Research Note: Effect of corn silage and alfalfa meal as alternative induced molt methods to improving Salmonella Enteritidis resistance in laying hens

Abstract

This experiment was conducted to evaluate diets containing a high level of corn silage and alfalfa meal in inducing molt and reducing susceptibility to Salmonella Enteritidis (SE) colonization in laying hens. Thirty-two healthy hens were examined by cloacal swab samples to be free of Salmonella. Then they were weighed individually and distributed to 4 experimental groups containing 8 hens each, including Full-fed (control, FF); total feed withdrawal (positive control for molt induction, FW); 80% corn silage (CS) + 20% layer diet (CS80), and 80% alfalfa meal (AM) + 20% layer diet (AM80). The molting program was initiated at 71 wk of age. On d 4 of the experiment, all hens were inoculated with SE by oral gavage. All hens were first weighed at the ending molting period on d 10 and then euthanized by CO2 gas. The internal organs including the ovary, oviduct, liver, and spleen, were excised aseptically and weighed. Cloacal swab and feed samples at the beginning and organ samples (liver, ovary, spleen, and cecum) were collected from each hen at the end of the experiment and examined for SE colonies. Molted birds lost roughly 14 to 27%t of their body weight and had significantly lower organ weight and egg production compared to FF group (P < 0.05). No significant difference was observed in the number of days to zero egg production between molted treatments. The SE positive organs did not significantly differ between CS80 and AM80 with FF treatment. Treatment CS80 had the lowest crop pH and differed substantially from treatment FW. In conclusion, results indicate that using corn silage and alfalfa meal, can improve resistance to salmonella Enteritidis during molt inducing compared to traditional feed withdrawal.