The ryegrass endophyte in a cool moist environment

Abstract

A field grazing experiment studying the impact of the ryegrass endophyte (Acremonium lolii) in a cool moist environment, was carried out at AgResearch regional station in Gore Southland. Four types of pasture were established, high (+E) and low (-E) endophyte ryegrass were sown with (+C) or without (-C) clover. The endophyte had no significant effect on the establishment of the pastures, neither did it affect total pasture production nor pasture composition. The presence of clover in pastures had a greater impact (30%) on animal production than did the presence of endophyte (6%). Mean daily weight gains over 3 years for lambs were 187,183,145 and 132 g/day for -E+C,+E+C, -E and +E respectively. Lambs grazing endophytic pasw genemlly had higher levels of dags. However, ryegrass staggers occurred only in the year with below average summer rainfall. Not all the conditions necessary to induce ryegrass staggers are therefore required to expose livestock to other deleterious effects of endophyte. A detailed study into the environmental requirements for the production of endophyte related toxins is required. The findings reported here significantly differ from findings in summer dry areas. Keywords Acremonium, animal production, Argentine stem weevil, endophyte, Lolium perenne, Southland, Trifolium repens