Nutritional Evaluation of Microbial Treated Rice Husk and Its Effect on the Performance of Growing West African Dwarf Goats in Nigeria

This study investigated the potential of using microbial treatment to enhance the nutritional value of rice husk (RH) and its subsequent effect on the performance and health of growing West African Dwarf (WAD) goats. Raw rice husk (RRH) was subjected to solid-state fermentation using Bacteria (Alcaligenes faecalis, BTRH), Fungi (Aspergillus flavus, FTRH), or a Combined treatment (B+FTRH). The combined treatment (B+FTRH) significantly improved the proximate composition of RH, resulting in the lowest Crude Fibre (62.04%) and the highest Crude Protein (11.14%) compared to RRH (66.79% CF, 9.88% CP). Forty growing WAD male goats were randomly assigned to four diets: a Maize-based control (T1) and three diets where maize was replaced by treated RH (T2, T3, T4). The formulated diets maintained a similar Crude Protein level (15.86% to 16.55%) across all groups, demonstrating the efficacy of microbial protein enrichment in the treated RH. However, incorporating the treated RH increased the structural fibre load (NDF: 76.99% in T1 vs. 78.60% in T4) and Acid Detergent Lignin in the experimental diets. Consequently, goats on T3 and T4 exhibited significantly lower Average Daily Feed Intake (ADFI: 0.38 kg/day) compared to T1 (0.52 kg/day), leading to a numerically lower Total Weight Gain (TWG: 2.58 kg in T4 vs. 3.60 kg in T1). Crucially, the Feed Conversion Ratio (FCR) and metabolic efficiency were not significantly different across treatments, indicating similar nutrient utilization quality. Rumen analysis showed T3 and T4 promoted a fibrolytic fermentation pattern with significantly higher Acetate and Butyric acid concentrations. Haematology and serum biochemistry confirmed the physiological safety of all diets, with stable PCV, HGB, and key liver enzymes, while T4 showed a favourable reduction in LDL-C and optimal MCHC.