Metabolism
of Liquid Whey
Fed to Sheep I M. J. ANDERSON Agricultural Research Service U. S. Department of Agriculture Utah State University, UMC 46 Logan 84322
ABSTRACT
cheese plants. Dairy cows will consume surplus whey in place of other feeds (1, 12, 15). Milk fat depression was prevented in cows fed high concentrate diets by feeding dried whey products (13, 14). Dried whey products (3, 8, 14) and lactose (3, 14) added to rations increased butyrate concentration but did not affect acetate (14). My study was to determine digestibility and volatile fatty acids (VFA) concentration of rations high in liquid whey.
Digestion was studied with three groups of four sheep each fed alfalfa hay. Treatments were whey only, whey plus water, and water only. Digestibilities of dry matter for the three rations were 71.3, 69.7, and 62.9%. Digestibilities of whey solids calculated by difference was 86.9% for whey only and 81.6% for whey plus water. Twelve sheep were in three trials to determine the intake of whey, water, and hay consumption. They were assigned to whey only, whey plus water, and water only. Hay, whey, and water consumption was 1.89, 8.73, and 0; 1.88, 7.62, and 1.21; and 2.05, O, and 6.07 kg per animal daily. Three mature fistulated wether sheep were fed 6 liters of liquid whey daily, and three similar sheep were fed water only. Rumen liquor samples were taken for analysis of volatile fatty acids at 0, 3, and 6 h after whey feeding on each of three alternate days. Alfalfa hay (1.2 kg/animal daily) was fed after the 6-h sampling. Molar percentage of acetic and valeric acids were lower and for butyric acid was higher for sheep fed whey. Propionic acid, acetate:propionate ratio, and total concentration were not affected significantly by whey feeding. Acetic acid decreased from 0 to 3 h, then partly returned to the prefeeding level at 6 h. The reverse was true for butyric acid. Valeric acid and total concentration of volatile fatty acids decreased from 0 to 6 h. Effects of day were unexplained.
EXPERIMENTAL PROCEDURE Digestion Study
I NTRODUCTIDN
Finding alternative methods of whey disposal to replace the discharge of whey into streams and sewers is a problem facing many Received January 24, 1975. 1Research paper 1964 of Utah Agricultural Experiment Station.
Twelve mature wether sheep weighing approximately 78 kg were assigned randomly to three groups of four animals each on one of the following treatments: (a) whey only, (b) whey plus water, and (c) water only. Whey or water, or both, were offered free choice. Chopped alfalfa hay was offered to each animal at 1.3 kg daily. During the preliminary feeding period, the animals had access to a trace mineralized salt and dicalcium phosphorus mixture, but this was not available during the collection period. Trials consisted of a 23-day preliminary period followed by a 10-day collection period. Animals were housed in individual pens during the preliminary period and individual crates during collection. Total collection of feces was saved. A 50-g sample of hay was taken daily. At the end of the trial, feces, hay, and weighbacks were each thoroughly mixed, and each was sampled for chemical analysis. Hay, feces, and weighbacks were analyzed for dry matter (DM), ash, cell walls (CW), acid detergent fiber (ADF), acid detergent lignin (ADL), and nitrogen by procedures described by Goering and Van Soest (7). Except for ash, wet samples of feces were analyzed. Whey intake was measured for animals on treatments A and B, and water intake was measured for animals on treatment C, but water intake was not measured for treatment B.
