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Autumn is here. Our pastures are spent, or nearly so. Our alpacas will soon convert from grass to hay diets. Although you may already have your hay in the barn, it is a good time to take stock of your needs and resources and strategize for purchases later this season or for your supplies and sources next year.
High Quality hay, according to the New Holland Haymaker's Handbook, 1987, edited by Dr. John E. Baylor of the Pennsylvania State University, "…is hay that is high in energy value…that livestock will consume in large amounts…contains an abundance of minerals and vitamins, is leafy, free of foreign material, shows little or no sign of weathering and spoilage losses, and under most conditions has a bright green color."Energy comes from protein, carbohydrate, and fat. Potential caloric energy in hay is measured as TDN (Total Digestible Nutrients) that includes the contributions of each of those sources. TDN is a useful number to compare feeds and to calculate feeding rations but should not be considered an accurate estimate of the caloric absorption or utilization. TDN and protein contents in hay relate to the type or mix of forage plants grown, the fertilization program practiced, the stage of maturity at which they are harvested, the care and mechanics of harvesting, and the method of storage.Grasses, like orchard grass, fescue, bromegrass, timothy, ryegrass, and bluegrass are lower in TDN and protein than are the legumes like alfalfa, trefoil, and clover. In Murray Fowler's Medicine and Surgery of South American Camelids, Second Edition, there is an excellent series of charts on pages 32-34 comparing typical nutrient compositions of usual forage plants.Whatever is grown on the hayfield, protein and TDN levels are higher when properly fertilized. A Texas A&M trial, reported in the Haymaker's Handbook, reported that a crop of coastal Bermuda grass grown with 0 and with 400 pounds Nitrogen per acre increased protein content from 7.9% to 11.7%. Similar effects are seen with appropriate ph management with lime and with potash fertilization. Both protein and TDN decline with advancing maturity of the forage stand. Young, tender shoots are at their highest nutrient value. The bulk of the TDN and protein is in the leaves of the plants. Levels decline slightly as the leaf grows and the flower develops then fall more quickly as the seed-head develops and matures. A leafy grass hay as the flowers begin to form may have about 12% protein compared to 6% when the seed-head is mature and the plant begins to brown. Effective TDN declines roughly 1% with each day past the early bloom stage that harvest is delayed.Whether the hay is first or second crop is less important than stage of maturity. The crop becomes important because of local factors for harvest. In Maine, most crops are in the ideal, early bloom stage in late May when most fields are still too wet to support harvesting equipment. First crop is typically removed in June, possibly one month past the ideal. Second crop, ready in August or September in Maine, is usually harvested closer to the ideal time. Harvesting factors are the next variables to consider. Understanding that most of the nutrition is in the leaves, it is obvious that harvest must protect the leaf both from mechanical losses and from spoilage. Hay needs to be cut, dried, baled, and collected. The crop can suffer TDN losses due to metabolism, weathering, and leaf shattering. When a plant is cut, metabolism continues for a period of time that relates mostly to moisture content. As the plant dries, metabolism slows and stops. Plant metabolism burns the carbohydrates that the plant has been storing and depletes the TDN. The longer it takes the plant to dry, the more metabolism reduces the TDN available for our animals. Losses in worst-case scenarios may amount to 16% of TDN.Rain hitting the cut hay crop is a double-whammy. By delaying the drying process, TDN is further consumed by metabolism. Rain, however, also dissolves and directly leaches or washes nutrients out of the hay. Losses by dissolution and leaching can amount to 10% of TDN.Mechanical losses occur because the highly nutritious leaf becomes more fragile as it dries. With handling, the leaf crumbles and the fragments cannot be contained by the bale and are lost. With vigorous handling, such as is experienced with raking and baling operations, leaf-loss is estimated at 5, 10, and 20% at 50, 30, and 25% moisture levels respectively. Typical raking losses seem to be between 5 and 15%, baler losses are typically 3-8%. Even rough-handling of the bales can account for additional losses.Storage losses are the final handling variable. Storage losses relate to weathering and spoilage. Just like cut hay in the field awaiting collection, hay stored outside is subject to weathering losses by dissolution and leaching of nutrients by the rain. Large round bales, often stored outside, depend on tightly wrapped outer layers to protect inner layers from rain damage. The outer layers of the round bale are sacrificed to protect the inner layers. Losses can be substantial. The outer 6 inches of the typical 6-foot diameter round bale contains 31% of the bale's mass. Thus, spoilage of the outer layers can represent substantial feed losses.In addition, stored hay is subject to spoilage related to moisture, heat, and microorganisms. Microorganisms are generally inactive at moisture contents at or below 15%. At higher moisture contents, metabolism of hay nutrients by microorganisms both consumes nutrients and increases the internal temperature of the bale. As the temperature increases, heat loving molds and fungi are activated, accelerating the metabolic nutrient consumption and further increasing the internal temperature. Nutrients are consumed, proteins become bound in indigestible forms, and hay becomes unpalatable. Above 170 degrees, microorganisms die, but chemical reactions continue to release heat. Spontaneous combustion and fire occurs when internal bale temperatures reach 450 to 550 degrees.We have talked about energy levels in hay, but hay also needs to be palatable to be high quality. Palatability is affected by many of the same factors that affect TDN content. And in most cases serves to magnify the affects. Particularly, plant maturity at time of harvest and spoilage issues are common to both discussions. In addition, texture is a factor.I find that alpacas like leaves. As the hay passes the flower stage and the seed-head develops and matures, the plant develops a tubular stem. I find the stems untouched on the floor and in the feeder. The larger the stem diameter, the more likely it is to be feeding time "leftovers." They tend to consume stems the diameter of angel-hair pasta but leave anything larger. Thus a thirty-pound rectangular bale of mature hay may in reality be fifteen pounds of feed and 15 pounds of barn-floor litter. Likewise, I find that weathered, browned, dusty, or moldy hay more often lands on the floor than adds to the diet.Vitamins and mineral content of the hay relate to the content of the soil on which the hay is grown. An "exhausted" soil, a soil from which generations of crops have been taken without replacement of minerals, will produce hay with low mineral content. Many of these sins can be covered up with judicious applications of the Nitrogen, Phosphorous, and Potassium "macronutrients," but the productivity and health of the stand will not be optimum without a healthy soil content of the mineral "micronutrients." Likewise, alpaca health cannot be optimum without a good supply of micronutrients. If not supplied by the forage, the micronutrients need to be provided by supplements. Supplements are never as comprehensive or palatable as the micronutrients provided by the forage.Test your hay. The Northeast region is served by a forage testing laboratory affiliated with Cornell University. The address is DHI Forage Testing Laboratory, 730 Warren Road, Ithaca, NY 14850, Phone (800)496-3344.If you buy hay, try to develop a relationship with a farmer who takes the hay crop seriously, fertilizing the fields, cutting at the right stage of maturity, giving appropriate attention to moisture levels, handling the hay with expedience, and storing the hay appropriately.For comments or questions, please contact cindy@mtbrookfarm.com
