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United States Department of Agriculture

Agricultural Research Service

Title: Passage rates in poultry digestion using stable isotope markers and INAA

item Dunkley, C
item Kim, W
item James, W
item Ellis, W
item Mcreynolds, Jackson
item Kubena, Leon
item Nisbet, David - Dave
item Ricke, S

Submitted to: Journal of Radioanalytical and Nuclear Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/20/2007
Publication Date: 1/20/2008
Citation: Dunkley, C.S., Kim, W.K., James, W.D., Ellis, W.C., McReynolds, J.L., Kubena, L.F., Nisbet, D.J., Ricke, S.C. 2008. Passage rates in poultry digestion using stable isotope markers and INAA. Journal of Radioanalytical and Nuclear Chemistry. 276(1):35-39.

Interpretive Summary: Salmonella continues to be a foodborne disease that causes illness in humans and animals. Literature shows that Salmonella can increase in laying hens during the molting process. Currently, we are evaluating different products that reduce this bacteria in poultry during molt. Literature shows that alfalfa is protective against Salmonella and increases the transit time of food in the intestine. In this study we evaluated a inert chemical which is found in soil and can be used as a label for feed products. We mixed the product with alfalfa and fed it to the chickens. We found that product did not bind to the alfalfa very well. We will continue to evaluate other markers to monitor the passage rate of food in the intestine. Understanding the interactions of food products in the intestine is valuable to the commercial industry, because they may reduce food-borne pathogens during molt.

Technical Abstract: A method has been developed for the study of passage rates and mean residence times (MRT) of test rations through the gastrointestinal tracts of layer hens. The use of rare earth elements as stable indigestible markers monitored by neutron activation analysis has been previously demonstrated in numerous species. In this study hafnium was used to mark corn and alfalfa rations as well as a combination ration made up of 90% alfalfa and 10% corn. The primary goal of the study was to evaluate the potential for use of rare earth stable markers in poultry digestion and to determine efficiency of meal marking, optimum exposure rates and determination limits for use in the design of future experimental protocols. Three groups of 10 hens each were fed a particular marked meal with fecal droppings monitored for 24 hours. The hens were sacrificed after a second dosed feeding and a delay of two or seven hours, and digesta was collected from each portion of the gastrointestinal tract. Fecal dry matter as well as digesta collected was then prepared for analysis and the elemental concentrations of hafnium were measured with instrumental neutron activation analysis (INAA). Element adsorption on alfalfa was far less efficient than on the corn ration, limiting the applicability of much of the alfalfa data to digestion studies. Passage rate curves were prepared for corn. The marker was found to primarily concentrate in the ileum at both sacrifice times.

Last Modified: 06/27/2017
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