The profitability of your business depends on minimiz- ing costs and maximizing returns. Feed costs account for approximately 60 percent of the annual cost of owning an animal. Extending the grazing season into the winter through the use of stockpiled forages and/or crop residues can reduce harvest and feeding costs. In research at the University of Missouri, Jim Gerrish showed a cost savings of more than $1 per head for each day a cow grazes and harvests her own forage rather than being fed hay in a drylot.
Stockpiling forage
Stockpiling is the accumulation of late-summer and fall pasture regrowth for fall and winter grazing after the growing season ends. Stockpiling should not be confused with allowing spring forage that outgrew livestock demand to accumulate and be carried
through the summer in a mature, low-quality condition. To stockpile forage, defer grazing of a pasture, hay field, or planted crop for a period of time to allow for late-season growth. The resulting forage can be grazed as a standing crop or swathed and grazed in windrows. Before planning to stockpile forage, ask yourself the following questions:
• Will irrigation or rainfall be available for regrowth? • What forage species are best for late-season grazing? • Should I consider windrow grazing?
• Should I use strip grazing to harvest the forage? Each of these questions is discussed below.
Water for forage regrowth—A key to successful for- age stockpiling is having irrigation or timely rainfall to allow forage regrowth during late summer and early fall. Irrigation will also allow you to plant late-seeded annual crops for later season grazing.
In low-rainfall regions, you can stockpile forage by de- ferring grazing during the early active growing season for utilization later in the fall and winter. Realize, how- ever, that the nutritive quality of the forage may be low and livestock may require protein supplements, unless they are allowed to graze selectively. Only dry cows and ewes should graze this mature forage.
Forage species selection—The biggest challenge with stockpiling regrowth of cool-season perennial species is that pasture growth rates are often at a sea- sonal low in late summer, and livestock often require all of the current pasture growth at that time. One op- tion is to use warm-season annual forage grasses, such as pearlmillet and sorghum x sudangrass hybrids, for more rapid growth during late summer. You also can plant winter cereals and forage brassicas in mid- to late summer for stockpiled winter forage. However, winter cereals usually provide more forage early in the follow- ing spring than in the fall of the seeding year.
In reality, any grass can be used in stockpiled forage systems, although yield and nutritive value differ among species. Robinson et al. (2007) analyzed the stockpiling characteristics of several forage species at the Brigham Young University (BYU) Agriculture Sta- tion near Spanish Fork, Utah. Among the grasses tested, tall fescue and orchardgrass produced the most dry matter while retaining forage quality. Studies at Iowa State University, University of Georgia, Univer- sity of Minnesota, and in Canada also found tall fescue and orchardgrass to be the best grasses for use in stockpiled forage systems. Fall regrowth of tall fescue forage often has higher digestibility than summer growth, and tall fescue quality is retained well during fall.
Among legumes tested in the BYU study, birdsfoot tre- foil showed promise. Alfalfa was not as productive as birdsfoot trefoil.
Species and management options for extending fall and winter grazing are provided in Forage Utilization
for Pasture-based Livestock Production(publication NRAES-173, Cornell Cooperative Extension) and by Ball et al. (2008) and Boyles et al. (1998).
Grazing stockpiled forage—Graze softer grasses with less structure earlier in the fall, while retaining those with more structure and upright stature for later grazing.
Animals that are inexperienced with grazing through deep snow cover often require some time and experi- ence to become competent at grazing stockpiled for- ages. Grazing can be difficult even for experienced animals if snow is crusted or icy.
One way of facilitating intake of snow-covered stock- piled forage is to swath or windrow an annual or perennial crop and leave it in the field to be grazed by livestock in late fall or winter. This practice of swath grazing maintains forage quality while reducing feeding costs. Swath grazing can reduce forage harvesting costs by as much as 60 to 75 percent compared to con- ventional hay harvesting methods (Berger and Volesky, 2006; Surber et al., 2001).
