Abstract

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.

KL, Isaacs, KP McNatty, BJ McLeod, L Condell, and RP Littlejohn

Proceedings of the New Zealand Society of Animal Production, Volume 52, , 175-178, 1992