Nutrient utilization and nitrogen metabolism by West African dwarf goat-bucks fed molasses-treated biodegraded rice husk

Abstract

The quest for meeting animal protein demand in the tropics with the use of unconventional feed resources without compromising the quality led to this study. Thus, the study was conducted to assess the nutritional potentials of biodegraded rice husk treated with or without molasses. Rice husks were incorporated with molasses at 0% (Diet 1 – control diet), 1% (Diet 2), 2% (Diet 3), 3% (Diet 4) and 4% (Diet 5) respectively and were mixed thoroughly with 1% salt and 3% yeast thereafter fermented anaerobically for 5days. Consequently, the diets were fed to twenty-five (25) WAD goat-bucks of five (5) replicates per treatment in a Completely Randomized Design experiment for 84 days. Parameters assessed included; nutrients and anti-nutrients composition, feed intake, weight gain, nitrogen utilization, digestibility and feed conversion ratio. Results showed that, inclusion level of molasses significantly (P<0.05) influenced the dietary treatments. Dry matter (DM) contents ranged from 90.58% (Diet 5) to 92.91% (Diet 1). Crude protein (CP) content of the diets and feed intake increased progressively with increased inclusion of molasses in the diets as Diet 5 had the highest CP content (11.29%) and bucks fed, had the highest CP intake (57.69 g/day). However, crude fibre (CF) declined as CP increases; the least CF (26.51% CF) was recorded for Diet 5. DM intake varied from 452.47 g/day (Diet 1) to 466.86 g/day (Diet 5). Fibre fractions and the anti-nutrients considered in this study were tolerable by goats and Diet 5 was better utilized. Nitrogen intake (9.97 g/day) and highest nitrogen retained (9.29 g/day) were highest in bucks’ fed Diet 5. Hence, the better average daily weight gain (68.00 g/day) and as well as the least feed/gain ratio (6.86). In conclusion, rice husk treated with molasses at 4% inclusion level fermented with 3% yeast improved the palatability, nutrient intake and weight gain of WAD goat-bucks and are therefore recommended.

Keywords: Molasses, Fermentation, Yeast, Nutrient intake, Agro-industrial waste, Ruminant farmers