The rate of herbage disappearance during periods of occupation in rotational grazing systems.

Abstract

The rate of herbage depletion during a period of occupation in a rotational grazing system is dependent on daily intake of animals which in turn is a function of the quality and the quantity of the forage available. When herbage is abundant, daily intake per head increases as nutritive value decreases up to a critical level; thereafter it decreases progressively. The rate of herbage disappearance will increase with increasing intake, but decrease as less herbage is consumed. Where forage quality remains constant, both intake and the rate of herbage disappearance will be constant. As soon as the quantity of herbage available becomes limiting, intake per head is restricted and the rate of herbage disappearance will diminish progressively. In sweet grassveld, nutritive value is likely to remain constant while herbage is abundant, causing herbage to disappear linearly with time. This could have useful application in grazing experimentation.

Keywords: experimentation; forage quality; grassveld; grazing; grazing systems; herbage; intake; model; period of occupation; rotational grazing