i a n H o e c h s t Ltd., M o n t r e a l , P.
Q.) The three dietary treatments consisted of w h o l e m i l k a n d m i l k d i l u t e d 1:1 or 1:3 w i t h r e c o n s t i t u t e d skim m i l k p o w d e r (10% w t / w t ) ; t h e l a t t e r t w o diets were f o r t i f i e d w i t h v i t a m i n s a n d t r a c e m i n e r a l s ( T a b l e 1). Diets c o n t a i n i n g s k i m m i l k p o w d e r were p r e p a r e d weekly, were s t o r e d at --5°C, a n d were t h a w e d a n d w a r m e d t o 3 7°C p r i o r t o feeding. Calves were fed liquid diet t w i c e a day u p t o 2 4 d a n d t h e n given o n l y t h e a.m. feeding for d 25 to 38 t o e n c o u r a g e c o n s u m p t i o n o f s t a r t e r r a t i o n ( T a b l e 2). L i q u i d diet was l i m i t e d t o 2 . 0 kg p e r f e e d i n g for t h e first 3 d o n t e s t f o l l o w e d
b y 5% o f liveweight for each o f t h e r e m a i n i n g feedings. Calves were weighed w h e n feed t r e a t m e n t s c h a n g e d a n d at w e e k l y intervals a n d liquid diet allowances a d j u s t e d accordingly. W e a n i n g was d o n e a b r u p t l y a f t e r 38 d. Fresh s t a r t e r r a t i o n ( T a b l e 3) was p r o v i d e d daily f o r ad l i b i t u m c o n s u m p t i o n f r o m d 14 t o 52.
Analyses All analyses o n milk, skim m i l k p o w d e r , a n d s t a r t e r r a t i o n f o r dry m a t t e r , p r o t e i n , a n d lipid were t h o s e of t h e A s s o c i a t i o n of Official A n a l y t i c a l C h e m i s t s (1).
TABLE 2. Feeding procedure for calves. Liquid diet Time on experiment, d
a.m.
p.m.
Starter ration
0--3 4-24 25--38
2.0 kg 5% BW 5% BW
2.0 kg 5% BW Nil
39-52
0
0
0 Starter ration provided for ad libitum consumption from d 14 to 52
Journal of Dairy Science Vol. 70, No. 10, 1987
FEEDING CALVES RECONSTITUTED SKIM MILK POWDER TABLE 3. Composition of calf starter ration.
2093
RESULTS A N D DISCUSSION
Ingredient
(%)
Rolled barley Ground corn Wheat bran Soybean meal (49% CP) Dehydrated alfalfa meal (17% CP) Molasses Limestone Dicalcium phosphate Trace mineralized salt I Vitamin mix 2
37.4 25.0 5.0 20.0 5.0 5.0 .7 .5 .4 1.0
Crude protein content (% DM): 19.0 1Composed of (%) CuSO4"SH20, .5; ZnSO 4, 1.0; MnSO 4-H20 , 1.0; Na~SOa, 17.0; cobalt-iodized salt, 74.5; MgO, 6.0. UProvided in 1000 kg of ration: 4.5 × 106 IU stabilized vitamin A, 7.2 × l0 s IU stabilized vitamin D3, and 4.5 × 104 IU stabilized vitamin E.
Statistics
Data w e r e a n a l y z e d statistically b y analysis o f variance and D u n c a n ' s m u l t i p l e range t e s t using 5% p r o b a b i l i t y (4).
