An economic comparison of beef cattle genotypes for feedlot traits at their optimal slaughter end point

Abstract

A bioeconomic model is used to compare beef breeds and crosses for their economic performance in the feedlot. Breeding objectives for each breed and cross are also calculated. Comparisons are made on the basis of the expected purchase-price premium paid for a breed, cross or animal when slaughtered at its profit-maximizing end point. These comparisons are relevant to commercial beef producers who ultimately have to choose between genotypes. Purebred Charolais are expected to capture a premium over purebred Angus of approximately $71 and $45 animar−1 for steers and heifers, respectively. Simmental, Limousin and Hereford purebreds are intermediate, with differences between them relatively small in comparison with the expected effects of errors in model parameters. Crosses between exotic type (Charolais, Simmental and Limousin) and British type (Hereford and Angus) breeds have larger increases in purchase-price premiums over the mid-parent mean than crosses within the types. Averaged economic weights for 1% changes in the mean of +12 g d−1, −80 g d−1 and 0.6% in daily gain, daily feed intake and dressing percentage are $3.7 animal−1, $1.8 animal−1 and $8.4 animal−1, respectively. These are relatively consistent across breeds, crosses and sexes. In contrast, economic weights for fat depth at a constant weight are shown to be nonlinear and therefore are highly dependent on the breed, cross and sex and the slaughter end point at which they are calculated. At the economic optimum slaughter point in the base, exotic breeds and crosses between them tended to have negative economic weights for a reduction in fat depth, whereas British breeds were the opposite. Economic weights tend to be small and positive for a reduction in fat depth in crosses between the two breed types. Key words: Beef cattle, feedlot, end point, optimization, bioeconomic model