The present invention describes a method of inducing lactation in non-human mammals by using a single administrations of an estrogen compound, a dopaminergic antagonist, and oxytocin. For example, the estrogen compound may be a long acting composition and is administered at least one week before the dopaminergic antagonist. However, the oxytocin administration may be given the day after the dopaminergic antagonist, after which lactation may begin immediately. Preferred compounds may comprise a non-17&bgr； estradiol and domperidone. Such an injection protocol has resulted in the production of commercially viable volumes of milk from transgenic pigs.
