I know I am going to get heck for this, but you should check the bite on the dead calf. If it has an underbite, it was likely exposed to one or all three of the most used highly teratogenic (birth defect causing) pesticides (according to recent studies). Those three teratogenic pesticides are Glyphosate-based Herbicides, the insecticide, imidacloprid and the fungicide, Chlorothalonil. Exposure to all three is quite damaging to ungulate fetuses, and according to other recent studies to human fetuses.