EVALUATION OF BREEDS OF SHEEP ON BASIS OF CROSSBRED LAMB PERFORMANCE

Birth weight and weaning weight of crossbred lambs from the females of the Minnesota 100, Minnesota 102, Minnesota 103, Minnesota 105, Minnesota 106 and Minnesota 107 were analyzed in an attempt to evaluate the breeds at the crossbred level. The breeds used as males included the Hampshire and Suffolk in addition to the 6 Minnesota breeds. Effects for breed of ram, age of ewe, sex, type of birth and rearing, and station-year-breed of ewe were estimated. Based on the breed of ram effects on 100-day weight of lambs, the breeds can be grouped into 3 categories. The Suffolk breed was superior and significantly different from the rest of the breeds. The Hampshire and the Minnesota breeds 106, 100, 105 and 102 may be placed in the 2nd category. The Minnesota 103 and Minnesota 107 breeds were inferior to the rest of the breeds. Heterotic effects were estimated for 14 specific breed combinations. Crossbreds excelled the purebreds for birth and 100-day weight of the lambs by 4.7% and 8.1%, respectively.