The effect of photic entrainment and restricted feeding on food anticipatory activity in Ovis aries

The aim of this study was to investigate the influence of light/dark (L/D) cycle, associated with restricted feeding, on total daily locomotor activity in sheep. Eight clinically healthy Comisana ewes were housed individually in a soundproof box and subjected to three different light and feeding periods. During period 1 (light on 8:00; light off 20:00) and during period 2 (light on 20:00; light off 8:00) hay and water were available ad libitum. During period 3 the animals were subjected to constant light and restricted feeding. Total locomotor activity was recorded by means of an Actiwatch-Mini actigraphy-based data loggers. The application of one-way for repeated measures ANOVA showed a significant effect of 24 h (P < 0.0001) on locomotor activity. The highest daily amount of locomotor activity was observed during the photophase than the scotophase (P < 0.001). During all three periods locomotor activity exhibited robust daily rhythmicity with diurnal acrophases. During period 3 locomotor activity started before food supplement and it was concentrated during food availability. In conclusion, we can claim that the daily rhythm of locomotor activity in sheep is entrained by the light/dark cycle in couple with food availability.