The quality of herbage ingested by cattle in rotationally grazed semi-arid grassveld of the eastern Cape.

Abstract

Oesophageal fistulated steers were used to sample herbage daily during periods of occupation on veld in good and moderate condition. Forage quality was assessed in terms of in vitro dry matter digestibility and digestible crude protein. The quality of herbage ingested remained fairly constant as forage availability declined during periods of occupation, even when swards were grazed very severely. Digestibility declined somewhat from spring through to winter, but digestible crude protein content in the diet was unaffected by time of year. The quality of forage ingested during winter was nevertheless still high, even after a full growing season's rest. It was sufficient for growing steers to gain 0, 75 kg livemass per day. Trends were similar on both veld condition types. It was concluded that, in semi-arid grassveld of the eastern Cape, forage availability is likely to have a greater influence on animal performance than forage quality.

Keywords: animal performance; cattle; crude protein; crude protein content; diet; digestibility; dry matter digestibility; eastern cape; forage quality; grassveld; herbage; oesophageal fistulas; semi-arid grassveld; south africa; veld condition