Drought: Weathering Troubled Times - University of Wyoming

1. College of Agriculture
Cooperative Extension Service
Agricultural Experiment Station
a A parched Wyoming eagerly drank the recent spring
precipitation. However, the grim news is that one of the
worst dry spells in the state’s history is still a reality.
Agriculturally speaking, drought means hard times for ranchers,
farmers, livestock, crops, gardeners, and the economy. Ultimately, it
impacts almost everyone.
In this special section, University of Wyoming College of
Agriculture faculty members and Cooperative Extension Service
educators join forces to help advise drought victims about how to
best manage and recover their operations and lands and about how
to be resilient as they weather tough times.

2. Page 2 Spring, 2003 UW College of Agriculture
Dry weather calls for summer
Steve Paisley mals is the safest route. When
UW Cooperative Extension feeding, introduce the high-
Service Specialist, Department nitrate feeds gradually. Cattle
of Animal Science do have a limited adaptation
to higher nitrate levels. By in-
A lthough parts of the state
received much-needed
moisture during recent
troducing feed slowly, one can
reduce but not eliminate the
risk of having problems. Also,
months, perhaps enough to at making sure the overall ration
least “green up” this spring, is balanced by providing ad-
there are still no guarantees of equate energy (small amounts
additional summer moisture of supplemental grain) will re-
to maintain grass or replenish duce the risk.
the already low reservoirs or If forced to feed bales of
livestock water sources. While high-nitrate feed, introduce
the recent moisture will allow them slowly, feeding some of
nearly everyone to turn out both the high-nitrate and safe
this spring, there are a few is- hay each day. Generally feed
sues to consider as the sum- the high-nitrate feed first fol-
mer progresses. lowed by the safe feed. There
is still the risk that some cows
Water Concerns
will eat only the high-nitrate
As stock ponds remain
hay. For example, dominant
low, the quality of the remain- Pictured are a cow and spring calf. cows may push the thin or
ing water becomes a nutrition
timid cows away from the bet-
and health concern. In the fall, ings suggest that sulfate lev- nitrate susceptible forages, pro- are that nitrate levels of 6,000 ter hay, forcing them to eat
adult cows typically require 7 els less than 1,000 ppm are ducers can reduce the risk ppm (1 percent KNO3) or less only the high-nitrate forage. To
to 11 gallons of water per day generally safe, with 1,000 to through livestock and forage are generally safe. Nitrate lev- reduce the risk of this, sort the
depending on outdoor tem- 2,500 ppm levels causing re- management. els of 6,000 to 9,000 ppm (1 to cattle into thin/weak cows and
peratures and stages of pro- duced performance and occa- 1.5 percent KNO3) are poten- adult cows.
duction. Ewes typically require sional cases of polio. Levels ap-
Nitrate-Susceptible tially toxic and should be fed When managing high-ni-
2 to 3 gallons per day. Poor proaching 2,500 to 4,000 ppm Forages with caution. Nitrate levels over trate forages, it is better to feed
quality stock water can actu- of sulfate indicate very poor In most cases forages to 9,000 ppm (1.5 percent KNO3) frequently and not allow cattle
ally decrease water intake, put- water with definite reductions be most concerned about are are extremely dangerous and to go hungry. Also, it is impor-
ting additional stress on an ani- in animal performance and an drought-stressed warm season must be diluted and blended tant to manage feeding
mal. Most water tests report increased occurrence of polio. annual forages such as sor- with other feeds. When testing closely, especially during se-
Total Dissolved Solids (TDS) as Additional concerns with ghum/sudan “cane” hays and hay for nitrates, be sure to vere weather. If cattle go with-
a measure of the concentration poor water quality include millet hays. Weed species such sample from at least 10 bales out feed for a day, they may
of dissolved salts. TDS levels mineral interactions and sec- as kochia, lambsquarters, sun- since there is a lot of variation go back and pick through
less than 3,000 parts per mil- ondary mineral deficiencies flower, and pigweed can also in nitrate levels from bale to coarse stalks from previous
lion (ppm) are generally safe that can occur with high TDS accumulate nitrates, so emer- bale. It is generally safer to feed feedings. Those lower stalks
for livestock. Levels of 3,000 to and high sulfate water. High gency feed resources should susceptible forages to non- are where most of the nitrate
5,000 may not dramatically levels of sulfate or other min- be watched closely. Finally, pregnant animals, and it is located, increasing the risk
affect adult livestock, but erals can compromise an under extremely stressful con- should be remembered that of nitrate problems.