1856
METABOLISM OF LIQUID WHEY
1857
TABLE 1. Digestion coefficients of whey rations. Criteria
Whey
DM digestibility (%) Protein digestibility (%) Cell wallsfi digestibility (%) ADF b digestibility (%) Whey DM digestibilityc (%) Whey protein digestibilityc (%) % DM of ration from whey % protein of ration from whey Liquid consumed/day (kg/day)
71.3 72.3 56.9 58.3 86.9 73.0 28.9 20.9 7.38
+_ 2.1 a +- 3.5 +- 5.8 +- 3.7 +- 12.3 -+ 19.0 +- 3.6 +- 2.7 -+ 1.14
Whey + water
Water
69.7 74.0 54.6 53.1 81.6 81.6 25.7 17.9 5.04
62.9 +-2.5 72.6 +- 1.2 58.1 +- 3.7 58.0 + 4.6 ••• ... ... ... 3.99 +- .32
+- 2.3 +- 2.5 -+ 1.9 +- 3.9 +- 9.5 +-16.9 +- 4.5 +- 3.3 +- 1.33 d
astandard deviation. bCalculated on the basis of no cell walls or acid detergent fiber in whey. CCalculated by difference when the water only ration was used as the base. d Only whey consumpuon measured. I ntake Study
A f t e r the digestion study, the 12 sheep were used in an intake trial of w h e y and water. Three treatments were used over three periods in a Latin square design. Animals were assigned to one of f o u r replicates. T r e a t m e n t s were (a) w h e y only, (b) w h e y plus water, and (c) water only. Period 1 consisted o f a 15-day preliminary period and a 5-day e x p e r i m e n t a l period. Periods 2 and 3 consisted of a 5-day preliminary and a 5-day experimental period. C h o p p e d alfalfa hay, whey, or water, or w h e y and water were offered ad libitum. Intakes o f hay, whey, and water were measured during the experimental period. Volatile Fatty Acid (VFA) Study
Six mature fistulated wether sheep were assigned r a n d o m l y to t w o groups of three animals each. One group received a p p r o x i m a t e ly 6 kg of liquid w h e y daily, and the o t h e r group served as a control (no whey). Both groups received water ad libitum. T h e animals were fed 1.2 kg of c h o p p e d alfalfa daily. Trace mineralized salt and dicalcium p h o s p h a t e were available. The animals were given w h e y in the
2 Obtained from Varian Aerograph, Walnut Creek, CA. Trade names are used in this publication solely for the purpose of providing specific information. Mention of a trade name does not constitute a guarantee or warranty of the product by Utah State University or the U. S. Department of Agriculture, or an endorsement over other products not mentioned.
m o r n i n g and hay in t h e a f t e r n o o n . After a 3-wk adjustment, r u m e n liquors were taken just before and 3 and 6 h after feeding the w h e y o n a Monday, Wednesday, and Friday. The hay was fed after the last r u m e n sampling period. T h e r u m e n liquor was treated with metaphosphoric acid according to the p r o c e d u r e o f Erwin et al. (5) and was analyzed for acetic, propionic, butyric, and valeric acids. A m o d e l 1840 Varian gas c h r o m a t o g r a p h 2 e q u i p p e d with a 1.5 m stainless steel c o l u m n filled with F F A P 2 on 177 microns c h r o m o s o r b was used. RESULTS AND DISCUSSION Digestion Study
Results of the digestion study are in Table 1. The dry m a t t e r (DM) digestibility of w h e y solids calculated by difference was approxim a t e l y 87% when w h e y solids c o n s t i t u t e d 29% o f the ration. This value a p p r o x i m a t e s the value of barley listed in the National Research Council atlas of feeds (11) when digestible DM is c o n v e r t e d to digestible energy by the f o r m u l a suggested by Moir (9). Because w h e y solids are very soluble and c o m p o s e d of a b o u t 75% lactose, t h e y w o u l d be e x p e c t e d to be similar in feeding value to m o s t cereal grains. Access of water for the animals did n o t influence digestibility. The protein digestibility of t h e total ration for the three t r e a t m e n t s was similar with a range o f 72.3 to 74%. Failure o f w h e y treatm e n t to change the digestibility of protein in the total ration agrees with the findings of Journal of Dairy Science Vol. 58, No. 12
1858
ANDERS ON
TABLE 2. Average daily intake of hay, whey, water, and total liquid by sheep1. Treatment Daily intake
Whey
Whey + water
Water
SE
Hay Whey Water
1.89 8.73 c 0a
(kg/day) 1.88 7.62b 1.21 b
2.05 0a 6.07 c
.088 .387 .706
Total liquid Dry matter (total)
8.73 b 2.22b
8.83 b 2.14b
6.07 a 1.81 a
.413 .077
1Values with different superscripts differ (P
of Liquid Whey
Fed to Sheep I M. J. ANDERSON Agricultural Research Service U. S. Department of Agriculture Utah State University, UMC 46 Logan 84322
ABSTRACT
cheese plants. Dairy cows will consume surplus whey in place of other feeds (1, 12, 15). Milk fat depression was prevented in cows fed high concentrate diets by feeding dried whey products (13, 14). Dried whey products (3, 8, 14) and lactose (3, 14) added to rations increased butyrate concentration but did not affect acetate (14). My study was to determine digestibility and volatile fatty acids (VFA) concentration of rations high in liquid whey.
