Composition of body and carcass gain of castrate Matabele goats fed complete cereal-based diets differing in roughage inclusion level to slaughter after 10 kg liveweight gain

Abstract

Four maize-based diets containing either 50 per cent (VH50), 33 per cent (VH33), 22 per cent (VH22) or 10 per cent (VH10) rangeland (veld) hay were offered ad libitum to 40 castrated Matabele goats aged either 18 or 24 months and slaughtered after 10 kg liveweight gain. Ten additional goats of the same age and weight comprised a preliminary group that was slaughtered at the start of the experiment. Mean cold dressed carcass weights of the fed groups and the preliminary slaughter group were 17.2 kg and 10.6 kg respectively (P<0.001). Corresponding carcass yields expressed as a proportion of empty (gut-free) body weight were 0.569 and 0.523 g/kg (P<0.001). Chemical proportions of the right carcass side, exclusive of the kidney, kidney-knob and channel fat for the two groups, were 509 and 588 g/kg H2O, 284 and 159 g/kg ether extract, 48 and 73 g/kg ash, and 157 and 180 g/kg crude protein (P<0.001). Chemical composition was, however, not significantly different for the four diet treatments. Visceral fat deposition was positively related to diet energy concentration (P<0.001).