Growth performance in pigs derived from in vitro produced embryos is enhanced compared to their artificial insemination-derived counterparts from birth to adulthood

Research suggests that assisted reproductive technologies may lead to adverse effects on the offspring. To date, long-term effects from fetal development through adulthood have been scarcely researched. In the present observational study, we aimed to describe growth (body weight, BW; crown-rump length, CRL; and average daily gain, ADG), and growth-related hormone levels (growth hormone, GH; insulin-like growth factor 1, IGF-1; thyroxine, T4; cortisol) of pigs derived from artificial insemination (AI) and from embryos produced in vitro under two different conditions, C-IVP, with Bovine Serum Albumin (BSA), and RF-IVP, with reproductive fluids and BSA, as protein source in culture, from birth to 5 years of age. In vitro-produced animals showed greater BW, CRL and ADG than AI. Additionally, C-IVP animals had greater BW, CRL and ADG than RF-IVP up to 6 months of age. Regarding hormones, GH concentration was greater in RF-IVP compared to AI and C-IVP. In males, IGF-1 levels of RF-IVP were greater than those of AI. Instead, T4 levels of AI males were greater than C-IVP and RF-IVP. Males showed greater IGF-1 and GH than females, the latter only from 1 year old. Instead, females had greater T4 concentration than males. No differences in cortisol were observed between groups or sexes. In conclusion, this study sets reference values of growth and hormone concentrations for adult pigs that are missing in literature. Although the differences observed between the experimental groups were within physiological ranges, there was a greater growth performance in the IVP groups.