Effect of concentrate supplementation and season on apparent digestibility and growth performance of sheep in smallholder production system

The effect of concentrate feed supplementation, healthcare and season on dry matter and nitrogen apparent digestibility and growth performance of sheep were investigated in the smallholder production system. A total of 819 sheep belonging to 36 smallholder farmers were studied. Animals in each pen were randomly assigned to one of 2 feeding regimes. The first regime (control) was grazing and crop residues supplementation (75 g DM/d). In the second regime, sheep were treated as in first and given an additional package of concentrate feed (180 g DM/d) plus orthodox prophylactic and curative healthcare. Dry matter and nitrogen apparent digestibility and growth performance of animals were determined seasonally. The dry matter intake among animals on concentrate supplementation was higher (P<0.05) than those on control (608 vs. 515 g DM/d) but the faecal output was similar. Seasonally, DM intake was found highest during the early wet season (679 g DM/d) and lowest in the main wet season (397 g DM/d). Nitrogen intake was significantly affected by concentrate supplementation (11 vs. 8 g DM/d for concentrate supplemented and control groups respectively). Season significantly affected dry matter and nitrogen digestibility with the early wet season having the highest digestibility. The concentrate supplementation and healthcare provision package improved feed digestibility and increased ADG of animals from 19 g/d to 34 g/d in the smallholder production system.