Molting in laying hens and Salmonella infection

Molting is a natural occurrence in the avian species. It involves the shedding and replacement of feathers and the regression of the reproductive system thereby giving the birds a rest from reproduction. Reproductive molt is of particular interest to the commercial U. S. layer industry as it involves a period of declining productivity leading to reduced profitability for egg producers. Historically, complete removal of feed was practiced by the industry due to the fact that it was economical and delivered productive additional egg laying cycles. However, feed withdrawal can lead to the depression of the hens' immune system and changes in the gastrointestinal (GI) microflora, making laying hens susceptible to Salmonella infection. To alleviate these concerns, the development of alternative molting has become a focus of recent research efforts. Several approaches have been examined based on their ability to reduce physiological susceptibility in the hen and retain fermentative GI microflora. However, a key requirement for these approaches is their ability to effectively induce a molt and bring about post-molt performance that is similar to that of feed deprived hens.