NUTRITION, FEEDING, AND CALVES Effects of Feeding Diets Containing Calcium Salts of Long-Chain Fatty Acids to lactating Dairy Cows1 D. J. SCHAUFf2 and J. H. CLARK Department of Animal Sciences University of Illinois Urbana 61801 ABSTRACT
fects on ruminal fermentation and digestibilities of most nutrients. (Key words: calcium salts of long-chain fatty acids, ruminal fermentation, milk composition, nutrient digestibilities)
Four cows were utilized in a 4 x 4 Latin square design to investigate the effects of feeding Ca salts of long-chain fatty acids. Treatments were control diet with 1) no added fat, 2) 3% Ca salts of long-chain fatty acids, 3) 6% Ca salts of long-chain fatty acids, and 4) 9% Ca salts of long-chain fatty acids. Cows were fed chopped alfalfa hay, alfalfa haylage, corn silage, and concentrate (15:22:13:50) on a DM basis. Dry matter intake, energy intake, and ruminal fermentation were not altered greatly until Ca salts of long-chain fatty acids constituted 9% of OM!. Oigestibilities of OM, OM, ADF, NDF, and hemicellulose were not affected by treatment. Digestibilities of cellulose, soluble residue, total CIS fatty acids, and total fatty acids followed quadratic patterns. Absorption of N was increased linearly when fat was fed, but digestibility of Ca was decreased linearly. Milk production, CP, and SNF were not altered greatly by inclusion of 3 or 6% Ca salts of long-chain fatty acids in the diet, but inclusion of 9% Ca salts of long-chain fatty acids decreased their production. Calcium salts of long-chain fatty acids increased milk fat percentage and production of fat and FCM when fed as 3 or 6% of the dietary OM but decreased yields of milk fat and FCM when fed as 9%. Calcium salts of fatty acids can be fed to provide up to 6% of the dietary OM without deleterious ef-
Abbreviation key: Ca-LCFA = Ca salts of long-chain fatty acids, DE digestible energy, EE ether extract, LCFA long-chain fatty acids, ME = metabolizable energy, PE = partial efficiency of energy utilization for milk production, UE = urinary energy.
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INTRODUCTION
Received November 12, 1991. Accepted June 18, 1992. ISupported in part by the University of lllinois Agricultural Experiment Station and a gift from Church and Dwight Co. Inc., Princeton. NJ. 2Agri-King, Inc., Box 208, Fulton, n. 61252. 1992 J Dairy Sci 75:2990-3002
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In early lactation, dairy cows have large requirements for energy. The addition of fat sources, such as Ca salts of long-chain fatty acids (Ca-LCFA), to the diet of high producing dairy cows may improve their energy status. Increasing the intake of long-chain fatty acids (LCFA) by addition of fat to the diet should improve the metabolic efficiency of energy utilization for milk production. Preformed fatty acids of dietary origin can be incorporated directly into milk fat, reducing the energy cost for synthesizing fatty acids incorporated into milk, thereby sparing energy for other productive functions in the mammary gland. Although the energy obtained from oxidation of LCFA may be relatively small, the yield of ATP from the oxidation of LCFA is 10% more efficient than from the oxidation of acetate (30). Several scientists (3, 22, 30) indicated that efficiency of milk production was maximized when LCFA constituted 16 to 20% of the total metabolizable energy (ME) intake. Maximal efficiency of milk production is achieved when diets for lactating dairy cows contain about 7 to 8% total fat or 5% supplemental fat (3, 22, 30). However, most of these efficiencies of energy utilization for milk production were estimated using cows producing 20 to 30 kgld of milk. Recent research (10)
2990
CALCIUM SALTS OF LONG-CHAIN FATTY ACIDS
indicates that maximal responses in milk production were obtained when cows were producing greater than the aforementioned amounts of milk. Data from several experiments that evaluated supplementation of 2 to 6% Ca-LCFA to diets for lactating dairy cows have shown no major deleterious effects on ruminal fermentation (14, 20, 21, 29, 35, 38) or total tract nutrient digestibilities (14, 20, 21, 35). However, data are not available to determine the optimal or maximal amount of Ca-LCFA to incorporate in diets fed to lactating cows producing large amounts of milk. Information about nutrient intakes, milk production, milk composition, ruminal fermentation, nutrient digestibilities, and energy and N utilization is needed to define optimal and maximal amounts of Ca-LCFA to feed to lactating dairy cows consuming large amounts of feed and producing large amounts of milk. Therefore, the objective of this experiment was to investigate the effects of increasing dietary concentrations of Ca-LCFA fed to high producing dairy cows on nutrient intakes, ruminal fermentation, nutrient digestibilities, energy and N utilization, milk production, and milk composition. MATERIALS AND METHODS Experimental Design, Diets, and Management of Cows
