Effect of several housing alternatives on the well-being of laying hens : an assessment of production, physiological, and behavioral responses

Abstract

The objectives of this study were to provide better standardized procedures for determining relationships between stress (or the lack of it) and well-being for laying hens maintained in different management alternatives. To accomplish this, quantitative data collection in the areas of production, physiology, and behavior were examined. A method was developed for sampling blood parameters in several flocks of laying hens with minimal disturbance to the birds. Laying hens restrained for up to 133 sec, showed non-significant increases in plasma corticosterone. Hens housed in (1) cages, (2) floor pens, and (3) range pens showed significant corticosterone differences between afternoon and morning samples (P < .05). Hens in cage and floor management alternatives exhibited different (P < .05) corticosterone responses between management alternatives using a submaximal dose of ACTH. In two experiments, laying hen responses to several management alternatives were examined for hens in cage, floor, and range pen systems. In the first study, hens in small and large cages, floor pen hens at three densities, and range pen hens at one density were compared. Egg production favored caged hens (P < .05), but plasma corticosterone was significantly elevated (P < .05) for floor hens. Walking, standing, and object pecking were different between cage and floor management alternatives (P < .05). In the second study, hens in deep and shallow cages housing four populations at two densities and floor pens housing hens with and without roosters at two densities were compared. Some production, physiological, and behavioral parameters differed among cage treatments, however, floor treatment affects were less apparent. Egg production was better for (P < .05) caged hens, and floor hens had significantly higher (P < .01) plasma corticosterone levels. Caged hens preened, stood, and crouched more than floor hens, but floor hens drank and moved about more. This study demonstrated that quantitating laying hen responses of multiple traits in the areas of production, physiology, and behavior was important in determining stressful or non-stressful environments. The integration of all measurements presented indicated that properly managed caged hens may have a better environment (and certainly not worse) than laying hens housed in floor pens.