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Show Page 6 THE OGDEN VALLEY NEWS Volume II, Issue XV 1 August 2000 Small Pasture Management As more people make Utah their home, more of our large traditional farms are being divided into small acreage home lots. Many of these small acreage owners would like to have verdant green pastures where they can raise horses, calves or sheep. However, many of them lack the experience and training to successfully establish and maintain a healthy grazing system. Grazing is measured in Animal Unit Months, or AUM. One AUM is the amount of forage consumed by a 1000pound animal in one month. On average, 1 horse will consume 1.25 AUM; 1 cow, 1.2 AUM; 1 sheep, .2 AUM; 1 llama, .3 AUM; and 1 goat, .2 AUM. If we compare an animal’s needs with the carrying capacity of a pasture, proper planning practices can be implemented to ensure proper management of pastures. Proper pasture management can increase forage production, cutting costs for supplemental feed for livestock. One acre of irrigated pasture with fertile soil, on average, can maintain 6 to 10 AUM. An irrigated pasture with poor soil, only 3 to 6 AUM. A non-irrigated pasture with fertile soil will sustain 1 to 2 AUM; and a non-irrigated pasture with poor soil, only .5 AUM. Using these parameters, if you have three horses that graze from May through October (6 months) on 10 acres of fertile non-irrigated soil you can determine if you will need to supplement your pasture feed. 3 horses x 1.25 of forage/month x 6 months = 22.4 AUM. Ten acres (fertile non-irrigated soil) x 1 AUM/acre = 10 AUM. In this example, the owner needs 22.4 AUM, but the current carrying capacity of the pasture is only 10 AUM. The pasture will soon become a dust bowl. To prevent overgrazing, the owner needs to buy additional feed or rent additional pasture; increase pasture production, through irrigation and fertilization; improve grazing management; and/or reduce the number of animals utilizing the pasture. Plants receive energy needed for growth from the sun through photosynthesis in their green leaves. The root system is in the dark and totally reliant on the leaves to supply the carbohydrates required for maintenance and growth. When grass plants are continuously grazed short, the root mass decreases to what the leaf area can support. The general rule of thumb is to begin grazing when the pasture grasses are 7 to 8 inches tall and stop grazing when the average height of the pasture is 3 inches tall. Over grazing not only reduces the health and vigor of the plants, causing a decrease in the vegetation regrowth rate due to stunted root growth, it also pre-disposes the pasture to weed invasion. After 50% of a grass plant is removed, as through grazing, root growth begins to stop. At 50% removal, the root growth stops by 2 to 4%; 60% removal, root growth is stopped by 50%; 70% removal, 78% root growth is stopped; 80% of growth removed, 100% of the root growth is stopped. The cool season grasses grown in Utah have a large flush of growth in the spring. This flush can be beneficial in providing the increased nutrient demands of lactating mother animals and their growing young. When this spring flush of growth isn’t used, the grass gets overly mature, animals avoid eating it, and new leaf growth is suppressed. If this happens, the pasture should be mechanically clipped to encourage uniform regrowth of young vigorous grass plants. Animals will seek out the most palatable forage in a pasture. If livestock are allowed to continuously remain in one pasture too long, they will re-graze the succulent regrowth instead of eating more mature plants. This continuous grazing is very hard on plants, using up their root reserves and slowing their future recovery. Rotational grazing involves confining animals in one section of pasture or paddock while the remainder of the pasture “rests.” These paddocks are small enough that all the forage is grazed to a uniform height in a relatively short period of time. The timing of rotations must be adjusted for the growth rate of the forage. However, most irrigated paddocks are ready to be regrazed after three to four weeks of rest. A minimum of four paddocks is necessary to achieve the major advantages of a rotational grazing system. For maximum animal growth, more paddocks will be needed. Be sure to design the system so that animals have access to water in each paddock. Having access to a corral where animals can be fed hay, greatly increases the flexibility of a rotational grazing system. The corral can be used as one or more of the paddocks rotated through, or used to limit the animals grazing to a specific number of hours. For example, some horse owners will let their animals into the pasture for a few hours in the morning and evening. This meets the nutritional needs of most horses and eliminates excessive trampling. Helpful hints: Eliminate continuous season-long grazing. Corral livestock and feed them hay until your pasture