Effects of Omnigen-AF® Supplementation on in Vitro Embryo Development and Gene Expression in Superovulated Donor Beef Cows

Embryo quality is a crucial factor when selecting embryos for transfer. Variation in embryo quality can be attributed to poor oocytes and semen, inflammation, and potential immune system dysregulation. OmniGen-AF® (OG) supplementation supports immune system function and animal health. Previously we observed feeding beef cattle donors OG during superovulation decreased percent degenerate embryos recovered, decreased cortisol, and increased progesterone concentrations. Therefore, we evaluated the effects of OG supplementation on in vitro embryo development and gene expression of two immune system markers in superovulated beef cattle. Twenty-four cross-bred beef cows that had never been superovulated were randomly assigned to four treatment groups: 0 g OG/hd/d and 200 mg FSH (0/200); 0 g OG/hd/d and 400 mg FSH (0/400), 56 g OG/hd/d and 200 mg FSH (56/200) and 56 g OG/hd/d and 400 mg FSH (56/400). Cows were fed OG for 49 d (where d 0 = start of the feeding period). Superovulation was started on d 28 and ova were nonsurgically recovered on d 49. Good to excellent quality morulae and blastocysts were cultured for 8 d to evaluate in vitro embryo development. Blood samples for evaluating CD62L (L-selectin) and CXCR2 (IL-8R) gene expression in circulating immune cells were collected on d 0, 10, 14, 21, 28, 38, 42, and 49. The protocol was repeated on all cows 90-120 d later with cows reassigned in original groups and fed OG for 49 d. In the first superovulation percent blastocysts hatching was greater in embryos recovered from 0/200 and 56/400 cows compared to 0/400 cows (P<0.05). Greater (P<0.05) embryo volumes were attained by embryos recovered from cows treated with 200 vs. 400 mg FSH. Although similar trends were observed in the second superovulation, feeding OG had no significant effects on in vitro embryo development. CD62L and CXCR2 expression was not affected (P > 0.10) by OG feeding in the first superovulation; however, CD62L was upregulated (P<0.05) and CXCR2 tended to be upregulated (P=0.07) in cows fed OG in the second superovulation. In summary, OG supplementation improved in vitro development in embryos recovered from cows first superovulated with the standard 400 mg FSH dose and during second feeding experimental period induced expression of immune system markers.