On-station assessment of performance of the DS synthetic and parental sheep breeds, D’man and Sardi

Performances of the DS synthetic breed of sheep (50% D’man and 50% Sardi genes) were compared to those of the contemporary parental breeds using records collected between 1998 and 2000. Results from reproductive traits showed that breeds differed for weight at breeding, litter size at birth and at 90 days, and litter weight at birth (P<0.01), but were similar for fertility, litter weight at 90 days and gestation length (P>0.05). Performances of DS ewes were, in general, intermediate to those of the parental breeds. DS ewes were lower than the average of the parental breeds for weight at mating by 3%, litter size at birth by 0.9%, litter size at 90 days by 3.5%, and litter weight at birth by 10.2%. Milk production during the 2-month lactation was identical for Sardi, D’man, and DS breeds (P>0.05). DS lambs were intermediate to those of D’man and Sardi lambs for weight at birth, 30 and 90 days, whereas preweaning growth was higher. DS lambs were 9.4% lighter at birth but 0.6 and 2.3% heavier at 30 and 90 days than the average of the parental D’man and Sardi breeds. Likewise, carcass characteristics of DS lambs were close to those of the best parental breed. Lamb survival to 90 days, fattening growth and feed efficiency did not differ among breeds (P>0.05). It was concluded that the DS synthetic breed could be considered as a purebred flock or maternal breed for market lamb production.