The effect of ruminal incubation of bioactive yeast (Saccharomyces cerevisiae) on potential rumen degradability of Panicum maximum and Centrosema pubescens in West African dwarf sheep

Abstract

The rising interest in the use of organic and inorganic substances in manipulating rumen function for improved fermentative activity has provided avenues for the inclusion of various species of yeast cultures in ruminant diets. In this study, we investigated the effect of bioactive yeast (Saccharomyces cerevisiae), on rumen degradative function of the West African Dwarf Sheep (WADS) in terms of fermentable organic matter, crude protein and crude fiber of Panicum maximum and Centrosema pubescens. Three inclusion levels of Saccharomyces cerevisiae, 200, 500 and 800 milligrams were infused into the rumen of three groups (A, B and C), of three WAD sheep each. Another group (D) of same animal number served as the control. In vivo rumen potential degradability studies, using the nylon bag technique was performed using Panicum maximum and Centrosema pubescens in all the groups. The result of the study showed  that bioactive yeast improved the potential rumen degradability of crude protein, crude fibre and organic matter fractions of Panicum maximum and Centrosema pubescens in a rather dose dependent manner compared to the control. There was a significant correlation (r = 0.56) between degradability, dose and time of incubation for crude fibre and organic  matter fractions but not for crude protein. These observations suggest that regulated dietary inclusion of bioactive yeast can be used to bioengineer the rumen towards efficient fibre breakdown, particularly forages of poor protein quality and high fibre content, for efficient production of volatile fatty acids as well as probably enhancing other aspects of rumen functions.

Keywords: Bioactive Yeast, Degradability, Forages, Rumen, WADS.