Grazing Management: Grazing Management Systems
Excerpt from Publication 19, Pasture Production, Order this publication
Table of Contents
Grazing management should:
The art of grazing management is to ensure that there is sufficient pasture in a stage suitable to graze at all times throughout the grazing season. Several grazing management systems define different methods of harvesting the forage.
In North America continuous grazing means putting a set number of animals out on a pasture and leaving them there for as much of the season as the pasture will support them. The number of animals the pasture can support is determined by the forage yield during the period of poorest pasture productivity, usually July and August. In most cases, the stocking rate needs to be very low or the animals will lose weight during the summer. Individual animals can milk or gain well under this type of grazing management if stocking rates are low enough.
The drawbacks to this type of grazing management are:
Continuous grazing in Great Britain has a different meaning. The animals stay in an area for a long time, but the size of the area available for grazing is constantly adjusted by moving fences. The manager makes a large area available when the forage is slow growing and less area available during periods of fast growth. Surplus pasture is harvested as stored feed. An alternative is to add or subtract animals as determined by pasture productivity. Growth is measured by taking the height of the pasture. If the plants are taller than the target height, more animals are added; if the plants are shorter, animals are taken out.
This form of continuous grazing requires the manager to: check pasture growth daily, have a flexible approach to harvesting the forage, or have additional land for pasturing livestock. This is one form of controlled grazing.
The advantages of controlled grazing are:
Rotational grazing involves fencing a pasture into several small paddocks. Subdivision is a useful way to balance livestock needs with forage supply. Livestock graze the paddocks in sequence, moving to a new paddock when the forage is ready for grazing. In general, put livestock into a paddock when the forage is 2530 cm tall; remove livestock when the pasture is grazed down to 8 cm. A relatively high stocking rate for the size of the paddock forces the animals to be less selective in their grazing and to graze the paddock off evenly. The animals are removed before they start to graze new plant growth and the paddocks are rested.
Dividing the fields allows some of the paddocks to be harvested for hay early in the season. This hay can be fed back if and when the pastures do not produce enough forage for the livestock. When planning the area to be cut, consider how much will be needed to support the livestock until the hay aftermath is ready to be grazed. The later the first cut, the slower the regrowth. This delays putting the cut area back into pasture rotation and puts extra pressure on the grazed area.
Rotational grazing does not necessarily increase daily liveweight gains but does allow a heavier stocking rate to be carried, which increases gains per hectare.
In this system the animals are given just enough pasture to supply 1/2 to 1 days requirements. The fence is moved once or twice daily to provide fresh forage. A second wire can "follow" the animals to prevent movement back onto grazed areas. While this is the most labour intensive method of grazing, it results in the highest quality feed, the least waste and least damage to a pasture.
This is a variation of rotational grazing where the pasture is grazed by 2 groups of animals.
The first group into a paddock are those with the higher nutritional needs. They graze the tops of the plants the most nutritional and are not forced to graze forage of lower quality. The second group, with lower nutrient requirements, graze the forage left by the first group. This system works well where milking cows are the first to graze a paddock, with dry cows or heifers used to clean up the pasture.
Young animals are allowed access to pastures ahead of their dams. This system provides higher weaning weights when forage is limited or where competition between young stock and dams exist. It is easy to establish, using creep gates or installing a division fence high enough in mid to late summer to allow young animals to be first grazers.
This is a form of rotational grazing. Very large numbers of animals graze the paddocks and are left in a paddock until all the forage is grazed down evenly and closely. This approach is normally used to clean up pastures with a lot of coarse, mature plants. Mob grazing can replace clipping.
This approach to grazing management takes advantage of the fact that different types of livestock like to graze different plants. Two or more types of animals graze the paddock at the same time or follow one another through the paddocks. Sheep and cattle make a good combination. Do not graze sheep with horses.
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