Evaluating effects of supplemental fat in flushing diet on reproductive traits of Lori-Bakhtiari ewes.

The aim of this study was increase kilograms of weaned lambs per ewe exposed to mating by use of supplemental fat (Iran Megalac) in ewe's diet before and during ram introduction. This experiment conducted on a flock of Lori-Bakhtiari sheep from 1389 to 1391 in Chaharmahal and Bakhtiari province. Threehundred ewes were selected and allotted to three groups (n=100) as: Control (c) without any flashing diet, B treatment (flashing with barley grain) and BF treatment (flashing with barley grain + supplemental fat). Ewes in groups B and BF received dietary supplement from day 14 before up to day 21 after ram introduction in the evening at place that the flock spend the night. At lambing, the number, weight and sex of lambs and lambing date of ewes, conception rate and lamb weaning weight were recorded and data were analyzed using the GLM procedure of the SAS. Although treatment means were differ from each other with respect to conception rate but, differences were not significant. It was observed that number of lamb born in group BF was the highest (p 0.01). Differences between groups B and control with respect to number of born lamb was not statistically significant. Mean of birth weight of lambs per each mated ewe was highest in group BF but not statistically differ from group B. Mean of birth weight of lambs per each mated ewe were lowest in control group and differ from groups B and BF (p 0.01). Total birth weight of lambs per ewe exposed to mating was differ (p 0.05) and was highest in group BF and lowest in control. Total weaned lamb weight was highest in group BF and lowest in control group (p 0.01), however, the differences between groups BF and B, and B and control were not statistically significant. It is concluded that use of supplemental fat with barley grain in ewe flashing diet can improve reproductive performance especially when the risk of low reproductive performance is the greatest