Study of sire selection in view of genetic relation involving fitness traits in Malpura sheep in an organized farm of Rajasthan, India

The genetics of fitness traits, viz. replacement rate (RR) and selective value (SV) were studied in the flock of Malpura Sheep along the production parameters of the animals. The study was carried out on 10 years records for 2307 lambing sired by 187 sires. Sire wise incidence of replacement traits was as follows: abnormal birth (0.30%), sex ratio (49.98%), mortality (17.26%), culling (15.37%), RR on total lamb basis (33.98%) and RR on female lamb basis (68.44%). The selective value or adaptive value for the flock was 1.37. Sire did not affect abnormal birth, mortality, culling and SV significantly, whereas sire significantly affected sex ratio, and RR on total female lambs born basis. Ranking of the sires for selective value was incoherent with the ranking for production parameters such as age at first service, age at first lambing, weight at first service, productive flock life and longevity. Study indicated that the selection of sires for SV would not bring desired correlated change on any of the production parameter of the animals.