Productive performance of hair and wool type Dorper sheep under extensive conditions

Abstract

The reproductive performance, growth, slaughter traits, and several conformation characteristics in Dorper sheep (hair and wool types) were evaluated under extensive conditions in the north-western Karoo region of South Africa. From 1993 to 2000, lambs of hair ( n=1070) and wool ( n=1044) type Dorper sheep, and corresponding reproductive records from 872 and 874, respectively, were analysed. There was no significant differences between hair and wool type lambs for body weight from 42 days till 12 months of age, and for pre- or post-weaning growth rate. The analysis of conformation tend to suggest that the hair type lambs were blockier with shorter legs, compared to the leggier appearance of the wool type lambs. This is also evident from the longer carcass length (108.5 vs. 107.2 cm) and hind leg length of wool type lambs compared to hair type lambs. With regard to other carcass traits, wool type lambs had heavier carcasses (19.6 vs. 19.2 kg) and higher dressing percentage (49.9 vs. 49.0%), though, fat measurements and carcass grades were similar. The ewes of the hair type were heavier at mating than wool type (57.4 vs. 56.4 kg). No differences were, however, observed for percentage of ewes lambed, lambs born, lambs weaned, survival rate of lambs or kg lamb produced per ewe per year. It was concluded that the economically important reproduction and growth traits were similar between the hair and wool types of Dorper sheep. Differences that do occur in some conformation and carcass traits will not effect the economic realisation from the different types.