Behavior, Production, and Well-Being of the Laying Hen.: 1. Effects of Movable Roosts, Relationship of Cage Mates, and Genetic Stock

Abstract

The effects of movable roosts, relationship of cage mates (siblings versus nonsiblings), and genetic stock on measures of behavior, production, and physical condition were investigated. Sibling and nonsibling pairs of hens derived from two male parental stocks (designated MPS1 and MPS2) were randomly assigned to two cage batteries (384 hens total). The batteries were identical except that the cages of one had individual wood roosts, which were automatically raised at night and lowered the next morning. The laying phase comprised 13 28-day periods. On the first 4 days of Periods 1, 3, 5, 7, 9, and 11, video recordings were made of 8 cages per day. Video-recorded data for Period 5 were discarded, however, because equipment failure caused an unplanned photoperiod ratio. Direct visual observations were carried out in Period 13. Egg production and feed consumption were recorded in each period. Feather scores were determined in Periods 3, 6, 9, and 12, and in Periods 6 and 13, hens were weighed and the number of lesions to the feet counted.Overall, roosts appeared to improve well-being. Resting occurred more in cages with roosts, feathering was better initially, body weights were slightly higher, and foot lesions were fewer. Egg production was not affected except that egg cracks were more frequent in roost cages. Relationship of cage mates had relatively little influence. However, in conventional cages, nonsiblings manifested more bobbing behavior, and in MPS1, nonsiblings had higher feed consumed per dozen eggs. Hens of MPS1 performed more head flicking, drinking, physical displacement, aggression, and cage wall climbing than MPS2 hens. They also had higher egg production, weaker egg shells, poorer feathering, and more lesions to the feet. The genetic stock differences suggest that hens of MPS1 experienced poorer well-being. None of the treatments significantly affected mortality.