|Nisbet, David - Dave|
Submitted to: Journal of Food Safety
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/29/2003
Publication Date: 12/30/2003
Citation: Park, S.Y., Birkhold, S.G., Kubena, L.F., Nisbet, D.J., Ricke, S.C. 2003. Survival of a Salmonella typhimurium poultry marker strain added as a dry inoculum to zinc and sodium organic acid amended feeds. Journal of Food Safety. 23(4):263-274. Interpretive Summary: It is estimated that about 4 million cases of Salmonella associated stomach and intestinal illnesses occur in the United States each year. Over 1 billion dollars is spent each year on food borne illness caused by Salmonella infection. Poultry contaminated with Salmonella are regarded as a primary source of food-associated outbreaks of human salmonellosis and contaminated feed is considered one of the important carriers of Salmonella to animals. Zinc is a required trace element, is commercially supplemented in poultry feeds, and is known to have properties that slow down or stop bacteria from growing in food animal products and in food animal production. In the present study, we examined the effects of zinc compounds as zinc acetate or zinc propionate added at l% zinc to poultry layer diets on the survival of Salmonella typhimurium inoculated in a dry form to simulate conditions for commercial feeds. Results show that the Salmonella population was reduced by over 92% in the feed with added zinc in the form of zinc acetate or zinc propionate compared to the Salmonella populations in the layer diet without the added zinc. This research is important because it shows that zinc compounds can be used to reduce Salmonella populations in poultry diets during the early stages of storage. This decreases the possibility that poultry will be contaminated by Salmonella, thus lessening the risk of stomach and intestinal illnesses caused by Salmonella.
Technical Abstract: The effects of different organic acid compounds on the survival of a Salmonella typhimurium marker strain added to poultry feed were determined. Organic acids were added as 1% zinc (Zn) or sodium (Na) salts (w/w) to poultry layer diets and stored at room temperature (21+/-1C) for 9 days. Reduction of S. typhimurium populations from 0 to day 9 was not substantially different between poultry layer unamended feed (96.76%) and Zn acetate (99.72%) or Zn propionate (99.60%) amended feed. However, over 90% reduction of S. typhimurium populations occurred in feed containing either Zn acetate or Zn propionate by day 3, while poultry layer feed populations reached 90% reduction by day 5. S. typhimurium populations after 9 days were nearly 40% more reduced in Na propionate amended feed than Na acetate amended feed. The results of this study indicated that compared to Zn acetate, Zn propionate at 1% of Zn may have more potential to reduce survival of S. typhimurium in a poultry diet during storage.