Ruminal pH pattern, fermentation characteristics and related bacteria in response to dietary live yeast (Saccharomyces cerevisiae) supplementation in beef cattle

Abstract

Objective: In this study we aimed to evaluate the effect of dietary live yeast supplementation on ruminal pH pattern, fermentation characteristics and associated bacteria in beef cattle.Methods: This work comprised of in vitro and in vivo experiments. In vitro fermentation was conducted by incubating 0, 0.05, 0.075, 0.1, 0.125, and 0.15% active dried yeast (Saccharomyces cerevisiae, ADY) with total mixed ration substrate to determine its dose effect. According to in vitro results, 0.1% ADY inclusion level was assigned in in vivo study for continuously monitoring ruminal fermentation characteristics and microbes. Six ruminally cannulated steers were randomly assigned to 2 treatments (Control and ADY supplementation) as two-period crossover design (30-day). Blood samples were harvested before-feeding and rumen fluid was sampled at 0, 3, 6, 9 and 12 h post-feeding on 30 d. Results:After 24 h in vitro fermentation, pH and gas production were increased at 0.1% ADY where ammonia nitrogen and microbial crude protein also displayed lowest and peak values, respectively. Acetate, butyrate and total volatile fatty acids concentrations heightened with increasing ADY doses and plateaued at high levels, while acetate to propionate ratio was decreased accordingly. In in vivo study, ruminal pH was increased with ADY supplementation that also elevated acetate and propionate. Conversely, ADY reduced lactate level by dampening Streptococcus bovis and inducing greater Selenomonas ruminantium and A c c e p t e d A r t i c l eMegasphaera elsdenii populations involved in lactate utilization. The serum urea nitrogen decreased, whereas glucose, albumin and total protein concentrations were increased with ADY supplementation. Conclusion:The results demonstrated dietary ADY improved ruminal fermentation dose-dependently. The ruminal lactate reduction through modification of lactate metabolic bacteria could be important reason for rumen pH stabilization induced by ADY. ADY supplementation offered a complementary probiotics strategy in improving gluconeogenesis and nitrogen metabolism of beef cattle, potentially resulted from optimized rumen pH and fermentation.

A Mixture of Prebiotics, Essential Oil Blends, and Onion Peel Did Not Affect Greenhouse Gas Emissions or Nutrient Degradability, but Altered Volatile Fatty Acids Production in Dairy Cows Using Rumen Simulation Technique (RUSITEC)

“…In the present study, pH values ranged from 7.22 to 7.30 across the treatments, indicating minimal effects on ruminal fermentation since it is associated with gas production, DMD, and VFA concentration [32]. Abnormal ruminal pH, resulting from dysfunctional ruminal acid metabolism, can adversely impact the microbial community structure and lead to life-threatening metabolic disorders, such as acidosis [32].…”

Diet supplementation with Saccharomyces cerevisiae influences the electrophoretic parameters in blood in young Charolaise bulls

“…In contrast, Ma et al ( 21 ) found no statistically significant differences in serum albumin concentration between yeast-supplemented and unsupplemented groups. However, increases in the serum total protein and the serum albumin values can be indicators of greater protein outflow from the rumen because of improved ruminal nitrogen utilisation to synthesise microbial protein ( 29 ). Also, in the same research of which the findings suggested the higher nitrogen use, Zhang et al ( 29 ) found increases in serum total proteins and the serum albumin concentrations in a treated group as consequences of improved ruminal fermentation and feed utilisation efficiency after the administration of yeast supplementation in the diet.…”

Effect of Ca-octanoate supplementation on concentrations of ghrelin and ghrelin-related hormones in plasma and milk of beef cattle

“…In a previous study, feeding medium chain triglycerides increases preprandial concentrations of glucose in plasma by enhancing glycolytic flux [ 42 , 43 ]. It is also reported that MCFAs offered to ruminants increased that of propionate, an indispensable precursor of gluconeogenesis [ 44 ], in in vitro and in vivo studies [ 45 , 46 ]. Thus, a possible enhancement of glycolysis and/or an increase in concentrations of propionate in the rumen likely account for increased concentrations of glucose in plasma of cows in the OCT group.…”