THE EFFECTS OF BREED AND CERTAIN ENVIRONMENTAL FACTORS ON BIRTH AND WEANING TRAITS OF RANGE SHEEP

Data collected during a 4-year period from 830 lambs of the Rambouillet, Romnelet, Canadian Corriedale, and Romeldale breeds were used to estimate the effects of breed and certain environmental factors on birth weight, weaning weight, face cover, conformation, and condition score.Rambouillets ranked first in birth weight and weaning weight, had most wool on the face, and scored poorest in conformation. Romnelets ranked second in weaning weight, had least wool-covering on the face, and were judged superior to the other breeds in conformation and condition. Canadian Corriedales had heavier lambs at birth than Romeldales; however, the Romeldales were more open in the face and scored better in conformation and condition.Year was one of the major sources of variation in weaning weight and conformation. Breed and sex contributed largely to variation in face-cover score. Effects of birth and rearing type (single, twin, or twin raised singly) on birth weight, weaning weight, conformation, and condition were signi...