Description
An F2 cross between two highly divergent porcine breeds for most productive traits, including prolificacy, was generated. F2 sows were classified as of high or low prolificacy based on phenotypic records of four consecutive parities (total number of piglets born and number of piglets born alive were recorded). At the fifth gestation, sows were slaughtered at day 30-32 of gestation, and the number of corpora lutea and number of embryos were registered. Samples from different tissues were snap frozen in liquid nitrogen for further studies. Uterus samples were used for total RNA extraction and hybridized on the affymetrix porcine genechip for comparison between high and low prolificacy F2 sows.