Piglet production by non-surgical transfer of vitrified embryos, transported to commercial swine farms and warmed on site.

Abstract

We investigated the feasibility of piglet production by non‐surgical embryo transfer (Ns‐ET) of vitrified porcine blastocysts and expanded blastocysts transported to commercial farms and warmed on site (V/T/W embryos). Ns‐ET was performed by depositing 11–20 vitrified and warmed embryos at a proximal site within the uterus via a catheter. In Experiment 1, the effect of donor–recipient estrous cycle asynchrony on the efficiency of Ns‐ET of vitrified and ordinary warmed embryos was investigated at the experimental facility. With a 1‐day delay recipients relative to that of donor, the farrowing rate was 50.0% and the survival rate to term was 21.1%. In Experiment 2, Ns‐ET using recipients with a 1‐day delay and vitrified embryos after one‐step warming and dilution was evaluated at the experimental facility. Although the resulting farrowing rate was 42.9%, the survival rate was 6.4%. In Experiment 3, Ns‐ET was conducted using V/T/W embryos at four commercial farms, where piglets derived from them were produced. When artificial insemination was conducted prior to Ns‐ET, the farrowing and survival rates obtained using V/T/W embryos were 75.0%, and 21.3%, respectively. These results show that Ns‐ET of V/T/W embryos using this protocol would be feasible for piglet production at farms.