Calves in atl t h r e e lots p e r f o r m e d well t h r o u g h o u t t h e 52-d e x p e r i m e n t ; n o n e died a n d i n c i d e n c e o f diarrhea and r e s p i r a t o r y i n f e c t i o n was low. All liquid diets w e r e c o n s u m e d readily and f e e d refusals for each t r e a t m e n t w e r e f e w . F o r t h e first 13 d, w h e n o n l y liquid diet was fed, calves o n w h o l e milk ( c o n t r o l s ) had sign i f i c a n t l y b e t t e r gains t h a n t h o s e fed t h e 1 : 1 or 1:3 c o m b i n a t i o n s o f w h o l e m i l k and r e c o n s t i t u t e d skim milk p o w d e r (Table 4). T h e relative w e i g h t gains a m o n g t r e a t m e n t s closely f o l l o w e d t h e e n e r g y densities o f t h e diets, w h i c h w e r e 72, 56, and 4 8 k c a l / l O 0 ml m i l k replacer f o r diets 1, 2, and 3. S t a r t e r r a t i o n was p r o v i d e d f o r ad l i b i t u m c o n s u m p t i o n starting at 14 d, a n d w i t h this change, t h e calves fed t h e 1 : 3 d i e t and c o n t r o l s h a d similar overall gains at 24 d. Gains for t h e calves fed 1:1 diet, h o w e v e r , r e m a i n e d b e h i n d t h e c o n t r o l s . Calves t h e n were r e s t r i c t e d t o o n l y o n e daily f e e d i n g o f liquid diet f o r 2 wk. With this change, at 38 d t h e average gains for all lots w e r e similar d u e t o a 15 and 23% higher i n t a k e o f s t a r t e r r a t i o n by t h e 1:1 a n d 1:3 calves over c o n t r o l s during this interval. Calves w e r e
TABLE 4. Effect of partial replacement of whole milk with reconstituted skim milk powder on c~f performance. Liquid diet Item Number of calves Starting weight, kg Average cumulative gain, kg 13 d 24 d 38 d 52 d
Whole milk control
Whole milk + skim 1 1:1
Whole milk + skim I 1:3
SE
8 42.3
8 40.9
8 43.0
113
3.6 a 8.2 a 22.9 37.5
2.6 b 6.6 b 21.8 36.9
2.4 b 7.2 ah 21.5 37.7
.3 .5 1.1 1.4
16.5 ab 9.4 7.1
15.4 b 4.7 10.7
18.3 a 51.0 a
19.5 a 52.4 a
Average cumulative dry matter intake, kg Liquid diet Entire experiment 17.9 a From milk 17.9 From skim I ... Starter d 14-38 15.9 b Entire experiment 45.3 b
.5 . .. ... .7 1.5
a'bltems in rows with unlike superscripts differ (P<.05). 1 Skim milk powder (94.3% DM) reconstituted at 10% (wt/wt). Whole milk (12.6% DM) and skim combined on a weight basis. Journal of Dairy Science Vol. 70, No. 10, 1987
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JENKINS AND BONA
weaned abruptly on the 39th d and after 2 wk starter ration weight gains remained similar for all lots. During this period, intake of starter tended to be lower for the controls than for the other treatments but not statistically different. Although the average daily gain ( A D G ) f o r calves fed each diet was similar for the 52 d experiment (approximately .7 kg/d), composition of the three diets contributing to that gain was markedly different. From liquid diet, dry matter consumption per calf was 17.9 kg from whole milk for the controls, 9.4 kg from whole milk plus 7.1 kg from skim for the 1:1 lot, and 4.7 kg from whole milk plus 10.7 kg from skim for the 1:3 group (Table 4). Weight gain data for the 1:3 lot showed that it was possible to replace three-quarters of the whole milk with reconstituted skim milk powder at 10% (wt/wt) without any reduction in calf performance. There was a 23% increase in starter ration consumption over controls, but this represented a minor increase in feed cost. Conclusion
With the simple feeding procedure outlined, as much as three-quarters of whole milk fed to calves up to weaning could be replaced by reconstituted skim milk powder (10% (wt/wt), fortified with vitamins and minerals) without any reduction in calf performance. In countries with a milk surplus, diluting over-quota milk with reconstituted skim milk powder would permit producers to extend the milk used for calf feed or enable more replacement and dairy beef calves to be raised to weaning at lower cost
Journal of Dairy Science Vol. 70, No. 10, 1987
per animal. A low price for the skim powder would be required. In countries with milk shortages, use of reconstituted skim milk powder could free three-quarters of the milk normally fed to calves for the domestic fluid market. Also, if much of the milk consumed by the public were whole milk, the same principle might be utilized again to stretch the milk supply further by diluting whole milk with reconstituted, high quality skim milk powder to 2% fat and encouraging the consumption of this product. ACKNOWLEDGMENTS
The authors gratefully acknowledge the technical assistance of G. Griffith and caring of the calves by D. Featherston and staff. The Canadian International Development Agency provided financial support for this study as part of an Agriculture Canada-Brazil cooperative dairy cattle project. REFERENCES
1 Association of Official Agricultural Chemists. 1970. official methods of analysis. 1lth ed. Assoc. Offic. Agric. Chem., Washington, DC. 2 Atlas of Nutritional Data on United States and Canadian Feeds. 1971. Natl. Acad. Sci., Washington, DC. 3 Gorrill, A.D.L. 1972. Feeding and nutrition of young replacement and veal calves. Digestive physiology and nutrition of ruminants. Vol. 3. D. C. Church, ed. Oregon State Univ. Bookstores Inc., Corvallis. 4 Steel, R.G.D., and J. H. Torrie. 1960. Principles and procedures of statistics. McGraw-Hill Book Co., Inc., New York, NY.
