By Dr. Donna Amaral-Phillips, UK Dairy Specialist

Alfalfa is a versatile crop that can be planted in pure or mixed stands with cool-season grasses (i.e. orchardgrass/tall fescue) for grazing or harvesting as stored forage. These fields can be harvested for hay when excess pasture exists and re-enter the grazing rotation when the growth of other forages slow. When alfalfa stands are starting to thin, they can be grazed instead of being preserved as hay, which can extend the use of the stand by a year or more. Grazing tolerant varieties have been developed, which can be used for both hay and grazing. The UK Grazing Variety Trials should be consulted when selecting a variety to plant that has improved tolerance toward grazing.

High Quality Grazing

Alfalfa and alfalfa-grass pastures are high quality when grazed at the proper stage of maturity and can support excellent performance. They can be used for grazing higher performance cattle, such as stockers, grass-finished cattle, lactating dairy cows, or as a creep for beef calves. They can support daily gains of 2 lbs or more and have produced on average 790 lbs of beef per acre.

Forage Gap Filler

Alfalfa can be used for grazing throughout most of the grazing season. Cool-season grasses, such as tall fescue, grow best when environmental temperatures are between 70 and 80°F. Whereas, alfalfa grows best when temperatures are between 75 and 90°F or at slightly higher temperatures than cool season grasses. This characteristic extends grazing into the summer. In the fall, alfalfa should not be grazed or harvested between September 15 and a killing frost (or November 1) to allow the plant to store root carbohydrates and improve winter survival. If grazing is needed between Sept. 15 and Nov. 1, alfalfa can be rotationally grazed to maintain a height of at least 6 to 8 inches at the time cattle are moved.

More Drought Tolerant

Alfalfa plants have a deep tap root that allows them access to water stored deeper in the soil than grasses. Thus, they have a higher probability of growing and providing grazing during times of mild drought stress.

More Pounds of Grazable Forage

When compared to cool-season grasses, alfalfa yields more pounds of grazable forage over the grazing season. Tested alfalfa varieties in UK variety trials averaged 5.6 tons per acre, whereas tall fescue averaged 3.5 tons per acre. Thus, established alfalfa stands out-yielded tall fescue by 2.1 tons. To put this another way, an acre of pure alfalfa could support 100 more animal unit grazing days. Thus, incorporating alfalfa into a grazing program can increase the animal-carrying capacity of a farm especially during the summer months.

Graze then Rest - Management Needed

Alfalfa and alfalfa-grass stands need to be rotationally grazed where the forage is grazed beginning at a height of 10 to 16 inches, and cattle are removed when forage is grazed to no shorter than 3 inches. At that time, plants are allowed to regrow without grazing for 25 to 40 days. After this rest period, the plants can be harvested as hay, baleage, or grazed again. This rest period is needed to extend the life of the stand and for optimum plant growth. Regrowth of the alfalfa plant comes from the crown and not the stem of the plant, thus grazing to this height increases utilization of the plant.

Essentially, you want to have small enough paddocks that the animals eat the entire plant (stem and leaves) versus just the top of the plant. Cattle should not graze alfalfa plants longer than 5 to 7 days since new shoots start to develop after this time frame. Also, cattle eat the alfalfa plant from the top down. The top of the plant consists primarily of leaves, which are high in protein with little fiber. The stem is lower in protein and higher in fiber. By restricting the area grazed at one time, cattle will consume the entire plant more uniformly, which helps minimize bloat risk. Thus, cattle grazing alfalfa and alfalfa-grass pastures ideally are rotated at least every 3 days. With dairy cows, cows are moved twice daily to the milking parlor so a new area can easily be provided twice daily. Cross fencing within a paddock can be used to achieve this.

Forage for Creep Grazing

Alfalfa and alfalfa-grass stands can be used to creep graze beef calves. The calves, not cows, are allowed access to the alfalfa or alfalfa-grass area. By allowing access to this high quality forage, gains for calves can be improved. Only a small acreage is needed when using alfalfa for creep grazing.

Incorporate Grasses in Alfalfa Stands

Incorporating grasses in stands of alfalfa can reduce soil erosion, numbers of weeds, hoof damage and bloat. Stands that contain greater than 50% grass have a lower risk for bloat, but pure stands of alfalfa can be grazed with little or no risk for bloat. Management of the cattle is key.

Manage Bloat Risk

Animal management can reduce the risk for bloat. These management practices include, but are not limited to: (1) move cattle to pastures after the morning dew has dried and cattle have grazed in the morning, (2) do not put hungry cattle on pastures, (3) avoid grazing immature alfalfa, (4) do not remove cattle at the first sign of bloat, (5) observe cattle closely, and (6) feed appropriate amount of bloat-reducing compounds, such as poloxalene. For more information on bloat prevention, see UK publication ID-186: Managing Legume-Induced Bloat in Cattle.

Cattle Management to Extend Stand Life

Under wet, muddy weather conditions, cattle should be removed from alfalfa fields to protect the crowns of alfalfa from hoof damage. Cattle should be placed on a sacrifice, grassy lot with a good sod base.

Grazing alfalfa after a hard freeze or November 1 can help decrease alfalfa weevil problems the next spring. The alfalfa weevil lays its eggs on the stems in the fall. By removing the stems through grazing to a height of 2-3 inches, the eggs are removed, decreasing problems next spring. This regrowth often is lower in yield, thus not worthy of harvest as hay under less than ideal weather drying conditions.

Categories: 
Spring
Extending the Grazing Season