Poultry by-product meal as a substitute for soybean meal in the diets of growing hair sheep lambs fed whole chopped sugarcane

Abstract

Poultry by-product meal (PBM) was examined as a substitute for soybean meal (SBM) in the diets of tropical hair sheep lambs fed fresh whole chopped sugarcane (WCS). Forty-eight growing crossbred (Barbados Blackbelly x Blackhead Persian) intact ram lambs with a mean initial BW of 13.8 ( ± SD, 0.8) kg were utilized. There were three lambs per pen, group fed and four treatments A, B, C and D where PBM nitrogen replaced 0, 33, 67 and 100% of the nitrogen from SBM in the diet, respectively. All diets were formulated to be iso-nitrogenous (16.0% CP, NPN supplied 28% of the total CP) and iso-caloric 13.9 MJ DE/kg DM. Dry matter intake was ( P>0.05) (A) 0.825, (B) 0.788, (C) 0.743 and (D) 0.800 kg/d/lamb or 3.98, 3.76, 3.79 and 3.72 g/100 g BW; average daily gain ( P<0.05) was 142, 171, 148 and 161 g/d/lamb and feed conversion efficiency (FCE) was 5.86, 4.62, 5.02 and 4.97 kg/kg BW gain, respectively. Lambs fed the 100% SBM diet (A) had lower daily gain ( P<0.05) than those fed the 100% PBM diet (D). Feed cost decreased and income over feed cost increased with increasing levels of PBM nitrogen in the diet. It was concluded that PBM was a useful and cheaper protein substitute for SBM in a WCS-based ration.