Birds found outside sheds show less feather damage than birds found in sheds

An observational study conducted on three commercial layer farms showed that environmental enrichment increases number of birds on the range (see Dekoning et al. in this APSS Proceedings). In the same study, we aimed to determine if plumage damage score is different between birds found inside versus outside sheds. The farms were stocked with HyLine Brown flocks (all beak-trimmed); Farm-1 & Farm-3 had one shed each and Farm-2 had two sheds (all 3 farms & four flocks with a fixed range). Farms 1 & 3 had flock sizes of 3,000 and 11,700 hens, respectively, at a stocking density of 1,500/ha. Farm-2, had two flocks, each with 10,000 hens: Farm 2-1 at 10,000 hens/ha and Farm 2-2 at 1,500 hens/ha. Plumage damage score was conducted on 100 random birds inside and 100 random birds outside each shed. The AssureWel (http://www.assurewel.org) score system was used: 0 = no or minimal feather loss; 1 = slight feather loss; and 2 = moderate/severe feather loss. Plumage was scored (without catching) across five body parts: head/neck, back, base of tail/around preen gland, tail and wings. Plumage score per hen was summed (maximum of 10; 2 x 5). All farms were visited once a month for six months. In general, the average total plumage damage increased with age (P< 0.05); outdoor birds had significantly less (P< 0.05) damage than birds found inside (Fig. 1). The most severely affected body part was the neck region. When the total plumage score was categorized for the level of damage: No (0), Low (1-3), Medium (4-6) and Severe (≥7), well over 50% of birds on the range had No to Low damage across all farms. Furthermore, Flock 2-2, the oldest flock, had 80% of birds on the range with No to Low plumage damage. Conversely, there were fewer range birds in the Medium to Severe plumage damage range. We conclude that attracting birds out onto the range minimizes the level and severity of plumage damage in layer birds. Further, the benefit did not diminish with age of hens.

Figure 1 - Total plumage score observed on hens found inside and outside sheds across farms.