Swine

Pre-farrowing Gene Expression Differences in Blood of Sows with High and Low Colostrum Brix Values

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Abstract

Colostrogenesis in pigs begins in late gestation as immunoglobulins, carbohydrates, and lipids accumulate within the mammary gland through two pathways: transport from maternal circulation and de novo synthesis within mammary epithelial cells. Variations in immunoglobulin trafficking may influence concentrations of colostrum IgG and therefore the correlated Brix refractometer values. The objective of this study was to compare pre-farrowing gene expression in blood of primiparous females (PF) that produced high or low Brix colostrum to elucidate the underlying mechanisms contributing to colostrogenesis. Whole blood samples were collected from 24 Yorkshire PF at 110 days of gestation, and white blood cells were isolated using a buffy coat prep. Colostrum was collected from each PF within 0-3 h after the birth of the first piglet and Brix values were recorded. The six PF with the highest Brix values (HIGH; Average: 31.4%) and the six PF with the lowest Brix values (LOW; Average: 24.9%) were selected for differential expression analysis. Total RNA was extracted from white blood cells and sequenced in a 2x150 bp format using an Element Biosciences AVITI Instrument. Trimmed reads were aligned to the Sus scrofa 11.1 reference genome using HISAT2 and gene counts were obtained using HTSeq. Differential expression analysis was performed by DESeq2 with a model including Brix group, farrowing group, and blood collection order. Differentially expressed genes (DEGs) were assessed as HIGH relative to LOW. Gene set enrichment analysis (GSEA) was carried out with the g:GOSt function of g:Profiler (FDR LGALSL, which is associated with higher milk yield in dairy cows. Other DEGs with higher transcript abundance included SELP, ITGB3, and ITGA2 which are involved in leukocyte migration. Of the 30 DEGs with higher transcript abundance in HIGH, GSEA revealed significant enrichment of gene ontology terms involved in immune system regulation and nutrient metabolism. Additionally, KEGG and Reactome pathways were significantly enriched for platelet activation, signaling, and aggregation. In summary, enrichment of pathways involved in immune system regulation and nutrient metabolism within HIGH may reflect enhanced immune system function and transport of immunoglobulins and lipids compared to LOW. Future investigation into quantifying serum IgG and colostrum IgG could provide insight into how these transcriptional differences may impact production of circulating IgG and transport into colostrum.

Keywords: 2026

How to Cite:

Collier, S., Luttman, A., Raney, N. & Ernst, C., (2026) “Pre-farrowing Gene Expression Differences in Blood of Sows with High and Low Colostrum Brix Values”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285801. doi: https://doi.org/10.31274/wcgalp.23796

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