This experiment was to test the hypothesis that suckling behavior in Bos taurus is related to milk ejection. Intra-gland milk transport was manipulated by applying four different treatments to four cow-calf pairs: T1, injection of oxytocin during the post-stimulation period; T2, injection of oxytocin before a meal; T3, injection of saline solution at the same times as oxytocin was applied (control) in T1 and T2; T4, injection of an oxytocin antagonist in a similar way as T1. Drugs were applied i.v. and by remote control in order to prevent the animals from noticing the injection. All non-control treatments resulted in significant changes in the time calves spent performing uninterrupted suckling at a specific teat.