Four ruminally fistulated multiparous Holstein cows averaging 43 DIM were utilized in a 4 x 4 Latin square design with 14-d periods. Each period consisted of 7 d for cows to adjust to diets and 7 d for sample collection. Treatments were control with 1) 0% Ca-LCFA, 2) 3% Ca-LCFA (Megalac
fects on ruminal fermentation and digestibilities of most nutrients. (Key words: calcium salts of long-chain fatty acids, ruminal fermentation, milk composition, nutrient digestibilities)
Four cows were utilized in a 4 x 4 Latin square design to investigate the effects of feeding Ca salts of long-chain fatty acids. Treatments were control diet with 1) no added fat, 2) 3% Ca salts of long-chain fatty acids, 3) 6% Ca salts of long-chain fatty acids, and 4) 9% Ca salts of long-chain fatty acids. Cows were fed chopped alfalfa hay, alfalfa haylage, corn silage, and concentrate (15:22:13:50) on a DM basis. Dry matter intake, energy intake, and ruminal fermentation were not altered greatly until Ca salts of long-chain fatty acids constituted 9% of OM!. Oigestibilities of OM, OM, ADF, NDF, and hemicellulose were not affected by treatment. Digestibilities of cellulose, soluble residue, total CIS fatty acids, and total fatty acids followed quadratic patterns. Absorption of N was increased linearly when fat was fed, but digestibility of Ca was decreased linearly. Milk production, CP, and SNF were not altered greatly by inclusion of 3 or 6% Ca salts of long-chain fatty acids in the diet, but inclusion of 9% Ca salts of long-chain fatty acids decreased their production. Calcium salts of long-chain fatty acids increased milk fat percentage and production of fat and FCM when fed as 3 or 6% of the dietary OM but decreased yields of milk fat and FCM when fed as 9%. Calcium salts of fatty acids can be fed to provide up to 6% of the dietary OM without deleterious ef-
Abbreviation key: Ca-LCFA = Ca salts of long-chain fatty acids, DE digestible energy, EE ether extract, LCFA long-chain fatty acids, ME = metabolizable energy, PE = partial efficiency of energy utilization for milk production, UE = urinary energy.
=
INTRODUCTION
Received November 12, 1991. Accepted June 18, 1992. ISupported in part by the University of lllinois Agricultural Experiment Station and a gift from Church and Dwight Co. Inc., Princeton. NJ. 2Agri-King, Inc., Box 208, Fulton, n. 61252. 1992 J Dairy Sci 75:2990-3002
= =
In early lactation, dairy cows have large requirements for energy. The addition of fat sources, such as Ca salts of long-chain fatty acids (Ca-LCFA), to the diet of high producing dairy cows may improve their energy status. Increasing the intake of long-chain fatty acids (LCFA) by addition of fat to the diet should improve the metabolic efficiency of energy utilization for milk production. Preformed fatty acids of dietary origin can be incorporated directly into milk fat, reducing the energy cost for synthesizing fatty acids incorporated into milk, thereby sparing energy for other productive functions in the mammary gland. Although the energy obtained from oxidation of LCFA may be relatively small, the yield of ATP from the oxidation of LCFA is 10% more efficient than from the oxidation of acetate (30). Several scientists (3, 22, 30) indicated that efficiency of milk production was maximized when LCFA constituted 16 to 20% of the total metabolizable energy (ME) intake. Maximal efficiency of milk production is achieved when diets for lactating dairy cows contain about 7 to 8% total fat or 5% supplemental fat (3, 22, 30). However, most of these efficiencies of energy utilization for milk production were estimated using cows producing 20 to 30 kgld of milk. Recent research (10)
2990
CALCIUM SALTS OF LONG-CHAIN FATTY ACIDS
indicates that maximal responses in milk production were obtained when cows were producing greater than the aforementioned amounts of milk. Data from several experiments that evaluated supplementation of 2 to 6% Ca-LCFA to diets for lactating dairy cows have shown no major deleterious effects on ruminal fermentation (14, 20, 21, 29, 35, 38) or total tract nutrient digestibilities (14, 20, 21, 35). However, data are not available to determine the optimal or maximal amount of Ca-LCFA to incorporate in diets fed to lactating cows producing large amounts of milk. Information about nutrient intakes, milk production, milk composition, ruminal fermentation, nutrient digestibilities, and energy and N utilization is needed to define optimal and maximal amounts of Ca-LCFA to feed to lactating dairy cows consuming large amounts of feed and producing large amounts of milk. Therefore, the objective of this experiment was to investigate the effects of increasing dietary concentrations of Ca-LCFA fed to high producing dairy cows on nutrient intakes, ruminal fermentation, nutrient digestibilities, energy and N utilization, milk production, and milk composition. MATERIALS AND METHODS Experimental Design, Diets, and Management of Cows
Four ruminally fistulated multiparous Holstein cows averaging 43 DIM were utilized in a 4 x 4 Latin square design with 14-d periods. Each period consisted of 7 d for cows to adjust to diets and 7 d for sample collection. Treatments were control with 1) 0% Ca-LCFA, 2) 3% Ca-LCFA (Megalac
