SUPPLEMENTING LIVE DRIED YEAST (Saccharomyces cerevisiae) TO DIETS VARYING IN ROUGHAGE: CONCENTRATE RATIO: 1- DIGESTIBILTY COEFFICIENTS, FEEDING VALUES AND FERMENTATION IN THE RUMEN OF ZARAIBI GOAT BUCKS

Abstract

This study was conducted to investigate the effect of live dried yeast (Rumi-Yeast, RY) (Saccharomyces cerevisiae) supplementation, which is a commercial probiotic containing yeast, on digestion coefficients, feeding values and some rumen parameters of Zaraibi goats diets at two roughage (corn silage, CS): concentrate (concentrate feed mixture, CFM) ratios (70: 30 and 30: 70%) i.e. high roughage (HR) and high CFM (HC). Both diets were either used with RY (3 g/h/d) or without RY addition. Twelve mature Zaraibi bucks with an average live body weight of 60±0.4 kg were selected randomly from station herd and divided into four equal groups according to their body weight (3 bucks in each). Four experimental diets were formulated as follows: Diet 1: 70% CFM + 30% CS with RY, Diet 2: 70% CFM + 30% CS without RY, Diet 3: 30% CFM + 70% CS with RY and Diet 4: 30% CFM + 70% CS without RY. The main results showed that addition of RY significantly (p˂0.05) enhanced all nutrients digestibility coefficients, as well as digestibility of cell wall constituents (NDF, ADF, ADL, cellulose, hemicelluloses). Live dried yeast addition improved nutritive values as total digestible nutrients (TDN) and digestible crude protein (DCP %). Rumen parameters (pH values, TVFA'S and ammonia-N concentrations) were improved with HC diets compared with HR ones. In conclusion, live dried yeast (Rumi-Yeast) addition to diets of Zaraibi goats diets improved most of the tested parameters mentioned before and has a higher influence when included with HC than with HR diets under field condition.