PSX-A-9 Late-Breaking: Effects of farm noise on ileum intestinal barrier function of pullets

Abstract

Abstract Noise is a potential but not negligible environmental factor in animal husbandry. To investigate the effects of farm noise on intestinal barrier function of pullets, 336 Hailanhe pullets aged 1 day were randomly divided into 3 groups: control group (CON), low noise group (LN), high noise group (HN). LN group and HN group were exposed to noise respectively at 65–75 dB and 85–95 dB, the average and the range of the highest loudness of noise in laying hens’ farms for 6h every day (7:00-19:00, hourly intervals for one hour) and lasted 4 weeks. Non additional noise addition in CON group, noise loudness of which was less than 40dB. 6 birds were randomly chosen form each group after every week of noise stimulation for ileum tissue samples. Hematoxylin-eosin stain (HE stain), immunofluorescence, and real-time quantitative PCR (qRT-PCR) were used to determine changes in ileum structure, expression of intestinal barrier related proteins and mRNAs and HSPs. Results shown that 1 week and 2 weeks after noise exposed inflammatory cell infiltration reduced, the expression of intestinal barrier related proteins (Occludin, Mucin2 and ZO-1) and mRNAs (Claudin-1, Claudin-4, E-cadherin, Occludin, Mucin2, ZO-1 and ZO-2) were significantly increased (P < 0.05), the mRNA expression of HSPs decreased (P < 0.05) or have no significate changes (P > 0.05). After 4 weeks of noise treatment, the expression of mRNAs of intestinal tight junction protein and mucin, HSPs were significantly decreased (P < 0.05). There was no difference between the LN and HN groups on those indicators (P > 0.05). The study indicates that noise at 65-75dB and 85-95dB does not cause stress to ileum of pullets while promote the development of intestinal barrier of chicks within 2 weeks maybe by mild stimulation and birds restored to balance due to habitualization after 4 weeks of noise treatment.