The comparisons of fattening performance of Angus, Brangus and Hereford Bullocks at different initial body weight

Abstract

The aim of this experiment was to evaluate the fattening performance of growing beef cattle differing in initial body weight and breeds. The experiment was carried out with 314 imported 8-12 months old growing Hereford, Angus and Brangus bulls. They were allocated to three initial body weight groups (low:242; medium:280 and high:323kg). Fattening diet was formulated with 24.10% roughages (alfalfa and wheat straw) containing 14.0% crude protein. After two week adaptation period with 8 step diets (100, 83, 75, 67, 54, 43, 33, 24% roughage) were used. The fattening period of all groups was lasted 124 days. Breeds affected daily gain, final body weight and feed to gain ratio significantly (P<0.01). Angus (1.5kg d-1) and Hereford 1.51kg d-1) had higher daily gain than Brangus (1.41kg d-1). Similar trends were obtained for final body weight and feed to gain ratio as well. Initial and final body weight was different significantly as expected (P<0.01). Daily gain were not affected by initial body weight although the daily gain tended to be higher in high initial body weight group (Low: 1.46kg d-1; Medium: 1.45kg d-1 and high 1.51kg d-1, P>0.05). Dry matter intake was in accordance in size group (Low: 8.35kg d-1, Medium: 8.94kg d-1 and High: 9.02kg d-1). The growing cattle having medium initial body weight worsened feed to gain ration due to relatively high feed intake and lower daily gain compared to other initial body weight groups. Any parameter investigated was not affected by breed and initial body weight interaction (P>0.05). Breeds affected daily gain, final body weight and feed to gain ratio significantly (P<0.01). Angus (1.5kg d-1) and Hereford 1.51kg d-1) had higher daily gain than Brangus (1.41kg d-1). Higher daily gain in Angus and Hereford compared to Brangus in the present study may be related to frame size and/or maturity of the breeds. Angus is early maturing, Hereford is medium maturing and Brangus is late maturing relatively. Furthermore the study revealed that size of growing animal having higher than 300 kg may be fattened more efficiently (higher daily gain) as they have enough feed intake capacity and frame compared to lower body weight groups.