Effects of lipid-encapsulated conjugated linoleic acid supplementation on milk production, bioenergetic status and indicators of reproductive performance in lactating dairy cows
AuthorHutchinson, Ian A.
de Veth, Michael J.
Dewhurst, Richard J.
Butler, Stephen T.
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CitationIan Hutchinson, Michael J de Veth, Catherine Stanton, Richard J Dewhurst, Pat Lonergan, Alex C O Evans and Stephen T Butler (2011). Effects of lipid-encapsulated conjugated linoleic acid supplementation on milk production, bioenergetic status and indicators of reproductive performance in lactating dairy cows. Journal of Dairy Research, 78, pp 308-317. doi:10.1017/S0022029911000422. Copyright © Proprietors of Journal of Dairy Research
AbstractConjugated linoleic acid (CLA) reduces mammary milk fat synthesis in a dose-dependent manner. Our objective was to determine the effects of lipid-encapsulated CLA (LE-CLA) supplementation on milk production, reproductive performance and metabolic responses in lactating dairy cows fed a grass silage-based diet. Seventy-two Holstein-Friesian cows (32 primiparous and 40 multiparous) were used in a completely randomized block design. Cows received either 80 g of LE-CLA daily or 60 g of calcium salts of palm fatty acids daily (control) from parturition until 60 days in milk. LE-CLA contained a 50:50 mix of cis-9,trans-11 CLA and trans-10,cis-12 CLA, resulting in a daily intake of 6 g of each isomer. Milk production and dry matter intake were recorded daily, and blood samples were collected 3-times a week. Blood samples were analysed for circulating concentrations of glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), insulin and insulin-like growth factor-I (IGF-I). Progesterone was measured in blood samples collected after the first post-partum insemination. Ovarian ultrasound examinations commenced at 8–10 d post partum and were carried out 3-times a week until first ovulation. LE-CLA treatment resulted in decreased milk fat concentration, with consequent improvements in energy balance and body condition score (BCS). The peak concentration of NEFA in blood was reduced by LE-CLA, but circulating concentrations of insulin, glucose, IGF-I, BHBA and progesterone were not affected. There was no effect of LE-CLA supplementation on the post-partum interval to first ovulation. Services per conception tended to be reduced. The reduction in milk energy output and improvement in energy status and BCS in LE-CLA-supplemented cows provides a strong rationale for further studies with greater cow numbers to test effects on reproductive performance.
FunderNational Development Plan Ireland