Where snow depths are likely to exceed 12 to
14 inches, swathing is useful for concentrating limited stockpiled forage mass so that animals can easily lo- cate it beneath the snow. Thus, they do not have to for- age as extensively to meet nutritional requirements. Animal access to swaths covered with crusted or icy snow can sometimes be improved by driving a tractor along swath edges so that a rolling tire disrupts the hard layer.
Swathing stockpiled forages is particularly beneficial where it is desirable to capture the quality of a crop canopy before excessive maturation or freezing dam- age occurs. Thus, it is especially useful for species that experience a deterioration in quality following freezing and weathering. Alfalfa and red clover, which lose leaves in freezing weather, are examples. Swathing can also improve accessibility of forages that would be likely to lodge in winter. Deterioration of swath struc- ture and quality are potential problems in areas that do not have dry fall and winter conditions, including dry snow.
Grass hay crops and annually seeded forages can be used in a windrow grazing system. In a study con- ducted at North Dakota State University in 2006, oat hay cut in the soft dough stage worked well. Beardless barley and triticale also work well, along with some warm-season grasses such as millet, pearlmillet, and sudangrass.
Species and management options for swath grazing are discussed in Windrow Grazing (publication G1616, University of Nebraska-Lincoln), Swath/Windrow
Grazing: An Alternative Livestock Feeding Technique
(Montguide MT 200106 AG, Montana State University Extension Service), and Hutton et al. (2004).
Grazing system—Regardless of whether stockpiled forage is grazed as standing or swathed forage, use strip grazing and movable electric fences to ration out the pasture. This will reduce forage waste due to tram- pling, bedding, or soiling. Allowing livestock access to a 1- or 2-day supply of forage is ideal. If this is not pos- sible, limit livestock to no more than a 1-week supply of forage at a time.
Waste is always an issue, however. Losses range from 5 percent (if a 1-day supply of forage is provided) to more than 30 percent (if livestock have access to a large section of stockpiled forage at one time). Keep waste in mind when deciding stocking rates.
Grazing crop residues
Crop residues are another low- to medium-quality for- age source for extension of the grazing season. See chapter 11 for more information.
For more information
Forage Utilization for Pasture-based Livestock Production. Natural Resource, Agriculture, and Engineering Service Publication NRAES-173. Cornell Cooperative Extension (2007). http://www.nraes.org/
Long-Term Grazing Intensity Research in the Missouri Coteau of North Dakota. North Dakota State University Central Grasslands Research Extension Center. 2008 Annual Report.
http://www.ag.ndsu.nodak.edu/streeter/2008report/GI/ Grazing_intensity_intro.htm
Stocking Rate and Grazing Management. Publication MF-1118. Kansas State University Cooperative Exten- sion Service (1994).
http://www.ksre.ksu.edu/library/crpsl2/MF1118.aspx Swath/Windrow Grazing: An Alternative Livestock Feeding
Technique. Montguide MT 200106 AG. Montana State University Extension Service (2001).
http://animalrangeextension.montana.edu/Articles/ NatResourc/swathwindrow_grazing.htm
USDA Natural Resources Conservation Service soil sur- veys. http://soils.usda.gov/survey/
Windrow Grazing. Publication G1616. University of Ne- braska-Lincoln Extension (2006).
THE BASIC REASON FOR SUBDIVIDING PASTURES is to achieve better control of your grazing operation. The ultimate goal is to in- crease profit, while maintaining or improving animal and pasture health. This overall goal can include a wide range of interrelated man- agement goals, both economic and environmental.
If you have selected a rotational grazing system (chapter 14), how well you design your grazing cell will affect whether you can achieve your goals. This chapter will introduce concepts related to grazing cell design and provide examples for irrigated pasture in the Pacific Northwest. We will also discuss fencing and stock water options and how to match your grazing system to your irrigation system.
To design and build a successful irrigated pasture management sys- tem, you must also carefully consider your available resources (see chapter 1) and understand basic principles of pasture management and livestock behavior (see chapters 13 and 14).