Do other female mammals also have menstruatinal cycle ??.and if they dont have it the how is the egg formed there??
The reproductive cycle in the females of order primates of mammals (e.g. monkeys, apes and human beings) is called menstrual cycle.
In females of non-primate vertebrates, for example rats, mice, horses, pig etc. another similar cycle known as oestrous cycle occurs.
One difference between the two cycles is that the animals having estrous cycles reabsorb the uterine lining if fertilization does not occur during that cycle. Animals that have menstrual cycles shed the uterine lining through menstruation instead.