title: Impaired immune responses in broiler hatchling hindgut following delayed access to feed.
abstract: One of the key stimulators of intestinal development in the chick is physical exposure to feed, while feed withholding delays the onset of gut development. A delay of 24-72 h in onset of feeding is quite common in the poultry industry due to variation in hatching time and hatchery treatments. As intestinal development occurs in concert with the development of the gut associated lymphoid tissue (GALT), we investigated the effects of short term feed withholding on development of GALT in broiler hatchlings. GALT activity was determined by antibody production (systemic and locally in the gut), distribution of B and T lymphocytes in the gut, expression of lymphocyte specific genes, and distribution of B and T lymphocytes in the cloacal bursa. Our findings show that while development of GALT in the foregut (duodenum, jejunum, ileum) was only slightly and temporarily impeded by feed withholding, GALT activity in the hindgut and the gut-related cloacal bursa was significantly delayed during the first 2 weeks of life: Systemic and intestinal antibody responses following rectal immunization to antigen were lower, colonization of the hindgut (cecum and colon) by T and B lymphocytes was delayed, as well as the expression of chIL-2 mRNA in hindgut T lymphocytes. We also found that the increase of B and T population size in the cloacal bursa was delayed with time. Full recovery occurred from 2 weeks of age. The 2-week vulnerable period should be seriously considered in circumstances where hatchlings are in transit for extended periods from hatcheries to farms.
authors.affiliation: Section of Immunology, Department of Animal Sciences, Faculty of Agriculture, Food and Environmental Sciences, Hebrew University of Jerusalem, POB 12, Rehovot 76100, Israel.
authors.forename: Enav Bar
authors.initials: EB
authors.lastname: Shira
authors.forename: David
authors.initials: D
authors.lastname: Sklan
authors.forename: Aharon
authors.initials: A
authors.lastname: Friedman
mesh_terms: D000818:Animals; D000906:Antibodies / Q000097:blood; D001402:B-Lymphocytes / Q000276:immunology; D017252:CD3 Complex / Q000235:genetics / Q000276:immunology; D002645:Chickens / Q000276:immunology*; D005434:Flow Cytometry / Q000662:veterinary; D005508:Food Deprivation; D006433:Hemocyanins / Q000276:immunology; D018928:Immunity, Mucosal / Q000276:immunology; D007114:Immunization / Q000379:methods / Q000662:veterinary; D007376:Interleukin-2 / Q000235:genetics / Q000276:immunology; D007422:Intestines / Q000166:cytology / Q000276:immunology*; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology*; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012710:Serum Albumin, Bovine / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D017252:CD3 Complex; D007376:Interleukin-2; D012710:Serum Albumin, Bovine; D012313:RNA; D006433:Hemocyanins