young, growing livestock may animal’s immune system, ditions, additional crops such nitrates remain in the plant no Finally, be aware of all
have poor performance and leading to an increased inci- as corn, wheat, oats, and bar- matter how long hay is stored. sources of nitrates. Some
characteristic looseness. TDS dence of health problems. It ley can also accumulate ni- stock water sources can be
levels of 5,000 to 7,000 should is always a good idea to trates. From a management Feeding
high in nitrates, adding to the
not be offered to pregnant or sample and test water sources standpoint, the plant nitrates Recommendations risk. Also, poor water sources
lactating animals. to avoid future problems. are generally located in the Once the nitrate level of a can reduce a herd’s water con-
Another water quality lower 1/3 of a stalk. Raising the forage is known, one can sumption, also adding to the
concern is the sulfate level of Concerns of High cutterbar when swathing or manage accordingly. The best problem.
water. High iron and sulfate Nitrate Forages reducing the grazing pressure situation is to keep the overall While there are risks asso-
levels can affect trace mineral During Drought so animals are not forced to ration nitrate level below ciated with using high-nitrate
absorption, especially copper, While concerns about ni- graze the lower portion of 6,000 ppm nitrate (1 percent feeds, weather conditions, hay
but high sulfate water can also trates typically occur during the stalks will help reduce the ni- KNO3). This may mean blend- availability, and hay prices may
increase the risk of fall and winter when produc- trate concerns. ing or mixing hays. When limit any other alternatives.
polioencephalomalacia or po- ers are purchasing and feeding feeding nitrate-susceptible for-
lio. Symptoms of polio in Nitrate Testing ages, the safest method is to
Following a few basic guide-
hay, it may be just as impor- lines and managing cattle
cattle include blindness, signs When testing forages for
tant to think about nitrate con- tub grind and blend with low- closely will definitely reduce
of nervousness, and uncoor- nitrate levels, pay close atten-
cerns early in the year and re- nitrate hay. If a producer is the risk of nitrate problems.
dinated movement. South tion to how the nitrate levels
duce the risk of nitrates unable to tub grind, some im-
Dakota State University re- through forage-selection deci-
are reported. Depending on
portant management consid- Supplementation
cently reported results from sions, harvesting, and grazing
the lab, nitrate levels may be
erations result. Strategies
an ongoing project evaluating described as nitrate (NO3), ni-
management. Although dry, As mentioned before, Catering the Supplement
water sulfate levels. Based on trate nitrogen (NO3N), or po-
stressful weather increases the feeding susceptible forages to to the Situation. One of the
two years of data, their find- tassium nitrate (KNO3). Gen-
risk of nitrate accumulation in growing (non-pregnant) ani- common misconceptions con-
eral nitrate recommendations

3. UW College of Agriculture Spring, 2003 Page 3
herd management
cerning the use of supple- fordable supplements are of- SITUATION 2: Early Weaning
ments is the “one-size-fits-all” fered, summer supplementa- Adequate to limited hay/ Raising the cutterbar Another important sum-
mentality. In reality, there is a tion programs are going to be forage available, and the mer management consider-
wide range of responses to an option to consider. It is im- forage is not providing when swathing or ation is early weaning, espe-
enough nutrients to
supplements, depending on a portant not only to capture all
meet a cow’s
reducing the grazing cially if summer rains do not
number of factors. Some of of the benefits that are avail- come and forage becomes
these factors include the qual- able through drought assis- requirements pressure so animals limited. Studies involving early
This situation describes
ity of the forage being grazed, tance programs but also to are not forced to weaning indicate that remov-
the quantity or availability of make the supplement fit the common conditions when ing a calf during mid to late
the forage, the nutrient re- situation to help get the de- cows are close to calving or graze the lower summer reduces a cow’s for-
have just begun calving and
quirements of the animal be- sired results. When evaluating portion of the stalk age requirement by 35 to 50
ing supplemented, the range supplements, there are are being fed a medium-qual- percent. This reduced forage
amount of supplement being three general situations to con- ity meadow hay. The in- will help reduce the requirement may help buy
creased energy demands of
fed, the source and quantity sider. Each has its own unique nitrate concerns. time, allowing cows to stay on
of TDN or energy being sup- solution provided by the late gestation and early lacta- summer grass rather than hav-
plied by the supplement, and supplementation program. tion are greater than what is ing to bring pairs home early.
