Water consumption and water turnover of sheep grazing semiarid pasture communities in New South Wales

Abstract

The water consumption and water turnover of Merino sheep grazing on three natural pastures of south-western New South Wales were recorded throughout 1 year, and supplementary data on the water consumption of sheep on some pastures were collected for a further 2–4 years.

On Danthonia caespitosa grassland, water was consumed for up to 7 months each year over the summer months. Maximum intakes were 3–3.5 litres per sheep per day, but this was reduced for 1–2 weeks after falls of rain of less than 25 mm and for longer periods after heavier falls. The provision of shade reduced water turnover by a maximum of 0.3–0.5 litre per day on some occasions only, which indicates that shade is of little importance to woolled sheep.

On the saltbush (Atriplex vesicaria) and belah-rosewood (Casuarina cristata-Heterodendrum oleifolium) communities, water intakes were up to 6–7 litres per day in summer. In the particularly dry summer of 1972–73, water intakes of the sheep on saltbush rose to 12 litres per day for several months. The higher water intakes of these sheep were attributed mainly to the high mineral content of the Atriplex and Bassia spp. eaten by them, although the sheep on the belah-rosewood community were also in a hotter environment. In contrast to the sheep on Danthonia, those on the bush communities consumed significant amounts of water throughout the winter in years of low rainfall.