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ARS Home » Midwest Area » West Lafayette, Indiana » Livestock Behavior Research » Research » Publications at this Location » Publication #312574

Research Project: Reducing Animal Stress and the Incidence or Prevalence of Human Pathogens through Enhanced Gastrointestinal Microbial and Immune Functions in Farm Animals

Location: Livestock Behavior Research

Title: The influence of dietary zinc source and coccidial vaccine exposure on intracellular zn homeostasis and immune status in broiler chickens

Author
item Troche, C - Purdue University
item Eicher, Susan
item Applegate, T - Purdue University

Submitted to: British Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2015
Publication Date: 4/14/2015
Citation: Troche, C., Eicher, S.D., Applegate, T. 2015. The influence of dietary zinc source and coccidial vaccine exposure on intracellular zn homeostasis and immune status in broiler chickens. British Journal of Nutrition. 114:202-212. doi:10.1017/S0007114515001592.

Interpretive Summary: It has been well established that zinc partitioning is altered during immune challenge. Many studies focus on changes in the plasma or liver, however the main effector tissues for coccidial infection in poultry are intestinal. Therefore these experiments determined how supplemental zinc regimens impacted jejunal and cecal immune status along with zinc transporter expression. Exposure to a coccidial vaccine challenge decreased cellular intracellular free zinc in both jejunal and cecal tonsil cells. With coccidial vaccine challange, ability to phagocytize a pathogen was decreased in jejunal cells whereas cecal tonsil cell’s phagocytic capacity was increased. An overall increase in the ratio of zinc-iron protein transporters: zinc transporters were observed during the coccidial vaccine challenge. Taken together it appears that intestinal mucosal tissues experience a decrease in intracellular free zinc during coccidial challenge, which is coupled with an upregulation of measured Zip transporters. This suggests that under coccidial challenge intestinal cells attempt to compensate for the drop in intracellular zinc.

Technical Abstract: Zinc (Zn) partitioning is altered during immune challenge and many prior studies have focused on changes in the plasma and/or liver. However the main effector tissues for coccidial infection in poultry are intestinal. Therefore these experiments determined how supplemental Zn regimens impacted jejunal and cecal immune status along with Zn transporter expression. Two experiments were designed in which zinc was provided through: a basal diet (Corn/SBM basal), supplementation of ZnSO4 (ZnSO4), or supplementation of a 1:1 blend of ZnSO4 and Availa-Zn (Blend). Coccivac-B was administered via gavage at 10 times the recommended dose to mimic mild coccidial challenge (10CV). Exudates from jejunal (Experiment 1) and cecal tonsils (Experiment 2) were evaluated for intracellular Zn concentrations and phagocytic capacity. Messenger expression of Zn transporters ZnT5, ZnT7, Zip9 and Zip13 were also evaluated to determine the impact of treatment on Zn trafficking. Dietary Zn regimen appeared to have little impact on any of the measured cellular parameters. Exposure to 10CV decreased cellular intracellular free zinc in both jejunal (58%) and cecal tonsil cells (27%). With 10CV, phagocytic capacity was decreased in jejunal cells by 2% whereas cecal tonsil cell’s phagocytic capacity was increased by 5%. An overall increase in the ratio of ZIP: ZnT transporters were observed during 10CV. Thus, intestinal mucosal tissues experience a decrease in intracellular free Zn during coccidial challenge, which is coupled with an upregulation of measured Zip transporters. This suggests that under coccidial challenge, intestinal cells attempt to compensate for the drop in intracellular Zn.