Effect of genotype, sire, sex, gestation length on birth weight of lambs

Abstract

The birth weight of lambs has an essential role in satisfying sheep production. Also reflected as primary factor later development of young organism. In the study included: gestation length, sire (two sires in each genotype during parenting), sex of lambs at birth, the birth weight of single lambs from well nourished mature ewes of the next genotypes: Miss (1), Wurttemberg (2) and Ile de France (3). The highest birth weight was obtained in genotype 3 with an average birth weight of 4.63 kg in sire 2 and 4.44 kg in sire 1 with a difference of 0.19 kg. Gestation length of genotype 1 ranged from 144 to 153 days; genotype 2, from 148 to 154 days and the genotype 3, from 144 to 151days. The highest average birth weight in genotype 1 with gestation length of 153 days weighed 5.10 kg. Average birth weights of male lambs in all genotypes were higher than the females. There were a very significant effect of genotype, sire, gestation length on birth weight of lambs (P<0.01), but sex have no significant effect on birth weight of lambs (0.065;P>0.05). The result achieved therefore can be explained that the effect of genotype, sire and gestation length and the interaction between subjects effects such as the next: Sire*Gestation length; Sire*Sex; Gestation length*Sex; Sire*Gestation length*Sex were highly and significantly affected the birth weight of lambs (P<0.01; P<0.05). The interactions between subjects? effects will be a good indicator to be acquainted more on their influence in a certain trait.