Grazing Management

Table 1. Overview of Grazing Considerations and Capacity in Common Perennial Forages Grown in Georgia.

¹ Anticipated yield, energy, and protein are based on estimates from literature. Actual results on your farm will vary with management, inputs, and weather. 

Principles of Good Grazing Management

Maintain Sufficient Residual Forage

Residual forage is critically important to the forage’s resiliency and regrowth rate. Residual forage refers to the stubble that is left behind after the animals have grazed the pasture. This material is needed for photosynthesis after the defoliation (grazing) event.

Allow Pastures Time for Rest

Rest is critical for stand longevity. Generally, forages require time (rest) between defoliation events to restore root carbohydrate levels that may be depleted as the plant initiates regrowth following the grazing event to allow for long term plant persistence and stand survival of perennial forages. Even though perennial forages can persist under continuous management, proper rest will help the stand survive indefinitely.

Practice Rotational Grazing

The best way to ensure adequate residual forage and protect rest periods is by implementing rotational grazing. Rotational grazing refers to practice of moving a group of livestock between two or more pastures. This practice may also be referred to as management intensive grazing, strategic grazing, or rational grazing. For more information on rotational grazing, please visit UGA Extension Bulletin B1568, Understanding Stocking Rate in Pasture Systems.

Monitor Forage Availability

Successful forage producers monitor forage availability and use this information to guide their grazing decisions. The fastest and most cost-effective way to measure forage availability is by using a grazing stick or ruler to measure average forage height. This value can be used to calculate an estimate of forage availability and length of time to graze the pasture. For more information determining forage availability, please visit UGA Extension Bulletin B1567, How to Use a Grazing Stick.

Match Stocking Rate to Forage Availability

Stocking rate decisions should be made based on forage availability. Stocking rate refers to the number of animals being grazed within a given system over a defined period. Stocking too high leads to shorter rest periods and overgrazed forage thus increasing the need for supplementation. Stocking too low can result in under grazing, thus overmature forage with declining quality. For more information on matching stocking rates to available forage, please visit UGA Extension Bulletin B1568, Understanding Stocking Rate in Pasture Systems.

Know When to Stop Grazing

Great grazing managers know when to STOP grazing. There may be periods of drought that limit forage growth or excessive rainfall that restricts access to certain parts of the farm. Instead of overgrazing or creating mud issues and tracks in the pasture during these times, restrict the animals to a designated “sacrifice lot”. This refers to an area where animals may be comfortably contained and supplemented with hay and/or grain until the grazing situation improves. The sacrifice area will preferably in need of renovation in the near future. Using this practice, you can protect the majority of your acres during these weather challenges. 

Special Considerations for Grazing Perennial Forages

General Considerations

Beef Cattle

The nutritive value of perennial grass forage can be adequate for mature dry cows. However, it cannot meet nutrient requirements of lactating cows, replacement heifers, weaned calves, or stocker yearlings. Because these forages can be deficient in both crude protein and energy to meet nutritional requirements of such classes of beef cattle, supplementation is needed to maximize animal performance and reach a desired level of production.

A simple supplementation strategy can be a mixture of an energy and protein supplement. A few examples of energy sources are soybean hulls, molasses, citrus pulp, and whole or cracked corn. For protein sources, dried distiller’s grains, corn gluten feed, cottonseed meal, and soybean meal are all good options. Whole cottonseeds can also be a good source of both energy and protein. The choice on what to use will depend on what is available in the area and cost per pound of nutrient provided by each source.

Sheep and Goats

Perennial forages in a vegetative stage of growth will likely meet the nutritional requirements of many classes of sheep and goats. However, late gestation or lactating females and young growing animals will most likely need energy and protein supplementation to meet their nutritional requirements.

Goats prefer browse or woody species that usually grow at or above their shoulder height. Though they will browse, sheep prefer grasses and forbs (weedy plants). If allowed to graze low to the ground, sheep and goats are more likely to encounter infective intestinal parasite larvae [i.e. Barberpole worm (Haemonchus contortus)]. This infection can result in high mortality rates for both sheep and goats but can be prevented by maintaining a good stubble height.

Horses

While perennial forages vary in their quality, they tend to push the limits of acceptable fiber quality and digestibility for equine diets. These forages may meet the nutritional needs of mature non-working or light-working horses but typically require supplementation with another energy source for mature horses in moderate to heavy work, and it requires supplementation of energy and protein for growing horses and pregnant or lactating mares. Trace mineral and salt supplementation is recommended for all classifications of horses consuming perennial grass pasture.

