Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 21, 2004
Publication Date: January 31, 2005
Citation: Huff, G.R., Huff, W.E., Rath, N.C. 2005. Feed supplementation strategies for reducing reliance on antibiotics in poultry production [abstract]. Antibiotic Growth Promoters: Worldwide Ban on the Horizon, January 31 - February 1, 2005, Amsterdam, The Netherlands. p. 120. Technical Abstract: One of the mechanisms by which growth promoting antibiotics improve animal production may be through their ability to decrease sub acute bacterial disease. Our research program has demonstrated that sub acute respiratory infections with Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes result in significant decreases in body weight and feed conversion. The stresses of intensive poultry production can lead to changes in the immune response that result in decreased resistance to respiratory infection with opportunistic pathogens. We have conducted a series of experiments in both broiler chickens and turkeys which have evaluated the efficacy of various feed additives for their ability to protect birds from low levels of bacterial challenge both with and without glucocorticoid immunosupression. A strategy which has shown efficacy in reducing the effects of respiratory challenge of both turkeys and broilers is dietary supplementation with 20g/ton of ß-1,3/1,6-glucan, a helical polysaccharide derived from the cell wall of Saccharomyces cervisiae, which increased body weights and improved feed conversion of both unchallenged turkeys as well as those challenged with air sac injection of 50-100 cfu of Escherichia coli. Broiler chickens fed the same product at 20g/ton for 7 days prior to challenge with 800 cfu of E. coli were protected from the adverse effects of challenge on both body weight and feed conversion. However, supplemented birds that were not challenged had lower body weights than non-supplemented non-challenged birds. Water supplementation of turkeys with vitamin D3 prevented disease incidence, mortality, and body weight loss due to dexamethasone treatment and E. coli challenge. Water supplementation of turkeys with Vitamin E or sodium salicylate prevented mortality and body weight loss in birds challenged with approximately 50 cfu of E. coli however again, body weights of supplemented non-challenged controls were lower than those of non-supplemented controls. These studies illustrate the dramatic effects that stress and sub acute respiratory disease can have on production and suggest that nutritional supplementation with immune stimulating products may be protective in challenging commercial environments, but also warn that such immune modulation may be costly in decreased production values in birds raised in an environment with minimal disease challenge.