Estimation of genetic and phenotypic trend of growth traits for Moghani Sheep using the best model

The objective of this study was estimate of the genetic and phenotypic trends of growth traits in Moghani sheep. In this study, a total of 21,423 records of growth traits belong to Moghani lambs that collected by raising and breeding of Moghani sheep station between 2003 and 2010, was used. The SAS 9.1 statistical software was used to evaluate the effect of environmental factors. Variance components and genetic parameters were estimated using restricted maximum procedure and univariate animal model and with wombat software. Animal breeding value of were estimated using the best univariate animal model. Environmental factors, like birth year, sex, herd, type of birth, and the age of mother are the significant factors as fixed effects. Estimation of direct genetic trend for birth weight, weaning weight, 6 month weight, 9 month weight and 12 month weight were as 6±1, 8±1.5, 8±6, 11±5 and 86±5 gr per year, respectively. The phenotypic trend for mentioned traits was estimated 30±1, 116±1, 37±6, -342±5 and -43±5 gr per year, respectively. The results showed that before designing any breeding program, optimum environmental condition must be prepared for appearance of maximum genetic potential, so phenotypic and genetic trends will be desirable in the herd.