Category: poisonous cherry leaves.

With so many cherry trees that have blown over with the recent floods as cattle are put back into these environment be advised that those cherry leaves once wilted may contain cyanide. I have talked to several veterinarians and have found that once the leaves have fallen off the plant the cyanide levels will drop. However if the leaves are still connected to the plant stems the leaf tissue can draw toxins from the branches into the leaves.  Many factors lead to the breakdown of cyanide through hydrolosis and that will depend on many factors most notably if the leaves are still connected to the branches. They are recommending to clean the trees out ASAP and get as much of the dropped leaves off the ground before commencing grazing activities.
I have personally been involved in  cases where several large dairy cows were killed by eating the leaves of cherry.  Pretty simple to diagnose since the cherry tree was down in the dry cow lot and you could see the hoof prints. The lab test came back to confirm so watch out.  Another case was with Ewe bushes that several young stock were killed by consuming the plants. The producer had fenced off a section around an abandoned home which had the ewe bushes and the cattle in there were dead in a week. Necropsy also confirmed.
Here is a factsheet that details the issue. I have some cherry that had gone down and I cleaned up as much as I could then turned the cattle out. I had thought I had removed most cherry trees but missed a couple and sure enough they were the ones to go over.  Once you cut the stump you need to apply the stump treatment before the tissue dries can be minutes in dry weather. A great reference for stump treatments from Florida State University is here http://edis.ifas.ufl.edu/ag245.

So take a small sprayer and pre mix have it ready when you cut the final stump then treat it immediately.  Here is a complete write up of the situation.

Cherry Poisoning

Melissa Bravo had this to report pertaining to poisonous plants.