A modelling study of the productivity and profitability of
unmated and mated ewes on North Island hill country
W.J. Parker, D.I. Gray, S.T. Morris, S.N. McCutcheon
Department of Agricultural and Horticultural Systems Management,
Massey University, Palmerston North, New Zealand
Proceedings of the New Zealand Society of Animal Production.
1992, 52: 221-224
Feed intake and wool production data on unmated, single- and
twin-bearing/rearing ewes from a year-long field trial were incorporated
into feed budget models of a hill country farm. Increasing the basal
liveweight of an unmated ewe from an average of 45 to 55 kg increased
greasy wool production from 4.15 to 5.10 kg/ewe. Relative to the annual
feed requirements (614 kg DM/y) of a typical breeding ewe (1 sheep stock
unit (ssu) on the case farm the annual feed requirements of unmated 45,
50 and 55 kg ewes were estimated to be 0.58, 0.66 and 0.72 ssu. At 1991
costs and prices the gross margins (GM) were $15.50/ssu for breeding
ewes (100% lambs weaned) and, depending on liveweight, from $7.12 to
$8.11/ssu for the all-wool options. The breeding ewe policy remained
more profitable even if low lamb prices or a poor lambing percentage
were achieved.
Keywords: NZSAPAB;
Feed budget model; wool production; unmated ewes; hill country;
profitability.
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Last Updated 25-01-1997
