Recording of total locomotor activity in laying hens maintained under different light conditions

Locomotor activity is a major component of animal behavior and an important animal welfare index. The daily individual total locomotor activity (TLA) of two different laying hens maintained under different conditions has been performed. Six Hy-Line W hens (HLWC) and six Hy-Line Brown (HLBC) were housed in conventional cages with controlled light programme (light on from 05:30 to 22:00); six Hy-Line Brown (HLBF) were housed in an open-air rearing system with a controlled light programme (light on from 08:00 to 18:00). Total locomotor activity was recorded on 11-minute interval for 20 consecutive days with Actiwatch-Mini placed on the wing. HLWC showed the lowest activity, and the HLBC was more active than HLBF. The average daily activity was diurnal. The activity increased at about 1 hour and a half after the switching light on and decreased immediately before the switching light off in each group. Several activity peaks were observed during the dark phase in groups living in cages. Single cosinor method showed all groups' daily TLA rhythm. The daily rhythm of TLA in hens is different based on line and housing conditions. The present findings could be useful in the chicken farming management.