In Vitro effects of Megasphaera Elsdenii Ncimb 41125 and Saccharomyces Cerevisiae 1026 on Rumen fermentation in early lactating cows

Abstract

This study was conducted to evaluate the effect of microbial feed additives Megasphaera elsdenii NCIMB 41125 and Saccharomyces cerevisiae 1026, individually and combined on rumen pH,ammonia-N and volatile fatty acids (VFAs) fermentation. An in vitro batch fermentation was conducted using rumen fluid from two early lactating Holstein cow donor fed the TMR for lactating cows which was evaluated under two diets, differing in concentrate to forage ratio. The diets were high concentrate, a 60:40 concentrate to forage ratio diet (HC) and low concentrate, a 40:60 (LC) concentrate to forage ratio diet. The treatments were; Control (diet with no additives), Me (diet with M. elsdenii NCIMB 41125 10mm (108 CFU/ml)), LY (diet with live yeast, S. cerevisiae 1026), and Me+LY (diet with mixture of M. elsdenii and S. cerevisiae). The average rumen pH was 5.8 and ammonia nitrogen was not affected by Me and LY supplemented separately or in combination (Me+LY) in both low and high concentrate diets. Total VFAs were increased with the addition of LY alone and in combination Me+LY+Me) in high concentrate diet only but the addition of Me had no effect in both diets. Acetate, lactate and A: Pr were decreased (P<0.05) by all the treatments (Me and LY alone and in combination) on both diets, except in high concentrate diet where the addition of Me tended to decrease (P<0.07) acetate and had no effect on lactate. Propionate was increased by all the treatments in low concentrate diet and tended toincrease (P<0.08) by addition of Me and Me+LY in high concentrate diet. In a low concentrate diet, butyrate was increased by LY but tended to be decreased by Me, however, all the treatments lacked effects on high concentrate diet. Live yeast appears to act differently compared to Me by showing two times more effects on high than low concentrate diets.This in vitro study showed that both Me and LY had a tendency to modify rumen fermentation and that might indicate their potential to mitigate the metabolic challenges and improve energy status of Holstein dairy cows during the transition and early lactation period. However, there is a need for further research that will include in vivo study.