The mechanics of hay production should begin with a caution to check and service all equipment thoroughly during the weeks before haying season. it is impossible to calculate the tons of hay that have been damaged because of poorly maintained equipment that was not field ready at harvest time.
The goal during the wilting process is to eliminate production should begin with a caution to check and water as quickly as possible. This conserves nutrients by service all equipment thoroughly during the weeks limiting respiration within the forage mass. Generally, before haying season. It is impossible to calculate the grasses wilt much faster than legumes. Some legumes tons of hay that have been damaged because of poorly are notorious for their slow drying rate; for instance, red maintained equipment that was not field ready at clover dries even slower than alfalfa. For this reason, it harvest time. is essential that alfalfa and other legumes be conditioned when they are mowed.
Normally, sickle-bar type mowers with conditioning rollers are used for this purpose. Generally, disc-type mowers are preferred for harvesting bermuda grass and other perennial grasses. Many grasses, such as bermuda grass, dry rapidly, and the conditioning step can often be omitted. When conditioning alfalfa hay, especially with roller-type conditioners, the risk of crushing blister beetles increases. Crushed blister beetles are lethal to horses consuming these forages; however, the stems of alfalfa plants dry so slowly that there is really no alternative to conditioning with either crushing rollers or a tine-type conditioner.
Summer annual grasses such as sudangrass, pearl millet and the sorghum-sudangrass hybrids should always be conditioned to increase the drying rate. In these forages, water can remain trapped in uncrushed stems long after the leaves are dry enough to bale. In contrast, conditioning rollers should be opened to a wide gap or disengaged when harvesting cereal grains with filling grain heads. By the soft-dough stage of growth, most of the nutritive value in these forages is associated with the grain head and not the stover. Therefore, an improperly adjusted conditioner that thrashes grain will greatly reduce the overall quality of the hay or silage.
The various mechanisms used by forages to convert carbon dioxide into sugars and then store these energy compounds to support regrowth after harvest have an important effect on forage management. Generally, plants that store their growth reserves underground, such as alfalfa, are unaffected by cutting height and can be mowed very short. In addition, plants that store growth reserves in stolons or “runners” that lay on the soil surface (bermuda grass and white or ladino clovers) typically are tolerant of close mowing or grazing heights. Many cool-season perennial forages, including smooth bromegrass, orchardgrass and, to a lesser extent, tall fescue, are somewhat sensitive to extremely close mowing heights. These types of plants store their growth reserves in the stem bases. Removal of this part of the plant by mowing too close will limit the regrowth potential of these forages, resulting in thin stands. Leave at least 2 to 3 inches of stubble when harvesting these forages.
Some types of forages require much higher (6- to 8-inch) mowing heights. These forages include sudangrass, pearl millet, sorghum-sudangrass hybrids, johnsongrass and eastern gamagrass. For annuals such as sudangrass, pearl millet and the sorghum-sudangrass hybrids, clipping at shorter heights will slow the regrowth response after harvest. In addition, these forages are notorious for accumulating nitrates when growing conditions are stressful. Typically, nitrates are most likely to accumulate in the highest concentrations in the lower portions of the stem. Maintaining a mowing height of 8 inches or higher will encourage aggressive regrowth and provide some help in reducing the risk of nitrate poisoning. Eastern gamagrass is a warm-season perennial that is extremely sensitive to close mowing heights. It is absolutely essential to leave at least 6 to 8 inches of stubble, measured from the top of the crown, when mowing this forage as a hay or silage crop.
If forages are to be baled as hay, they should be mowed in wide swaths to encourage drying. Dense, narrow windrows will not dry as fast; however, this can be used to slow wilting when alfalfa or other crops, such as cereal grains, are being harvested as silage and maintaining moisture in the windrow is essential. As the yields increase, the drying time required before baling increases regardless of windrow width.
Drying agents, such as sodium and potassium carbonate, that can be sprayed on alfalfa or other legumes at mowing are available. These products can reduce drying time, but the cost must be weighed against the likelihood of rainfall events. Drying agents do not usually enhance the drying time for cool-season grasses. This may occur because the leaf sheath prevents the drying agent from contacting the stem directly.
Unlike most grasses, alfalfa and other legumes should not be raked or tedded when the moisture content falls below 35 to 40 percent.
In addition, these processes should be as gentle as possible. The ground speed of the rake and the general aggressiveness of the raking mechanism should be reduced if leaves are obviously being shattered. Various mechanical process that are improperly managed will greatly encourage leaf and DM losses in alfalfa and most other legume hays.
Grasses and legumes, however, are fundamentally different. In grasses, both the leaf and stem have some structural function; therefore, they are more similar in quality than in legumes. In alfalfa, the function of the stem is almost entirely structural, while the leaf is extremely fragile and contains most of the metabolic machinery of the plant. Therefore, legume leaves are extremely high in nutritive value, relative to the stem tissues that are heavily lignified. In addition, the quality of legume leaves changes only marginally with maturity, but the quality of the stems will decrease rapidly. In contrast, the digestibility of leaves and stems both decrease markedly with maturity in most grasses. Therefore, it is necessary to conserve the extremely fragile leaves of legumes during the haymaking process to maximize the nutritive value of the hay.
Using the proper baler is important when producing quality alfalfa hay. Generally, large round balers should be avoided. Some studies have reported losses of 13 percent of DM and 21 percent of alfalfa leaves with these balers.Conventional rectangular balers or large square balers that use a plunger system do a much better job of conserving leaves. The window of opportunity for baling alfalfa can be very short. Generally, alfalfa hay needs to be wilted to 20 percent moisture to prevent excessive spontaneous heating during storage; however, significant leaf loss will occur with any baler when the moisture content falls below this level. Preservatives are occasionally sprayed onto the forage at the baler in an effort to bale hay that is slightly wet, thereby conserving leaves.
The most common of these preservatives is propionic acid, which can be effective in limiting the undesirable effects of respiration and spontaneous heating. These products generally permit the safe storage of hays that are marginally wet (probably < 30 percent moisture), and should not be viewed as a technique that allows producers to bale excessively wet hay.