Analysis of the non-genetic factors affecting the growth traits of Balouchi sheep
By: Reza Tohidi, Arash Javanmard, Vahid Shamsabadi
Key Words: Balouchi sheep, Growth traits, Environmental factors.
J. Bio. Env. Sci. 8(6), 67-73, June 2016.
A study was conducted to evaluate the effects of non-genetic factors on the growth behavior of Balouchi sheep breed. The data of growth traits, birth weight (BW), weaning weight (WW), weight at 6, 9 and 12 months of age (W6, W9 and W12, respectively) were taken from 1400 lambs belonging to historical data from Abbasabad Sheep Breeding Station located at the North-east of Iran during a period of five years. Statistical analyses were performed using a general linear model including non-genetic factors: lamb sex, birth year and litter size as main effects, the lamb’s age when weighed as covariable, and the interactions between these factors. Results showed that all traits were significantly (P < 0.001) affected by all factors. However, the interaction between sex and litter size was not significant for BW, WW and W6. Environmental factors have very important roles in the development and growth of Balouchi sheep at different ages. Therefore, a correction is necessary to increase the accuracy of direct selection on lamb weight at different growth stages.