|Byrd Ii, James - Allen|
Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 8/13/2002
Publication Date: N/A
Technical Abstract: The use of feed deprivation to induce molting and stimulate multiple egg-laying cycles in laying hens is a common practice in commercial egg production. Unfortunately, this method causes an increased risk of Salmonella enteritidis (SE). Methods to stimulate multiple egg-laying cycles without increasing the risk of SE are needed. Hens over 50 wk of age were divided into groups of 12 hens and placed in individual laying cages. One wk prior to dietary changes, hens were put on an 8-h light and 16 h-dark photoperiod that continued for the 9-day experiments. Individual hens in all treatments were challenged orally with 10**4 cfu of SE on the fourth day. Treatments were non-fed hens (molted, M), full fed hens (non-molted, NM), a high zinc diet (HZ), a moderate zinc-low calcium diet (MZ), and an alfalfa diet (AL). When compared with the NM treatment, weight losses were higher in the M, HZ, MZ, and AL diets. Feed consumption was reduced by 50%, 20%, and 80% in hens fed diets HZ, MZ, and AL. Ovary weights were reduced in M and AL hens and to a lesser degree in HZ hens. Cecal propionic acid and total volatile fatty acids (VFA)in the HZ and MZ hens were comparable to the NM hens and were lower in the M and AL hens. Crop pH was increased in the MZ and HZ hens and further increased in the M and AL hens. Colonization of SE in the crop and the ceca was higher in the M hens. Organ invasion by SE was 14/180 for NM hens, 112/180 for M hens, 25/180 for HZ hens, and 42/180 for AL hens. The HZ and AL regimens may be useful tools to induce molting without increasing the risk of SE.