Effect of Flushing Diets With Different Omega‐6 to Omega‐3 Fatty Acids Ratios on Reproductive Performance and Blood Biochemical Attributes in Shall Ewes

The aim of the present study was to evaluate effects of flushing diet supplemented with omega-6 and omega-3 sources on reproductive performance and blood biochemical parameters in ewes. Twenty-five Shall ewes (30 ± 6 months) allocated to a completely randomized design with three experimental groups: (1) control diet with no fat supplementation (CON, n = 9), (2) control diet supplemented with calcium salt of soybean oil (CSSO, n = 8) and (3) diet supplemented with calcium salt of flaxseed oil (CSFO, n = 8). The ratio of omega-6/omega-3 in CON, CSSO and CSFO groups was 3.2, 5.3 and 1.5, respectively. The oestrous cycle of all ewes was synchronized with a progesterone-impregnated sponge for a period of 13 days. From 4 days before to one day after removing sponges, the growth and activity of ovarian follicles were checked using transrectal ultrasound technique. Results showed supplementation diet with CSFO increased the number of large follicles near the time of sponge removal (p < 0.05). The CSFO group showed a significant (p < 0.05) increase in progesterone concentration on Day 12 post-oestrus and improved oxidative status with decreasing (p < 0.05) in MDA and increasing (p = 0.06) TAC. The CSSO supplementation increased (p < 0.05) blood triglyceride and cholesterol levels. However, numerically higher prolificacy and fecundity were observed in the CSFO group. In conclusion, CSFO supplementation enhanced follicular growth and luteal function without affecting oestrus timing and reproductive outcome in Shall ewes.