Growth performance, nutrient digestibility, nitrogen utilization and economic efficiency of West African dwarf rams...

This study evaluated the effects of rice straw, maize stovers, and maize cobs supplemented with poultry-litter-based concentrate on feed intake, growth performance, nutrient digestibility, nitrogen utilization, serum metabolites, and economic efficiency of West African Dwarf (WAD) rams. Twenty-four rams were allotted to three dietary treatments, with each crop residue offered as the basal feed and supplemented with a common concentrate containing 20.8% crude protein and 10.5 MJ/kg DM metabolizable energy. Significant differences (P < 0.05) were observed among treatments for feed intake, growth performance, nutrient digestibility, nitrogen utilization, selected serum metabolites, and economic returns. Rams fed maize stovers had the highest dry matter intake (910 g/day), final body weight (27.8 kg), weight gain (9.2 kg), and average daily gain (132 g/day), compared with 780 g/day, 24.2 kg, 5.8 kg, and 82 g/day for rice straw and 720 g/day, 23.5 kg, 5.0 kg, and 71 g/day for maize cobs, respectively. Feed conversion ratio was lowest with maize stovers (6.89). Maize stovers also produced the highest dry matter (68.4%), crude protein (70.2%), and neutral detergent fibre (59.6%) digestibility. Nitrogen retention was greatest in maize stover-fed rams (9.2 g/day; 62.1%). Serum total protein, albumin, and glucose were higher with maize stovers, whereas serum urea and cholesterol were unaffected. Maize stovers had the highest net profit (USD 38.4) and benefit-cost ratio (1.61), with the lowest cost per kilogram of gain (USD 1.08). Thus, maize stovers supplemented with poultry-litter-based concentrate provided superior biological and economic performance and represent a promising basal feed resource for WAD rams.