Effect of Type of Pregnancy on Transcriptional and Plasma Metabolic Response in Sheep and Its Further Effect on Progeny Lambs.

The following study was performed in order to determine the effect of type of pregnancy on the transcriptional expression of genes that are engaged in angiogenesis and cell turnover/lactogenesis in the ewe mammary gland, evaluating its impact on the plasma metabolic response. In addition, an assessment of its further influence on plasma metabolic response, performance, and muscle transcriptional expression of lipogenic enzymes in progeny lambs was made. Thirteen Ile de France sheep (six twin- and seven single-bearing ewes) were allocated to graze ad libitum naturalized pasture from d 45 pre-partum to day 70 post-partum, while keeping their lambs on the same diet until day 60 after weaning. The samples were collected at different times and analyzed by qRT-PCR and plasma metabolic indicators. The data were processed using SPSS package. The results showed that twin-bearing ewes overexpressed VEGFR1 at birth, and BCL2 at birth and day 35 post-partum; however, single-bearing ewes overexpressed CAIV and IGF1 at day 35 post-partum. Similar metabolite concentrations in blood plasma were found between groups of ewes. The plasma metabolic response in lambs was similar between groups and it did not influence their performance, where a similar transcriptional expression of lipogenic enzymes in muscle was observed. Therefore, the type of pregnancy can explain the slight differences in mRNA expression that were found in angiogenesis and cell turnover/lactogenesis in mammary gland, although these differences not only did not affect the plasma metabolic response in ewes, but they also had no influence on plasma metabolic response, performance, and muscle transcriptional expression of their lambs.