Nutritive Value of Pasture. IX. The Influence of the Intensity of Grazing on the Yield, Composition and Nutritive Value of Pasture Herbage.

Abstract

The main conclusions from the present investigation, which was undertaken in order to obtain an insight into the consequences of the adoption of a 5-weekly rotational close-grazing system, may be summarized as follows:The lengthening of the interval between successive cuts from a month to 5 weeks leads to a definite, though not very serious, reduction in the digestibility of the herbage. This reduction is most noticeable during the flush period of growth, and the constituent most affected is the crude protein. During the fore-flush and post-flush periods, it appears to be immaterial, from the standpoint of digestibility, whether a system of monthly or 5-weekly cutting is adopted. The falling off in digestibility is not connected with the onset of lignification in the herbage, since the digestion coefficient of the fibrous constituent remains high throughout the season, and it may be concluded that, during a season of favourable rainfall, it is possible by cutting (or close-grazing) at intervals of 5 weeks, to prevent the herbage from becoming lignified and of greatly reduced digestibility. The possibility, however, during seasons of a droughty character, of a premature onset of lignification under a system of cutting (or close-grazing) at 5-weekly intervals is discussed.