Context Biodegradation of agricultural wastes by enzyme from microorganisms, especially white rot fungi has been promising in degrading structural carbohydrates or structurally modifying proteins and their anti-nutritional properties thereby producing high quality products. Aims To evaluate the nutrient intake, body weight changes, digestibility and nitrogen utilisation of West African dwarf goats (WADG) fed Pleurotus tuber-regium treated cassava root sievate (PTRCRS) based diets. Methods The experimental diets were formulated such that PTRCRS was included in the different diets at 0, 20, 40 and 60% inclusion levels. Thirty-two WADG between six and eight months old averaging 5.26 kg in weight were randomly divided into four groups of eight goats each. The groups were randomly assigned to four experimental diets {T1 (0%), T2 (20%), T3 (40%) and T4 (60%)} in a completely randomized design. Each animal received a designated treatment diet in the morning (08:00 h) for 90 days. Feed offered was based on 3.5% body weight per day in addition to 1 kg wilted chopped Panicum maximum which was fed at 16:00 h. Fresh drinkable water was provided ad libitum. Key results There were significant (P < 0.05) differences for dry matter intake (DMI), DMI as percentage of body weight (% BW), crude protein (CP), organic matter (OM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes. Daily weight gain was significantly (P < 0.05) improved in T3 and T4. Feed conversion ratio decreased (P < 0.05) with increasing levels of PTRCRS. Dry matter, CP, crude fibre, NDF and ADF were better (P < 0.05) digested in T4. Nitrogen intake was higher (P < 0.05) in T4 (19.62 g/day) and lowest in T1 (12.39 g/day). Nitrogen balance, nitrogen retention and nitrogen absorbed were significantly (P < 0.05) higher for T4 goats. Conclusion Incorporation of PTRCRS in WAD goat diets generally enhanced intakes, body weight gain, nutrient digestibility and nitrogen utilisation. Implications The treatment of cassava root sievate, which is in abundance and hitherto without any known economic value other than causing environmental nuisance with PTR, could solve the challenges of feed scarcity which has been a major factor in ruminant production. The feeding of WAD goats with PTRCRS generally enhance their performances.
