Prediction of Percent Retail Product, Retail Product Weight and Hot Carcass Weight From Serially Measured Live Animal Traits

A total of 1,072 observations collected over a six-year period were used to develop prediction models for retail product (percentage and weight) and hot carcass weight from live cattle measures. Independent variables used were: ultrasound fat thickness (UFAT), ultrasound longissimus muscle Area (ULMA), age, hip height (HT), live weight (WT), ultrasound-predicted percent Intramuscular fat (UIMF) and breed composition. Pearson product moment correlations between the dependent and independent variables were often significant (P < .01, P < .05). In the prediction of percent retail product, UFAT accounted for 29 to 42% of the variation. A complete model including all the independent variables explained 20% more of the variation. In the prediction of retail product weight, WT remained a highly significant independent variable accounting for 32 to 78% of the variation. Similarly, WT accounted for 38 to 81% of the variation in hot carcass weight. When independent variables were adjusted to a constant age, models from data adjusted to earlier ages (M-414, M-382) explained more variation than models from data adjusted to a mean age at slaughter (M-448).