Meta-analysis of the influence of Saccharomyces cerevisiae supplementation on ruminal parameters and milk production of ruminants

Abstract

The effects of yeast supplementation on intake, production, and rumen fermentation characteristics have been widely studied, but results are inconsistent between different studies. A quantitative meta-analysis was applied to 110 papers, 157 experiments, and 376 treatments dealing with yeast supplementation in ruminants. The objective was first to highlight the major quantitative effects of live yeast supplementation on intake, rumen fermentation, and milk production, and second, to identify major differences in experimental conditions between studies that can affect the response to treatment. Some of these experimental conditions are referred to as interfering factors. Yeast supplementation increased rumen pH (+0.03 on average) and rumen volatile fatty acid concentration (+2.17 mM on average), tended to decrease rumen lactic acid concentration (-0.9 mM on average), and had no influence on acetate-to-propionate ratio. Total-tract organic matter digestibility was also increased by yeast supplementation (+0.8% on average). Yeast supplementation increased dry matter intake (DMI; +0.44 g/kg of body weight; BW), milk yield (+1.2 g/kg of BW), and tended to increase milk fat content (+0.05%), but had no influence on milk protein content. Dose effects of yeast supplementation, expressed as log(10) [1+(cfu per 100 kg of BW)], globally confirmed the qualitative effects observed in the first analysis. The positive effect of yeast supplementation on rumen pH increased with the percentage of concentrate in the diet and with the DMI level. It was negatively correlated with the level of dietary neutral detergent fiber (NDF). The positive effect of yeast supplementation on rumen volatile fatty acid concentration increased with DMI and crude protein levels. The positive effect of yeast supplementation on organic matter digestibility increased with the percentage of concentrate and NDF in the diet. The negative effect of yeast supplementation on lactic acid concentration tended to decrease when the DMI level and the percentage of concentrate in the diet increased. The effects of interfering factors were globally similar when either dose effect or qualitative effect of yeast was taken into account. Although rumen fermentation efficiency per se was not measured, these results suggest an improvement in rumen fermentation by yeast supplementation. This effect could, however, be modulated by several different factors such as DMI, percentage of concentrate or NDF in the diet, or species.

Microbial biodiversity of the liquid fraction of rumen content from lactating cows

“…Data on the effects of S. cerevisiae on microbiome composition are not available in the literature, and some evidence, summarized by Desnoyers et al (2009) and Robinson and Erasmus (2009), does not allow to postulate how yeast can affect the rumen bacterial microbiome. The results presented in Table 2 for the three experimental diets indicate a limited influence of dried yeast (DY group) on rumen bacteria, which is significant (P < 0.05) for the percentages of Bacillus (P < 0.05), for a non-assigned genus of Erysipelotrichaceae, and for a non-assigned genus of the phyla TM7 and Tenericutes, even if the metabolic meaning of these variations is currently unknown.…”

“…Meta-analysis (Desnoyers et al, 2009;Robinson and Erasmus, 2009) of published lactation experiments with S. cerevisiae supplementation has shown an increase in milk production of 0.9 kg milk/day or 1.2 g milk/kg BW, but many factors were claimed to interfere with the results (e.g. strain and level of supplementation, DMI, dietary NDF, % of dietary concentrates).…”

Effects of different dietary concentrate to forage ratio and thiamine supplementation on the rumen fermentation and ruminal bacterial community in dairy cows

“…Therefore, it is a major concern to prevent or alleviate the occurrence of SARA in dairy herds. In the past decade, several dietary strategies proposed for use in preventing SARA, such as sodium bicarbonate buffer and monensin iono-phones as well as probiotics, have been found to stabilise ruminal pH and improve animal production (Mutsvangwa et al 2002;Paton et al 2006;Chaucheyras-Durand et al 2008;Desnoyers et al 2009;Packer et al 2011). However, none of these approaches has consistently maintained higher and stable ruminal pH.…”

Nutritional strategies to control ruminal acidosis in feedlot cattle

“…Yeast cultures of Saccharomyces cerevisiae have also been reported to stimulate lactate utilization by S. ruminantium and M. elsdenii , and could contribute to increase rumen pH (Chaucheyras-Durand et al, 2012). As previously reviewed (Desnoyers et al, 2009;De Ondarza et al, 2010), S. ruminantium supplementation to dairy cattle increases in milk production, but studies on beef cattle are scarce and controversial. Inconsistences in the response to malate and S. ruminantium supplementation may be explained by variations in the dose, growth rate and age of the animal, diet composition and farming conditions, among other factors (Yoon and Stern, 1995;Carro and Ungerfeld, 2015).…”

“…These authors reviewed 14 experiments with dairy cattle and reported that fat-corrected milk production was increased on average by 3.5% (P<0.01) in dairy cows supplemented with S. cerevisiae, with significant improvements in feed efficiency (1.75 vs. 1.70 kg/kg for live yeast and control, respectively; P<0.01), milk fat yield (1.28 vs. 1.25 kg/d; P<0.01) and milk true protein yield (1.02 vs. 1.00 kg/d; P<0.001); without any effect on DMI. Desnoyers et al (2009) also performed a meta-analysis (involving 110 scientific papers and 157 experiments) on the effects of live S. cerevisiae cultures on ruminal parameters in dairy and growing cattle, sheep, goats and buffaloes. These authors concluded that yeast supplementation increased rumen pH (+0.03 on average) and ruminal VFA concentrations (+2.17 mM on average), tended to decrease lactic acid concentrations (-0.9 mM on average), increased DMI (+0.44 g/kg of BW) and milk yield (+1.2 g/kg of BW), and tended to increase milk fat content (+0.05%).…”