>>54142006The determining factor in lactation is the amount of prolactin in the body. Without thoroughly stimulating the nipples to cause the hormonal glands to produce more prolactin, the average man has about 1/20 the amount of prolactin a new/expectant mother does.
Basically, men could lactate, but it would be a piddling amount unable to reasonably sustain a child and would require a massive spike in hormones to even start.
Anyway, if Sylveon is a mammal like the rest of the Eevee line, there is no reason to assume it could not lactate. That is, in fact, one of the defining features of mammals. However, they would be classified as monotremes (egg-laying mammals) and would likely lack nipples. Instead the parents would 'sweat' milk from the pores of their mammary glands.
That said, Miltank manage to produce enough milk to fuel a dairy industry, so we probably should not assume similar physiology with real-life animals.
