Abstract

Tesfaye Lemma, Tesfa Geleta, Amsalu Sisayand Tekle Abebe

Twenty four Borana bulls (average weight 218 ± 6.3 kg) were randomly assigned to 4 finishing diets to study the effects of basal diets on carcass composition. Diets were: R1 (teff straw 30%, local hay 10%, haricot bean straw 10%, molasses 20%, corn grain 20% and haricot bean grain 10%), R2 (teff straw 10%, haricot bean straw 20%, maize stover 10%, molasses 15%, corn grain 25%, noug cake 10% and linseed cake 10%), R3 (teff straw 10%, local hay 20%, molasses 25%, wheat bran 15% and wheat middling 30%) and R4 (teff straw 20%, molasses 30%, wheat bran 20% and wheat middling 30%). Animals were individually fed for 90 days at the recommended level of 3% of body weight. Results showed that, compared to other diets, R1 resulted in a significantly lower hot carcass weight (98.2 ± 18.4, vs 146.8 ± 6.7, 135.2 ± 8.1 and 135.2 ± 3.2, for R2, R3 and R4, respectively). Similar trends were observed for kidney fat, hump, scrotal fat weights and rib eye area. There was no significant difference in heart and omental and mesenteric fat weights, and back fat thickness among rations. However, R2 resulted in the highest weights. Although slight variations were observed in bone, fat and lean meat weight for different primal cuts, the difference among rations was not significant except for loin muscle, rack muscle and breast and shank muscle weights. R1 significantly (P<0.05) differed from other groups. R2 resulted in primal cuts with higher values. It was followed by R4, R3. R1 had the lowest values. Total feed cost did not differ among rations. However, it was highest for R2 and lowest for R3. R4 and R1 fall somewhere in between. Therefore, Borana bulls can be finished on any of the R2, R3 and R4 rations wherever they are available. Alternatively, R1 can be used anywhere else where other rations are scarce. Further studies are required on the effects of age and feeding duration on carcass characteristics of Borana bulls