the level and quality of the provided in the forage. Often If cows appear thin, early
SITUATION 1: There is the first limiting nutrient in
protein being offered in the situation would tend to either weaning may also help add
adequate forage, but these situations is energy, fol-
supplement. During drought increase forage intake or at
low forage quality is weight and condition while
conditions, the wrong match lowed closely by protein. An least maintain the current for- cows are still on grass. Data
limiting intake. additional supplement is
of supplement to the situation age intake. One way to stretch from the University of Wyo-
This is typically the situa- needed to provide extra en-
can have very negative results. the available forage is by feed- ming found that following
tion producers face when ergy and protein to meet the
For example, feeding small ing supplements that are rela- early weaning, cows gained
cows are grazing winter range. nutrient demands of a cow.
amounts of a high-protein tively high in energy and low approximately 85 pounds dur-
If the pastures have been The best supplement for this
supplement (30 percent CP and in protein. These high-energy, ing an 82-day period while
saved exclusively for fall and situation is a medium-protein
above) to cattle with very lim- low-protein supplements cows still lactating during that
winter grazing, there are typi- supplement that provides en-
ited forage may not be the best would not work in Situation 1 same period lost an additional
cally adequate amounts of for- ergy as well as protein. There
match of the supplement for the where the goal is to increase 40 pounds. This occurred
age for the herd. The lower are several supplements that
situation. Providing high-quality intake and digestibility. They while cows and cow/calf pairs
quality of the forage and slow fit this situation well such as
supplemental protein typically are designed to replace forage were grazing relatively low-
digestion/long retention times higher energy 20s cubes, liq-
improves the digestibility of the and actually decrease forage quality range forage in Sep-
in rumen limit the amount of uids, blocks, etc. High-fiber
forage and increases the intake intake while maintaining ad- tember and October. The early
forage cows can eat. As the byproduct feeds also work
of low-quality hay. In the situa- equate energy and protein. It weaned calves grazing high-
weather turns colder and fe- extremely well in these situa-
tion described above, the prob- has traditionally been called a quality meadow regrowth
tal growth begins to increase, tions. Byproduct feeds include
lem is lack of forage, not its qual- “negative associative effect” gained similarly to those
cattle need to increase intake wheat midds, corn gluten feed
ity or digestibility. Supplying a when supplements reduce for- calves still nursing their dams
to continue to meet their en- pellets, distiller’s grains, beet
lower-protein, higher-energy age intake, but in this situa- over this period of time. This
ergy needs. Providing small pulp pellets, and probably the
supplement may help to meet tion, where forage is limited, management strategy can
amounts of a digestible pro- most heavily used medium-
a cow’s energy needs while also it works to the producer’s ad- also have major implications
tein source will improve diges- protein supplement, alfalfa
reducing forage consumption. vantage. High-energy, low-pro- on nutritional costs and the
tion of low-quality forage, im- hay. The benefit of these high-
As drought assistance pro- tein supplements are typically breed-back efficiency of young
proving passage rate and in- fiber byproduct feeds are that
grams continue and more af- grain, grain-based range females as 3 and 4-year-olds.
