Individual consistency of feather pecking behavior in laying hens

Pecking behavior (severe feather (SFP), gentle feather (GFP), and aggressive (AP) pecks) of individual White Shaver non-cage laying hens (n = 300) was examined at 21, 24, 27, 32, and 37 wk. Hens were housed in 30 groups of 10 hens each and on 3cm litter with access to a feeder, perch, and 2 nest boxes. The number of SFP given and received was used to categorize hens as feather peckers (P), victims (V), neutrals (N), or feather pecker victims (PV) at each age. Hens categorized as PV exhibited pecking behaviors similar to P and received pecks similar to V. Severe feather pecks given were increasingly correlated with AP given. State transition plot maps illustrated that 22.5% of P remained P, and 44% of PV remained PV. Lifetime behavioral categories identified hens as a consistent feather pecker (CP; 5%), consistent neutral (CN; 3.9%), consistent victim (CV; 7.9%), consistent feather pecker-victim (CPV; 29.4%), or inconsistent (I; 53.8%) in their lifelong behavioral patterns. More SFP were performed by CPV than other categories, and CN received fewer GFP than CPV. Population level patterns of feather pecking behavior paralleled satiation addictive behaviors in humans, such as cigarette smoking. Some hens were more predisposed to perform feather pecking than others; approximately half of the population was classified as P at least once during the study; the remainder was never categorized as a P. Even if feather-pecking ontogeny may be multi-factorial, once the behavior has been developed, some hens may persist in feather pecking. As some hens were observed to never receive or perform severe feather pecks, emphasis should be made to select for these hens in future breeding practices.