No abstract

Background In vitro embryo production (IVP) and embryo transfer (ET) are two very common assisted reproductive technologies (ART) in human and cattle. However, in pig, the combination of either procedures, or even their use separately, is still considered suboptimal due to the low efficiency of IVP plus the difficulty of performing ET in the long and contorted uterus of the sow. In addition, the potential impact of these two ART on the health of the offspring is unknown. We investigated here if the use of a modified IVP system, with natural reproductive fluids (RF) as supplements to the culture media, combined with a minimally invasive surgery to perform ET, affects the output of the own IVP system as well as the reproductive performance of the mother and placental molecular traits. Results The blastocyst rates obtained by both in vitro systems, conventional (C-IVP) and modified (RF-IVP), were similar. Pregnancy and farrowing rates were also similar. However, when compared to in vivo control (artificial insemination, AI), litter sizes of both IVP groups were lower, while placental efficiency was higher in AI than in RF-IVP. Gene expression studies revealed aberrant expression levels for PEG3 and LUM in placental tissue for C-IVP group when compared to AI, but not for RF-IVP group. Conclusions The use of reproductive fluids as additives for the culture media in pig IVP does not improve reproductive performance of recipient mothers but could mitigate the impact of artificial procedures in the offspring.

Background: In vitro embryo production (IVP) and embryo transfer (ET) are two very common assisted reproductive technologies (ART) in human and cattle. However, in pig, the combination of either procedures, or even their use separately, is still considered suboptimal due to the low efficiency of IVP plus the difficulty of performing ET in the long and contorted uterus of the sow. In addition, the potential impact of these two ART on the health of the offspring is unknown. We investigated here if the use of a modified IVP system, with natural reproductive fluids (RF) as supplements to the culture media, combined with a minimally invasive surgery to perform ET, affects the output of the own IVP system as well as the reproductive performance of the mother and placental molecular traits.Results: The blastocyst rates obtained by both in vitro systems, conventional (C-IVP) and modified (RF-IVP), were similar. Pregnancy and farrowing rates were also similar. However, when compared to in vivo control (artificial insemination, AI), litter sizes of both IVP groups were lower, while placental efficiency was higher in AI than in RF-IVP. Gene expression studies revealed aberrant expression levels for PEG3 and LUM in placental tissue for C-IVP group when compared to AI, but not for RF-IVP group.Conclusions: The use of reproductive fluids as additives for the culture media in pig IVP does not improve reproductive performance of recipient mothers but could mitigate the impact of artificial procedures in the offspring.

BackgroundThe increased use of assisted reproductive technologies led to a higher risk of specific alterations in the offspring, as already described in human and other mammalian species. Nonetheless, it is yet to be totally understood how and which specific techniques are inducing these changes. The use of animal models may represent an advantage to find out answers to these questions due to the minimization of confounding factors. The pig is not only a great human reproductive model, but it is also of interest in the livestock industry to develop further technologies that may enhance meat production. This study was designed to decipher the impact of one of these technologies, namely embryo transfer, on mother´s reproductive performance and on the phenotype of the offspring in pigs.ResultsEmbryo transfer of in vivo derived embryos (ET) showed similar results in terms of pregnancy length, litter size and total litter weight per sow than sows artificially inseminated (AI). Bodyweight at birth was higher for ET-females than AI-females, but this difference was no longer observed at day 15 of postnatal life. Some of the major findings after haematological analyses were that concentration of red blood cells, haemoglobin and haematocrit in female-ET piglets at day 3 showed higher values than AI-females. Additionally, higher concentration of white blood cells was found at day 3 in both ET-derived piglets (males and females) in comparison to AI-piglets. Biochemical analysis showed a higher level of albumin at day 3 for ET-derived male piglets than AI but ET-females showed lower levels of bilirubin than AI in the same day. Despite the statistical differences between groups, all values were within the normal ranges, so that we cannot give them any clinical significance.ConclusionsPiglets derived from in vivo embryo transfer seem to be phenotypically similar, which provides evidence that the embryo transfer procedure is a safe technique, without relevant health implications to the offspring. Additionally, these findings may be of interest to the pig industry regarding the reference values provided for haematological and biochemical parameters in this species.