Reproductive performance of seasonal ewes fed dry fat source during their breeding season

This experiment was conducted to investigate the effect of dry fat inclusion in the diet on reproductive performance of Awassi ewes. Seventy-five dry Awassi ewes, 3-4 years of age, were selected and divided randomly into three groups of 25 females each in a completely randomised design. Treatment started 45 days before mating using one of three totally mixed rations (TMR) containing 0, 3, or 5% dry fat. Ewes were oestrally synchronised before mating and blood samples were collected to determine serum progesterone concentrations. Adding dry fat to diets did not increase plasma progesterone concentrations, with no differences between both levels of the added fat also. The overall conception rate for the first cycle was reduced (P < 0.05) following the addition of dry fat. However, 5% supplemental fat increased (P < 0.05) the second and third cycle conception rates. The gestation length was increased (P < 0.05) by increasing the level of fat in the diet. A 3% level of dry fat had no effect on litter size, twining rate or lambs' birth weight. However, feeding 5% supplemental fat adversely (P < 0.05) affected these parameters. Based on these results, it appears that adding dry fat to Awassi ewes' diets does not improve reproductive performance.