A trial evaluated growth performance, carcass characteristics, meat quality, and economic returns of fattened lambs fed on diets containing different protein sources. Six castrated male Tswana lambs per treatment were used in a completely randomised design (CRD) trial and fed on complete diets containing Lucerne (CD; commercial diet), morula kernel cake (MKC), or sunflower seedcake (SC) as protein sources over a 103-day experiment. No significant differences (p > 0.05) were observed in the dry matter intake, final body weight, average daily gain, and FCR. This was attributable to all the diets providing an equal supply of nutrients to the lambs. Meat quality attributes and proximate composition values were similar (p > 0.05) across the treatments. Longissimus dorsi muscle organoleptic quality did not differ (p > 0.05) across the treatments. The gross margin analysis was significantly greater (p < 0.05) when feeding SCD than feeding CD and was intermediate for lambs fed MKCD. Morula kernel cake (Sclerocarya birrea) can be used for fattening lambs when common protein sources are either not available or expensive.
Keywords: lamb; morula kernel cake; nitrogen retention; organoleptic attributes.