The effects of prepartum fatty acid supplementation on colostrum and milk fatty acid profies and production.

D. COLEMAN; A. E. RELLING

Pittsburgh

Congreso; 2017 American Dairy Science Association® Annual Meeting; 2017

">The objective of the present study was to evaluate the impact of supplementing ewes with eicosapentaenoic acid (EPA) and docosahexaenoicacid (DHA) during late gestation on ewe colostrum, and milk productionand composition. Eighty-four gestating ewes (28 pens) were blocked andrandomly assigned to a diet with an addition of 0.4% added fat duringthe last 50 d of gestation. The fat sources were rich in the monounsaturated fatty acid (MUFA) oleic acid, or the polyunsaturated fatty acids(PUFA) EPA and DHA. After lambing, ewes and lambs were placed onthe same pasture. Colostrum samples were taken at lambing for fatty acidanalysis. Milk yield, composition and fatty acid profie were analyzed 30d postpartum. Data was analyzed using a mixed model (SAS 9.4) withtreatment, time and their interaction as fied variables and ewe withinpen as a random variable. There was a treatment by time interaction(P < 0.05) with PUFA yielding greater EPA and DHA concentrationsthan MUFA at lambing, but not at 30 d in lactation. A treatment bytime interaction (P < 0.05) was also observed for trans-9 18:1, trans-1018:1, cis-15 18:1 and conjugated linoleic acid (CLA) isomers other thantrans-10, cis-12 18:2, and cis-9, trans-12 18:2, with PUFA ewes havingsignifiantly greater concentrations than MUFA ewes at lambing, but notat d 30. A treatment by time interaction (P < 0.05) was also observed forcis-12 18:1, with PUFA ewes having lower concentrations than MUFAewes in colostrum and at d 30. The concentrations of fatty acids with6?10 carbons were signifiantly increased (P < 0.05) in colostrum andmilk of PUFA ewes. Neither milk yield nor milk protein, fat, lactose,solids, somatic cell count, milk urea nitrogen, energy corrected milkor net energy of lactation were different (P > 0.05) among treatments.These results suggest that supplementation of EPA and DHA during lategestation alters the fatty acid profie of colostrum and milk, even 30 dafter stopping the supplementation, but not milk yield or composition.Future research should investigate the effects of supplementing higherdoses of EPA and DHA