Influence of Addition of Yeast Culture Supplement to Diets of Lactating Cows on Ruminal Fermentation and Microbial Populations

Abstract

Six ruminally fistulated Holstein cows were utilized in a randomized block design to examine effects of yeast culture supplement on ruminal metabolism and apparent digestibility. Cows were fed a diet of 40% corn silage and 60% concentrate (DM basis). Treatments were control (supplement without yeast cells) and yeast culture supplement. Treatment periods were 6 wk. Ruminal pH, ammonia, molar proportions of acetate and isovalerate, and acetate: propionate ratio were lower and molar proportions of propionate and valerate higher in cows receiving yeast. The concentration of anaerobic bacteria tended to be higher and cellulolytic bacteria concentrations were greater in cows fed yeast than in cows receiving control diet. Supplemental yeast did not affect molar proportions of isobutyrate or butyrate, total VFA, or viable yeast concentrations in ruminal fluid. Ruminal liquid dilution rate and total tract apparent digestibilities were not different between treatments. Rate of disappearance of cellulose in vitro was lower in cows receiving yeast. Less variation in ammonia concentrations and microbial numbers suggest that ruminal fermentation was more stable in cows receiving yeast culture supplement.

Yeast cells as a feed supplement for cattle 3. New yeast preparations for cows in the first period of lactation

“…The advantageous effect of yeast preparation on milk production, which was marked during all periods of the experiment, could also be a result of a better established fermentation pattern in the rumen compared with that in control animals (Harrison et al, 1988;Adams et al, 1995). This conclusion is supported by the higher persistence of milk yield after peak of lactation in our experiment.…”

“…The increased fat content in milk in the group receiving the Yea-Sacc supplement could result from a change in the rumen fermentation pattern that increased acetic acid production (Harrison et al, 1988). In our earlier studies on digestion in the rumen (Strzetelski et al, 1995b), a high ratio of C 2 :C 3 (4.4) was found in bulls fed diets supplemented with Yea-Sacc.…”

Growth and carcass characteristics of male dairy calves on a yeast culture-supplemented diet

“…The diet used in our study was a high-concentrate diet for the finishing of cattle. According to Harrison et al (1988) rumen fermentation is more stable in animals fed yeast culture than in unsupplemented animals. Several studies have suggested that yeast culture supplemented from the same source (Diamond V) affected the ruminal pH by increasing lactate utilisation by ruminal bacteria, which would result in the elimination of a lactate peak and the reduction of lactic acid concentrations in the rumen liquor (Piva et al, 1993;Lynch & Martin, 2002).…”

“…Feeding high-grain diets to ruminants to increase energy density has resulted in negative associative effects on fibre digestion in the rumen. Harrison et al (1988) concluded that rumen fermentation was more stable in dairy cows fed high concentrate diets supplemented with yeast culture than without the supplement, and several studies reported improved performance of dairy and beef cattle fed high-concentrate diets supplemented with yeast cultures (Higginbotham et al, 1994;Mir & Mir, 1994;Olson et al, 1994). Furthermore, inclusion of yeast culture in the diets of dairy cows produced variable responses in tolerance to heat stress (Higginbotham et al, 1994).…”

The effect of <i>Saccharomyces cerevisiae</i> on the <i>in vitro</i> degradability of maize grain, cellulose and wheat straw dry matter

“…Differing effects were obtained by Arcos-Garcia et al (1999) who observed changes in dry matter degradation affected by the addition of live yeast cultures only after 48 h incubation (Levucell). The addition of yeast may increase the counts of cellulolytic bacteria (Harrison et al, 1988), and, as a consequence, improve fibre digestibility (Carro et al, 1992). In vitro experiments reported that yeast metabolites (Diamond V XP) favourably altered rumen fermentation and stimulated lactate uptake and cellulose digestion by providing growth factors such as malate to bacteria utilizing lactate, and by elevating rumen pH (Callaway and Martin, 1997).…”