|Ricke, S - UNIVERSITY OF ARKANSAS|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 10, 2009
Publication Date: October 1, 2009
Citation: McReynolds, J.L., Genovese, K.J., He, H., Swaggerty, C.L., Byrd II, J.A., Ricke, S.C., Nisbet, D.J., Kogut, M.H. 2009. Alfalfa as a nutritive modulator in maintaining the innate immune response during the molting process. Journal of Applied Poultry Research. 18:410-417. Interpretive Summary: Using alternative molting diets that retain protective microflora during an induced molt would provide poultry producers with dietary approaches that could help reduce some enteric pathogens, and the physiological/immunological stresses associated with molting. The purpose of the study presented here was to determine how the avian immune system functionally responds to alfalfa through the measurement of several immunological parameters. The data showed that alfalfa increased the immune response compared to non-fed controls. This increased immune response will help the bird fight invasive bacteria such as Salmonella. Overall, the data on the use of alfalfa as a novel alternative molting diet is encouraging and may provide the commercial egg industry with an alternative to complete feed withdrawal during the molting process.
Technical Abstract: Force molting of laying hens increases enteric foodborne pathogens in the reproductive tract, leading to contaminated eggs and progeny of infected hens. Currently, we lack a complete understanding of how conditions such as molting affect the immune system. Previous reports show that alfalfa is effective in inducing a molt as well as producing protection against Salmonella enteritidis (SE) organ invasion. Our laboratory has also shown that immune functions are significantly reduced during molting. The present investigation evaluates a specific parameter of immune function, heterophil function, during an induced molt in hens fed alfalfa. Three replicate experiments utilized hens over 65 wk of age that were divided into 6 groups of 12 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 12 d experiment. Peripheral blood samples were taken from hens on d 0, 2, 6, 12 of molt. Hens were randomly placed into 3 treatment groups: non-fed hens (NF), full-fed hens (FF) and alfalfa-fed hens (AF). To evaluate heterophil functions, the production of an oxidative burst, and cellular degranulation assays were performed. In addition total and differential peripheral blood leukocyte counts were performed. When compared to the NF control, AF birds showed significantly (P< 0.05) higher oxidative burst and degranulation activites. Although not significant, trends in luekocyte numbers were noticed when AF birds were compared to NF control birds. The data confirms previous observations that herterophil functions are significantly decreased in NF birds and the data shows that birds fed alfalfa have increased heterophil functions over a 12 d molting period when compared to heterophils of NF controls. Commercial intergrators should consider using alfalfa when developing new molting programs.