Question

why male have no mamry glands whats the real facts behind it​

Answer 1

Answer:

It is because of this reason

In male embryos, it is responsible for preventing the further development of the mammary bud. PTHrP produced by the bud itself stimulates the bud cells to make receptors for the 'male' hormones circulating in male embryos. This feedback mechanism causes the mammary cells to stop developing and eventually to degenerate.