Articles on forages, animals, and grazing systems
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Master Grazer Coordinator
821B W.P. Garrigus Building
University of Kentucky
Extension Forage Specialist
University of Kentucky
Phone: (859) 257-3358
Fax: (859) 323-1952
This article has been updated by June 2014 - Grazing Alfalfa
Alfalfa is one of the primary forage crops grown in the U.S. This high quality forage produces high yields that can be used for hay, silage, or pasture. This versatile crop can tolerate a wide range of soil and climatic conditions and has the beneficial nitrogen-fixing abilities of other leguminous species. Because of its nutritive value, alfalfa can be a useful forage for animals with high nutrient needs. Alfalfa is valuable for summer grazing when cool-season grasses are suffering from “summer slump” and growth rates have slowed. Although alfalfa is a cool-season legume, its deep root system makes it more drought tolerant than other cool-season species.
Although alfalfa is commonly harvested for use as a stored feed, grazing this forage can be an effective way to feed animals while reducing feeding costs. Grazing this crop can lower the use and cost of machinery and equipment. Grazing can also increase soil fertility and may lower fertilizer expenses when used in a stand mixed with grasses. When cutting for hay or silage, a large portion of plant and soil nutrients are removed from the field. However, over 80 percent of the nutrients are returned to the soil as manure and urine when pastures are grazed. Taking steps to promote good manure distribution will increase benefits of nutrient return. Alfalfa stands can be used strictly for grazing or can be used for both hay and grazing. Research has shown that if managed correctly, using a system where a stand is used for both grazing and hay does not reduce total yield. If alfalfa is grazed in the early spring and then allowed a rest and regrowth period, the crop can then be cut for hay when weather conditions are more favorable. Often older hay fields which have become undesirable for hay production because stands are thinning or have become weedy are used for grazing to extend the use of the stand.
To maximize yield, quality, and stand life, alfalfa should be grazed using a rotational grazing method. Giving this crop a rest period and time for regrowth is vital to keep a healthy stand. If grazed continuously or not given an adequate rest period, stands will decline and weed and other plant populations will increase. To protect new shoots, animals should not be kept on one paddock for more than one week and the stand should be allowed four to six weeks of regrowth time before grazing. As with any forage crop, alfalfa stands need to be well established before grazing and should not be overgrazed. Begin grazing when plants are in the bud stage and move animals to a new area when there is two to three inches remaining. Alfalfa should be grazed down to a height so that regrowth will occur from the crown and not the stems.
There are few possible detriments of feeding alfalfa. First, there is a potential for bloat. If certain precautions are taken, this risk can be greatly decreased. Second, the crowns of alfalfa can be damaged by hoof traffic when pastures are wet. To protect the stand, it is suggested that animals be removed from alfalfa stands under muddy conditions. For more information on reducing the risk of bloat, see Managing Legume-Induced Bloat in Cattle (ID-186).
Grazing alfalfa can help reduce machinery and equipment costs and may also reduce fertilizer expenses. This high-yielding, high quality crop is tolerant of a wide range of soil and climatic conditions. Its increased drought tolerant makes for good grazing in the warm summer months in comparison to other cool-season grasses and legumes. Alfalfa is one of the most important forage species not only in Kentucky, but in the United States. For more information see Grazing Alfalfa (ID-97).