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
New Zealand Journal of Agricultural Research, 1998, Vol. 41: 191-199
0028-8233/98/4102-0191 $7.00/0 (c) The Royal Society of New Zealand 1998
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