Grazing Management

Grazing management will help to increase productivity, lower costs and contribute to the health and value of the land. Over grazed land will produce less forage and contribute to poor health in livestock. Establishing an effective grazing management plan will benefit the producer, the animals and the environment. The small acreage land owner should strongly consider an intensive grazing, pasture rotation program in order to maximize forage production.

Grazing Management and Livestock Health

In Oregon, where we are located, livestock are usually grazed April through October during the plants growing season and fed hay November through March. Times will vary according to the specific area.

Forage is what ones animals consume by grazing. Forage production is measured in animal unit months (AUMs). One AUM is equivalent to the amount of forage consumed by a 1000-pound animal in one month, or approximately 26 pounds of forage per animal per day.

Feed is the hay provided an animal when forage is not available. Hay production is measured in tons per acre.

How much feed and forage do animals need yearly? Average requirements are listed here, but may vary with season, level of use and the age and size of the animal.

To determine how much feed and forage your land can produce, read about Pasture and Irrigation Management.

To find out if your forage requirements balance with your land, you can do your own calculations following these examples:

• Feed requirement - 3 horses X .5tons/month X 6 months = 9 tons of hay
• Feed production - 10 acres (fertile non-irrigated soil) X 1 ton/acre = 10 tons of hay
• Forage requirement - 3 horses X 1.25 AUMs/month X 6 months = 22.5 AUMs
• Forage production - 10 acres (fertile non-irrigated soil) X 1 AUM/acre = 10AUMs

In this example, the land will produce enough hay to feed the animals for 6 months. however, there is not enough forge (grazing) to meet the animals' needs. To avoid overgrazing the pastures each year you must:

• Buy additional feed or rent pasture
• Increase the pasture production
• Improve the grazing management
• Reduce the number of animals

Overgrazing occurs when more than 50 percent of the grass plant is removed at once. Overgrazing stops root growth and reduces grass production. This table shows what happens when you try to sneak in another 10 percent harvest. 50 percent of the roots stop growing! Beyond that and the damage increases rapidly. Production from a pasture damaged by overgrazing is seriously diminished. A pasture in poor condition causes:

• Colic and respiratory problems from eating dirt
• Weight loss
• Parasites
• Poor coat
• Polluted runoff
• Lost wildlife habitat

Grazing Management Produces More Grass

Continuous grazing allows weeds to grow where grass roots have been weakened. A less dense leaf canopy allows sunlight to reach invading weeds. Pasture rotation and good grazing management produces more grass, fewer weeds, and a minimum amount of bare ground.

For a successful grazing program:

• Eliminate continuous season-long grazing
• Subdivide large pastures into smaller pastures and develop a pasture-rotation grazing system
• Corral livestock and feed them hay until the pasture grasses are 6 to 8 inches high. Move livestock when 3 to 4 inches remains. Do not re-graze until grasses are at least 6 inches high (1 to 3 months)
• During winter months hold animals in a corral to avoid compacting saturated soils. If soils are well-drained and pasture is actively growing, continue the rotation to distribute manure and feed wastes evenly across the pastures
• Allow long rest periods or use a high-intensity, short-duration grazing system to rejuvenate poor-condition pasture
• Provide a water source for each pasture
• Irrigate each pasture (if you have irrigation) immediately after grazing to get plants growing again. Do not graze on wet soils
• Horses do not need 24-hour access to feed or forage. Their nutrition needs can be met with only a few hours of grazing on good pasture each day. Corral animals for the remainder of the day to prevent overgrazing of plants and extend the forage available in the pastures.