Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2005
Publication Date: 8/1/2005
Citation: McReynolds, J.L., Kubena, L.F., Byrd II, J.A., Anderson, R.C., Ricke, S.C., Nisbet, D.J. 2005. Evaluation of Salmonella enteritidis in molting hens after administration of an experimental chlorate product (for nine days) in the drinking water and feeding an alfalfa molt diet. Poultry Science. 84:1186-1190. Interpretive Summary: Salmonella bacteria can cause illness and death in humans consuming contaminated poultry products. Poultry eggs may become contaminated with Salmonella after the molting process. In this study, we looked at combining an experimental chlorate product and an alfalfa diet for their effectiveness in reducing Salmonella during an induced molt. Salmonella possess an enzyme that converts chlorate to chlorite that will build-up inside the bacteria causing it to die. Supplemental diets such as alfalfa have been shown to help keep the bacterial populations balanced in the gastrointestinal tract during a molt. When the birds were treated with these products, Salmonella was reduced in the bird. This finding is important because it will aid in designing management practices to reduce or prevent contamination of eggs and egg products by Salmonella bacteria.
Technical Abstract: The method most commonly used to induce molting and stimulate multiple egg-laying cycles in laying hens for commercial egg production is feed deprivation. Unfortunately, an increased risk of Salmonella enteritidis (SE) may result from the use of this method. Hens over 50 wk of age were divided into 12 groups of 11 hens each and placed in individual laying cages. Two wk prior to dietary changes, hens were placed on an 8-h light and 16 h-dark photoperiod that continued for the 9-day experiment. All hens were challenged orally with 106 cfu of SE on the fourth day. Treatments were non-fed hens with distilled water (NFD), non-fed hens with the experimental chlorate product (ECP which provided 15mM chlorate ion concentration) water (NFECP), alfalfa diets with distilled water (ALD), and alfalfa diets with ECP water (ALECP). In the NFD hens, 67% (Log10 2.74) of the crops and 94% (Log10 5.62) of the ceca were colonized; whereas, for the NFECP hens a significant reduction to 22% (Log10 1.05) of the crops and 61% (Log10 2.44) of the ceca when compared to the NFD controls. In the ALD hens, 61% (Log10 2.52) of the crops and 94% (Log10 4.06) of the ceca were colonized. In the ALECP hens, a highly significant reduction to 11% (Log10 1.26) of the crops and 39% (Log10 1.12) of the ceca when compared to the ALD controls. When compared with the NFD hens, a significant reduction in SE invasion of the ovary, liver, and spleen occurred in all other treatments, except the ovary in the ALD hens. These results suggest that ECP added to the drinking water may be a useful tool to reduce the risk of SE during an induced molt by feed deprivation or the use of alfalfa molting diets. For several parameters, ECP combined with the alfalfa diet was most efficacious.