Submitted to: Arkansas Agricultural Experiment Station Research Series
Publication Type: Experiment Station
Publication Acceptance Date: 6/1/2005
Publication Date: 10/15/2005
Citation: Looper, M.L., Burke, J.M., Mcbeth, L.J., Krehbiel, C.R., Flores, R., Rosenkrans Jr, C.F., Aiken, G.E. 2005. Growth, feedlot performance, and carcass characteristics of Angus and Charolais-sired calves castrated at birth or weaning. Arkansas Agricultural Experiment Station Research Series. 535:109-111. Interpretive Summary: Castration of bulls is labor intense, and most small farms have limited labor capabilities. Therefore many small producers frequently do not castrate male calves. Performance of non-implanted male calves castrated at birth or weaning was investigated in this study. Castration at birth or weaning did not influence weight gain or carcass traits of Angus and Charolais-sired steers. Quality grade was better for carcasses from Angus-sired steers. This information is of interest to beef producers, extension personnel, and agricultural professionals who advise beef producers on beef management practices.
Technical Abstract: Spring-born Angus and Charolais-sired calves (n = 54) were utilized to determine the effects of time of castration on growth, feedlot performance, and carcass characteristics. Calves were surgically castrated at birth (CB; n = 25; within 24 hours) or at weaning (CW; n = 29; average age = 197 ± 2 days). At weaning, steers were supplemented with 6 pounds/day of a medicated receiving ration and visually appraised for morbidity for 14 days. After weaning, all steers were supplemented with 3.3 pounds/day of a ground corn:soybean meal ration (crude protein = 17%) for 95 days, and then grazed Elbon rye for an additional 104 days until transport to the feedlot. Steers were weighed at weaning, initiation and termination of grazing rye, and at 28-day intervals in the feedlot. Adjusted 205-day weaning weights were similar (P > 0.10) between CB and CW steers (585 ± 10 vs 601 ± 9 pounds, respectively). For the first 56 days of the feedlot phase, CW steers (6.6 ± 0.2 pounds/day) gained more (P < 0.05) than CB steers (6.0 ± 0.2 pounds/day). However, average daily gain throughout the feedlot phase (average daily gain = 5.0 ± 0.1 pounds/day) was similar (P > 0.10) between castration treatments. Carcass characteristics were not influenced (P > 0.10) by castration treatment. Carcasses from Angus-sired steers had greater (P < 0.05) fat thickness, marbling and yield grade than Charolais-sired steers. Castration at either birth or weaning did not alter overall growth, feedlot performance, or carcass characteristics of Angus and Charolais-sired steers.