Start Date
1-16-2016 9:00 AM
Description
Many cattle producers in Kentucky manage tall fescue as their perennial forage base. Tall fescue has served cow-calf producers well because of its productivity and persistence with minimal management. Like most things, however, “you must take some bad with the good.” The agronomic traits we like so much about tall fescue can be attributed to a fungal endophyte that infects most fescue plants. Without the endophyte, the grass is no longer productive and tolerant of environmental stresses (dry weather, low fertility, and grazing). Unfortunately, the endophyte also produces ergot alkaloids that cause a toxicosis in cattle, which costs the U.S. Beef Industry approximately 1 billion dollars per year in lost production. Signs of toxicosis are: 1) severe heat stress in moderate to warm air temperatures, 2) maintaining rough hair coats during the summer, 3) fescue foot (loss of tail switches, ear tip, or gangrenous condition of the lower limbs), 4) poor weight gain of calves and poor body condition of cows. Ergot alkaloids cause constricted blood flow to peripheral tissues to incapacitate the animal’s ability to regulate body temperature. The alkaloids also reduce the amount of prolactin in blood circulation, which can reduce milk yields and are also thought to adversely affect other functions (hair coat growth, growth and development).
Included in
Tall Fescue Endophyte-Animal Relations: Cutting Edge Research and Implications
Many cattle producers in Kentucky manage tall fescue as their perennial forage base. Tall fescue has served cow-calf producers well because of its productivity and persistence with minimal management. Like most things, however, “you must take some bad with the good.” The agronomic traits we like so much about tall fescue can be attributed to a fungal endophyte that infects most fescue plants. Without the endophyte, the grass is no longer productive and tolerant of environmental stresses (dry weather, low fertility, and grazing). Unfortunately, the endophyte also produces ergot alkaloids that cause a toxicosis in cattle, which costs the U.S. Beef Industry approximately 1 billion dollars per year in lost production. Signs of toxicosis are: 1) severe heat stress in moderate to warm air temperatures, 2) maintaining rough hair coats during the summer, 3) fescue foot (loss of tail switches, ear tip, or gangrenous condition of the lower limbs), 4) poor weight gain of calves and poor body condition of cows. Ergot alkaloids cause constricted blood flow to peripheral tissues to incapacitate the animal’s ability to regulate body temperature. The alkaloids also reduce the amount of prolactin in blood circulation, which can reduce milk yields and are also thought to adversely affect other functions (hair coat growth, growth and development).