Something is killing all my cows and pigs. I had them in an enclosure right next to my chickens and my sheep, then suddenly one day, all the cows and pigs were gone. So I put a glass roof over them, and then a few days later, all gone again. Do I need to make the glass roof wider to prevent a lightning strike next to the enclosure from killing them all? What's the kill zone of a lightning strike? My enclosure is roughly 7x12 measuring the wooden fence and glass roof area. Could something else be killing them off?