Shortages of home-grown forages on dairy farms can occur because of drought or other adverse conditions. Questions that arise are: "What should be done now?," "Should forage intakes be kept at a minimum?," "Should hay or other forage be purchased?," and "Should roughages or high-fiber feedstuffs be used?." The economics of the situation, including effects on cash flow and interest charges, should receive top priority. In addition, potential feed ingredient sources should be considered based on their palatability and suitability for use in the feeding system.
One of the first things a producer can assess is the condition and yield potential of the crop. Weather stressed crops, like corn and soybeans, can make nutritious silages even if they have been drought-stricken. Whenever possible, drought-stricken corn should be allowed to reach as much maturity (days from planting) as possible. The moisture content of the whole plant material should not drop below 60 to 63%. The plant will increase in sugar and energy content even if no kernels formed due to lack of pollination.
Soybeans can make an acceptable forage source. As with corn, drought-stricken soybeans should be allowed to mature as much as possible before ensiling. Some pod or bean development enhances their feeding value. The plant should be ensiled before it drops below 65% moisture. Soybean silage will approach the nutrient content value of a mixed mainly legume silage (average analysis), but it may not be as palatable. If soybeans are high in moisture and lack pod or bean development, add 100 to 200 pounds of ground grain per ton when direct-cutting, rather than wilting to 65 to 70% moisture. This will dry the crop and add a fermentable carbohydrate source for better silage preservation.
Emergency forage crops such as small grains can be planted in late fall and early spring to use as supplemental forage. Spring oats can be used for fall grazing or silage. They can be planted during August and early September. Winter grains can be used for forage in the fall (grazing) or the following spring (grazing or silage).
Normal harvest dates (boot to head emerged stages) are rye in late April, barley in early May, wheat in mid May, and triticale in mid to late May.
Producers should evaluate their on-farm inventory to estimate the extent to which forages may be short. If considerable amounts of forages need to be purchased to meet minimum forage intake levels, then forage feeding rates should be reduced to near safe minimum levels as soon as possible. Check costs and supplies of various quality hays, roughages, and high-fiber feeds.
If it is determined that forages will be in short supply, then feeding limited amounts of forage is an alternative. However, a minimum of forage dry matter intake is needed to keep cows healthy and the milk composition normal. At least 40% or more of the total dry matter intake should be in the form of forages. When forage intake is held at minimum levels, high-fiber concentrate ingredients and some roughages may be needed to maintain the fiber content of the ration.
Recommended guidelines on forage neutral detergent fiber (NDF) intake and total NDF intake should be followed (Table 1). Forage dry matter intakes in conventionally fed herds should be at least 1.40 to 1.60% of body weight daily. Forage dry matter intake should be at least 1.20% of body weight daily for heifers.
Table 1. Neutral detergent fiber (NDF) intake levels from forages.
|Forage NDF, as % body weight||NDF intake level|
|aA higher minimum may be necessary if forage is chopped too finely.|
|0.75a||Minimum if ration provides 1.3 to 1.4% total NDF by use of byproduct ingredients.|
|0.85a||Minimum if ration provides 1.1 to 1.2% total NDF by heavy use of grains or starch ingredients.|
|0.95||Average. Example: 1300 lb cow x 0.0095 = 12.35 lbs forage NDF|
When forage inventory reveals shortages and feeding alternatives are being evaluated, don't overlook least cost ration formulations. Another option is to use feed-evaluation factors to determine the economic nutritional value of various ingredients fed to dairy cows (see the Feed Value Calculator spreadsheet). With these factors, the economic value of each available forage can be compared with number 2 shelled corn, 48% soybean meal, and alfalfa hay. Various concentrate ingredients can be considered if they are obtainable at prices appreciably below their relative maximum worth based on prices for shelled corn and soybean meal. The Feed Value Calculator spreadsheetautomates the calculation of feed values based on feed-evaluation factors. The only inputs required are current market prices for corn, soybean meal, and alfalfa hay. The calculated feed value ($/ton) can then be compared to current market prices. (Note, farm grain prices per bushel may be converted to ton or hundredweight prices using factors given in Table 2.)
Table 2. Conversion factors for bushel and hundredweight prices of selected feeds.a
|aTo convert price per bushel to price per hundredweight, multiply price per bushel by the appropriate factor (bu/cwt). Example: Oats @ $0.90 per bu = 0.90 x 3.12 = $2.81/cwt or $2.81 x 20 = $56.20 per ton. To convert price per cwt to price per bushel, multiply price per hundredweight by pound per bushel as a percent Example: Oats @ $2.81/cwt x 0.32 = $0.90 per bu.|
If an ingredient is shown to be a good buy, it should be used in accordance with usual restrictions for palatability, fat content, and other reasons. See Table 3 at the end of this article for a directory of common ingredients in dairy rations.
