ETD

• Cinta Senese
• Escherichia Coli
• ETEC
• Gene MUC4
• PWD

Post-weaning diarrhoea (PWD) is a significant health and economic problem in pig farming and is often associated with enterotoxigenic Escherichia coli (ETEC) infections, particularly strains with F4 fimbriae. Susceptibility to infection is genetically determined by the presence of specific intestinal receptors, including those encoded by the MUC4 gene. Previous studies have shown that native breeds, particularly Cinta Senese, have a high frequency of the resistance allele, while commercial breeds more often show the susceptibility allele. In a context of reduced antibiotic use, genetic selection represents an interesting preventive strategy. The study evaluated whether crossbreeding between Cinta Senese, Duroc and Large White pigs has modified the frequency of the MUC4 gene polymorphism associated with susceptibility to ETEC. Blood samples from Cinta Senese pigs and a three-way hybrid bred in Tuscany were analysed. Genomic DNA was extracted, amplified by PCR for the g.8227C>G polymorphism of the MUC4 gene, then sequenced and compared with reference sequences in international databases. The results showed amplicons of expected size and high homology (>97%) with the reference sequences. The susceptibility allele was not detected in any sample: all subjects, including hybrids, were carriers of the resistance genotype. The study concludes that the cross considered did not compromise the genetic resistance typical of Cinta Senese and confirms the MUC4 gene as a valid marker of ETEC resistance, suggesting hybridisation as a sustainable strategy for improving production performance without compromising health resilience.