creasing forage intake. This they provide needed energy cubes, grain/byproduct mix- While it may not be fea-
example of a “positive asso- while also containing ad- tures, etc., with protein levels sible to wean all of the calves
ciative effect,” providing a equate protein. They have a below 20 percent. Again, the early, consider weaning a por-
small amount of supplement very positive effect on energy
While there are risks to increase forage consump-
net effect is reducing forage tion of the spring calves early.
intake because they can be fed intake while maintaining ad- First and second calf heifers
associated with using tion and improve the energy at 3 to 6 pounds daily, and equate energy and protein lev- would definitely benefit from
and protein status of a cow, cattle continue to maintain the
high-nitrate feeds, has been used for decades. A
els for cattle. having the calves removed a
same level of forage intake. The three examples de- month to two months early.
weather conditions, protein supplement can be of- They are essentially an energy scribed may over simplify the Weaning in two groups may
fered as high-protein range and protein “boost” that
hay availability, and cubes or pellets, blocks, lick
situations. There are obviously also help reduce the stress on
doesn’t affect forage intake. several types of supplements, weaning facilities and allow
hay prices may limit tubs, liquid supplements, etc.
The key points are that the SITUATION 3: Cattle several ways of delivering the more time to address the
any other protein level needs to be rela- performance and forage supplements, and additional health and management of
alternatives. tively high (30 percent CP and quality are adequate, management considerations. the calves during weaning. It
higher), the supplement needs
but forage supply is However, they are a step be- may also provide some flex-
Following a few basic to be fed or offered in small limited yond the “one-size-fits-all” ibility in marketing calves.
This is the situation that mentality with supplementa- Early weaning may be an
guidelines and amounts, and the protein
many producers were faced tion programs. For additional important consideration every
needs to be a highly digestible,
managing cattle good quality one with rela- with last summer. Cattle were help or ideas, visit with a Co- year, especially with young
in good condition, but there operative Extension Service cows. Getting cows in good
closely will definitely tively low levels of NPN to get
was little forage left for them educator. He or she can pro- shape before winter sets in is
maximum benefit.
reduce the risk of to graze. Feeding high or mid- vide additional information important in maintaining ad-
protein supplements in this and help work through some equate condition and in improv-
nitrate problems.
of the choices. ing reproductive performance.

4. Page 4 Spring, 2003 UW College of Agriculture
Not much water? Water-wise choices
Karen L. Panter properly. Always keep in mind
Cooperative Extension Service that any new plantings will
Specialist, UW Department of require consistent moisture
Plant Sciences until they are established, es-
pecially during the winter.
T he drought situation has
hit Wyoming hard. Even
though there may still be snow
Step 1 – Developing a
Landscape Plan
Spend some time plan-
on the ground in some places,
ning and designing on paper.
the situation is that many
Analyze the site, taking into ac-
Wyoming cities will put water-
count existing structures,
ing restrictions in place this
other plants, and neighbors.
year. Some already have.
Then decide what areas are
Many believe people
needed: turf area for the kids,
should practice water conser-
a vegetable garden, a center
vation all year long inside and
for entertaining, or a dog zone.
outside homes rather than just
in the landscape during the Step 2 – Limiting Turf
growing season. Try simple Areas
things like washing only full Note that this does not say
loads of laundry or dishes, eliminate turf areas. For areas
Gazania linearis – Gazania with little to no foot traffic,
keeping a pitcher of water in
the fridge, cutting bath water consider groundcovers such as
down a gallon or two, and cut- carpet bugle (Ajuga), thyme
ting down shower time a (Thymus), vinca (Vinca minor),
minute or two. These will all nettle (Lamium), or sweet
go a long way towards saving woodruff (Galium). For heavily
the most precious western re- used areas, consider mixtures
source – water. of turfgrasses. For areas that
In the landscape there are may be tough to maintain and
all sorts of wonderful plant mow, consider perennial orna-
types from annuals to ever- mental grasses such as feather
greens that don’t require reed grass (Calamagrostis
much water. And for plants acutiflora), northern sea oats
that require a bit more irriga- (Chasmanthium latifolium),
tion, there are watering sys- blue oats (Helictotrichon
tems and mulches available to sempervirens), or switch grass
keep the water in the ground (Panicum virgatum).
