Feed Intake in Hereford Calves Infused Intraperitoneally with Toxic Fescue Extract

Abstract

Thirteen Hereford calves weighing 137 to 228 kg were used to determine whether tall fescue contains an extractable substance that would limit voluntary intake of alfalfa pellets. Extracts were prepared via ion exchange chromatography from harvested tall fescue which had caused fescue foot when grazed by cattle during February, 1972. The extracts were administered intraperitoneally, two calves per extract plus two saline controls and an animal with no treatment. Dosage was approximately equivalent to an animal consuming 1.8 to 2.7 kg of toxic hay in 60 to 120 min. A crude ethanolic extract and an anion fraction depressed voluntary intake of alfalfa pellets. The four animals treated with these extracts also developed fescue foot. A physiologically active compound in tall fescue may be responsible for depressed voluntary intake of the forage. Whether the same compound is responsible for the fescue foot syndrome is not clear. © 1974, American Dairy Science Association. All rights reserved.