Release of oxytocin in the cow during milking.

Jugular vein oxytocin concentrations were determined at 15-s intervals on 10 Holstein cows during milking. Oxytocin ranged from .5 muU/ml plasma prior to udder washing to 652.7 muU/ml plasma at 1 min after application of teat cups. The results indicate a gradually increasing release of oxyctocin after stimulation and a maximal oxytocin release 1.5 min after start of udder washing and 1 min after teat cup application.