The Effect of Early Weaning on Performance, Health Parameters, and Carcass Traits of Bonsmara Bull Calves Under Feedlot Conditions

Abstract

A feedlot is an intensive farming system used for finishing livestock. This study analyzed the performance, health, and carcass traits of Early-Weaned Calves (EWC) and Traditionally-Weaned Calves (TWC). A total of 285 Bonsmara bull calves were grouped into two weaning strategies, with 136 EWC (255±27.30 kg) and 149 TWC (308±24.60 kg). Backgrounding was followed by a finishing phase, with a grower-adaptation and finisher ration provided ad libitum at 3% body weight. Performance traits evaluated included Initial Body Weight (IBW), End Body Weight (EBW), Dry Matter Intake (DMI), Average Daily Gain (ADG), and Feed Conversion Ratio (FCR), while health parameters focused on morbidity, mortality, and case fatality rates. Carcass traits, including Hot Carcass Weight (HCW), Cold Carcass Weight (CCW), Dressing Percentage (DP), Chilling Loss (CL), Carcass Grades (CG), Carcass Conformation (CC), and Marbling Score (MS), were assessed. The IBW and EBW of EWC were lower (P<0.001) by 54 kg and 69 kg, respectively, compared to TWC. Weaning treatment significantly (P<0.05) affected the overall ADG and FCR without impacting DMI (P>0.05). The TWC had 7.23% greater ADG and 5.08% lower FCR than EWC. The TWC exhibited higher total morbidity, mortality, and case fatality rates by 0.83%, 0.67%, and 10% than EWC, respectively. Although TWC had heavier carcasses than EWC (P<0.05; 328.41 vs. 285.89), no significant differences (P>0.05) were noted in other carcass traits. Weaning treatment influenced BW, carcass weights, ADG, and FCR without impacting DMI and carcass traits assessed in this study.