Growth of Targhee and Targhee Crossbred Lambs on Utah Rangelands

Growth data were collected on 1848 Targhee and Targhee crossbred lambs from the Utah Agricultural Experiment Station flock at Cedar City for 1981 and 1982. The study objectives were to establish growth curves for seven lamb genotypes and examine within genotype growth differences among four grazing treatments (sheep alone, sheep and cattle mixed, both continuous and rotation). Body weights were measured at birth, and at mean ages of 56, 120, and 154 (weaning) days of age. Linear, quadratic, and cubic regressions of weight on age were used to establish growth curves. Among genotype comparisons of entire growth curves were impossible as non-linear components were significant. (p Overall growth patterns were the same for all genotypes with the most rapid gains occurring between 56 and 120 days of age (combined mean .66 pounds). Suffolk-sired lambs from Suffolk-Targhee and Targhee-Finn-Targhee ewes were faster gaining (p The second most rapid gains (combined mean .56 pounds) occurred between birth and 56 days. All crossbred lambs had higher average daily gains than Targhee lambs (p%lt;.05). The slowest rate of gain (mean .16 pounds) occurred int he 34 days prior to weaning. Not all differences in body weight among pastures can be attributed to grazing treatments as three genotypes exhibited a significant (