Levels of first winter feeding in relation to performance of Cheviot hill ewes: IV. Body growth and development from 18 months to maturity

Abstract

1. The effects of different levels of first winter nutrition over 3 years were studied from 18 months to maturity on the growth and development of groups of North and South Country Cheviot ewe hoggs (sheep between 6 months and 1½ years).2. Differences in live weight amongst treatment groups within breeds and years were not significant at 30 months or any subsequent age. Live weight increase continued up to 54 months. Although leg growth had virtually ceased in all treatment groups by 18 months, body growth continued beyond 27 months and differences between treatments, although not always significant, were still present at that time.3. The effects of first-winter treatment were also studied on the heavy and light hoggs (i.e. those above and below average weight) prior to treatment. Differences in weight and size between treatment groups were less persistent in the heavy animals, disappearing by 30 months, while in the light animals they were still present at that time. Regardless of treatment the within-group differences between heavy and light animals increased up to 54 months, the light animals showing relatively slower rates of gain.4. The difficulty of interpreting data on liveweight change due to age, state of maturity, level of feed, and season interactions is commented on. The probable effects of differential productivity resulting from treatment on growth and development from 18 months onwards are discussed.