RESUMEN
To determine the effects of adding of different supplemental fats to flushing diet on reproductive parameters in Iranian Zandi fat-tailed ewes. Randomized complete block. Fifty two Six- year- old Zandi ewes. Four experimental diets: without supplemental fat [1], containing 4.5% calcium salts of fatty acids from tallow [2], containing 4.5% calcium salts of fatty acids from soybean oil [3] and containing 2.25% calcium salts of fatty acids from tallow plus 2.25% calcium salts of fatty acids from soybean oil [4] were tested. After laparascopy, follicles [3 mm diameter] and corpus luteums [CL] on both ovaries were counted. Number of CLs were designated as ovulation rate [OR] index. At lambing number, weight and sex of lambs and lambing date of ewes were recorded. Analysis of variance was done by general linear model procedure of the SAS. OR in group 3 was higher than the other ones [p<0.05]. Number of follicles in group 2 were lower than the other groups [p<0.05]. Pregnancy rate from first, total of two and three first periods in group 3 were higher than the other groups [p<0.05]. Pregnancy rate from first and total of two first service periods in groups 2 and 4 were higher than group 1 [p<0.05]. Lambing rate and lamb crop from each of the three service periods were highest in group 3 and lowest in group 1[ p<0.05]. Twining rate from the first service period in group 3 was higher than, the other groups and in groups 2 and 4 was higher than group 1 [p<0.05]. Twining rate from total of two first service periods in groups 3 and 4 was higher than group 1 [p<0.05]. Fat supplementation especially from rich sources of unsaturated fatty acids to flushing diet had positive effect on the OR and reproduction performance of ewes