Diet selection and intake by sheep and cattle grazing together on stubbles of wheat, oats or barley

Abstract

Single plots of wheat, oats and barley stubbles were grazed by sheep and cattle in common on a 19 day rotation for 76 days. Initially the stubbles contained 600-1200 kg dry matter ha-1 of green weeds and 3300-4800 kg dry matter ha-1 of cereal residues. Serial estimates were made of diet selection, in vitro digestibility and intake by both species. Sheep consistently selected a diet with a higher proportion of green material than did cattle, but neither species utilized the crop residues to any extent. The overall mean digestibilities of the diet were 68 and 54 per cent fop sheep and cattle respectively (P < 0.01) ; the mean N concentration in the faeces of sheep was 0.64 percentage units higher than for cattle (P < 0.01). Differences in selection by the animals were greatest at the lowest level of green plant material. Estimates of the mean daily intakes of DOM (g kg-1) per unit of metabolic liveweight (W0.9) were 32 and 15, and of dead plant material dry matter (g kg-1) 4.2 and 13.2 for sheep and cattle respectively. There were no differences in selection between stubble species. The results are discussed in relation to maximizing the use of cereal stubbles for animal production.