Effect of steroid immunisation in the performance of 3 breeds of
sheep under hill country conditions
T.W. Knight, J.F. Smith and R.M.W. Sumner
Whatawhata Hill Country Research Centre, Ministry of Agriculture
and Fisheries, Hamilton and Ruakura Agricultural Research Centre,
Ministry of Agriculture and Fisheries, Hamilton
Proceedings of the New Zealand Society of Animal Production.
1985, 45: 181-183
The first two years' (1983, 1984) results of a trial to
determine the effect of immunisation with Fecundin(r) on the reproductive
performance of Romney, Coopworth and Perendale ewes under hill country
conditions are reported. Immunisation increased ovulation rate by 40 to
60%, lambs born/ewe present at lambing by 19 to 26% and lambs present at
weaning by 4 to 9%. The major reason that the increased potential lamb
production of the immunised ewes was not realised in practice was the
failure of the ewes that lambed to produce as many lambs as expected
from their measure ovulation rate.
Immunisation tended to produce a larger increase in ovulation rate in
Romneys than in Coopworth and Perendales and in older ewes than in
younger.
Lambs of immunised ewes had lower birth weights and higher mortality
rates within each birth rank than lambs from non-immunised ewes.
Keywords: NZSAPAB;
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Last Updated 03-05-1997