where the plants need it. Keep in mind that turf ar-
Years ago, Denver Water eas help to cool down the en-
coined the term “xeriscape” to vironment, soften the land-
denote landscaping with low- scape, and provide essential
water-using plant material. oxygen. Using rock or gravel
Cerastium tomentosum – Snow in Summer (No, it’s not pronounced mulch near a home may end
“zeroscape.”) Unfortunately, up heating the area. Any sav-
many people think this means ings in water might be offset
gravel and cactus, but nothing by air conditioning costs in-
could be farther from the side.
truth. Others have used the Step 3 – Selecting and
term “water wise.” Either way, Zoning Plants
there is a definite process in- Appropriately
volved in landscaping to cut Put the right plants in the
down irrigation needs. right places. Group plants with
There are seven steps in- similar water requirements to-
volved in setting up a water- gether to make irrigation sim-
wise landscape or xeriscape. pler and more efficient. Look
These steps are, briefly: 1) for microclimates around
developing a landscape plan, structures. Every yard or land-
2) reducing turf areas, 3) im- scape will have shady areas
proving the soil, 4) selecting that stay moister than south-
appropriate plants, 5) mulch- facing zones. Use plant mate-
ing the soil, 6) irrigating effi- rials that will fit these particu-
ciently, and 7) maintaining lar areas.
Helictotrichon sempervirens – Blue Oat Grass

5. UW College of Agriculture Spring, 2003 Page 5
important for gardens and landscapes
Step 4 – Improving the Step 6 – Irrigating Step 7 – Maintaining
Soil Efficiently Properly
This is probably the most Note that this does not say A no-maintenance land-
important step in any land- stop watering. Water accord- scape is almost nonexistent,
scaping, xeric or otherwise. ing to area and plant type as but low maintenance is pos-
Before any plants are put in well as weather patterns. Use sible, depending on the plant
the ground, add good quality drip irrigation where possible material. Some xeriscape or
organic matter. Put a layer for annuals, perennials, and water-wise gardens may need
about two inches thick on the vegetables. Other types of as much maintenance as a
area to be planted and then watering systems should be more traditional garden. Such
till or spade it in to a depth of used for large trees and shrubs routine tasks as weeding,
about six inches. Also, core as well as turf areas. These can deadheading, fertilizing, and
aerate lawn areas at least once include overhead sprinklers occasional mowing will still
a year. This allows better wa- Perovskia – Sage Calamagrostis acutiflora – and automatic systems. Re- need to be done.
ter and air penetration to the Feather reed grass member to change the auto- The tables below list some
grass root systems. Leave the landscaping. Good quality or- ganic mulches (gravel, rock, matic clock according to the suggestions for water-wise
cores on the turf since they ganic mulches (bark, straw, etc.) can also be used but can weather and season. “Set and plant materials from trees to
will add nutrients back to the etc.) keep moisture in the soil, be warm. The type that should forget” is too common and is annuals and even a few shade
area as they break down. minimize evaporation, moder- be used (inorganic or organic) not appropriate. Whatever sys- plants.
ate soil temperatures, mitigate tem is used, make sure it is
Step 5 – Using Mulches depends on the landscape de-
freeze/thaw damage, and add sign and the long-term goals functioning properly and is
This is arguably the sec-
organic matter back into the for the area. not clogged or split or leaking.
