Clinical manifestations of tall fescue (Festuca arundinacea) and perennial ryegrass (lolium perenne) toxicosis in Oregon and Japan

Abstract

There are multiple vehicles for endophyte toxicosis in animals including exposure from pasture, straw residues and seed screenings. This report discusses the clinical cases typically seen with tall fescue and perennial ryegrass toxicosis in Oregon and Japan. Case I involves a herd of 330 Black Angus cattle. Before the March calving season the owner wished to increase the protein content of the feed ration by feeding pellets made of seed screenings and grass hay. Forty two animals were lost to tall fescue toxicosis and dry gangrene of the feet and legs. Case II involves 1300 beef cows in Eastern Oregon fed grass straw; 485 animals were lost due to dry gangrene characteristic of tall fescue toxicosis. Case III describes 4 of 15 cases of both tall fescue and perennial ryegrass toxicosis in Japanese black cattle. Case IV involves llamas and alpacas on pasture and lawn paddocks where some animals were affected by tall fescue and some by perennial ryegrass. Keywords: tall fescue, Festuca arundinacea L., perennial ryegrass, Lolium perenne, endophyte, Neotyphodium coenophialum, Neotyphodium lolii