Shi, H., Li, B., Tong, Q. et al. 2019. Influence of nest boxes and claw abrasive devices on feather pecking and the fear responses of layer breeders in natural mating colony cages. Applied Animal Behaviour Science 220, 104842.

Natural mating colony cages for parent-stock layer breeders, instead of conventional cages with artificial insemination, have been widely adopted by many commercial farms in China. Although some natural mating behaviours can be expressed and broader activity space is provided compared with that of conventional artificial insemination cages, the environment is still relatively barren. The aim of this study was to investigate the effects of providing nest boxes and claw abrasive devices (CADs) in this colony cage system on feather pecking (FP), feather condition, fear and physiological stress in layer breeders. Twelve treatments were compared in a factorial arrangement, including 2 types of nests (large and small), 3 types of CADs (abrasive strips, rubber mat with grooves, and metal plates with holes), and the control (without the provision of nests and CADs). Nine cages per treatment were involved, with 10 roosters and 90 hens per cage. The results showed that the nests had a significant effect (P ≤ 0.05) on the frequency of severe feather pecking (SFP); environmental pecking (ENP); food pecking (FOP); back, rump, and belly coverage condition; tonic immobility (TI) duration; avoidance distance (AD); and corticosterone and 5-HT concentrations. Except for the blood parameters, the CADs had a significant effect (P ≤ 0.05) on the frequency of SFP and FOP; back, rump, tail coverage condition; duration and latency of TI test; hens’ novel object (NO) recognition score; and distance in the AD test. In addition, significant nest × CAD interactions (P ≤ 0.05) were noted for SFP, ENP, and FOP; back, rump, and tail coverage condition; duration in the TI test; hens’ novel object (NO) recognition score; distance in the AD test; and the concentration of corticosterone. Mortality was significantly (P ≤ 0.05) reduced by nests, CADs and their interaction. It was concluded that the nests and CADs that were equipped in our study could be regarded as rewarding environmental necessities that could alleviate FP activities, improve feather coverage condition, and reduce stress levels and mortality rates. Large nests and abrasive strips were the preferred choice over colony cages without nests and CADs.