THE GRAZING MANAGEMENT OF SHEEP ON GRASS-WHITE CLOVER PERMANENT PASTURE

A 2-year experiment was designed to examine the effects of grazing management (rotational or continuous) and number of paddocks (3 or 6) on a lowland sheep system using a permanent grass sward into which white clover had been sown. No nitrogen fertilizer was applied. There were two rotational treatments; one was based on a fixed number of grazing days per paddock (RF) whilst on the other the sheep were moved when residual sward height fell below 5 cm (RH). A third treatment involved continuous grazing until weaning followed by rotational grazing based on a fixed number of grazing days (CRF). There was significantly more clover on RH than on RF or CRF and on 6- than on 3-paddock systems. During the course of the experiment ryegrass increased and bare ground decreased on all three grazing treatments. Lambs on RH grew faster than those on RF or CRF from birth to sale and particularly from weaning to sale, and the lambs on the 6-paddock system grew significantly faster than those on the 3-paddock system. The percentage of lambs finished and sold on RH was 90% in the first year and 88% in the second. On the 6-paddock system 89% and 95% of lambs were sold compared with 66% and 58% on the 3-paddock system. Ewe weight was also heaviest on RH and on the 6-paddock system. Other measures of productivity, the quantity of silage made and the number of grazing days in the autumn were also highest, and the amount of supplementary feed was lowest on RH-6 treatment combination, indicating advantages from this more flexible method of grazing management.