FEAR LEVELS IN LAYING HENS CARRIED BY HAND AND BY MECHANICAL CONVEYORS

The fear levels of five groups of 16 end-of-lay hens were assessed on 3 consecutive days using the tonic immobility test. The groups were su bjected to the following conditions: Group 1 to conveyance on a flat b elt conveyor, Group 2 to inversion and conveyance by hand; Group 3 to conveyance by a processing shackle; Group 4 to noise of the conveyor; Group 5 to tonic immobility only. Inversion and conveyance by hand or on a processing shackle was significantly more fearful than mechanical conveying. Inversion and restraint by the legs was a significant fear stimulus to the birds. There was evidence to suggest that birds expos ed to shackling or manual conveyance became sensitized to the treatmen ts on consecutive days, though the ranges in duration of tonic immobil ity, for the other three groups, resulted in no statistical difference s being observed. In general there was a trend towards increased durat ions of tonic immobility, indicating that some birds may have become s ensitized to a frightening treatment. The use of carefully designed co nveyor systems for transporting hens into and out of the rearing and p roduction houses is potentially beneficial in welfare terms.