Growth performance and carcass characteristics of Tanzania Shorthorn Zebu cattle finished on molasses or maize grain with rice or maize by-products
Department of Animal Science and Production, Sokoine University of Agriculture, P.O. Box 3004, Morogoro, Tanzania; Department of Animal Science, Au Foulum, Aarhus University, Blichers Alle 20, Tjele, Denmark; Department of Larger Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
Forty five steers (2.5-3.0 years of age and 200±5 (SEM) kg body weight) were allotted randomly into five diets to assess the effects of finishing Tanzania Shorthorn Zebu (TSZ) cattle in feedlot using diets based on either molasses or maize grain combined with maize or rice by-products. The diets were hay and concentrate mixtures of hominy feed with molasses (HFMO), rice polishing with molasses (RPMO), hominy feed with maize meal (HFMM), rice polishing with maize meal (RPMM) and a control of maize meal with molasses (MMMO). All concentrate mixtures contained cotton seed cake, mineral mixture, salt and urea. Both hay and concentrate were fed ad libitum and with free access to drinking water for 90 days. Feed intake, body weights and carcass characteristics were recorded. The daily total dry matter intake (DMI, kg/day) was greater (P<0.05) in molasses based diets (7.64 for RPMO and 7.35 for HFMO) than in maize grain based diets (6.94, 6.73 and 6.19 for RPMM, MMMO and HFMM, respectively). Energy intake was highest (P<0.05) in HFMO (86 MJ/day) and lowest in RPMM (69 MJ/day). Crude protein intake was highest in HFMO (867 g/day) and lowest in RPMO (725 g/day). Feed conversion ratio (kg feed DMI/kg gain) was lower (P<0.05) for steers fed on HFMM (7.87) and HFMO (8.09) than those fed on MMMO (10.4), RPMM (11.0) and RPMO (11.5). Steers fed on HFMO had the highest (P<0.05) daily weight gain (919. g/day), total weight gain (83. kg), final live weight (283. kg), empty body weight (268. kg) and hot carcass weight (151. kg). The proportion of internal fat to empty body weight (2.7%) in steers fed on HFMO was higher (P<0.05) than those from other diets. Nevertheless, all carcasses showed relatively high fat cover (1.1-1.6. cm). It is concluded that agro-processing by products are good feed resources for finishing TSZ cattle in feedlots with formulations based on molasses being superior over those based on maize meal, and hominy feed being superior over rice polishing. A combination of molasses and hominy feed (HFMO) could be used successfully as an alternative to maize meal in finishing TSZ cattle in feedlot. © 2015 Elsevier B.V.