Gentle Feather Pecking Research Articles

Early feather pecking as a form of social exploration: the effect of group stability on feather pecking and tonic immobility in domestic chicks

In two lines of White Leghorns that differ in their propensity to feather peck, feather pecking was already present 1 day after hatching. A significant line difference developed within 3 days and this difference remained in the following weeks. There was no clear relationship between feather pecking and ground pecking, instead feather pecking was associated with other socially orientated pecks. When chicks were confronted with feathers as an inanimate stimulus pecking at these feathers did not reflect pecking in a social context. These results suggest that feather pecking has an underlying social component, rather than being a redirected behaviour. To test the influence of social factors on feather pecking, chicks from the high feather pecking line were subjected to regular rehousing or regular rehousing plus confrontation with unfamiliar peers. Gentle feather pecking increased significantly in groups that were rehoused with unfamiliar peers. Directly after confrontation chicks displayed a preference in the total number of pecks toward these unfamiliar birds. Gentle feather pecking as a separate pecking orientation showed a similar trend. Increased righting times in a tonic immobility test were recorded in the experimental groups, hence frequent confrontation with unfamiliar peers may be experienced by chicks as stressful, which is consistent with the hypothesis that stress mediates the expression of feather pecking. In contrast to the dominant hypotheses in the field, we argue that gentle feather pecking at an early age plays an important role in the building (social exploration) and maintenance of social relationships between chicks.

Domestic chicks’ responses to PECKA-BLOCKS and string enrichment devices

The PECKA-BLOCK (Breckland International Ltd.) is a commercially available, cereal and baked-sand-based device designed to enrich the environment and reduce the incidence of behavioural vices, such as feather pecking and cannibalism. Pecking at this novel stimulus loosens cereal grains that can then be eaten. This device reduced inter-bird pecking in broiler chicks (Guy, 2001) though it is not clear whether the authors measured gentle or severe feather pecking, allopreening, or aggression. White string (polypropylene twine) elicits sustained interest by chicks and hens of various laying and its provision reduced feather pecking and pecking-related feather damage (Jones, 2001). The present study compared the responses of layer chicks to simple string devices and to soft and hard PECKA-BLOCKS.

The social transmission of feather pecking in laying hens: effects of environment and age

Abnormal behaviours, such as feather pecking, can become an even greater problem if they spread through the flock. Domestic hens are a social species and it has been suggested that feather pecking behaviour can be socially transmitted from few feather pecking individuals to many. The purpose of this experiment was to investigate whether feather pecking is transmitted from an experimental strain of high feather peckers to an experimental strain of low feather peckers when housed together. The effects of environment and age were also investigated. Four hundred and twenty chicks were housed in either cages or pens in one of three treatment groups; all high feather peckers, all low feather peckers, and a mixed group of half high feather peckers and half low feather peckers. During the rearing phase, severe and gentle feather pecks were recorded at 13–15 weeks and feather plumage scored at 12 and 17 weeks. At 17 weeks of age, the groups of mixed hens were removed from the study and the remaining hens resorted into the same three treatment groups. During the laying phase, severe and gentle feather pecks were recorded at 30–32 weeks of age and feather plumage was scored at 29 weeks of age. There was significantly less feather pecking and plumage damage in the pens than in the cages. There was no evidence of severe feather pecking spreading from feather peckers to non-feather peckers, even when actual rates of feather pecking were examined rather than only considering the strain of hen. There was some evidence that gentle feather pecking was transmitted in laying hens housed in cages. However, as gentle feather pecking does not lead to plumage damage, this is less relevant to commercial practice.

Changes in feather condition in relation to feather pecking and aggressive behaviour in laying hens

1. The aim of this experiment was to describe and examine the relationship between pecks received by individual birds and the feather and skin damage of those birds at different ages. The effect of group size was also studied. 2. Laying hens were raised in floor pens in group sizes of 15, 30, 60 and 120 birds, each with 4 replicates. Behavioural observations were performed at the ages of 22, 27, 32 and 37 weeks. Detailed feather scoring was carried out at the ages of 18, 23, 28 and 33 weeks. 3. Behavioural observations focused on the number of feather pecks (gentle and severe) and aggressive pecks received, and on the part of the body that was pecked. Scoring of feather and skin damage focused on the same 11 parts of the body. 4. Increasing numbers of aggressive pecks received were associated with decreased body weight and increased feather damage at the ages of 27 and 32 weeks. 5. The number of severe feather pecks received was significantly related with feather damage at all ages; however, no relation with gentle feather pecks received was found. 6. Group size had a significant effect on feather condition, with large group sizes having most feather damage.

Development of emotional expressions in young chimpanzees: The influence of early experience and individual differences

Feather pecking (FP) can cause feather loss, resulting in physical injuries, which may lead to cannibalism. FP appears to be a redirection of foraging behavior, which intensifies when hens have difficulty coping with stress and fear. Dynamic environmental enrichment (EE) may allow expression of natural foraging behavior thus reducing conspecific pecking behavior and alleviating hen injury. Three treatments (plastic box: BOX; hay bale: HAY; and no enrichment: CON) were randomly applied to 30 identical floor pens (10 hens/pen; 10 pens/trt). At the pen level, hen behavior, and the number of severe FP (SFP), gentle FP (GFP), aggressive pecks (AP), and enrichment pecks (EP) were recorded from video prior to (21 wk) and after (24 wk) treatment implementation, and when hens were 27, 32, and 37 wk of age. A manual restraint test (MR) was performed immediately after behavioral observations and levels of blood serotonin (5-HT) and glucocorticoids (GC) measured. Short-term (ST) and long-term (LT) analyses identified the impact of EE over the ST (21 vs. 24 wk of age) and LT (21 vs. all other ages) at the pen level. At the pen level, HAY (3.18 ± 0.33) tended to reduce GFP compared to CON (4.10 ± 0.34) over the ST (P = 0.15) and LT (P = 0.09), but did not impact the number of SFP, or AP over the ST or LT. More EP was observed in HAY (3.56 ± 0.14) than BOX (1.61 ± 0.18) throughout the study (P < 0.0001). More HAY hens perched (P = 0.05) at 24 wk (0.28 ± 0.12) compared to 21 wk (0.19 ± 0.11), and more HAY hens (3.69 ± 0.25) performed dust bathing compared to CON (4.14 ± 0.22, P = 0.05) throughout the study. CON performed more struggles (1.13 ± 0.04, P = 0.04) and were quicker to vocalize (4.87 ± 0.07 s, P = 0.05) during MR than HAY (latency to vocalize(s): 5.16 ± 0.05; number of struggles: 0.96 ± 0.05), counter-intuitively suggesting CON were less fearful. Treatment did not affect 5-HT or GC. HAY appears to be a promising EE for mitigating GFP in non-cage laying hens. Future studies should examine the impact of EE on individual, rather than group-level responses. These results suggest that the presence of a hay bale is stimulating and may reduce GFP while encouraging hens to redirect pecking towards a dynamic and manipulable EE.

Role of precursor availability in control of monoamine biosynthesis in brain.

Role of precursor availability in control of monoamine biosynthesis in brain.