Effect of supplementation with water-washed neem fruit and/or yeast on the performance and digestibility of west african dwarf sheep
This experiment was conducted to determine the performance of rams fed diets supplemented with water-washed neem (Azadirachta indica) fruits with or without yeast (Saccharomyces cerevisiae). Sixteen West African Dwarf (WAD) rams with an average weight of 14.41 (s.d = 2.54kg) were assigned to one of four diets with 4 animals per diet in a complete randomized design. The diets were: a total mixed ration (A); B (A plus 5.0g of baker's yeast per animal per day); C (A plus 5.0% water-washed neem fruit inclusion in the diet); and D (A plus 5.0% water-washed neem fruit inclusion in the diet and 5.0g of yeast per animal per day). The animals were fed at 5% body weight. At the end of the 56-day feeding trial, three animals per treatment were moved into individual metabolic cages. Average daily gain was higher (P < 0.05) in the D (120 g) compared to the other diets. Average daily dry matter intake (g) in C (929.58) and D (958.62) was similar (P > 0.05) but higher (P < 0.05) than B (839.32). The feed conversion ratio for A (10.05) was similar (P > 0.05) to B (11.99) and C (11.61) but higher (P < 0.05) than D (7.99). The digestibility of dry matter, crude protein and ash were similar (P > 0.05) for A, B and C. However, there was a significant difference between A and D. There was no significant (P > 0.05) difference in the digestibility of neutral detergent fibre, acid detergent fibre and cellulose of A and B. The metabolizable energy intake and the digestibility of organic matter was not different (P > 0.05) among B, C and D but were higher(P < 0.05) than A. The nutrients digestibility of D was consistently higher (P < 0.05) than A except for ether extract and hemicelluloses components. Water-washed neem fruits significantly (P < 0.05) increased nitrogen intake (g) in C (14.02) and D (14.76). Nitrogen retention (g) was higher (P < 0.05) for D (11.32) than for A (5.47), B (6.49) and C (8.78) respectively. These results suggest a positive synergic effect of baker's yeast and water-washed neem fruit on the performance characteristics, digestibility and nitrogen retention of WAD rams.
Keywords: baker’s yeast, water-washed neem fruit, nitrogen retention