Back transformed mean plasma oxytocin concentration in Bos taurus cows assigned to one of four treatments.

Treatments included 1) Non-lactating, saline (NL-S, ‒ ‒ Δ ‒ ‒; n = 5), 2) Non-lactating, oxytocin (NL-OXT, ‒ ‒ ○ ‒ ‒; n = 5); 3) Lactating, saline (L-S, ──▲──; n = 5); and 4) Lactating, oxytocin (L-OXT, ──●──; n = 3). Intra-nasal treatments (S or OXT) were administered at 0 minutes followed by two hours of head restraint, as indicated by the black bar. Oxytocin was administered intra-nasally at a rate of 0.60 IU/kg bodyweight. A treatment by time interaction was detected from 60 to 90 minutes (P < 0.01) and from 90 to 110 minutes (P < 0.05).