Feed intake, growth performance and carcass characteristics of Damara lambs fed bush-based rations from four encroacher bush species.

The effect of feeding bush-based finishing rations on the performance of Damara lambs was studied. Thirty weaned lambs weighing 16.7 ± 1.9 kg were allocated to five treatments in a completely randomized design over a 90-day feeding period. The control diet (T1) consisted of Lucerne (10%), grass hay (30%) and concentrate mix (60%). The other diets consisted of roughage (40%) from the milled bushes Senegalia mellifera (T2), Dichrostachys cinerea (T3), Terminalia sericea (T4) and Rhigozum trichotomum (T5) and concentrate mix (60%). At the end of the feeding trial, the lambs were slaughtered and carcass characteristics were evaluated. The average daily feed intake (ADFI) was affected (P < 0.05) by sex, treatment, week and treatment x week interactions. The ADFI for T1 exceeded (P < 0.05) that for T2 and T3, at most time points. The ADFI of T1 and T4 were similar (P > 0.05) at weeks 6 to 10, but differed (P < 0.05) at other time points. The average daily gain (ADG) and feed conversion ratio (FCR) were affected (P < 0.05) by sex and treatment. The ADG (g/day) least squares means (± S.E) for T1 - T5 were 148.0 ± 6.9, 156.4 ± 6.9, 124.2 ± 6.9, 133.7 ± 6.9 and 133.7 ± 6.9, respectively. Treatment T2 had a better (P < 0.05) FCR compared to other bush-based treatments. Males had heavier (P < 0.05) final, hot and cold carcass weights than females. Lambs fed T4 had greater (P < 0.05) rib eye area than T1 (8.3 ± 0.5 vs. 5.9 ± 0.5 mm). Bush-based diets can serve as production diets for weaned sheep and result into acceptable weight gain and carcass quality.