grasses are 6” to 8” high. Remove animals when 50% of the available forage has been eaten (3” height remains). Do not regraze until grasses are at least 6” tall (will take 3 to 4 weeks on irrigated pasture). During the winter non-grazing period, hold animals in a corral. Allow long rest periods to rejuvenate pastures in poor condition. Provide a water source for each pasture. Irrigate each pasture immediately after grazing to stimulate regrowth. Avoid hoof compaction on wet soils. Horses do not need continuous access to pasture. Their nutritional needs can be met with only a few hours of grazing on good pasture. Corral animals for the remainder of the day to prevent over grazing of plants and avoid excess trampling of vegetation. On limited acreage, you may have only enough pasture to exercise your animals and will need to feed yearround. Before starting over on a run down pasture, consider invigorating it with improved irrigation, fertilization, weed control, and grazing management. Replanting the pasture area may be necessary. For more information on seed bed preparation, species selection, and planting considerations, contact your local USU county extension agent. In Weber County, contact James Barnhill at 399-8200. Animals on pasture should have access to a windbreak or other shelter to protect them from cold winter winds, hot summer sun, and wet, rainy weather. When introducing livestock to pasture in the spring, it is wise to limit access for a few days to decrease the chances of colic or founder from abrupt change in diet. Begin by turning animals out for two hours the first day. Increase this gradually over a week or two. After this adjustment period, it should be safe for them to remain in pasture full-time. Pastures that contain a large percentage of alfalfa or clover pose an increased risk for bloating animals. Make sure animals are not hungry when they enter these fields, and watch them closely. Owners of any kind of livestock know that animals can affect neighbors. Some fairly general complaints livestock owners receive concern dust, flies, and odors. Dust can be reduced in corrals by periodic wetting. If your pasture is producing dust, it needs serious attention. Flies hatch from maggots that grow in warm, wet manure. The most unpleasant odors also come from wet manure. As a solution, feed dealers have mineral supplements that stop flies from growing in manure. You can also Valley Cleaning Services Spring Cleaning Construction - Residential - Commercial 745-1238 Realtor/Appraiser drag manure to spread it over the field to dry it out. Divert runoff water away from corrals to help keep them dry. Trees and shrubs are an asset in most pasture settings. They work like an evaporative cooler in the summer and are a windbreak in cold weather. They also increase the value of your property. If animals are peeling bark or otherwise damaging trees, consider protecting the trees with a fence. Trees and shrubs protect stream banks and enhance wildlife habitat. If they are removed, the stream is likely to cut into the stream bank on your property. People downstream then have to deal with the sediment that used to be your land. Sediment kills fish and fills canals, lakes and ponds. Having a pasture on a stream can be an advantage, however it carries increased responsibility. Fencing livestock off stream banks allows willows and trees to grow and protect the soil, especially from erosion. You don’t have to find another way to water the stock if you utilize proper fencing. Make a small stream access area with panels or a fence. The access should be small enough to keep animals from wading into the stream. Putting gravel in the access area will provide a firm base to keep animals from disturbing the stream soil. Take a hard look at the lay of your land. When it storms, where does the water go? It is not good stream stewardship to let your runoff carry manure with it because most Utah streams are somebody’s drinking water source. Even people using well water know that often their water source is the ground water from pastures. Spread manure on land that is away from the stream, and manage irrigation water. When grass is well managed, it cleans and filters water and uses the nutrients in the manure for growth. If you have a well-managed pasture, you can actually improve the quality of water for everyone. Utah has a Noxious Weed Law. Landowners are required to make all efforts to control noxious weeds on their property. Control may be achieved through various methods, including the use of chemicals, cutting, burning, and tillage. Weed control requires proper identification. Help with identification of weeds is available through the USU Extension Service at 399-8200, or Natural Resource Conservation Service (NRCS) at 629-0580 extension 27. Note: This information provided courtesy of the USU Extension Service, NRCS, USDA, Farm Service Agency, Utah Soil Conservation Districts, and Bonneville Resource Conservation District (RC&D). |