In the Northern Plains, most beef cows are wintered on relatively expensive harvested feeds at a time in their reproductive life when their nutrient requirements are the least. Reducing winter feed costs without hurting cow performance would increase rancher net profit. The logical way to reduce wintering costs is by extending the grazing season from the current 7-8 months to 10-12 months. Wintering cattle on rangelands in the United States was widely practiced before the winters of 1867-1868 and 1889-1890 when cattlemen suffered extensive animal losses, because of severe blizzards and the lack of reserve feed supplies (Young and Evans, 1984). Stories of those blizzards still linger in the minds of producers, making them reluctant to defer pasture for winter grazing, because they are concerned that heavy snows will prevent winter use, resulting in a loss of feed that could have been used in the summer. Swathing or bunching annual forages for fall or winter grazing is an alternative to stockpiling (not grazed or hayed in summer) perennial grass. Grazing either stockpiled forage or swaths causes cows to do more of the forage harvesting, processing and transporting themselves, thus reducing feed costs. Barley chaff left in swaths after harvest has been successfully used by Canadian producers to winter beef cows (Klein, 1994; Klein, 1996). Small grain crops such as oats (McCartney, 1996), barley, fall rye, and winter triticale have also been used for winter swath grazing (Anonymous, 1998). In the Nebraska Sandhills, weanling calves have been wintered on swathed wet meadow forage (Volesky et al., 1999). In addition to lower feed costs, cattle utilizing forages on the site where they are produced distribute urine and manure over the field benefiting next year’s crop, whereas drylot feeding concentrates manure and increases the potential for runoff, that could pollute nearby streams and waterways. Integrating dryland crop and livestock production in the Great Plains may benefit both crop production (soils) and livestock (Krall and Schuman,1996). The concept of extending the grazing should not be limited to grazing season length, it should also involve increasing the period of time when high quality forage is available to support optimum weight gains and milk production of yearling cattle and lactating beef cows, respectively.

1.Use forages that more nearly meet the nutrient requirements and production goals of specific animal groups. Growing/finishing steers gaining 1.77 pounds per day need a diet containing 8.5% crude protein and 60% TDN, as shown in the accompanying table (NRC, 1996). If these steers were fed a diet containing 5.99% crude protein and 45% TDN which is adequate for dry pregnant cows in mid-gestation performance would be impaired or reduced. On the other hand, if dry pregnant cows in mid-gestation were fed a diet containing 8.5% crude protein and 60% TDN, they would be wasting nutrients and unnecessarily increasing winter feed costs. Therefore, it is important to plan your forage program according to the class of cattle you are going to feed.

2. Use forages that maintain their quality well with advancing maturity, and are adapted to winter grazing either when stockpiled (not grazed in summer) or after swathing or bunching. The accompanying graph shows that crested wheatgrass (Agropyron desertorum), Russian wildrye (Psathyrostachys juncea) and Altai wildrye grass (Leymus angustus) have the same organic matter digestibility in mid-May, but by early July crested wheatgrass is slightly less digestible than Russian and Altai wildrye. By early September the digestibility of Russian and Altai wildrye are considerably higher than crested wheatgrass (Lawrence and Knipfel, 1981). In the fall, crude protein also remains higher in Russian and Altai wildrye than crested wheatgrass (Lawrence et al., 1982; data not shown). These data show why Russian and Altai wildrye grasses are recommended for fall and winter grazing.

3. Optimize use of legumes to improve diet quality and fix atmospheric nitrogen for enhanced crop production. Legumes should be considered in mixtures with perennial grasses as well as in annual crop mixtures. In an integrated/crop livestock operation strategic use of legumes could decrease the need for commercial fertilizer. Hairy vetch (Vicia villosa) is a biennial legume that stays green late in the fall and could improve diet quality during this critical time of the year. Most legumes however, will not extend the length of the grazing season, but they can improve forage quality during the critical late summer period.

4. Use annual crops to provide the quantity and quality of forage or grain to meet animal needs at a point in time when perennial forages may not be nutritionally adequate. During late summer, crude protein in most perennial grasses is usually quite low as indicated in the graph. Yearling steers weighing 840 pounds and gaining 2 pounds per day have a crude protein requirement of 8.8% (NRC, 1996), which is well above levels in native range, but the biennial legume hairy vetch and rape (brassica) have crude protein levels well above requirements for growing steers or lactating cows (10.69%).

5. Expand the use of annual crops, which are more water-use efficient than perennial grasses. In the semi-arid Great Plains adequate water for crop production is always a concern. Thus, annual crops that use water efficiently to produce dry matter should be considered as a supplement to perennial forages when possible. In the accompanying graph siberian millet (Setaria italica) and corn (Zea mays L.) use ⅓ and ½, respectively, the amount of water to produce a pound of dry matter that smooth bromegrass (Bromus inermis Leyss.) does. Put another way, on the same amount of water, corn and millet would produce 2 and 3 times as much dry matter, respectively, as smooth bromegrass.

6. Using annual forages adapted to no-till seeding is another means of conserving limited soil moisture. No-till seeding may save up to an inch of water (Tanaka, 1985) compared to conventional tillage. Thus no-till corn, which seems to do well seeded no-till into crop residue could add another 624 pounds of corn dry matter per acre. The additional dry matter was calculated as follows: one inch of water=0.0833 foot x 43,560 sq. feet per acre=3628 cubic feet of water per acre; 7.48 gallons per cubic foot equals 27,141.5 gallons; 8.3 lbs. per gallon would equal 225,275 lbs. of water per acre. Corn requires 361 lbs. of water to produce 1 lb. of DM; therefore 225,275/361=624 lbs. of corn dry matter per acre from one conserved inch of water.

