‘Let-down’ of Milk in the Sow

Abstract

A CONSIDERABLE amount of work has been carried out in recent years on the problem of the ‘let-down’ of milk in the cow; but, so far as we are aware, nothing has been published on any such work on the sow. From the lactational point of view, the sow differs from the cow in several ways; she has, for example, an exceptionally strong control over the release of her milk. While the normal cow lets down her milk easily, it is normally impossible to obtain by hand any milk from the sow unless let-down is first artificially induced by the intravenous injection of an extract of the posterior pituitary lobe¹. In addition, it is necessary to rope the sow during the process of obtaining the milk, and consequently the condition of co-operation which normally exists in the routine milking of the cow does not obtain.