Specific Considerations

Tall Fescue Toxicosis

Tall fescue toxicosis negatively impacts production in livestock and equine operations. These symptoms will appear when animals are grazing any wild-type fescue or Kentucky 31. If you need more information on the tall fescue endophyte, please review the Oregon Seed publication on Understanding the Tall Fescue Endophyte: Practical Solutions to the Fescue Toxicity Problem.

Grazing novel endophyte tall fescue is the best way to alleviate symptoms in grazing livestock associated with fescue toxicosis. Renovation of these fields will take time, so you may need to consider diluting the effects of the toxic endophyte until renovation is complete. These options include:

• Interseed perennial clovers
• Incorporate rotational grazing to avoid grazing overmature forage with seedheads
• Avoid grazing below 4 inches
• Feed non-toxic hay or graze non-toxic pastures

Eye Irritation from Bahiagrass Seedheads

At times, seed heads from bahiagrass may be blamed for pinkeye in beef cattle but the disease is primarily caused by bacterial infection of the surface of the eyeball and the inner surface of the lids. Contrary to popular belief, the presence of seed heads on tall stems does not cause pinkeye by itself, as the causative bacteria must be present. They can still cause some eye irritation in grazing cattle.

Options for Extending the Grazing Season with Annuals

Options in Warm-Season Perennial Systems

Since bermudagrass is a warm season forage, there will be a gap in forage production from approximately November to April each year. Livestock will need to be supplemented during this period with stored forages or supplementation if cool season grazing is not available.

Winter annuals can be interseeded into established bermudagrass pastures or hayfields to extend the growing season. The dense bahiagrass sod can make overseeding or interseeding winter annual forages a challenge because of poor seed to soil contact. Furthermore, bahiagrass often stays green later in the year compared to bermudagrass, so winter annuals may not be able to outcompete the existing stand.

There are many cool season annual forages available for use in Georgia. Please check out the species lists and establishment guidelines at the top of the page. For more detailed planting information, please review UGA Extension Bulletin B1584, Planting and Growing Annual Forages in Georgia.

Options in Cool-Season Perennial Systems

Since tall fescue is a cool season forage, there will be a gap in forage production from approximately June to September each year. Livestock will need to be supplemented during this period with stored forages or supplementation if other grazing is not available.

It is risky to overseed tall fescue with summer annual grasses since the fescue stand may not go summer dormant. Therefore, we recommend planting summer annuals in a separate pasture or use them as part of your tall fescue renovation plan. Although economics are not addressed here, summer annuals are nearly always a more cost-effective option compared to hay or grain.

There are several warm season annual forages available for use in Georgia. Please check out the species lists and establishment guidelines at the top of the page. For more detailed planting information, please review UGA Extension Bulletin B1584, Planting and Growing Annual Forages in Georgia.

Options for Improving Grazing with Legumes

Legumes offer many benefits to grazing systems including improved forage quality, species diversity, and biological N fixation. Integrating legumes into perennial grass systems have shown success because the legumes can complement the seasonal growth, production characteristics, and management requirements of these grasses. Integrated grass-legume systems are more efficient than total renovations to a new monoculture because they do not require removal of the grass prior to planting the legume. Further, the addition of legumes decreases the need for N fertilizer, increases the forage quality, decreases financial risks, and extends the forage production season.

Recommended Species

The forage legumes that are typically used in Georgia are annual clovers and white clover. Alfalfa is one of the primary perennial legumes that has been successfully interseeded into bermudagrass. Specific species and varieties may be found under the forage species tab at the top of the page.

Considerations Before Planting a Legume

Answer the questions below to determine if your field is suitable for planting this season. You may need to delay planting until next fall.

1. s it the right time of year to plant the annual crop or legume?
2. Is the soil pH near neutral?
3. Are there fertility deficits that need to be addressed?
4. Has a pre-emergent herbicide been applied within the last two years?
5. When was the last time a grass or broadleaf herbicide was applied? What is their plant back interval?
6. Has your pasture entered dormancy?
7. Are you willing to use a non-selective herbicide to induce chemical dormancy if applicable?
8. Are you willing to fertilize the legume?