Studies of the Relationship Between Fear-Related Responses and Production Traits in Japanese Quail (Cotumix coturnix japonica) Bidirectionally Selected for Dustbathing Activity

In three experiments, female Japanese quail originating from lines selected for low or high dustbathing activity and the randombred control were studied. Fearfulness was measured as latencies to emerge from a box and to recover from induced tonic immobility (TI), and the influence of social disturbance by repeated placement in male cages during the breeding season, and the effect of repeated frightening by exposure to unfamiliar objects on egg quality traits was examined. Eggs (a total of 790) were collected over a 5-day period, weighed, and examined; body weight at 12 wk was recorded for all birds. Low line females had longer latencies to emerge than high line birds. It is suggested that selection for dustbathing activity had resulted in correlated changes in the susceptibility to fear. These genetic differences in fearfulness, however, may be only detectable at lower levels of induced fear. The social disturbance and frightening treatments did not affect egg production or the incidence of shell-less eggs. Repeated disturbances caused a significantly lower degree of egg shell calcium coating on the posttreatment day, suggesting that eggs were laid prematurely. As only 12.8% of all eggs examined were classified as uncoated, it is concluded that coatings are part of the normal egg shell pigmentation in the quail lines studied. There was no apparent correlation between emergence test and TI. The association between fear-related responses and production traits was of low magnitude.