Conditioned taste aversion: potential for reducing cattle loss to larkspur

Abstract

Barbey larkspur (Delphinium barbeyi L. Huth) is a palatable poisonous plant that causes a large number of cattle deaths on mountain rangelands. The objective of the study was to determine whether or not cattle could be conditioned to avoid eating larkspur. Five heifers were conditioned to avoid eating larkspur by intraruminal infusion of lithium chloride whenever they consumed larkspur in a pen feeding trial. Five control heifers were likewise infused with distilled water. Following the conditioning, the heifers were taken to mountain rangeland in central Utah and observed in 1986 and 1987. The non-averted heifers consumed larkspur throughout the 1986 field trial, while the averted heifers generally consumed little larkspur. The aversion from the previous summer persisted as the averted heifers refused to eat larkspur in the first grazing trial in 1987. During the second grazing trial in 1987, the averted heifers were placed in a pasture with non-averted heifers to determine if social influences would affect learned aversions. A rapid breakdown of the aversions was observed and the averted heifers continued consuming larkspur after being separated from non-averted heifers.