I have a flock of Southdowns, among other breeds, and I understand the breed is so docile due to having been grazed on South Downs (short downland grasses and wild flowers) during the day then brought back and folded onto cropped arable fields at night, thus bringing the fertility of the hills back to the farmstead in the form of dung. The Downs are chalk, not noted for its fertility! This meant, of course, that the shepherd stayed with them most of the day, almost every day.