ARS | Publication request: DRINKING WATER TREATMENT AND DIETARY TREATMENT EFFECTS ON SALMONELLA ENTERITIDIS IN LEGHORN HENS DURING FORCED MOLT

Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: July 24, 2001
Publication Date: N/A

Technical Abstract: The layer industry uses feed deprivation to induce molting and stimulate multiple egg-laying cycles in laying hens. Unfortunately, the stress involved with this method of molting causes an increased susceptibility to Salmonella enteritidis (SE) under laboratory conditions and increases the risk of SE positive eggs and internal organs. There is the need for methods to stimulate multiple egg-laying cycles without the increased risk of SE. Leghorn hens over 50 wk of age were divided into treatment groups of 12 hens each and placed in individual laying hen cages. One wk before water and feed changes, hens were exposed to an 8-h light and 16 h-dark photoperiod that was continued throughout the 9-day experiment. Individual hens in all treatments were challenged orally with 10**4 cfu of SE on the fourth day. Treatments consisted of full-fed hens (NM), non-fed hens (M), M hens administered 0.25% lactic acid (LA) in the water, or hens fed a diet containing 10,000 mg zinc/kg (HZ). Crop pH and ovary weights were lower in the NM and HZ treatments, when compared to the M treatment. Cecal propionic acid and total volatile fatty acids were decreased in the M treatment when compared to the NM and HZ treatments. The number of crop and ceca culture positive hens and the numbers of SE per crop and per gram of cecal contents were higher in the M treatment, when compared to the NM and HZ treatments. This regimen or other dietary regimens may prove to be useful tools for reducing the incidence of SE in eggs and internal organs during and following molting of laying hens.