When compared to fetal body length at birth, the ruminant umbilical cord is the shortest of all the domestic mammals. In the bovine and sheep, it is ____ of body length, while in the goat, only ____. The two umbilical arteries are not spirally twisted and the two umbilical veins fuse before reaching the ____. Amniotic plaques are present and are particularly well developed. The umbilical cord has no ____ component as in the horse.