Nutritive value of some crop residues with or without baker’s Yeast (Saccharomyces cerevisiae) as supplements for West African Dwarf sheep

Abstract

Two experiments were conducted to evaluate the growth performance, digestibility and nitrogen retention of sheep fed some crop residues with or without baker’s yeast (Saccharomyces cerevisiae). In experiment I, sixteen West African Dwarf (WAD) sheep weighing 13.28±0.66kg were assigned to one of four total mixed diets containing one of the following: Brewers’ dried grain (Control); Groundnut haulms (GNH); Guinea corn wastes (GCW) or Cowpea husk (CPH) with 4 animals per diet in a completely randomised design. In experiment II, sixteen WAD sheep weighing 17.85±0.40kg were assigned to the same diets with each animal on the GNH, GCW and CPH diets receiving 5g of baker’s yeast supplementation per day. The animals were fed at 5% of their body weight. The experiments lasted 70 days each. On day 59 of each experiment, three animals per treatment were moved into individual metabolic cages to determine digestibility and nitrogen metabolism. In experiment I, there were no significant (P>0.05) differences in the average daily dry matter intake when the diets were fed without yeast supplementation. However, significant (P<0.05) reduction was observed for average daily dry matter intake in experiment II when animals were supplemented with baker’s yeast: 774.11, 752.00, 726.67 and 740.92 g/day for BDG, GNH, GCW and CPH respectively. Average daily weight gain was significantly (P<0.05) different across treatments in experiment I. Average daily weight gains in this experiment were  91.00, 65.10, 51.00 and 69.02 g/day for BDG, GNH, GCW and CPH respectively. However, there were no significant (P<0.05) differences in the average daily weight gain and feed conversion ratio in experiment II. Nutrients digestibility was similar in both experiments I and II except the digestibility of crude protein in experiment I that was lower (P<0.05) for GCW compared to the other diets. There were no significant (P>0.05) differences in nitrogen metabolism for both experiments I and II. Groundnut haulms, Guinea corn wastes and Cowpea husk have the potential to sustain sheep production when supplemented with baker’s yeast and effectively replace brewer’s dried grain in their diets.