Comparison of four induced molting methods based on subsequent performance and welfare of Single Comb White Leghorn hens.

A total of 400 Single Comb White Leghorn hens at 80 weeks of age were used in present study. Four treatment groups that were consisted of six replications with 10 hens per each replication were considered. In the first treatment, food and water were removed for the first 2, 4, 6 and 8 days. However, on days 3, 5, 7, 9 and on day 10 until day 28 hens were fed 45 g of food per hen (ON-OFF group). In the second and third groups, food was withdrawn for 10, 14 days, respectively and oyster shell and water were provided for ad libitum until day 28 (California and North Carolina treatments (CAL, NC groups)). The last group (full-food treatments (FF group)) was the hens that were non-food-deprived and were fed corn molt diet for 28 days ad libitum. In all treatment groups at day 29, hens were returned to a full food layer ration and received 16 h of light day(-1). Body weight, egg production, egg weight, relative eggshell weight, internal egg quality, egg specific gravity and mortality were determined. Differential leukocyte count and antibody response were also measured. The results demonstrated that induced molting increased egg production according to pre-molt egg production. There was not a significant difference in the rate of egg production during the peak period of post molt production for treatments. No significant differences were detected in differential leukocyte counts and antibody response against Sheep Red Blood Cell (SRBC) between treatments at pre molt and post molt of the experiment. This study indicated that diets with high corn level (FF groups) are effective and simplified nonfood removal procedure for welfare molting hens.