Effect of feed restriction and realimentation on nutrient utilization and carcass composition of Zebu bulls

Abstract

Forty.eight Sokoto Gudali bulls were used to study carcass compositional changes and nutrient efficiency  following feed restriction (25% ad libitum feeding, L., and 54% ad. Iibitum reeding, M) and  realimentation (ad. libitum feeding, H). The treatments were designated as LLH, LMH and LHH according to the level of feeding for each of three periods within each treatment group. Representative bulls were slaughtered at the beginning of the study and at the end of each feeding period. At the end of the mid period, animals on the LLH and LMH feeding regimes had higher percentages of water, similar percentages of protein and ash but lower proportions of fat and energy compared to animals on the LHH feeding regime. Following realimentation in the final period carcass gains contained approximately 21.0, 15.0, 18.5% protein and 22.0, 31.0 and 29.6% fat for LLH, LMH and LHH bulls respectively. The LHH animals were more efficient in utilizing metabo· lizable energy for carcass energy gain than the LLH and LMH animals. Digestible crude protein (DCP) efficience for carcass protein gain averaged 17 .6, 26.2 and 35.4 g DCP/g protein gain for LLH, LMH and LHH bulls respectively. The results suggest that improved efficiency of protein utilization is lagely responsible for compensatory carcass growth in zebu bulls.

Key word:· Realimentation, nutrient utilization, carcass composition, zebu bulls