The decision to use a particular ingredient should not be determined solely by price. Some feeds that are more costly than their maximum relative value indicates, may have to be used to meet the animals' nutritional needs. For example, some purchased hay may be necessary to meet minimum forage needs or soybean meal is needed to furnish part of the supplemental protein needs regardless of price.
Several options are available to producers if the supply of home-grown forages is inadequate. The following is a list of the main choices that can assist producers in making some sound decisions.
- Check prices and availability on several types and quality hays or hay cubes. Some relatively low protein and energy hay or straw may be used if only 4 to 6 pounds are needed per head daily for milk cows. Such hay may be more economical for feeding dry cows and heifers. If more purchased hay needs to be fed, allocate the average to higher quality hays to milk cows.
- Purchase ensiled forages and grains based on a dry matter basis. Test the moisture content of feeds periodically to use in making payments. When buying on a volume basis, such as feed stored in a silo, agree ahead of time on the amounts present. Capacity tables or charts can differ in their estimates of what storage structures can hold.
- Check availability and costs on various roughages such as corn stalklage, corn cobs, corn cannery waste, bean or pea-vine silage, straw, and apple pomace with or without hulls.
- Obtain costs and check supplies of various high-fiber feedstuffs such as whole cottonseed, beet or citrus pulp, dehydrated alfalfa, wet and dry brewers grains, distillers grains, and soyhulls. Whole cottonseed may enter into least-cost rations when forage is relatively high in price.
- Check costs and availability of various energy and protein sources such as barley, oats, wheat midds, corn gluten feed, and whole soybeans (raw or heat treated). Fat and oil products may be considered if they can be handled in the mixing or feeding system. Compared to shelled corn, barley, ear corn, and sometimes oats are a better buy.
- Consider harvesting corn as ear corn if forage is in short supply. Ear corn provides more fiber when forages are limited.
- Choose a course of action based on least-cost formulation of rations. Check prices on suitable complete dairy feeds, roughage substitutes, and protein mixes. Seek professional help to make certain that rations meet the dairy cow's nutritional and physical requirements.
- Recalibrate feed scoops and other equipment when feeding by volume and when changes in feed formulas occur. Concentrates containing a lot of bulky, high-fiber ingredients may weigh considerably less per unit of volume than a corn and soybean meal mix. A high barley mix may weigh much more than one containing oats.
- Balance rations for all groups of heifers and dry cows in addition to the milking animals. When conserving forages, feed a balanced ration to all animal groups to minimize wasted feed. If more heifers are on the farm than what are needed, consider selling the excess heifers. Possibilities exist to contract heifers out to areas where pasture or other feeds are plentiful. This may be cheaper than bringing feed to the farm.
- Make sure cows are paying their way. They should be covering feed costs, labor, utilities, and other costs. Culling unthrifty animals and providing more and higher quality forages to the more efficient producers may improve production, especially if they are being limited by a lack of good feed.
Table 3A. Nutritive value of some alternative concentrate feedstuffs for dairy cattle (all values on a dry matter basis).
|Feed||DM, %||CP, %||NDF, %||NSC, %||NEL, Mcal/lb||Considerations|
|Shelled corn||88.0||10.0||9.0||75.1||0.89||A high energy, low fiber, high starch feed.|
|Ear corn||87.0||9.0||25.0||60.4||0.87||A high energy, highly digestible fiber feed. Have it analyzed as fiber will vary depending on the amount of cob and husks included.|
|Oats||89.0||13.0||31.0||47.5||0.80||A bulky feed. Limit amount used in pelleted grain mixes to 40% when feeding conventionally.|
|Barley||89.0||12.8||21.0||61.4||0.87||A good substitute for shelled corn if the price is right. Limit the amount used in pelleted grain mixes to 35% when feeding conventionally.|
|Wheat||89.0||11.3||14.0||70.2||0.89||Limit to 15 to 20% of the finished grain mix when in meal form and 35% when pelleted. Too much wheat may cause compaction in the stomach. Use a medium grind and preferably include with bulky ingredients. Wheat should not be used in rations for calves under 4 to 6 months of age.|
|Wheat bran||89.0||17.1||51.0||20.6||0.73||A highly palatable and bulky feed that has a mild laxative effect. It is a good source of phosphorus. Limit to about 25% of a grain mix in meal form or 35% when pelleted.|
|Brewers-wet||22.0||28.0||49.1||11.2||0.68||A good source of protein, rumen bypass protein and fiber. Limit to no more than 40 pounds of wet material/cow/day. Test for dry matter, protein and fiber content. Check ration potassium levels when large quantities of brewers or distillers grains are fed. Spoilage can be a problem, especially in warm weather if enough is not being fed.|
