|Kahl, Stanislaw - Stass|
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2018
Publication Date: 9/1/2018
Citation: Proszkowiec-Wegla, M.K., Schreier, L.L., Miska, K.B., Kahl, S., Russell, B.A., Elsasser, T.H. 2018. Effects of delayed feeding post-hatch on gut barrier-related genes expression during early neonatal development in broiler chickens. Poultry Science Association Meeting Abstract. 97:108.
Technical Abstract: Gut plays a key role in the digestion and absorption of nutrients, but also forms a physical barrier and first line of defense between the host and the luminal environment. Functional gut barrier (mucus and epithelial cells with tight junctions (TJ)) is essential for optimal health and efficient production in poultry. In current broiler system, chicks are deprived of food and water up to 72 h due to uneven hatching, hatchery procedures and transportation time to farms. Post-hatch (PH) feed delay results in lower body and organ weight, higher FCR and mortality, and delay PH growth and gut development. Little is known about the effects of early neonatal development and delayed feeding immediately PH on gut barrier function in chickens. Therefore, the aim of the present study was to characterize gene expression pattern of mucin 2 (MUC2) and TJ related protein genes in small intestine of broiler chickens during early neonatal development and delayed access to feed PH. Newly hatched chicks received feed and water immediately after hatch (FED) or were subjected to 48 h delayed access to feed (NOTFED) to mimic commercial hatchery setting and operations. Birds were sampled (n=6) at -48, 0, 4, 24, 48, 72, 96, 144, 192, 240, 288 and 336 h PH, and jejunum and distal part of the ileum were collected, cleaned of digesta and snap frozen in liquid nitrogen. The relative mRNA levels of MUC2, fatty acid-binding protein (FABP) 2, occludin (OCLN) zonula occluden 1 (ZO-1), junctional adhesion molecule (JAM) 2 and 3, cloudin (CLDN) 1 and 4 were measured by quantitative PCR and analyzed by two-way ANOVA. In both tissues, upregulation of MUC2 mRNA was observed in FED during development while FABP2 expression was characterized by an increase during the first 24 h PH followed by decrease afterwards (P<0.05). OCLN mRNA expression was downregulated (P<0.05) during development in jejunum and ileum of FED birds. Expression of TJ proteins ZO-1, JAM2 and 3 decreased in early phase of PH development (from -48 to 48-72 h) in jejunum and ileum of FED birds. Similar expression pattern was observed for CLDN1 and 4 in both tissues. Delayed feeding (NOTFED) for first 48 of PH development significantly (P<0.05) affected the mRNA expression level of MUC2, OCLN, FABP2, ZO-1 and JAM2 in jejunum, and MUC2, OCLN, ZO-1, JAM2, JAM3 and CLDN4 in ileum. In general, MUC2 expression was downregulated while, OCLN, FABP2, ZO1, JAM2 and JAM3 were upregulated between 24-72 h in NOTFED in comparison to FED. These results suggest that delayed access to feed PH may affect TJ structure and/or function, gut barrier function and overall health of chicken small intestine. Keywords (5): tight junction, gut, development, delayed feeding, chicken