Previous PageTable Of ContentsNext Page

Grazing for pasture management in New Zealand

D. Clark

DSIR Grasslands, Private Bag, Palmerston North, New Zealand

Summary

This paper provides a brief synopsis of modern pastoral farming principles, followed by a review of key New Zealand work on pasture management processes and the consequences of poor management, developed on a seasonal basis. The synopsis examines the interaction of photosynthesis, respiration, senescence and intake and its implication for optimising grazing intake. The compensatory mechanisms that exist in the plant-animal interaction are used to determine where benefits to either rotational grazing or set-stocking may apply.

The relative importance of management strategies such as feed profiling (stocking rate decisions, time of lambing), feed budgeting (overcoming deficits/surpluses), and grazing plans (rotation lengths and area grazed) are discussed. Critical parameters for New Zealand livestock systems are identified taking examples from sheep, beef and dairy farms.

Winter management is dominated by pasture rationing. The reason for rotation lengths of 60100 days and the use of supplements or deferred grazing areas in late autumn to start a rotation is discussed. Critical parameters such as pasture mass at the end of winter and the use of pasture in early lactation rather than late pregnancy are identified. Spring management is aimed at pasture control. Where conservation is not possible decisions must be made on priority areas for control and areas set aside for deferred grazing. The importance of maximising intake by either fast rotations (< 20 days) or continuous grazing is stressed. Pastures are less stable in spring and winter thus giving the scope for positive (legume dominance) or negative (loss of tiller density) changes. Summer management concerns control in moist areas and feed budgeting with sale of disposal stock in drought areas. The importance of avoiding patch grazing is stressed. Deferred grazing areas can be used from mid-summer onwards especially by cows and calves. Autumn management should aim at pasture recovery consistent with establishing a sustainable winter rotation. Critical factors are the use of feed budgeting, the achievement of liveweight targets and grazing plans to control dietary dependent disorders such as facial eczema.

Previous PageTop Of PageNext Page