Had one recently that was bit messy around the back and put that down to too much wheat from the pheasnt feeders.
They can always be found near the feeders and the ones turned over have been blamed on Deer.
Results of gorging on wheat. You get excess production of acid in the rumen and the reticulum which leads to excess gas production ( methane ) which the beast can't get rid of fast enough, leading to bloat which if severe enough presses on the diaphragm. This in turn can press on the ventricles of the heart stopping the blood getting into them leading to circulation failure and death. Normally if you find these animals they look swollen and if you look inside the rumen/reticulum the lining strips off easily. Also the lungs can be very red from the blood not getting back to the heart. A mild case of excess wheat can be diarrhoea with swollen wheat grains in it.