A 52-d study with 24 3-d-old calves compared the effect of feeding whole milk (controls) or milk diluted 1:1 or 1:3 with reconstituted skim milk powder (10%, wt/wt) on calf performance to weaning at 38 d. Skim powder diets were supplemented with vitamins and trace minerals. Liquid diet was fed at 5% body weight twice daily for 24 d, then once daily for 14 d followed by abrupt weaning. Starter was provided for ad libitum intake from 14 to 52 d. F o r the first 13 d, controls had the greatest weight gains, but at 38 and 52 d, gains were similar for all groups. Threequarters of the whole milk diet could be replaced with reconstituted skim milk powder (10% wt/wt) without any reduction in calf gain to weaning because starter intake increased 23%. INTRODUCTION
Many dairy producers feed whole milk to calves up to weaning despite its high cost. Some reasons include convenience, lack of confidence in commercial milk replacers, and a need to utilize milk produced over quota. One useful m e t h o d of reducing cost of feeding whole milk to calves would be to replace part of it with reconstituted skim milk powder. G o o d quality skim milk powder can be obtained relatively cheaply since there is a large surplus on world markets. When reconstituted, skim milk powder contains virtually all the nutritional value of whole milk except energy
Received February 9, 1987. Accepted April 17, 1987. I IAPAR, (Agriculture Research Institute of the State of Parana) CAIXA POSTAL 2301. 80.000, Curitibia-pr., Brazil. Contribution Number 1459. 1987 J Dairy Sci 70:2091-2094
content is lower. When mixed with milk, the fat concentration is reduced, but even at high proportions of skim milk with milk, sufficient fat remains to support good calf growth. A distinct advantage of skim milk powder over commercial milk replacers is that the quality of the product can be assured more easily. Most skim powders are of high quality, whereas there are no simple tests to determine milk replacer quality, which can vary depending or the content of poorly utilizable ingredients and the manufacturing procedures used. Also, skim powders tend be more resistant than milk replacer to deterioration during storage due to low fat content. This study compared the performance of calves fed whole milk and calves fed milk diluted 1:1 (1 part milk: 1 part skim) or 1:3 (1 part milk: 3 parts skim) with reconstituted skim milk powder (10%, wt/wt) to weaning at 38 d and then fed starter ration to 52 d. Early weaning minimized costs for feed and labor and minimized digestive upsets, which are more c o m m o n during milk feeding (3).
MATERIALS
AND METHODS
Calves and Diets
The Animal Research Centre dairy cattle breeding herd provided male calves. After receiving colostrum for the first 3 d, 24 calves were assigned in equal numbers to the three dietary treatments in a manner that provided a similar starting weight and the same number of purebreds, Holstein (H) or Ayrshire (A), and crossbreds (HA) for each lot. Calves were housed in individual pens with expanded metal floors in a heated, insulated, forced-air ventilated room. Water was provided for ad libitum consumption. When there was indication of respiratory infection (rectal temperatures exceeding 39.5°C), calves were treated with Reverin (pyrrolidinomethylte-
2091
2092
JENKINS AND BONA
TABLE 1. Composition of liquid diets (g/100 g).
Ingredient 1 Whole milk Reconstituted skim milk powder 2 Vitamin premix Micromineral premix Dry matter content, % Dry matter composition, % Protein (N × 6.38) Lactose 3 Lipid
Whole milk control
Whole milk + skim, 2 1 : 1
Whole milk + skim, a 1:3
100.0 ... . . . 12.6
49.72 49.72 28 .28 11.0
24.87 74.61 .26 .26 10.2
30.5 45.0 16.4
32.3 49.2 9.5
.
.
27.8 38.1 28.6
I Skim milk powder, low temperature (94.3% dry matter, 34.0% protein, .09% lipid), Gay Lea Foods Co-op Ltd., Guelph, Ont. Micromineral premix to supply (mg/kg diet dry matter):Kl, 1;FeSO,'7HaO, 500; ZnO, 60; CuSO4.5H20, 40; MnSO4.H~O, 120; Na2SeO4.10H20, .5; and Na2MoO,.2HaO, 2.5. Vitamin premix to supply (mg/kg diet dry matter): pyridoxine, 30; nicotinic acid, 20; riboflavin, 2; vitamin Bla, .04; pantothenic acid, 10; folic acid, 1; thiamine, 5; d-biotin, .5; and per kilogram of diet dry matter, vitamin A, 10,000 IU; vitamin D~, 2000 IU; vitamin E, 50 IU. 2 Reconstituted skim milk powder, 10% (wt/wt). 3 Lactose values were calculated from Atlas o f Nutritional Data on United States and Canadian Feeds (2).
t r a c y c l i n e ; C a n a d i a n H o e c h s t Ltd., M o n t r e a l , P.
