My friend found a dead calf in her pasture the other day. It was about 5 or 6 months old and weighed between 250-300 lbs. There was no visible signs on the calf with the exception of a little pink tinged foam at the mouth. After looking things over and thinking about where the calf was, my friend came up with the fact that they had recently fertilized the pasture and had parked the tractor in this spot to clean it. Could the calf have poisoned itself by licking the tractor or distributor? How much fertilizer would poison one? Thanks for the help.