Crop Selection for Supplemental and Emergency Forage
David W. Koch, Extension Agronomy Specialist, University of WyomingDrought, hail, loss of stands and other factors can diminish traditional sources of forage.
Many plant species have potential for livestock forage; however, the best candidates will
depend on amount of rainfall, availability of irrigation, soils and location.
Warm-season annual grasses and cereal crops establish quickly and provide forage
in as little as six weeks. With some crops (wheat, oats, triticale) the same varieties used
for grain can be used as forage, as they are adapted. With other crops (corn, barley,
millets) forage types and varieties are available.
Selecting an annual crop for emergency forage use depends on season of need.
Warm-season crops can provide summer and fall forage, a time when the cool-season
perennial grasses upon which Wyoming producers rely are in a growth slump. Cool-
season crops, such as the cereals, can provide forage for fall, winter and spring. In
contrast to crops grown for grain, those grown for forage need not mature, can be used
even if damaged by hail and there is more flexibility in planting date.
Water use efficiency is an important consideration when precipitation, on average, is
limited and varies considerably from year to year. As noted in Table 1, some crops, even
though adapted, require more than twice the water of other crops. Corn requires about the
same amount of water as sudangrass, yet in a dry year the latter will often outyield corn
under unirrigated conditions. That is because corn suffers more than sudangrass during
periods of drought. It is important to consider amount of reserve soil moisture at time of
planting.
Corn
Corn is one of the promising crop alternatives to wheat-fallow production in dryland
areas. It is a popular irrigated crop, grown as feed grain. Forage-type hybrids are
available. For example, high-sugar, male-sterile hybrids have been productive in
Wyoming, both under dryland and irrigation, for fall and winter grazing of the standing
crop. There is relatively little problem with nitrates or prussic acid in corn.
Sudangrass
The sorghum family requires higher soil temperature for seed germination and
seedlings are not a vigorous as corn. There is more potential for prussic acid, particularly
with sorghum-sudan hybrids. Sudangrass is more useful as summer grazing and will
regrow.
Sorghum-sudangrass hybrids
They are potentially more productive than sudangrass, particularly under irrigation
and are preferred for silage.
Foxtail millets
Like proso millets, which are grown for grain, these forage-type millets are growing
in popularity in Wyoming because they are efficient in water use, mature quickly and can
be grazed, hayed, or simply left in windrows for fall or winter grazing. There are few
animal health problems with these millets.
Winter wheat, rye and triticale
These fall-planted crops have been grown primarily for grain, but each year some
acres are grazed off when grain prices are low and/or prospects are poor. They can be
planted earlier than for grain for winter pasture, and grow when evapo-transpiration
demand is minimal. Triticale produces more forage than wheat and is much less likely to
volunteer than rye. It is probably, all around, the best cereal for forage. It has shown
promise as a pioneer crop on newly cleared or tilled land.
Oats and barley
These are spring planted. Spring varieties of triticale are also available. Oats can be
grown more successfully with later planting than barley; however, water use will be
greater than fall-planted cereals. A beardless barley variety should be used, particularly if
grown for hay. Barley has more drought resistance than oats.
Other crops with possible use as emergency livestock feed are Austrian winter peas and
hairy vetch (fall-planted), spring-planted peas and soybeans. Since these are legume,
nitrogen fertilizer is not needed and crude protein content of forage is usually improved.