|Brewers-dry||92.0||27.1||46.0||15.3||0.74||More expensive per pound of dry matter compared to wet brewers. Whenever using appreciable quantities of brewers or distillers, check the potassium level of the ration as these products are low in this nutrient. It is a source of rumen bypass protein.|
|Distillers-light||92.0||29.0||43.0||17.1||0.90||If solubles are included (dark color), the energy and mineral content is higher compared to the light. A good source of rumen bypass protein.|
|Hominy||90.0||11.5||24.0||55.4||0.91||It is somewhat higher in protein fiber, and fat than shelled corn. Limit hominy to about 40% of the grain mix for milking cows.|
|Wheat mids||89.0||18.0||37.0||35.3||0.71||Limit the amount fed to 15 to 20% of a grain mix.|
|Corn cobs||90.0||2.8||89.0||5.7||0.47||Can be incorporated into a TMR or a grain mix. Good source of digestible fiber when forage supply is limited.|
|Soy hulls||90.0||12.1||67.0||13.5||0.80||An excellent source of digestible fiber. Limit to less than 35% of the grain mix or 6 to 8 lbs/cow/day.|
|Beet pulp||91.0||9.7||54.0||31.3||0.81||An excellent source of fiber, energy, and calcium, but low in phosphorus. It is high in pectin.|
|Corn gluten feed||90.0||23.0||40.0||27.0||0.87||Relatively high in soluble protein. Limit to 15% of a finished grain mix with urea included and up to 20% without urea included. If the concentrate mix is pelleted, up to 30% can be used.|
|Cottonseed-whole||88.4||23.7||50.1||3.7||0.98||An excellent source of energy, fiber and protein when the price is right. Limit to 8 pounds or less for milking cows because of the oil content.|
|Soybeans-whole||90.0||41.8||13.0||21.3||0.96||An excellent source of protein and energy. They can be fed raw to mature ruminants but need to be heat treated for simple stomached animals and young calves. Roasting improves bypass protein. Because of fat content limit lactating cows to 6 to 8 lbs/cow/day. Don't feed raw beans in feeds with urea because beans contain urease which releases the ammonia.|
|Fats and oils||99.0||0.0||0.0||0.0||2.65||Need to limit to about one pound/cow/day for milking cows because fats and oils inhibit rumen fermentation at higher levels. Special forms are rumen inert but are considerably more expensive.|
|Corn gluten meal||90.0||67.2||14.0||14.5||0.94||Limit the amount fed, especially when used with corn grain/corn silage-based rations. It is low in lysine. It is a source of rumen by-passable protein. Limit to less than 4 pound/cow/day.|
|48% Soybean meal||90.0||54.5||8.0||30.0||0.91||Typically one of the most economical protein sources. Some companies stock a 44% soybean oil meal (50.0% DM).|
|Cottonseed meal||91.0||45.6||26.0||19.8||0.79||Do not use in rations for calves under 4 to 6 months of age.|
|Canola meal||92.5||40.8||28.0||19.8||0.77||An acceptable substitute for soybean meal when the price is right.|
Table 3B. Nutritive value of some alternative forages for dairy cattle (all values on a dry matter basis).
|Feed||DM, %||CP, %||ADF, %||NDF, %||RFV||Considerations|
|pre-bloom||90.0||> 19||< 30||< 41||> 151||Bud to pre-bloom, low fiber, soft stems, good color, over 50% leaves, no foreign material or grasses, pleasant aroma. High quality forage for high levels of milk production.|
|early-bloom||90.0||17 to 19||31 to 35||40 to 46||151 to 125||Usually contains 40 to 50% leaves and less than 5% foreign material. It should be free of mold or a musty odor.|
|mid-bloom||90.0||14 to 16||36 to 40||47 to 53||124 to 103||Usually contains 25 to 40% leaves and less than 15 % foreign material. It should be free of mold or a musty odor.|
|full-bloom||90.0||11 to 13||40 to 42||53 to 60||87 to 102||Usually contains less than 30% leaves and less than 20% foreign material. It has a brown to green color and should be free of mold or a musty odor.|
|early-head||90.0||13 to 18||33 to 38||55 to 60||103 to 124||Usually contains 40% or more leaves and less than 10% foreign material. It should have a pleasant aroma and soft stems. Early cut grasses can be excellent forages.|
|headed (milk to dough)||90.0||10 to 12||39 to 41||61 to 65||87 to 102||If feeding this quality hay to high producing cows, limit the amount to about 5 to 7 pounds. This quality hay may be a good feed for dry cows and heifers along with the proper grain mix.|
|Cornstalk silage||27.0||7.2||40.0||67.0||--||Limit to less than 15% of the total ration dry matter for high producing cows and springers.|
|Brassica tops||20.0||18.7||21.0||--||--||Include other forages in the ration.|
|Drought with few ears||25.0||9.9||--||--|
|Stunted, non-pollinated, growthy, mature||27.0||7.6||--||--||Watch for fermentation problems and for high nitrates in drought situations.|
|Small grain silage|
|Pre-head, 28+ inches||20.0||15.0||38.0||--|
|Early head||30.0||13.0||40.0||--||Watch for prussic acid and nitrates with young or stressed forage.|
Written by A. J. Heinrichs, V. A. Ishler and R. S. Adams