By contrast, the study of VanKlompenberg et al. [5] reported that provision of domperidone, a dopamine receptor antagonist known to induce hyperprolactinemia, to late-gestating gilts increased PRL concentrations from days 90 to 97 of gestation and stimulated mammary epithelial cells (MEC) differentiation before farrowing, with a subsequent increase in milk production and piglet growth. This evidence concerns the gene PRL and hyperprolactinemia.