The cause of reproductive loss in Gisborne-East Coast ewe flocks
K.T. Jagusch, M.M. Gray, K.S. Maclean; N.R. Towers, M.E. di
Menna; and W.H. McMillan
Ministry of Agriculture and Fisheries, Gisborne; Ruakura
Agricultural Research Centre, Ministry of Agriculture and Fisheries,
Hamilton and Whatawhata Agricultural Research Centre, Ministry of
Agriculture and Fisheries, Hamilton
Proceedings of the New Zealand Society of Animal Production.
1986, 46: 251-254
Low lambing rates are characteristic of ewe flocks on the
summer-dry East Coast. In the present experiment, groups of 4- and 6-
tooth 54 kg ewes were either kept on, or transferred between, non-facial
eczema-prone (NFE) and facial eczema-prone (FE) stations. Two
additional groups on the FE station received weekly dozes of zinc and
serial blood sampling of all groups identified ewes with a high
threshold resistance to FE. Ewes gained 4 kg in the 8 weeks prior to
mating. Groups on the NFE station had 3% barrenness and 55% twinning;
those on the FE station had 18% and 38%. Resistance to FE reduced
barrenness from 18 to 10% but did not increase twinning. Estimated
lambing percentages were 150 on the NFE station, 113 on the FE. The FE
factor was associated with some of the barrenness but most of the
reproductive loss appeared due to a factor which imitated an oestrogen.
The oestrogenic mycotoxin zearalenone, produced by some pasture Fusaria,
was detected in pasture samples collected from the FE but not from the
NFE station.
Keywords: NZSAPAB;
Facial eczema; mycotoxins; sporidesmin; zearalenone;
reproductive loss; ewes
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Last Updated 18-03-1997