Digestion was studied with three groups of four sheep each fed alfalfa hay. Treatments were whey only, whey plus water, and water only. Digestibilities of dry matter for the three rations were 71.3, 69.7, and 62.9%. Digestibilities of whey solids calculated by difference was 86.9% for whey only and 81.6% for whey plus water. Twelve sheep were in three trials to determine the intake of whey, water, and hay consumption. They were assigned to whey only, whey plus water, and water only. Hay, whey, and water consumption was 1.89, 8.73, and 0; 1.88, 7.62, and 1.21; and 2.05, O, and 6.07 kg per animal daily. Three mature fistulated wether sheep were fed 6 liters of liquid whey daily, and three similar sheep were fed water only. Rumen liquor samples were taken for analysis of volatile fatty acids at 0, 3, and 6 h after whey feeding on each of three alternate days. Alfalfa hay (1.2 kg/animal daily) was fed after the 6-h sampling. Molar percentage of acetic and valeric acids were lower and for butyric acid was higher for sheep fed whey. Propionic acid, acetate:propionate ratio, and total concentration were not affected significantly by whey feeding. Acetic acid decreased from 0 to 3 h, then partly returned to the prefeeding level at 6 h. The reverse was true for butyric acid. Valeric acid and total concentration of volatile fatty acids decreased from 0 to 6 h. Effects of day were unexplained.
EXPERIMENTAL PROCEDURE Digestion Study
I NTRODUCTIDN
Finding alternative methods of whey disposal to replace the discharge of whey into streams and sewers is a problem facing many Received January 24, 1975. 1Research paper 1964 of Utah Agricultural Experiment Station.
Twelve mature wether sheep weighing approximately 78 kg were assigned randomly to three groups of four animals each on one of the following treatments: (a) whey only, (b) whey plus water, and (c) water only. Whey or water, or both, were offered free choice. Chopped alfalfa hay was offered to each animal at 1.3 kg daily. During the preliminary feeding period, the animals had access to a trace mineralized salt and dicalcium phosphorus mixture, but this was not available during the collection period. Trials consisted of a 23-day preliminary period followed by a 10-day collection period. Animals were housed in individual pens during the preliminary period and individual crates during collection. Total collection of feces was saved. A 50-g sample of hay was taken daily. At the end of the trial, feces, hay, and weighbacks were each thoroughly mixed, and each was sampled for chemical analysis. Hay, feces, and weighbacks were analyzed for dry matter (DM), ash, cell walls (CW), acid detergent fiber (ADF), acid detergent lignin (ADL), and nitrogen by procedures described by Goering and Van Soest (7). Except for ash, wet samples of feces were analyzed. Whey intake was measured for animals on treatments A and B, and water intake was measured for animals on treatment C, but water intake was not measured for treatment B.
