Abstract

Ergovaline and lolitrem B are alkaloids produced by Neotyphodium endophytes in ryegrass. These toxins are associated with poor animal performance in many situations but influences on milk production by dairy cows had not been determined in NZ except for short-term trials. An on-farm trial was set-up at Te Hana to measure milk production responses in 2 groups of 16 cows which were maintained on a) ryegrass-based pastures which contained wild-type endophytes which produced ergovaline and lolitrem B [+Ev] or on b) ryegrass pastures that were either free of endophyte or contained a novel endophyte which did not produce ergovaline or lolitrem B [-Ev]. The trial ran from October 1997 til mid-April 1998 and milk production was recorded for each cow at each milking for 10 consecutive days per month culminating in a herd test. There was no difference in milk production in October and November, but a difference of 25% developed in December in favour of the -Ev group and substantial differences in production were maintained until the trial was terminated. Effects of ergovaline on cow performance are discussed in relation to environmental and behavioural factors.

RG, Keogh, M Blackwell, and P Shepherd

Proceedings of the New Zealand Society of Animal Production, Volume 59, , 254-257, 1999