It is considered a noxious weed and often invades pastures and rangelands. How It Affects Livestock Sheep are affected if they are exposed to direct sunshine after eating as much as 200 gm of the green plant. In advanced poisoning, all the white areas of the body may be affected. May. It is one of the first spring plants to emerge, and ewes may eat it soon after lambing. The udder and teats become so painful that the ewe will not allow the lamb to nurse.
Newborn lambs die of starvation and dehydration.
Surviving lambs usually are stunted from lack of milk. Cattle are affected if they are exposed to direct sunlight after eating about one pound of the green plant. Cows refuse to let calves nurse. In severe poisoning, all the white areas of the body may blister, and animals may lose weight rapidly. Sheep and cattle recover gradually after they stop eating spring parsley.