7. Use of sustainable multi-year annual-perennial forage systems could optimize high quality forage production and minimize lost grazing time. The accompanying figure describes two potential crop rotations that could provide high quality annual forages for late summer and autumn use. We have used the annual crops, but we haven’t followed through with the perennial crops in the rotation. Both rotations involve pearl millet which we have found to produce good yields of high quality forage in late summer. If cut or grazed, pearl millet (Pennisetum glaucum (L.) R. Br.) regrows rapidly extending the period of high quality forage availability. Hairy vetch provides a legume in the first year of rotation 1 and it remains green even under snow. Although we have not been able to complete these rotations, we visualized seeding a perennial legume with pearl millet in Year 2, and then dormant seeding intermediate wheatgrass (Thinopyrum intermedium (Host) Barkw. and Dewey) in the fall. In Year 3 a perennial grass-legume mixture should be available for mid-summer grazing. In the second rotation we added rape to a pearl millet-soybean mixture. Rape is a nutritious forage that stays green and maintains its quality even when night temperatures are below freezing.

8. Develop cropping systems with annual crop mixtures that complement each other in terms of maturity, water use and the ability to withstand high temperatures. Because precipitation is extremely variable in the Great Plains it is prudent to develop cropping systems that provide built in insurance against annual crop failure. Using mixtures that include crops that grow and develop at different rates and times increases the possibility that if precipitation comes too late for one crop it may be just in time for another crop. Including warm and cool season crops also offers protection against both cool wet periods and hot dry spells. Dominant crops may differ among years, but since forage not grain production is the goal, the crop that prevails is not as important as having something to graze.

9. Provide supplements to grazing animals that complement grazed forage and compensates for adverse weather conditions. If properly supplemented, beef cows can graze deferred perennial rangelands for an extra 30 to 60 days, if snow and ice are not problems. When planning to graze dormant forage in the Great Plains it is always prudent to have a backup plan in case of blizzards. Although the protein requirement of dry pregnant cows in mid-gestation is relatively low, it is likely that crude protein in perennial rangeland forages will be inadequate to meet the cow’s needs. Usually 1.5 to 3.0 lbs of a 30% crude protein supplement should be adequate for cow needs, but research results have been mixed. Kartchner et al. (1981) reported that providing a protein supplement to range cows during the fall and winter period may improve dry matter intake and digestibility. There may be times when energy as well as protein supplements would be beneficial, especially if cows are grazing cereal straw in cold weather. Although supplementing energy seems to work in practice, research on energy supplementation has not been supportive because readily available energy from grain may reduce fiber digestion (Chase and Hibberd 1987).

10. Calving in late May instead of March would extend the time that cows could be wintered on standing, swathed or bunched forage. Calving in late May would better synchronize cow nutrient requirements with forage quality (May et al. 1999). From the figure at the left it is easy to see when cows are calved in March swathed corn would be deficient in crude protein from January until mid-May and after calving it would not be feasible to graze cows and calves on swathed corn. On the other hand, May calving cows could be grazed on swathed corn all winter with a little protein supplement in March and April. Thus calving later would facilitate extending the grazing season using stockpiled perennial grasses and/or swathed crops. Calf weaning date also changes the nutrient requirements of cows. Calves that are weaned late put an additional stress on cows.

Beef cows in the Northern Plains are wintered on relatively expensive harvested feeds at a time in their reproductive cycle when their nutrient requirements are the least. To reduce winter feeding costs, it may be logical to extend the grazing season from the current 7-8 months to 10-12 months. To successfully extend the grazing season, we feel there are potential opportunities to enhance the grazing season in integrated crop/forage/livestock systems. 1) Use forages that maintain their quality, are adapted to winter or swath grazing, and meet the nutrient requirements and production goals of the specific animal groups. Animals may need to be supplemented to help compensate for adverse weather conditions. 2) Take advantage of annual and perennial legume crops to improve diet quality and fix atmospheric N. 3) Use water-use efficient annual crops that are easily adapted to no-till seeding and provide the quantity and quality of forage or grain to meet animal needs. 4.) Develop sustainable multi-year annual and perennial forage and/or grain systems that optimize high quality forage and/or grain production by having crops that complement each other in terms of maturity. 5) Calving and/or calf weaning dates may need to be adjusted to synchronize cow nutrient requirements with forage quality and availability.

Lawrence, T. and Knipfel, J.E. 1981. Yield and digestibility of crested wheatgrass and Russian and altai wild ryegrasses as influenced by N fertilization and date of first cutting. Can. J. Plant Sci. 61:609-618.

Lawrence, T., Winkleman, G.E. and Warder, F.G. 1982. The chemical composition of Russian and altai wild ryegrasses and crested wheatgrass as influenced by N fertilization and date of harvest. Can. J. Plant Sci. 62:373-390.

May, G.J., L.W. Van Tassell, J.W. Waggoner and M.A. Smith. 1999. Relative costs and feeding strategies associated with winter/spring calving. J. Range Manage. 52:560-568.