Rumen Fermentation Characteristic of West African Dwarf Does Fed Microbial Treated Bambara Nutshell

The high cost and seasonal scarcity of conventional feed ingredients remain major constraints to sustainable small ruminant production in Nigeria, necessitating the exploration of agro-industrial by-products such as bambara nut shell. However, the high fibre content and low digestibility of untreated bambara nut shell limit its efficient utilisation by West African Dwarf (WAD) does. This study therefore evaluated the effects of microbial treatment of bambara nut shell using Pleurotus pulmonarius and Aspergillus niger on rumen fermentation characteristics and microbial ecology of WAD does. Twenty-one does were assigned to seven experimental diets containing untreated or treated bambara nut shell at 25, 50 and 75 mL inclusion levels over a 56-day feeding trial. Results showed that diets treated with P. pulmonarius significantly (p < 0.05) improved rumen fermentation compared with A. niger, producing higher acetic (7.31 vs 5.50 mmol/100 mL), propionic (6.97 vs 4.86 mmol/100 mL), butyric (6.67 vs 4.67 mmol/100 mL) and total volatile fatty acids (112.48 vs 67.86 mmol/100 mL). Increasing treatment level enhanced fermentation, with the 75 mL inclusion yielding the highest acetic acid (9.89 mmol/100 mL), propionic acid (9.42 mmol/100 mL), butyric acid (8.98 mmol/100 mL), lactic acid (14.28 mmol/100 mL) and total volatile fatty acids (140.78 mmol/100 mL), alongside a favourable rumen pH (6.52). The interaction of 75 mL P. pulmonarius produced the highest total volatile fatty acids (142.11 mmol/100 mL) and optimal ammonia-nitrogen concentration (0.57%), indicating enhanced microbial efficiency. Overall, microbial treatment of bambara nut shell, particularly with P. pulmonarius, improved rumen fermentation, energy availability and microbial stability in WAD does, highlighting its potential as a cost-effective and sustainable alternative feed resource.