Sheep producers should use as much forage as is practical to meet the nutritional needs of their sheep, because it will help to reduce their costs for purchased and stored feeds.
Successful grazers must optimize pasture yields and quality while encouraging the persistence of the forage. This can be done via the development of a managed grazing program. This allows the grass producer to work smarter, not harder, while limiting forage waste.
Managed grazing allows shepherds to use a higher stocking density that requires fewer acres. This permits either additional sheep numbers or increased grazing days for the operation.
A series of smaller paddocks are used in which to rotate animals, allowing a forage rest period. Rest periods of 30 days are necessary to maintain legumes in the stand. Legumes (clovers and their relatives) are deeper-rooted than grass and have more summer productivity. They provide nitrogen to the companion grasses, thus adding quality and crude protein to the forage.
Sheep are moved more frequently among the paddocks, based upon forage quality, quantity and flock nutritional needs. The grazing period in each paddock should be short (six days or less). This reduces “spot grazing” and repeated grazing of palatable plants.
For dairy sheep, paddock grazing cycles of 1/2 to 1 day provide very high quality forage.
Finishing lambs on forage requires 1-3 day cycles.
Rams and ewes would have a 4 to 6 day cycle, depending upon nutritional needs.
Weaned lambs might be given access the first few days in a grazing cycle, followed by mature sheep to clean up the lower quality forage.
Good quality pasture increases the grazing or harvest efficiency of forage. Continuous grazing may only capture 25% to 30% of the available forage. Managed grazing may more than double the forage utilized by the sheep.
Animals should be moved to the next paddock when three to four inches of forage stubble remain, which will leave enough grass leaf surface to assist photosynthesis (for faster plant regrowth) and will prevent overgrazing.
Managed grazing fosters a closer contact between flockmaster and sheep and therefore, better flock management.
Managed grazing can be a sustainable, size-neutral technology, usable whether you have five ewes or 500 in the flock.
Identify water availability in each paddock. Research suggests the need for water within 800 ft. of grazing animals for best pasture utilization and waste recycling. Provide at least 2.5 gallons of water per ewe and her lambs daily.
Evaluate existing forages and browse areas. Then inter-seed the thin spots. This avoids destroying good root mass.
Identify paddocks that could be used for haythose with easy equipment access. Consider harvesting 20% of your paddocks for first-cutting hay to be fed during winter shortages or rainy periods on newer pastures. This will keep forages more vegetative (higher quality). Such paddocks can be brought into the grazing rotation later in the season, when there is a natural slump of forage production (hotter, drier weather).
Drawbacks of Managed Grazing
Soil compaction. This concern can be reduced by having an all-weather paddock or “sacrifice paddock” to move sheep into during wet, thawing or muddy periods.
There is a perception of an increased labor demand. After the system is set up the labor demand is actually reduced.
Initial investments in fencing and water systems may limit adoption by some producers.
Increased grazing management requires improved management skills of the operator.
Lambs and sheep prefer the type of tender new growth that keeps their noses up away from the ground, reducing parasite loads while getting the richest young forage. [Photo ©2008 by Eva Griffith]
Extending the Grazing Season
Each day sheep graze and harvest forages they require less purchased feed and hay.
Sheep producers should therefore use crop residues, annual forages, brassica crops (turnips, rape and kale), and stockpiled cool-season forages to maximize grazing days.
Corn crop residues can provide grain and forage for sheep. Vaccinate ewes or lambs for overeating disease two weeks before turnout. Strip or rotational grazing can reduce the amount of corn offered and improve residue quality. Grazing cornfields can help to reduce volunteer corn in following soybean crops. Protein and mineral supplementation may be required.
Annual cereal crops like oats, wheat or rye can be seeded to supplement spring, summer or fall grazing. They may be aerial seeded into standing corn in mid-August, which can greatly improve grazing quality of corn residue. Oats may be the more cost effective option because oats have more fall growth and will winter kill in December.
Sorghum, Sudan grass and their hybrids are warm-season annual crops that can provide grazing during the summer slump of cool-season grasses, or they may be used when stockpiling forages. However, early grazing (less than 24 inches tall) or following frost may lead to prussic acid poisoning.
Pearl milleta leafier warm-season grasscan be grazed earlier than the sorghums and has no prussic acid potential, but it yields less.
Brassica crops like turnip, rape, kale and their hybrids can be used to extend the grazing season. These may be planted early in the spring (April) or in July following wheat or oat harvest, depending upon forage needs. Brassicas are very high quality and are similar to feeding grain. They should therefore be planted with a fiber source like oatsor fed with hayto reduce digestive problems. Strip-graze brassicas to reduce waste.
Stockpiling Cool-Season Forages
Start “stockpiling” one or more paddocks 70 to 75 days before a killing frost.
Start with three to four inches of growth, applying 50 lbs. of nitrogen per acre. This should provide about one ton of forage dry matter per acre.
Stockpiled pasture should be strip-grazed in order to reduce trampling and waste.
Tall fescue is an excellent species for stockpiling, because it can be grazed until spring if you have enough acreage. Sheep will graze through six inches of snow, though they can be limited by ice.
Under most farm circumstances a forage grazing plan will require several years to implement.
Fencing is a key factor in organizing a sheep operation. It is necessary for animal control, predator reduction and makes a managed grazing system work. Adequate fencing should be employed early in the planning process.
Problem weeds should be controlled early in a managed-grazing venture, in order to reduce competition with grazing plants and before adding legumes or forbs to the pasture mix. Control could be mechanical, chemical or a combination depending upon the type of weed or brush.
Don’t let soil fertility limit your pasture productivity. Test to determine soil alkalinity or acidity (pH), and availability of phosphorus (P) and potassium (K). A nearly neutral pH is necessary when establishing legumes.
Small-seeded grasses (Orchardgrass or smaller seeds) or legumes like red or white clover can be frost-seeded by broadcasting seed in mid-February. Freezing and thawing of the soil surface is critical to provide seed soil contact and success.
Happy grazing in 2010!