1856
METABOLISM OF LIQUID WHEY
1857
TABLE 1. Digestion coefficients of whey rations. Criteria
Whey
DM digestibility (%) Protein digestibility (%) Cell wallsfi digestibility (%) ADF b digestibility (%) Whey DM digestibilityc (%) Whey protein digestibilityc (%) % DM of ration from whey % protein of ration from whey Liquid consumed/day (kg/day)
71.3 72.3 56.9 58.3 86.9 73.0 28.9 20.9 7.38
+_ 2.1 a +- 3.5 +- 5.8 +- 3.7 +- 12.3 -+ 19.0 +- 3.6 +- 2.7 -+ 1.14
Whey + water
Water
69.7 74.0 54.6 53.1 81.6 81.6 25.7 17.9 5.04
62.9 +-2.5 72.6 +- 1.2 58.1 +- 3.7 58.0 + 4.6 ••• ... ... ... 3.99 +- .32
+- 2.3 +- 2.5 -+ 1.9 +- 3.9 +- 9.5 +-16.9 +- 4.5 +- 3.3 +- 1.33 d
astandard deviation. bCalculated on the basis of no cell walls or acid detergent fiber in whey. CCalculated by difference when the water only ration was used as the base. d Only whey consumpuon measured. I ntake Study
A f t e r the digestion study, the 12 sheep were used in an intake trial of w h e y and water. Three treatments were used over three periods in a Latin square design. Animals were assigned to one of f o u r replicates. T r e a t m e n t s were (a) w h e y only, (b) w h e y plus water, and (c) water only. Period 1 consisted o f a 15-day preliminary period and a 5-day e x p e r i m e n t a l period. Periods 2 and 3 consisted of a 5-day preliminary and a 5-day experimental period. C h o p p e d alfalfa hay, whey, or water, or w h e y and water were offered ad libitum. Intakes o f hay, whey, and water were measured during the experimental period. Volatile Fatty Acid (VFA) Study
Six mature fistulated wether sheep were assigned r a n d o m l y to t w o groups of three animals each. One group received a p p r o x i m a t e ly 6 kg of liquid w h e y daily, and the o t h e r group served as a control (no whey). Both groups received water ad libitum. T h e animals were fed 1.2 kg of c h o p p e d alfalfa daily. Trace mineralized salt and dicalcium p h o s p h a t e were available. The animals were given w h e y in the
2 Obtained from Varian Aerograph, Walnut Creek, CA. Trade names are used in this publication solely for the purpose of providing specific information. Mention of a trade name does not constitute a guarantee or warranty of the product by Utah State University or the U. S. Department of Agriculture, or an endorsement over other products not mentioned.
m o r n i n g and hay in t h e a f t e r n o o n . After a 3-wk adjustment, r u m e n liquors were taken just before and 3 and 6 h after feeding the w h e y o n a Monday, Wednesday, and Friday. The hay was fed after the last r u m e n sampling period. T h e r u m e n liquor was treated with metaphosphoric acid according to the p r o c e d u r e o f Erwin et al. (5) and was analyzed for acetic, propionic, butyric, and valeric acids. A m o d e l 1840 Varian gas c h r o m a t o g r a p h 2 e q u i p p e d with a 1.5 m stainless steel c o l u m n filled with F F A P 2 on 177 microns c h r o m o s o r b was used. RESULTS AND DISCUSSION Digestion Study
Results of the digestion study are in Table 1. The dry m a t t e r (DM) digestibility of w h e y solids calculated by difference was approxim a t e l y 87% when w h e y solids c o n s t i t u t e d 29% o f the ration. This value a p p r o x i m a t e s the value of barley listed in the National Research Council atlas of feeds (11) when digestible DM is c o n v e r t e d to digestible energy by the f o r m u l a suggested by Moir (9). Because w h e y solids are very soluble and c o m p o s e d of a b o u t 75% lactose, t h e y w o u l d be e x p e c t e d to be similar in feeding value to m o s t cereal grains. Access of water for the animals did n o t influence digestibility. The protein digestibility of t h e total ration for the three t r e a t m e n t s was similar with a range o f 72.3 to 74%. Failure o f w h e y treatm e n t to change the digestibility of protein in the total ration agrees with the findings of Journal of Dairy Science Vol. 58, No. 12
1858
ANDERS ON
TABLE 2. Average daily intake of hay, whey, water, and total liquid by sheep1. Treatment Daily intake
Whey
Whey + water
Water
SE
Hay Whey Water
1.89 8.73 c 0a
(kg/day) 1.88 7.62b 1.21 b
2.05 0a 6.07 c
.088 .387 .706
Total liquid Dry matter (total)
8.73 b 2.22b
8.83 b 2.14b
6.07 a 1.81 a
.413 .077
1Values with different superscripts differ (P
