Effects of supplementing cassava peels with cassava leaves and cowpea haulms on the performance, intake, digestibility and nitrogen utilization of West African Dwarf goats.

A 16-week experiment was conducted to determine the utilization of ratios of cassava leaf meal, cassava peel and cowpea haulms by West African Dwarf (WAD) goats. Thirty WAD bucks aged 8 ± 1.3 months with body weights of 6-6.5 ± 0.12 kg were divided into five groups of six animals and each group randomly assigned to one of the treatments in a completely randomized design. The five dietary treatments were formulated to contain cassava peels, leaves and cowpea haulms at different proportions of 700:100:175 (T1), 500:200:275 (T2), 300:300:375 (T3) and 100:400:475 (T4) g/kg dry matter (DM), respectively. A standard diet formulated to meet the nutrient requirement of the animals with no cassava and cowpea haulms was used as the control diet (T5). DM intake ranged from 316.16 to 458.73 g/day and significantly increased (linear (L), quadratic (Q), cubic (C): P < 0.05) as the inclusion of cassava peels reduced and cassava leaves and cowpea haulms increased in the diets. The crude protein (CP) intake significantly increased (L, Q, C: P < 0.05) as the inclusion of cassava peels reduced and cassava leaves and cowpea haulms increased in the diets. Growth rate values significantly (L: P < 0.05; Q: P < 0.01) ranged from 21.55 g/day in T1 to 43.09 g/day in T4. The feed conversion ratio was significantly (L, Q: P <0.01) lowest in T4 (11.35) and was highest in animals in T5 (14.33). Dry matter digestibility significantly (L, Q, C: P < 0.05) ranged from 78.94 to 89.52 %. The digestibility increased as the inclusion of cassava leaves and cowpea haulms increased and reduced cassava peels in the diets. The highest N intake of 14.75 g/day obtained in T4 was significantly (L: P < 0.01; Q, C: P < 0.05) different from the values of 9.26, 10.56, 11.31 and 12.02 in T1, T2, T3 and T5, respectively. Nitrogen balance values significantly (L, Q, C: P < 0.05) ranged from 2.75 g/day in T1 to 9.15 g/day in T4. It is recommended that cassava peels, leaves and cowpea haulms in the proportion of 100:400:475 g/kg DM improved the growth and digestibility of WAD goats and can therefore be used to sustain animal performance during the dry season in a total mixed ration.