|OH, SUNGTAEK - US Department Of Agriculture (USDA)|
|RITTER, G. DONALD - Mountaire Farms, Inc|
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/19/2015
Publication Date: N/A
Technical Abstract: There is an increased interest in restricting the use of antibiotic growth promoters (AGPs) in animal agriculture. In order to better understand the mechanisms of AGPs in poultry, we carried out series of in vivo studies to investigate various aspects of host responses to AGPs in normal and necrotic enteritis (NE)-afflicted chickens. Antibiotic growth promoters used in this study were virginiamycin (VM) and bacitracin methylene disalicylate (BMD). Total one-hundred forty 1-d-old male broiler chicks were randomly divided into 4 experimental groups: (1) uninfected and untreated control; (2) NE infection; (3) NE infection with VM (5.51 ppm); (4) NE infection with BMD (5.51 ppm). At 14 days of age, birds were orally infected with 1 x 104 oocysts of E. maxima followed by C. perfringens infection (1 x 109 CFU/bird) at 18 days of age to induce NE. Parameters kinetically monitored included: (1) daily body weights; (2) gut lesions; (3) serum levels of C. perfringens a-toxin and NetB (Necrotic enteritis B-like) toxin; (4) intestinal morphology; (5) anti-oxidant and innate immunity biomarkers. After C. perfringens infection, all groups showed body weight loss accompanied by typical NE lesions. NE-afflicted chickens fed the dietary AGPs showed increased body weights and reduced gut lesions compared with NE-infected birds on the control diet at 6 day post NE infection. Morphological studies showed that the jejunum and ileum crypt depth and villi heights were decreased following E. maxima and C. perfringens infection. Anti-oxidant levels were decreased in NE-afflicted group compared with un-infected and AGP-alone groups. Findings on changes in innate immunity and growth-related biomarkers are being assessed to obtain enhanced insights into the AGP mechanisms.