Intake Stimulants in Perennial Ryegrass (Lolium perenne L.) Fed to Sheep

Abstract

Few studies exist on intake stimulants in forage plants, although a large amount of research has been conducted on deterrents to the feeding behavior of herbivore livestock. To study intake stimulants in plants, chemical components of perennial ryegrass were extracted, fractionated, and examined for their effects on the feeding behavior of sheep. Methanol extracts were found to be stimulants, and pentane extracts tended to be deterrents. The ethyl acetate fraction of the methanol extracts stimulated feeding, and the basic ethyl acetate-soluble fractions of the methanol extracts were bioactive. These results suggest that the basic and less volatile chemicals in perennial ryegrass stimulate feeding in sheep in the absence of other cues.