Survivability in Nilagiri and Nilagiri Synthetic Sheep: Genetic and Non-Genetic Effect

Data on 9333 records of Sheep Breeding Research Station, Sandynallah, The Nilagiris (Tamil Nadu) available for 25 years (1989 to 2015) were analyzed for pre- and post-weaning survivability (0- 3 months, 3-6 months, 6-9 months and 9-12 months of age). The effect of various genetic and non-genetic factors, viz., breed, contemporary group of birth, birth type, inbreeding, sex and birth weight on survivability were analyzed. The least squares means for survivability during 0-3, 3-6, 6-9 and 9-12 months were 92.8 ± 0.8, 95.3 ± 0.8, 98.6 ± 0.6 and 98.2 ± 0.7 % for Nilagiri sheep and 89.9 ± 1.0, 92.9 ± 1.0, 96.9 ± 0.7 and 97.0 ± 0.8 % for Nilagiri synthetic sheep, respectively. Breed and contemporary group of birth had significant (P<0.01) effects on pre-weaning survivability. Post-weaning survivability was significantly different in the two genetic groups. Contemporary groups and sex of lamb had a significant effect on all the survivability traits, except that for the period from 9-12 months. Birth weight of lambs had a significant influence on early survivability traits of pre weaning and 3-6 months group.