The effect of dietary inclusion of yeast culture (Yea-Sacc) on patterns of rumen fermentation, food intake and growth of intensively fed bulls

Abstract

The effects of a barley beef diet without (control) and with a yeast culture (YC) on rumen fermentation, in vivo diet digestibility, nitrogen retention, live-weight gain and food intake were evaluated using 13 Limousin × British Friesian bulls per treatment. The YC was composed of the yeast species Saccharomyces cerevisiae and its growth medium dried in such a manner that it maintained its fermentative capacity. The addition of YC significantly increased the concentration of acetate (P < 0·05) while propionate concentration tended to be higher for bulls given YC (P > 0·05). The acetate: propionate ratio remained unchanged. Concentration of total volatile fatty acid (VFA) was significantly higher in YC bulls compared with control bulls (P < 0·05). The in vitro studies using the Menke gas test confirmed these findings. Mean in vitro gas production in bulls receiving YC was lower than that in the controls (P < 0·05) and methane production was significantly reduced by the addition of YC after 12h (P < 0·01). Ruminal ammonia concentrations were not affected by treatment but ruminal pH was significantly depressed by the addition of YC (P < 0·05).Apparent digestibility of dry matter, organic matter, crude protein and neutral-detergent fibre were unaffected by treatment but tended to be higher with the control diet. Nitrogen retention was not affected by the addition of YC and mean values for allantoin excretion and plasma urea were similar.In a 28-week feeding trial, dry-matter intake was significantly greater for bulls given YC (5·55 kg/day) than for control bulls (5·32 kg/day, P < 0·05) but average daily gain, 1·55 and 1·58 kg/day for control and YC respectively, and food conversion efficiency were not improved significantly by YC (P > 0·05).

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

“…Our results are in accordance with those of other workers who found that supplementing yeast culture had no effect on the growth rate of intensively fed bulls (Mutsvangwa et al, 1992;El Hassan et al, 1996;Beauchemin et al, 2003), grazing steers (Cabrera et al, 2000) or lambs (Kawas et al, 2007). Others reported that yeast culture tended to reduce the average daily gain of steers (Mir & Mir, 1994) while Wehner et al (1998) found that yeast-fed calves tended to gain more than the control calves.…”

The effect of <i>Saccharomyces cerevisiae</i> on ruminal fermentation in sheep fed high- or low-NDF rations

“…The results of other researchers are also inconsistent. Some investigators reported increased proportions of acetate (Mutsvangwa et al, 1992), while others found increased proportions of propionate (Plata et al, 1994). The hypothesis that considerable discrepancies are caused mainly by the ratio of structural to non-structural carbohydrates was not confirmed in our study using high-and low-fibre diets.…”

“…In the current study, no significant effects of LYC and YC were observed on effective degradation of NDF from maize grain and wheat straw, similarly as in other experiments (Mutsvangwa et al, 1992;Enjalbert et al, 1999). Live yeast culture in the low-NDF diet increased the degradation of NDF from wheat straw (P<0.05) after 6 h incubation (data not shown), but the rate of degradation and effective degradability were not modified.…”

“…Yeast cultures can stimulate utilization of hydrogen by acetogenic bacteria, lactate uptake by Selenomonas ruminatium, and enhance the growth of cellulolytic bacteria (Martin and Nisbet, 1992;Chaucheyras et al, 1995). Live yeast cultures increased the proportion of propionate, decreased the lactate concentration, and increased the numbers of total viable bacteria and cellulolytic bacteria (Newbold et al, 1990;Mutsvangwa et al, 1992;Lila et al, 2004). Corona et al (1999) emphasised considerable inconsistencies between the quoted research results.…”

Effects of hydrolysed yeasts on ruminal fermentation in the rumen simulation technique (Rusitec)

“…In contrast, Bach et al (2007) demonstrated that yeast supplementation (Saccharomyces cerevisiae Strain CNCM I-1077) to dairy cattle (5 g/day) contributes to the rumen environment by enhancing the ruminal pH. On the other hand, Mutsvangwa et al (1992) showed that ruminal pH was depressed by the addition of yeast culture (YeaSacc) in bulls (8 to 10 g/day). Nevertheless, one of the main effects of yeasts is to stabilise the rumen pH.…”