Comparison of the prediction of carcass components using fat thickness measurements in heifers and steers [beef cattle]
1994
Johnson, E.R. (Queensland Univ., Pinjarra Hills (Australia). Dept. of Farm Animal Medicine and Production)
Predictions of carcass composition based on anal fold and 12th rib fat thickness measurements were compared in 12 Hereford heifers and 12 Hereford steers. For carcass proportions, simple regression equations indicated that heifers had less muscle (2-3 percent), more fat (2.5-4 percent), and more bone (0.9 percent, 12th rib only). For predictions of the weights of carcass components at a given fat thickness measurement, simple regression indicated that heifers had less muscle than steers (by about 6 kg), but for bone and fat the intercepts did not differ significantly between sexes. In multiple regression, empty liveweight contributed strongly to the predictions of weights of all 3 carcass components. In all regressions in which the weight of each of the 3 carcass components was regressed on a weight and a fat thickness measurement together, except for muscle and fat regressed on chilled carcass weight and 12th rib fat thickness, the fat thickness measurement failed to contribute significantly to prediction. Although chilled carcass weight and 12th rib thickness together contributed to the prediction of muscle weight and fat weight, chilled carcass weight was the stronger contributor.
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