ABSTRACT

Four experiments were conducted to evaluate African yambean seed meal as feed ingredient in cassava peel-based diets for West African Dwarf (WAD) goats. In experiment 1, the nutrient value of African yambean seed meal (AYBM) was investigated. The seed was subjected to boiling and toasting for 30 minutes and thereafter evaluated for proximate composition, gross energy, mineral assay and antinutritional properties. Boiling significantly (P<0.05) increased crude protein (CP), ether extract (EE) and gross energy compared to the raw and toasted seed. Toasting significantly (P<0.05) increased nitrogen free extract (NFE) and ash values. Processing had significant (P<0.05) effect on mineral composition of the seed except for phosphorus. Boiling however, significantly (P<0.05) reduced phytate, alkaloid, and trysin inhibitor contents. In experiment 2, four diets were formulated with AYBM at 0, 10, 20 and 30% designated A, B, C and D respectively. Sixteen weaner bucks weighing between 6.5kg and 10.5kg were assigned to the four diets with 4 bucks per treatment in completely randomized design (CRD) experiments which lasted for 56 days. Parameters measured were; average daily weight gain (ADWG), feed intake/gain ratio (FCR), feed cost per kilogram gain (N) and dressing percentage. ADWG was 36.07, 98.05, 124.82 and 108.04g for diets A, B, C and D respectively. These means were significantly (P<0.05) higher in the AYBM diets than in the control. Feed gain ratios were 10.98, 4.69, 3.88 and 4.56 for the respective diets. The group fed 20% (diet C) AYBM had better (P<0.05) feed conversion and lowest (P<0.05) feed cost per kilogram weight gain. Dressing percentage and bone to lean ratio also differed significantly (P<0.05) among the treatment groups with animals fed diet C recording better values. Liver and kidney weights increased significantly (P<0.05) with increase in AYBM. PCV(%) values decreased significantly (P<0.05) with higher levels of AYBM and also significantly (P<0.05) promoted higher WBC (ml x 103) in animals. Urea (mmol/L) decreased (P<0.05) with higher levels of AYBM in diets. Glucose (mmol/L) increased significantly (P<0.05) at 20 and 30% levels ofAYBM in diets. SGOT and SGPT values were lower (P<0.05) in animals fed AYBM diets. In experiment 3, 12 pregnant WAD does were used to determine the effect of AYBM based concentrate diets on colostrum and milk yield and composition. The does were divided into 4 groups of 3 does per replicate in a CRD experiment and assigned to one of the dietary treatments as in experiment 2. Daily colostrum yield, total solids (TS), crude protein (CP), ash and energy composition differed significantly (P<0.05) among the treatment groups. Colostrum yield per day, (15.68g), TS (18.52%) and CP (5.41%) were highest in diet C. While diet D promoted the highest percent values of butter fat (BF), solids-not-fat (SNF), ash and energy with values of 3.52%, 14.54%, 0.91% and 4.30MJ/kg respectively. Milk yield, TS, BF, CP, SNF, ash and energy composition differed significantly (P<0.05) among treatment groups. Milk yield (3.26kg), SNF (9.96%) and energy constituent (3.91MJ7Kg) values were highest in diet B. Diet D promoted the highest TS, BF, CP and ash. The values were 15.03, 5.49, 4.89 and 1.04% respectively. In experiment 4, eight (8) WAD bucks with mean liveweight range of 18.85 - 19.94 kg and aged between 12-24 months were used in a 4 x 4 latin square experiment to determine the intake and nitrogen balance of AYBM based concentrate diets. The respective dietary treatments were assigned to individual animals in metabolism cages. Weekly body weights were recorded, feed and dry matter intake measured and nitrogen balance study conducted. The metabolic fecal nitrogen (MFN), endogenous urinary nitrogen (EUN) and digestible crude protein (DCP) for maintenance were determined. The MFN (g/lOOg DM), EUN (g/day/kgW075) and DCP (g/kgW075) values were 0.17, 0.19, 0.22, 0.25; 0.02, 0.03, 0.02, 0.03 and 0.44, 0.56, 0.81, 1.81 respectively for diets A, B, C and D. All the diets promoted positive N-balance, without differing significantly (P>0.05) among the treatment groups.