The aim of this article is to propose that oxytocin not only stimulates milk let down, but also
adapts behaviour and physiology to facilitate lactation in mammals including dairy cattle.
Circulating oxytocin as well as neurogenic oxytocin participates in these regulatory processes.
In short, oxytocin stimulates maternal interaction and attachment between mother and
young. It also participates in the metabolic prerequisites for milk production by e.g. stimulating
glucagon release and thereby, mobilisation of glucose. Digestive and anabolic aspects of
metabolism are also stimulated, e.g. by increased vagal nerve activity. Adaptations consistent
with an antistress like pattern are also induced. Cortisol levels are decreased as well as blood
pressure, and behaviours characterised by calm, reduced levels of anxiety and more social activity
are promoted. These effects seem to be present in monogastric animals as well as in ruminants. The
expression of various aspects of these adaptations vary according to the special needs and living
environmental circumstances of different species. The mechanisms behind the effect spectrum of
oxytocin are being explored in other experimental models. A second aim of this paper is to suggest
that ef®ciency of lactation can be promoted by facilitating oxytocin release in connection
with milking by enhancing the amount of sensory stimulation. # 2001 Elsevier Science B.V. All rights reserved