hello, im new here..we have started a small cattle operation and have just had our first calf last nite. we have one other heifer due any day. i also have 6 new ones that i am going to breed. we have our own bull. my question is, when can these new mamas be put in with the bull and other girls? i have raised horses for years and always bred our mares back on their foal heat..but i think cows are not the same...any advice?