Q.) The three dietary treatments consisted of w h o l e m i l k a n d m i l k d i l u t e d 1:1 or 1:3 w i t h r e c o n s t i t u t e d skim m i l k p o w d e r (10% w t / w t ) ; t h e l a t t e r t w o diets were f o r t i f i e d w i t h v i t a m i n s a n d t r a c e m i n e r a l s ( T a b l e 1). Diets c o n t a i n i n g s k i m m i l k p o w d e r were p r e p a r e d weekly, were s t o r e d at --5°C, a n d were t h a w e d a n d w a r m e d t o 3 7°C p r i o r t o feeding. Calves were fed liquid diet t w i c e a day u p t o 2 4 d a n d t h e n given o n l y t h e a.m. feeding for d 25 to 38 t o e n c o u r a g e c o n s u m p t i o n o f s t a r t e r r a t i o n ( T a b l e 2). L i q u i d diet was l i m i t e d t o 2 . 0 kg p e r f e e d i n g for t h e first 3 d o n t e s t f o l l o w e d
b y 5% o f liveweight for each o f t h e r e m a i n i n g feedings. Calves were weighed w h e n feed t r e a t m e n t s c h a n g e d a n d at w e e k l y intervals a n d liquid diet allowances a d j u s t e d accordingly. W e a n i n g was d o n e a b r u p t l y a f t e r 38 d. Fresh s t a r t e r r a t i o n ( T a b l e 3) was p r o v i d e d daily f o r ad l i b i t u m c o n s u m p t i o n f r o m d 14 t o 52.
Analyses All analyses o n milk, skim m i l k p o w d e r , a n d s t a r t e r r a t i o n f o r dry m a t t e r , p r o t e i n , a n d lipid were t h o s e of t h e A s s o c i a t i o n of Official A n a l y t i c a l C h e m i s t s (1).
TABLE 2. Feeding procedure for calves. Liquid diet Time on experiment, d
a.m.
p.m.
Starter ration
0--3 4-24 25--38
2.0 kg 5% BW 5% BW
2.0 kg 5% BW Nil
39-52
0
0
0 Starter ration provided for ad libitum consumption from d 14 to 52
Journal of Dairy Science Vol. 70, No. 10, 1987
FEEDING CALVES RECONSTITUTED SKIM MILK POWDER TABLE 3. Composition of calf starter ration.
2093
RESULTS A N D DISCUSSION
Ingredient
(%)
Rolled barley Ground corn Wheat bran Soybean meal (49% CP) Dehydrated alfalfa meal (17% CP) Molasses Limestone Dicalcium phosphate Trace mineralized salt I Vitamin mix 2
37.4 25.0 5.0 20.0 5.0 5.0 .7 .5 .4 1.0
Crude protein content (% DM): 19.0 1Composed of (%) CuSO4"SH20, .5; ZnSO 4, 1.0; MnSO 4-H20 , 1.0; Na~SOa, 17.0; cobalt-iodized salt, 74.5; MgO, 6.0. UProvided in 1000 kg of ration: 4.5 × 106 IU stabilized vitamin A, 7.2 × l0 s IU stabilized vitamin D3, and 4.5 × 104 IU stabilized vitamin E.
Statistics
Data w e r e a n a l y z e d statistically b y analysis o f variance and D u n c a n ' s m u l t i p l e range t e s t using 5% p r o b a b i l i t y (4).
