Characterization and Comparative Analysis of Transcriptional Profiles of Porcine Colostrum and Mature Milk Across Multiple Parities

Abstract BackgroundThe expression of genes and their regulation during lactation in swine is not well-understood. In order to gain a better understanding of genes and pathways involved in sow lactation, total RNA from colostrum and mature milk samples were sequenced from 65 sows across four parities. A stringent bioinformatic pipeline was used to identify and characterize 44,234 transcripts. ResultsThe 44,234 identified transcripts included 41,875 previously annotated transcripts and 2,359 novel transcripts. Differential gene expression analysis was conducted using a generalized linear model coupled with the Lancaster method for P-value aggregation across transcripts. In total, 1,900 differentially expressed genes (DEG) were identified for the milk type main effect, and 373 DEG were identified for the milk type x parity interaction. Several gene ontology (GO) terms related to immune response were significant for the milk type main effect, supporting the widely-accepted hypothesis that immunoglobulins and immune cells are transferred to the neonate via colostrum.ConclusionsThis is the first study to perform global transcriptome analysis from whole milk samples in sows from multiple parities. Our results provide important information and insight into synthesis of milk proteins and innate immunity and potential targets for future improvement of swine lactation and piglet development.