The objective of the present study was to estimate direct and maternal genetic trends for body weight traits in IranBlack sheep using data which were collected for 24 years. The investigated traits were birth weight (BW), weaning weight (WW), 6-month weight (6MW), 9-month weight (9MW) and yearling weight (YW). A multivariate animal model analysis was applied to predict the breeding values of individual for the studied traits. For each trait, genetic trends were obtained by regressing the means of predicted breeding values on year of birth. Direct genetic trends were positive and highly significant (P<0.01) for BW, WW, 6MW, 9MW, and YW and were 0.93, 43.74, 81.72, 87.29, and 137.61 g/year, respectively. Also, maternal genetic trend for BW and 6MW was significant and were 4.60 and -14.38 g/year, respectively. The results showed that improvement of body weight traits of Iran-Black sheep seems to be possible in selection programs.
