Effects of season on the wool growth response of Romney ewes to pasture allowance.

Wool growth responses of New Zealand Romney ewes to increasing pasture allowance in the autumn (pre-joining), early winter (mid-pregnancy), spring (lactation) and summer (post-weaning) were examined. Wool growth increased curvilinearly with pasture allowance in each season, the response being greater in summer and autumn than in winter, with spring intermediate. Efficiency of wool growth was ranked summer > autumn > winter > spring. The wool growth of ewes at maintenance was ranked summer > autumn > spring > winter. For a given change in live weight the associated change in wool growth was ranked summer > autumn > spring, winter.