PSXI-14 Effects of Footpad Dermatitis on Gene Expression of Host Defense Peptides in Laying Hens

Abstract Footpad dermatitis (FPD) has a negative impact on the welfare and health production of poultry. The present study aimed to determine the effect of FPD on the expression of host defense peptides (HPDs). A total of fifty-four 55-week-old Hy-line brown hens housed individually in furnished cages were selected for investigating the mRNA expression of HPDs in foot, spleen, liver, and small intestine tissues. FPD score 0 group with normal foot, FPD score 1 with a small lesion of the foot pad epithelium and FPD score 2 with a larger lesion were divided by visual examination. The results showed that compared with group 0, hens from FPD group 1 and 2 had increased mRNA expression of HPDs of AvBD1, AvBD3, AvBD4, AvBD5, AvBD6, AvBD7, AvBD8, AvBD9, AvBD10, AvBD11, AvBD12, AvBD13, AvBD14 and LEAP2in foot and spleen tissues (P < 0.05). The relative expression of HPDs genes AvBD2, AvBD3, AvBD4, AvBD5, AvBD7, AvBD8, AvBD11, AvBD12, AvBD13, AvBD14, and LEAP2 in liver tissue increased, while the relative mRNA expression of AvBD6, AvBD9, and AvBD10 decreased (P < 0.05), and the expression levels of AvBD1, AvBD3, AvBD5, AvBD6, AvBD7, AvBD9, AvBD10, AvBD12, and LEAP2 in small intestinal tissue increased (P < 0.05), while the expression of AvBD2, AvBD8, and AvBD14 decreased (P < 0.05). Therefore, FPD can affect the expression of AVBDs in laying hens that the foot and spleen tissue had stronger responsiveness to the FPD. It is speculated that the increase in the expression of AVBDs on account of the possible infection with pathogenic bacteria. Then the increased HPDs participated in the host's defense responses and strengthened the immune regulation after FPD occurred.