Effect of conjugated linoleic acid on sex ratio and quality of in vitro produced bovine embryos

Abstract

The aim of this study was to evaluate the effect of culture medium supplementation with conjugated linoleic acid (CLA) on embryo cleavage, embryo production, sex ratio and embry o quality in in vitro produced bovine embryos at day 7 of culture. 308 COCs were used for the group supplemented with 100 µM of the CLA isomer Cis-9 trans-11 and Cis-10-Trans-12 and 257 COCs for the untreated control group; the embryo production was 25.32% vs 35.40%, respectively, with significant difference between them (P < 0.05). The embryos were classified according to the IETS in Mo, Bt, Bl and Bx stages for morphological and molecular analysis. PCR was used for sex determination; embryo quality was assessed as grade 1 (excellent or good) and Grade 2 (regular). The results showed no significant difference in the proportion of embryos male:female for any of the stages in the CLA supplemented group achieving the expected natural ratio (50:50), while the control maintained a greater number of males. The CLA improved quality in Bl and Bt stages for both females and males (P < 0.05) having a greater number of grade 1 embryos in supplemented group, while control embryos were more in grade 2. In conclusion, CLA adversely affects the production of bovine embryos in vitro, but the sex ratio equals the natural one in all stages and improves embryo quality in some stages of early development.