In this study 2510 records of reproductive traits from the mating of 879 ewes with 164 rams of Bakhtiari sheep breed, during 1989 to 1997, were used in order to estimate the effects of environmental factors on their reproductive performance. The mean and standard errors of reproductive traits were as follows: conception rate, 0.9±0.01 number of lambs born per ewe exposed, 1.06±0.01 number of la...
