Domesticated sheep are herd animals that are bred for agricultural trade. A flock of sheep is mated by a single ram, which has either been chosen by a farmer or, in feral populations, has established dominance through physical contests with other rams.[1] Sheep have a breeding season (tupping) in the autumn, though some can breed year-round.[1]
As a result of the influence of humans on sheep breeding, ewes often produce multiple lambs. This increase in lamb births, both in number and birth weight, may cause problems with delivery and lamb survival, requiring the intervention of shepherds.[2]