Effects of peripartal yeast culture supplementation on lactation performance, blood biomarkers, rumen fermentation, and rumen bacteria species in dairy cows

摘要

Feeding yeast culture fermentation products hasbeen associated with improved feed intake and milkyield in transition dairy cows. These improvements inperformance have been further described in terms ofrumen characteristics, metabolic profile, and immuneresponse. The objective of this study was to evaluatethe effects of a commercial yeast culture product (YC;Culture Classic HD, Phibro Animal Health) on performance,blood biomarkers, rumen fermentation, andrumen bacterial population in dairy cows from −30 to50 d in milk (DIM). Forty Holstein dairy cows wereenrolled in a randomized complete block design from−30 to 50 DIM and blocked according to expected calvingday, parity, previous milk yield, and genetic merit.At −30 DIM, cows were assigned to either a basal dietplus 114 g/d of ground corn (control; n = 20) or a basaldiet plus 100 g/d of ground corn and 14 g/d of YC (n =20), fed as a top-dress. Cows received the same close-updiet from 30 d prepartum until calving [1.39 Mcal/kg ofdry matter (DM) and 12.3% crude protein (CP)] andlactation diet from calving to 50 DIM (1.60 Mcal/kg ofDM and 15.6% CP). Blood samples and rumen fluidwere collected at various time points from −30 to 50 drelative to calving. Cows fed YC compared with controlshowed a trend for increased energy-corrected milk(+3.2 kg/d). Lower somatic cell counts were observedin YC cows than in control. We detected a treatment× time interaction in nonesterified fatty acids (NEFA)that could be attributed to a trend for greater NEFAin YC cows than control at 7 DIM, followed by lowerNEFA in YC cows than control at 14 and 30 DIM. In therumen, YC contributed to mild changes in rumen fermentation,mainly increasing postpartal valerate whiledecreasing prepartal isovalerate. This was accompaniedby alterations in rumen microbiota, including a greaterabundance of cellulolytic (Fibrobacter succinogenes) andlactate-utilizing bacteria (Megasphaera elsdenii). Theseresults describe the potential benefits of supplementingyeast culture during the late pregnancy through earlylactation, at least in terms of rumen environment andperformance.