PRL and Infertility: Such a role for prolactin is controversial, however (McNeilly, 2001; McNeilly, 1997; McNeilly, 1994; Sugimoto et al., 2022; Tay et al., 1996; Díaz et al., 1989; Ördög et al., 1998), with studies in a number of species suggesting that the neural stimulation of suckling may be more important than prolactin in maintaining lactational infertility (Maeda et al., 1990; Smith, 1978).