Alfalfa Grazing Management
Rotational grazing is a "must" for optimum returns in an alfalfa or alfalfa-grass grazing system. Rotational grazing is more labor intensive than continuous grazing because of the need to provide and maintain electric fencing and to move animals from one paddock to another on a carefully planned and executed schedule. Care also must be given to avoid damaging the alfalfa stand, because comparatively high numbers of animals graze on a relatively small area of alfalfa. However, the rewards can offset the extra effort.
There is no set rule on number of paddocks required or on paddock size. Most recommendations call for fields to be divided into a minimum of six to eight paddocks for most effective management. Paddock size depends on the number and size of animals being grazed. However, there should be enough animals in a paddock to harvest the available forage in less than four days.
As an example of a rotational grazing practice, a recent demonstration successfully grazing 24-beef cattle on a four-acre alfalfa plot. The field was subdivided into eight half-acre paddocks. After four days grazing on each paddock, the cattle were rotated. After all eight paddocks had been grazed, cattle were returned to the first paddock, which had recovered and was ready for another round of grazing.
Determining the number of animals that each acre of alfalfa will support in a grazing system is a difficult process. The number of animals per acre can be increased as alfalfa becomes more productive beyond the first year of stand life and as the management skills of the farm operator improve. A conservative suggested is 2 to 3 dairy cows or 3 to 5 stockers per acre during the early part of the grazing season.
The number of animals per acre is normally reduced when alfalfa production declines, such as during the typical mid-summer slump period. It is very important to closely monitor grazing to prevent overgrazing. Overgrazing can force animals to consume more supplement, if one is supplied, increasing production costs. Overgrazing also may force animals to eat the basal stems which are not very nutritious, thus limiting animal gain. Severe overgrazing also could damage the crowns of the alfalfa plants.
Undergrazing, on the other hand, can lead to uneven grazing. When unevenly grazed, the remaining plants become larger and less palatable. When the field is grazed again, the animals once more will favor the young tender plants. This in effect reduces the productive acreage unless the older, larger plants are clipped periodically.
One or more "sacrifice" paddocks also enhance a grazing program where alfalfa is the main forage. A sacrifice paddock is an area, preferably with grass sod, that can be used to hold animals during wet weather or to allow adequate regrowth of the alfalfa paddocks. Hay may be fed in sacrifice paddocks to keep pasture growing at an optimum rate.