Exploring the Link Between Mucin 2 and Weaning Stress-Related Diarrhoea in Piglets.

To explore the relationship between intestinal mucin 2 (MUC2) and weaning-induced diarrhoea in piglets, we analysed Min and Landrace piglets. The piglets were divided into a healthy weaned group, a weaned diarrhoea group, and a healthy unweaned control group. Intestinal tissues were collected, and goblet cell numbers, sizes, and degrees of intestinal injury were observed and recorded. Intestinal tissue MUC2 mRNA and protein expression were analysed via quantitative real-time PCR (qRT-PCR) and Western blotting. Min pigs presented significantly lower diarrhoea rates and intestinal injury scores than Landrace pigs (p < 0.01). The intestinal injury scores in the weaned diarrhoea group were significantly greater than those in the unweaned groups (p < 0.05), with Min pigs consistently exhibiting lower injury scores than Landrace pigs. Specifically, unweaned Min pigs presented significantly greater duodenal MUC2 mRNA (p < 0.05), and weaned healthy Min pigs presented notably greater expression in both the duodenum and jejunum (p < 0.01). These findings reveal enhanced intestinal protection against weaning stress and diarrhoea in Min pigs, with elevated MUC2 levels likely contributing to lower injury scores and milder symptoms, thus highlighting the influence of genetic differences.