Influence of the ryegrass endophyte (Neotyphodium lolii) in a cool‐moist environment II. Sheep production

Abstract

The impact of the ryegrass endophyte on sheep production in a cool moist environment was examined in a field experiment in Southland, New Zealand. Ryegrass staggers were observed in one year when drought conditions were experienced, but not in years with average summer rainfall. There was a negative correlation (r = ‐0.9) between ryegrass staggers score and liveweight changes in animals forced to consume a high proportion of basal plant material, and animals grazed endophyte‐infected pastures less closely than endophyte‐free pastures. Lamb liveweight gains were not significantly affected by the presence of endophyte, except when drought conditions were experienced, although this is probably more a reflection of differences in pasture composition than of a direct endophyte effect. Faecal soiling was higher (P = 0.052) on endophyte‐infected pastures, especially under drought conditions (P = 0.025), and wool yields on mixed ryegrass/white clover pastures were 10% higher on endophyte‐free than on endophyte‐infected pastures (P = 0.003). There was no evidence of an endophyte effect on fat deposit. It is concluded that the endophyte had moderate negative effects on animal production in a cool moist environment.

Keywords:

• lamb growth rates
• Neotyphodium lolii
• sheep production
• Southland
• Trifolium repens
• white clover
• wool production