State agricultural officials are investigating after dozens of horses reportedly fell ill and died last week at an Oklahoma ranch thats known for breeding generations of award-winning rodeo livestock.

As many as 40 to 70 horses died at the Beutler and Son Rodeo Co. farm near Elk City, which is about 110 miles west of Oklahoma City, after eating a bulk feed thats suspected of having been contaminated, according to local reports.

The ranchs co-owner, Bennie Beutler, told local station News 9 that the horses started dying not long after eating the feed.