Comparisons of diets of sheep and cattle grazing together on sown pastures on the Southern Tablelands of New South Wales by principal components analysis

Abstract

The botanical and chemical composition of the diets of oesophageal fistulated wether Merino sheep and cattle (mainly yearlings and dry cows) were compared when they grazed together on sown pastures varying widely in yield and botanical composition. Sheep diets were consistently different from cattle diets, independent of pasture conditions, in having lower normal-acid fibre contents (3.8 units lower), and higher water-soluble carbohydrates (1 unit) and in vitro digestibility (4.4 units). Differences in nitrogen content and in botanical composition of the diet were related, in part, to the botanical composition of the pasture being grazed. It is suggested that differences in composition of the diet arise from differences between sheep and cattle in their mechanical ability to be selective. Use of the principal components technique allowed reasonable biological conclusions to be drawn from multivariate intercorrelated data.