Grazing is the action whereby livestock feeds freely on a pasture. There are several ways of managing livestock grazing and feeding, but the main distinction that can be made is between continuous and rotational grazing. Rotational grazing consists of dividing the pastures into smaller paddocks and establishing a rotation over the paddocks.
Rotational grazing is based on two essential principles:
- A rest period which must be respected between two grazing events in order to ensure good plant regeneration. Plant regrowth is slower in summer than in spring. This rest time must be extended accordingly.
- The grazing period must be short with a stocking rate (number of animals per unit area) adapted to the amount of herbage available to avoid overgrazing. Thus residual herbage must after grazing must be high enough, otherwise the regrowth would be considerably slowed down.
Different rotational grazing techniques have been developed. For instance, simplified rotational grazing involves the grazing of animals on a paddock for about ten days while dynamic rotational grazing limits their presence on a paddock to one to two days.
Rotational grazing requires careful management as it is necessary to regularly move the animals to another paddock. The farmer has to pay attention to various indicators of the pasture condition: sward height, number of leaves on the plants, species present, phenological stage, pasture growth and rest time, duration and stocking rate at grazing.
This system makes it possible to reconcile quantity and quality of the pasture production. It ensures a proper utilization of the pastures by limiting losses linked to trampling and refusals. This method does not prevent the mowing of part of the pastures when it is useful.
Rotating grazing is part of an agro-ecological approach by promoting autonomy for animal feeding in the farms while reducing the use of tractors.
References to explore
Dan Undersander; Beth Albert; Dennis Cosgrove; Dennis Johnson; Paul Peterson. 2002. Pastures for profit: A guide to rotational grazing. (A3529). 43p.