North Dakota State University
Marc Bauer-Animal Sciences Department
Greg Lardy- Animal Sciences Department
Kendall Swanson-Animal Sciences Department
Steve Zwinger- Carrington Research Extension Center
* This article is taken from the link above and selectively published with the permission of North Dakota State University.
This publication provides information on the nutritional value of barley as feed for livestock when harvested as grain or forage. Guidelines on feeding and processing methods, as well as comparative research data on animal performance, are included.
ENERGY AND PROTEIN CONTENT OF FEED BARLEY
Barley grain is used primarily as an energy and protein source in beef cattle diets. The nutrient content of barley (Table 1) compares favorably with that of corn, oats, wheat, sorghum and field peas. The energy content of barley is slightly lower than the energy value of corn, wheat and sorghum, partially due to its higher fiber content (neutral detergent fiber, or NDF, and acid detergent fiber, or ADF). The crude protein content of barley is higher than in corn and similar to wheat and oats, but lower than in field peas.
MINERAL CONTENT OF FEED BARLEY
All cereal grains are low in calcium and relatively high in phosphorus (Table 2), necessitating the use of supplemental calcium in high-grain diets for beef cattle. The phosphorus content of barley is similar to that of other cereal grains. Barley is higher in potassium than corn, wheat or sorghum.
EFFECT OF BARLEY VARIETIES ON NUTRITIONAL VALUE
Barley varieties generally are classified as two-row or six-row, malting or feed type, covered or hull-less, and floury or waxy starch. Two-row varieties generally produce plumper kernels and higher test weights that are higher in starch than six-row varieties; however, average nutrient composition is generally only slightly different.
Two-row barley generally is more adapted to dry growing conditions. Several studies comparing two- and six-row barley varieties have not provided any clear-cut advantage for feeding.
High protein content is desirable in feed varieties. Hull-less barley has lower fiber and higher protein and energy levels than covered barley.
Growing conditions and cultural practices may have a much larger effect on nutrient content and animal performance than varietal differences. Variation in weather in barley-growing regions, year effect, soil fertility, pest management and harvest proficiency can affect barley grain quality significantly.
Bushel weight or other quality characteristics may be more useful in assessing feeding value than relying on variety alone. While opportunities exist for increasing the feeding value of barley through varietal selection, differences in feed value due to agronomic choices and growing conditions also pertain.
PROCESSING BARLEY GRAIN FOR BEEF CATTLE
A number of studies have investigated whole barley vs. processed barley for beef cattle. In general, animal performance with processed barley was greater than when whole barley was fed.
Whole barley fed to beef steers averaged 52.5 percent digestibility, while dry-rolled barley was digested at 85.2 percent (Toland, 1976). In this study, 48.2 percent of whole-barley kernels were recovered in the feces.
Barley has a fibrous hull, necessitating some form of processing for optimum utilization. Whole barley kernels are relatively undamaged during mastication, compared with corn (Beauchemin et al., 1994). This emphasizes the need for mechanical processing if beef cattle are to use barley effectively.
Dry-rolling is the most common and least expensive processing method. Barley should be crushed or cracked so each kernel is broken into two or three pieces. A single-stage roller mill with 10 to 12 grooves per inch works better than a roller with six to eight grooves (commonly used for processing corn or peas).
Hammer milling barley is not recommended for feedlot cattle, but if it is the only processing method available, a large screen and slow rotor speed will reduce the amount of fines. The grain should not be finely ground but rolled coarsely, with a particle size not less than about 3,000 microns.
Barley ferments rapidly in the rumen (Figure 1), compared with some other grains, and fine grinding accelerates this process. Small particle size increases the surface area exposed and rate of fermentation, increasing the potential for (subacute) acidosis, founder and poor feed conversions.
Feed additives such as ionophores and some yeast products help maintain a stable rumen environment, but proper grain processing, mixing of the ration and inclusion of some other fiber in the rations are critical for stable intake and digestion.
Variation in kernel size makes precise processing more difficult. In some cases, light and heavy barley may be blended to make a certain bushel weight grade prior to sale. For instance, barley weighing 50 pounds per bushel (lbs/bu) and 40 lbs/bu may be blended to produce barley weighing 45 lbs/bu. Processing separate lots prior to mixing and feeding will improve the consistency of the feed.
Tempering involves adding water to barley and allowing it to soak for 12 to 24 hours to increase the moisture level prior to rolling. The target moisture content is 18 to 20 percent. Higher-moisture barley rolls more easily, resulting in more of a flaked product than dry, hard pieces of barley kernels. The advantages of tempering include fewer fines produced during the rolling process and improved ration acceptability.
