اثر همخونی بر صفات رشد و تولید مثل در گوسفند زندی

The current study was conducted in aim to investigation of inbreeding and inbreeding depression for growth and reprtoductive traits in Zandi sheep. To do this, pedigree and data information of body weight and reproductive traits which has beed collected during the years of 1987 to 2011 at Zandi Breeding station was used. Inbreeding coefficients was calculated using pedigree information of 8186 individuals and by CFC software. Individual and maternal inbreeding depression for each trait was estimated by considering those coefficients as a covariable and fitting an animal model by WOMBAT program. The mean inbreeding coefficient of all animals was 1.15%. Totally, 30.09% (n=2955) of individuals were inbred with mean inbreeding coefficient of 3.16%. Amoung the inbreds, the individuals with 0 5%. The results showed that inbreeding have had a intensify fluctuations. Howere, the inbreebing level of the whle population was constant, the number of inbred have been increasing over the years. Inbreeding depression per 1 % increasing of individual (maternal) inbreeding for birth, 3,6,9 and 12 month weight and average daily gains in preweaning and post-weaning was 9.39 (5.71), 22.00 (28.6), 71.3(57.3), 56.8 (51.00), 54.00 (107.00), 0.21 (0.31) and 0.29 (0.21) g, respectively. In addition inbreeding depression for composite reproductive traits ranged from 11.83 (total litter weight at birth) to 48.55 (total litter weight at weaning). Keywords: Zandi sheep, Growth traits, reproductive traits, inbreeding, inbreeding depression.کلید واژه ها : گوسفند زندی، صفات رشد، صفات تولیدمثلی، همخونی، افت همخونی.