Calves in atl t h r e e lots p e r f o r m e d well t h r o u g h o u t t h e 52-d e x p e r i m e n t ; n o n e died a n d i n c i d e n c e o f diarrhea and r e s p i r a t o r y i n f e c t i o n was low. All liquid diets w e r e c o n s u m e d readily and f e e d refusals for each t r e a t m e n t w e r e f e w . F o r t h e first 13 d, w h e n o n l y liquid diet was fed, calves o n w h o l e milk ( c o n t r o l s ) had sign i f i c a n t l y b e t t e r gains t h a n t h o s e fed t h e 1 : 1 or 1:3 c o m b i n a t i o n s o f w h o l e m i l k and r e c o n s t i t u t e d skim milk p o w d e r (Table 4). T h e relative w e i g h t gains a m o n g t r e a t m e n t s closely f o l l o w e d t h e e n e r g y densities o f t h e diets, w h i c h w e r e 72, 56, and 4 8 k c a l / l O 0 ml m i l k replacer f o r diets 1, 2, and 3. S t a r t e r r a t i o n was p r o v i d e d f o r ad l i b i t u m c o n s u m p t i o n starting at 14 d, a n d w i t h this change, t h e calves fed t h e 1 : 3 d i e t and c o n t r o l s h a d similar overall gains at 24 d. Gains for t h e calves fed 1:1 diet, h o w e v e r , r e m a i n e d b e h i n d t h e c o n t r o l s . Calves t h e n were r e s t r i c t e d t o o n l y o n e daily f e e d i n g o f liquid diet f o r 2 wk. With this change, at 38 d t h e average gains for all lots w e r e similar d u e t o a 15 and 23% higher i n t a k e o f s t a r t e r r a t i o n by t h e 1:1 a n d 1:3 calves over c o n t r o l s during this interval. Calves w e r e
TABLE 4. Effect of partial replacement of whole milk with reconstituted skim milk powder on c~f performance. Liquid diet Item Number of calves Starting weight, kg Average cumulative gain, kg 13 d 24 d 38 d 52 d
Whole milk control
Whole milk + skim 1 1:1
Whole milk + skim I 1:3
SE
8 42.3
8 40.9
8 43.0
113
3.6 a 8.2 a 22.9 37.5
2.6 b 6.6 b 21.8 36.9
2.4 b 7.2 ah 21.5 37.7
.3 .5 1.1 1.4
16.5 ab 9.4 7.1
15.4 b 4.7 10.7
18.3 a 51.0 a
19.5 a 52.4 a
Average cumulative dry matter intake, kg Liquid diet Entire experiment 17.9 a From milk 17.9 From skim I ... Starter d 14-38 15.9 b Entire experiment 45.3 b
.5 . .. ... .7 1.5
a'bltems in rows with unlike superscripts differ (P<.05). 1 Skim milk powder (94.3% DM) reconstituted at 10% (wt/wt). Whole milk (12.6% DM) and skim combined on a weight basis. Journal of Dairy Science Vol. 70, No. 10, 1987
2094
JENKINS AND BONA
weaned abruptly on the 39th d and after 2 wk starter ration weight gains remained similar for all lots. During this period, intake of starter tended to be lower for the controls than for the other treatments but not statistically different. Although the average daily gain ( A D G ) f o r calves fed each diet was similar for the 52 d experiment (approximately .7 kg/d), composition of the three diets contributing to that gain was markedly different. From liquid diet, dry matter consumption per calf was 17.9 kg from whole milk for the controls, 9.4 kg from whole milk plus 7.1 kg from skim for the 1:1 lot, and 4.7 kg from whole milk plus 10.7 kg from skim for the 1:3 group (Table 4). Weight gain data for the 1:3 lot showed that it was possible to replace three-quarters of the whole milk with reconstituted skim milk powder at 10% (wt/wt) without any reduction in calf performance. There was a 23% increase in starter ration consumption over controls, but this represented a minor increase in feed cost. Conclusion
With the simple feeding procedure outlined, as much as three-quarters of whole milk fed to calves up to weaning could be replaced by reconstituted skim milk powder (10% (wt/wt), fortified with vitamins and minerals) without any reduction in calf performance. In countries with a milk surplus, diluting over-quota milk with reconstituted skim milk powder would permit producers to extend the milk used for calf feed or enable more replacement and dairy beef calves to be raised to weaning at lower cost
Journal of Dairy Science Vol. 70, No. 10, 1987
per animal. A low price for the skim powder would be required. In countries with milk shortages, use of reconstituted skim milk powder could free three-quarters of the milk normally fed to calves for the domestic fluid market. Also, if much of the milk consumed by the public were whole milk, the same principle might be utilized again to stretch the milk supply further by diluting whole milk with reconstituted, high quality skim milk powder to 2% fat and encouraging the consumption of this product. ACKNOWLEDGMENTS
The authors gratefully acknowledge the technical assistance of G. Griffith and caring of the calves by D. Featherston and staff. The Canadian International Development Agency provided financial support for this study as part of an Agriculture Canada-Brazil cooperative dairy cattle project. REFERENCES
1 Association of Official Agricultural Chemists. 1970. official methods of analysis. 1lth ed. Assoc. Offic. Agric. Chem., Washington, DC. 2 Atlas of Nutritional Data on United States and Canadian Feeds. 1971. Natl. Acad. Sci., Washington, DC. 3 Gorrill, A.D.L. 1972. Feeding and nutrition of young replacement and veal calves. Digestive physiology and nutrition of ruminants. Vol. 3. D. C. Church, ed. Oregon State Univ. Bookstores Inc., Corvallis. 4 Steel, R.G.D., and J. H. Torrie. 1960. Principles and procedures of statistics. McGraw-Hill Book Co., Inc., New York, NY.