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Grazing livestock or managing grass?

Dean Oswald Published on 11 November 2009

Generous rainfall in some areas in 2009 has given the potential for great grass growth, but was it managed to yield a high tonnage of quality forage?

Management is the main factor that varies from farm to farm. It makes the difference between high and low grass yield and is critical to the quality of forage offered to livestock.

The key to good animal performance on pasture is forage management. Let’s review a few of the principles of pasture management. Rotational grazing management and forage rest periods are essential for high pasture yields.

Length of the grazing cycle; length of the rest period; forage height at the onset of grazing and stubble residue left at the end of the grazing cycle; number of paddocks, stocking density, water availability, and production goals are all important factors to think about in a pasture grazing program.

Length of the grazing cycle
Grazing periods within a paddock should be relatively short depending upon the species and animal stage of production. Paddock size can be reduced to shorten the grazing period. This improves the harvest efficiency (percent of forage utilized) and the uniformity of grazing a paddock (less selective grazing).

For example, grazing periods might be half-day for dairy cows; one or two days for stocker calves; and six days for mature beef cows. Grazing cycles should be no longer than six days to limit re-grazing and reduced efficiency. Shorter periods also limit the amount of forage wasted due to trampling and treading.

Length of the rest period
Forage rest periods vary some-what depending upon forage species. Grasses need less and legumes more. When attempting to keep legumes such as alfalfa or red clover in a pasture rotation, 30 to 35 days of rest is needed. Grasses may only need 21 days. Legumes add quality and protein to the animal diet.

Forage height in grazing period
Orchard grass and tall fescue may only need to be 8 inches tall when livestock are turned into a paddock. Many producers wait much too long to start grazing and much of the extra production is wasted.

When the stubble or residue reaches 3 to 4 inches, animals should be moved to the next paddock to prevent overgrazing and robbing from the next grazing cycle.

Paddock number and stocking density
Paddocks need to be sized to your grazing cycle. Six paddocks with six-day grazing cycles should achieve at least a 30-day rest period per paddock to maintain legumes in the pasture. Again, stocking density should be high enough to uniformly graze the paddock in the given grazing cycle.

In general, cows, ewes and horses will all consume about 2.5 percent of their bodyweight in forage dry matter every day to meet their nutritional requirements. A 1,000- pound cow will eat about 25 pounds of dry matter or 75 pounds of fresh forage per day.

With continuous grazing, cows will consume about 25 percent of the forage offered and waste 75 percent. Rotational grazing or management intensive grazing can double the volume of forage utilized by grazing livestock.

Water availability
Water should be located within 800 feet of the grazing area to improve grazing efficiency and manure distribution within a paddock.

Grazing goals
1. Produce a large amount of high- quality forage from every pasture.
2. Meet a large portion of the animal’s nutrient needs from pasture.
3. Extend the grazing season to reduce purchased and stored feed cost.  FG

Dean Oswald
Animal Systems Educator
University of Illinois