Effects of acetate and long-chain fatty acids infusion into external pudic artery on lactation performance and milk fatty acid composition in lactating dairy cows
Bai, C.; Huo, X.X.; Khas-Erdene; Ao, C.J.; Liu, S.W.; Wang, X.J.; Zhang, F.Q.; Gao, P.
Canadian Journal of Animal Science 97(1): 127-135
ISSN/ISBN: 0008-3984 DOI: 10.1139/cjas-2015-0160
Our objective was to observe the effects of milk fat substrates (MFS) [acetate combined with long-chain fatty acid (FA)] supplementation on lactation performance and milk FA composition of cows fed an energy-and nutrient-deficient diet. Eight Holstein cows (99 +/- 11 d) were averagely assigned to two diets based on either corn stover (CS) or mixed forages (MFs). Experiment included two stages and each lasted for 27 d with a 21 d preliminary and a 6 d infusion. Cows with CS diet [NEL = 1.35 Mcal kg(-1) of dry matter (DM)] received carrier at the first 3 d and MFS at the following 3 d of infusion period. Cows with MF diet (NEL = 1.66 Mcal kg(-1) of DM) received carrier during the 6 d infusion period. The differences in milk production, milk yields of fat, and protein between the two diet groups were compensated by MFS infusion (from -3.5 to -1.3, -0.19 to -0.08, and -0.13 to -0.07 kg d(-1), respectively). Infusion of MFS increased the concentrations of 18: 2 and 18: 3 in milk fat. The results suggested that supplement of MFS could influence milk fat synthesis and lactation performance in cows fed an energy-and nutrient-deficient diet.