Heritability of daily activity over time in broilers

Individual activity is related to the health, welfare and performance of broilers. In previous work using a radio frequency identification system, we were able to collect individual activity data over time, and activity was found to be heritable. The aim of the current study was to estimate genetic parameters for activity while taking into account the effect of age. Therefore, two repeated measurement models were fitted. The model with an intercept and slope for genetic and permanent environmental effect, and a heterogeneous residual variance, yielded the best goodness-of-fit. First results showed that daily heritability varied between 7 and 30%. The heritability was lowest at the start and at the end of the production life. This study shows potential for selection on activity in broilers. Furthermore, this study shows that activity patterns (in time) can be changed, as both the intercept and slope of activity are heritable.