The effect of feeder space allocation on behavior of Hy-Line W-36 hens housed in conventional cages

Abstract

Insufficient feeder space for laying hens could increase competition at the feed trough, resulting in exclusion of low-ranking hens from the feeder. To test this hypothesis, the effects of feeder space allocation (FSA) on feeding behavior, aggression, feather scores, BW, and mortality were evaluated in a common commercial strain of egg-laying chickens. Beak-trimmed Hy-Line W-36 hens (n = 480) were obtained as pullets at 16.5 wk of age and housed in conventional cages on 4 tiers. Five pullets/cage were housed at a stocking density of 434 cm(2)/pullet and an FSA of 12.2 cm/pullet. After 1.5 wk of acclimation, baseline measurements were taken for 2 wk and then pullets were given either 5.8, 7.1, 8.4, 9.7, 10.9, or 12.2 cm of feeder space/hen (16 cages/treatment). Feeding behavior was evaluated in each cage over a 24-h period each month. For each hen, percentage of time spent feeding and synchrony (mean number of additional hens feeding at the same time) were determined and scores were averaged for each cage. For each cage, feeder switching (number of observations in which hens changed from feeding to not feeding) and feeder sharing (probability that feeder access was equally distributed among all hens) were calculated. At monthly intervals, individual hens were weighed and their feathers scored using a 5-point scale on 8 body regions. Data were analyzed using a repeated measures GLM incorporating cage, tier, FSA, and age of the hen. Hens with reduced feeder space spent less time feeding (P < 0.001), synchronized their feeding bouts to a lesser extent (P < 0.001), made fewer switches at the feeder (P < 0.001), and shared the feeder less (P < 0.001). However, feather scores, BW, and BW uniformity were not affected by FSA. There was almost no aggressive behavior and little mortality. These results demonstrate that Hy-Line W-36 hens did not respond to reduced feeder space by aggressively excluding cage-mates from the feeder but instead desynchronized their feeding behavior.

Providing laying hens in group-housed enriched cages with access to barley silage reduces aggressive and feather-pecking behaviour

“…They found that reduced feeder space did not negatively impact feed intake and did not affect egg production or body weight. Hens given less feeder space spent less time feeding and de-synchronized their feeding pattern, but did not use aggressive behaviour to gain access to the feeder (Thogerson et al 2009b). Similarly in the present research, there were no observations of birds being crowded or interacting aggressively during feeding.…”

The effect of feeder space allocation on productivity and physiology of Hy-Line W-36 hens housed in conventional cages

“…At 20 wk of age, feeder space in each cage was altered from 12.2 cm of feeder space/hen to 5.8, 7.1, 8.4, 9.7, 10.9, or 12.2 cm of feeder space/hen by blocking access to a portion of the feeder using corrugated plastic (see Figure 1 in Thogerson et al, 2009). It was anticipated that all 5 hens would be able to eat at the same time with 10.9 and 12.2 cm of feeder space, with fewer numbers at lower FSA.…”

“…Records of egg production and feed utilization/cage were maintained for the duration of the study (for BW data, see Thogerson et al, 2009). Feed utilization included feed eaten and wasted.…”

Flock size during rearing affects pullet behavioural synchrony and spatial clustering

“…dawn and dusk, sounds signalling food availability, etc.). When resources are clumped, some individuals in the group may prevent others from using a resource at the same time, through either physical obstruction or aggressive threat (Leone and Estevez, 2008;Thogerson et al, 2009). As a result, synchrony of resource use will decrease.…”

“…Caged laying hens feeding from a single trough exhibit a higher degree of feeding synchrony at greater feeding trough space allocations (Hughes, 1971;Thogerson et al, 2009;Webster and Hurnik, 1994). Based on such observations, it is often recommended that feeders should be long enough to allow all birds to feed simultaneously under the assumption that the birds are socially motivated to coordinate their behaviour and frustrated if unable to do so.…”