Evaluation of total locomotor activity and oxidative markers daily rhythms in sheep

For our study, five clinically healthy Comisana sheep, housed individually in a soundproof light-tight box, were exposed to artificial photoperiod (12/12 light/dark). Locomotor activity was continuously recorded and blood samples were collected every 3 h over a 24 h period. On blood samples, reactive oxygen metabolites (dRoms), antioxidant barrier (Oxy-ads) and thiol-antioxydant barrier (SHp) were assessed. A one-way ANOVA showed a significant effect of time on all parameters studied. Locomotor activity was mostly diurnal, with acrophase in the middle of the photophase. Oxidative stress markers showed robust daily rhythms with nocturnal acrophase. In sheep, the circadian system maintains the balance between dRoms production and removal. These rhythms are not affected by locomotor activity.