Effect of high dose omega-3 fatty acid feeding on the ovaries and reproduction of sows

Background: Omega-3 fatty acids feeding can have a significant effect on the reproductive performance of breeding sows, as they positively influence the maturation and growth of the follicles and increase the survival rate of the embryos. Objectives: The main objective of the experiment was to investigate the effect of fish oil feeding at a dose of 12.6 g/kg during two consecutive lactations, on reproductive performance of sows, as well as on the production parameters of them and their piglets. A goal was also to examine the ovarian units of sows after the abovementioned time period, on the 5th and 12th days post-weaning. Materials and Methods: The experiment was performed with 8-8 (large white x landrace, F1) breeding sows. Experimental animals received fish oil, rich in n-3 fatty acids, at a dose of 12.6 g/kg feed, during two consecutive lactations. Control animals received the same amount of sunflower oil supplementation. The feeding experiment started before farrows and ended at the subsequent weaning. Production parameters of sows and their piglets were evaluated, and ovarian units of sows (n=4) were also examined. Results and Discussion: Feeding of fish oil in the dose of 12.6 g/kg had a negative effect on total feed intake of sows during their first lactation (189.6 vs. 200.1 kg), and affected negatively their weight loss during lactation, as well as the performance of their piglets. The pregnancy rate was significantly higher in the control group, 87.5 vs. 66.7%. In the subsequent farrow the number of piglets born alive was significantly higher in the experimental group (9.43 vs. 13.33, p=0.03) The litter weight was also bigger in the trial group (16.74 vs. 19.37 kg). The results of the ovarian examinations performed on the 5th and 12th day after weaning showed a positive effect on the quantity and quality of follicles and other ovarian units, which may indicate more viable oocytes and larger, more developed corpus lutea and thus can contribute to an increase in the viability of the embryos.