Milk fatty acid composition and plasma energy metabolite concentrations in lactating cows fed medium-chain triglycerides.
Six lactating Holstein cows were used in a replicated 3 x 3 Latin square design to determine the effects of medium-chain triglyceride supplementation on milk fatty acid composition and plasma energy metabolites. Treatments were no supplemental triglyceride, 500 ml of odd-carbon, medium-chain triglyceride (fatty acid composition: 100% pelargonic acid), or 500 ml of even-carbon, medium-chain triglyceride (fatty acid composition: 65% caproic acid, 35% capric acid) added daily to a total mixed ration. Medium-chain triglyceride supplementation did not affect ruminal molar proportions of acetate or propionate but slightly increased the molar proportion of butyrate. Even-carbon and odd-carbon, medium-chain triglycerides reduced DM intake by 1.7 and 1.3 kg/d, respectively, but did not affect milk yield or milk protein percentage. Cows that did not receive supplemental triglyceride produced milk with 3.29% fat. Milk fat concentration was increased by even-carbon, medium-chain triglyceride supplementation relative to odd-carbon, medium-chain triglyceride supplementation (3.44 vs. 2.99%). Although changes in milk fatty acid composition were observed, they were minor and mostly unexplained. Feeding even-carbon, medium-chain triglycerides caused slight increases in plasma glucose and nonesterified fatty acid concentrations, but plasma beta-hydroxybutyrate concentration was not affected by treatments. Odd-carbon, medium-chain triglyceride supplementation (500 ml/d) does not appear to be antiketogenic.
Grummer
R R
RR
Department of Dairy Science, University of Wisconsin, Madison 53706.
Socha
M T
MT
D000704:Analysis of Variance; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D004041:Dietary Fats / Q000378:metabolism*; D004734:Energy Metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D016014:Linear Models; D008892:Milk / Q000378:metabolism*; D012417:Rumen / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism*
D004041:Dietary Fats; D005227:Fatty Acids; D014280:Triglycerides