The effect of summer management of perennial ryegrass-dominant swards on plant and animal responses in the autumn when grazed by sheep. 2. Herbage intake and grazing behaviour

The effects on herbage intake and ingestive behaviour by ewes and weaned lambs of grazing aftermath and previously continuously grazed perennial ryegrass-dominant swards at two different sward heights (4 and 8 cm) in the autumn were studied. The experiment had a factorial design, was replicated twice and was conducted from mid-August to early November. There were six ewes and six weaned lambs per treatment plot and measurements were made in three periods. The effects of previous treatment of swards on herbage intake by ewes and weaned lambs were greatest in August, with herbage intakes being significantly lower on the aftermath swards. Differences disappeared by October. The lowest herbage intakes were obtained on the aftermath sward at the lowest sward height, with ewes being more affected under those conditions than lambs. Grazing time and biting rate increased with a reduction in sward height and were higher on aftermath swards. However, these increases did not compensate for reductions in estimated bite size on the aftermath swards. It was concluded that the effects of the sward management treatments in the summer on tissue turnover of the sward and herbage intake in the autumn were considerable in the early part of the autumn but had largely disappeared by the end of the autumn period.