Residual Feed Intake in Hereford Steers: Is It Associated with Carcass and Meat Quality Characteristics?

Carcass and meat quality traits were evaluated on 136 Hereford steers categorized according to their residual feed intake (RFI): high RFI (HRFI), medium RFI (MRFI), and low RFI (LRFI). Steers from the 3 groups of RFI did not differ (P > 0.05) on final live weight, hot carcass weight, carcass yield, marbling scores, ribeye area, and subcutaneous fat thickness. No differences (P > 0.05) were observed in the weights of tenderloin, strip loin, bottom round, knuckle, and tri-tip among RFI groups; however, steers from LRFI and MRFI had heavier (P < 0.05) top sirloins than HRFI animals and inside rounds from more efficient animals (LRFI) were heavier (P < 0.05) than HRFI steers. Steers from HRFI showed a greater (P < 0.05) proportion of intramuscular fat (IMF) than LRFI animals. Longissimus muscles from HRFI steers presented greater (P < 0.05) concentrations of saturated (SFA), monounsaturated, and polyunsaturated fatty acids (PUFA) than those from MRFI and LRFI animals. The PUFA/SFA ratio of IMF did not differ (P > 0.05) between LRFI and HRFI steers and neither between LRFI and MRFI. In addition, the omega 6:omega 3 fatty acids ratio did not differ (P > 0.05) among the 3 RFI groups. Consumer's panel acceptability scores for tenderness, flavor, and overall liking were not significantly different (P > 0.05) among meat samples from LRFI, MRFI, and HRFI steers. Our findings indicated that RFI would not be associated with carcass traits and meat quality of Hereford steers, except for the IMF content and fatty acids concentrations. Therefore, end-product quality would be only marginally affected when RFI characteristic is included in a Hereford breeding program.