Rolling tempered barley required 11.3 percent less energy than rolling dry barley (Combs and Hinman, 1985). Tempering and rolling barley increased intake and gain vs. dry rolling in some studies and improved efficiency in other trials (Hinman and Combs, 1983; Combs and Hinman, 1989; Wang et al., 2003). Decreasing the flake thickness of tempered rolled barley increased the digestibility of starch (Beauchemin et al., 2001).
Harvesting High-moisture Barley
High-moisture barley grain can be harvested up to 12 days sooner than dry barley with up to 16.7 percent more yield due to reduced field losses (Alberta Agriculture and Forestry, 2008). Moisture at harvest should be 25 to 30 percent, with higher moisture levels possible, but kernel fill may not be complete.
High-moisture grain must be processed immediately and stored as one would silage. Appropriate preparations for high-volume processing and storage are needed to facilitate rolling or grinding and storage of grain being harvested. Bunker or upright silos or large plastic bags are useful for this purpose.
Properly processed and stored high-moisture barley will ensile and become brownish yellow, giving off a distinctive fermented malt-alcohol odor. High-moisture barley feeds as well as dry barley, with the advantages of extra yield and the grain is already processed for feeding. Visit the Alberta Agriculture and Forestry website at http://www1.agric.gov.ab.ca/$department/ deptdocs.nsf/all/agdex101 for more information on storing high-moisture barley.
Barley starch may act as a binder in manufactured pellets but the optimum level of inclusion has not been determined. Pelleting barley in combination with other ingredients may work in modest-energy growing diets; however, dry-rolled barley supported improved performance better than pelleted barley in finishing trials (Williams et al., 2008).
No advantages in average daily gain, feed intake and feed efficiency were observed when steam-rolling (or flaking) was compared with dry rolling or temper rolling barley in feedlot diets. While marbling scores increased for steers fed steam-rolled barley (Hinman and Combs, 1984), other trials have reported mixed results for carcass quality (Grimson et al., 1987; Zinn, 1993; and Engstrom et al., 1992).
BARLEY AS FORAGE
Barley is a cool-season crop that can be planted early into cool soils. Barley is a very competitive plant that matures quickly and can be harvested for forage in approximately 58 to 65 days. Given the short growing season, barley could be planted in some environments for double cropping.
The seed cost for barley is low, and seed can be saved from most varieties for reseeding. Some specific barley varieties have been developed for annual forage, and seed often is available commercially.
Barley varieties developed for forage are generally awnless and can be harvested at a later stage of maturity (milk-soft dough stage), compared with grain varieties. Forage barley varieties can be two-row or six-row types. Rosser et al. (2016) noted that the digestibility of whole-crop barley silage decreased as the stage of maturity progressed from hard dough to ripening.
Awned varieties developed for grain production can be used for forage, although they need to be harvested shortly after heading to avoid mature awns, which can be irritating to the mouth of cattle.
Barley can be grown as a monoculture or planted with peas to produce forage with increased protein and greater yield. Trials at various university and seed company plot sites around the region provide localized forage yields and quality information.
Forage barley or barley-pea mixtures can be harvested and stored as haylage if the crop is wilted to 40 to 60 percent moisture. See the NDSU Extension publication “Haylage and Other Fermented Forages” (http://tinyurl. com/Haylage-OtherFermentedForages) for more information on haylage harvest and storage guidelines.
Forage or grain varieties of barley may be harvested as whole-crop silage or as “head chop,” in which the top of the plant or head is cut and allowed to cure to proper moisture, then chopped and stored as silage. Forage barley or mixed barley-pea stands can be harvested as dry hay as well.
The stage of maturity at harvest will make a significant difference on the quality of the forage. Harvesting at heading to milk stage is recommended for optimum quality, although the soft dough stage may yield slightly more forage and still provide reasonably good quality. The addition of peas allows the forage mix to be harvested at a later stage to increase yield while still maintaining high-quality forage.
Barley or barley pea mixtures harvested as hay or silage can be used as forage in feedlot rations as well as in beef cow diets. Barley straw may be used as forage when properly supplemented, but awns are a concern.
Barley grain is a useful feedstuff for several different classes of beef cattle. When properly processed, mixed and fed, barley is an excellent feed grain. It can be used in growing and finishing diets for feedlot cattle, as supplement in forage rations for replacement heifers, and as an energy and protein source for gestating and lactating beef cows. Research indicates beef cattle are less affected by DON than monogastric animals.
Barley processing requires careful attention to maximize digestion efficiency and maintain stable rumen function. Thorough mixing of rations and good bunk management are essential with barley rations, as with other grains.
This article is taken from the link above and selecyively published with the permission of North Dakota State University.