CARCASS CHARACTERISTICS OF YEARLING BULLS AND HEIFERS FROM F1 DAMS BRED TO A RED POLL BULL

Abstract

Carcasses from 36 bulls and 39 heifers, sired by a Red Poll (R) bull and out of Simmental × Angus (SA), Charolais × Angus (CA), Hereford × Angus (HA), and Jersey × Angus (JA) cows were evaluated. These animals were slaughtered at an average age of 389 days. Hot carcass weights and estimated weights of total deboned, defatted primal cuts per day of age were greater (P < 0.05) in RCA animals than in RHA or RJA animals. RJA animals had lower (P < 0.05) dressing percentages than RCA or RHA animals. Carcasses of RJA animals had higher percentages of flank (P < 0.05) than those from RSA, RCA, or RHA animals. Carcasses from RSA animals had higher (P < 0.05) percentages of untrimmed and externally defatted round than RHA or RJA animals. Bulls produced heavier and leaner carcasses than heifers, as indicated by average fat depth over the rib-eye per 100 kg hot carcass weight and amount of external fat trim from the five primal cuts. Bull carcasses had greater estimated cutability, estimated total deboned, defatted primal cuts per day of age, cooler shrink, and percentages of externally defatted chuck, rib, and total primal cuts than heifer carcasses. Marbling was greater and percentages of untrimmed hind quarter, short loin, sirloin butt, and flank were higher in heifer than bull carcasses. The magnitude of differences in growth rates of carcass product between offspring of the F1 dams in this study suggests that the influence of F1 dam type on efficiency of feedlot beef cattle should be considered when selecting the breed cross of F1 dam to use in a beef production enterprise.