ond most important step in
soil as they decompose. Inor-
Trees Groundcovers
Acer ginnala deciduous amur maple Antennaaria dioica pussytoes
Crataegus crus-galli deciduous cockspur hawthorn Cerastium tomentosum snow-in-summer
Gymnocladus dioicus deciduous Kentucky coffeetree Polygonum affine fleece flower
Juniperus scopulorum evergreen Rocky Mountain juniper Santolina chamaecyparissus lavender cotton
Pinus aristata evergreen bristlecone pine Sedum (many species) stonecrop
Pinus ponderosa evergreen ponderosa pine Sempervivum sp. hens and chicks
Pinus cembroides edulis evergreen pinyon pine Thymus pseudolanuginosus wooly thyme
Prunus virginiana deciduous chokecherry Veronia pectinata blue woolly speedwell
Quercus macrocarpa deciduous bur oak
Grasses
Shrubs
Agropyron cristatum bunch turf grass crested wheatgrass
Caryopteris x clandonensis deciduous blue mist spirea Bouteloua gracilis clump blue grama grass
Ceratoides lanata or ornamental, turf
Krascheninnikovia lanata deciduous winterfat Calamagrostis acutiflora ornamental feather reed grass
Cercocarpus ledifolius deciduous mountain mahogany Festuca arundinacea turf grass tall fescue
Cotoneaster apiculatus evergreen cranberry cotoneaster Festuca ovina glauca ornamental blue fescue
Juniperis chinensis evergreen Chinese juniper Helictrotrichon sempervirens ornamental blue oat grass
Juniperus communis evergreen common juniper Oryzopsis hymenoides ornamental Indian rice grass
Juniperus horizontalis evergreen spreading juniper
Juniperus sabina evergreen savin juniper Annuals
Potentilla fruticosa deciduous cinquefoil
Robinia neomexicana deciduous New Mexico locus Coreopsis tinctoria tickseed
Eschscholzia californica California poppy
Perennials Gaillardia pulchella blanket flower
Gazania (several species) gazania
Achillea sp. yarrow Gomphrena globosa globe amaranth
Asclepias tuberosa butterfly weed Lavatera trimestris annual mallow
Callirhoe involucrata wine cup Pennisetum setaceum rubrum purple fountain grass
Centranthus ruber valerian Portulaca grandiflora moss rose
Eriogonum umbellatum sulfur flower Portulaca oleracea purslane
Gaillardia x grandiflora blanket flower Sanvitalia procumbens creeping zinnia
Hemerocallis sp. daylily Zinnia angustifolia narrowleaf zinna
Nepeta x faassenii catmint
Oenothera missouriensis evening primrose Shade plants
Perovskia atriplicifolia Russian sage
Penstemon (some species) beardtongue Arctostaphylos uva-ursi evergreen shrub kinnikinnick
Salvia (many species) sage Heuchera sanguinea perennial coral bells
Sedum sp. stonecrop Mahonia repens creeping grape holly
Tanacetum densum partridge feather Symphoricarpos x chenaultii chenault coral berry
Vines
Lonicera (some species) honeysuckle vine
Parthenocissus quinquefolia Virginia creeper
Polygonum aubertii silver lace vine

6. Page 6 Spring, 2003 UW College of Agriculture
Drought affects livestock disease
Donal O’Toole particularly dairy cattle, when
Professor and Department concentrations exceed 1,000
Head, UW Department of ppm. Concentrations in ex-
Veterinary Sciences cess of 5,000 ppm will de-
crease production in range
Merl Raisbeck
animals and may cause illness
Professor, UW Department of
and/or death.
Veterinary Sciences
Salt poisoning leads to
Lynn Woodard seizures and prostration. Salt
Professor, UW Department of poisoning/water deprivation is
Veterinary Sciences especially hazardous during
times of high temperatures.
T hree years of drought in
the high plains have had
an appreciable impact on the
High levels of magnesium
(greater than 250 ppm) may
aggravate the problem. Thus,
range of diseases that Univer- This is the brain of a steer with PEM. The arrows point to areas of damaged gray matter. Higher
complete salt screens should
magnification of the boxed area shows necrotic gray matter of brain.
sity of Wyoming diagnosti- be requested when water
cians at the Wyoming State which can be obtained from a ties suggest concentrations of during drought due to irritation samples are collected for test-
Veterinary Laboratory (WSVL) county agent, to collect 10 less than 500 ppm as a safe caused by dust. Fine dust par- ing. One recent case occurred
recognize in Wyoming live- to15 sub-samples from each cutoff for water. If both feed ticles enter the airways and when yearlings were moved to
stock. Many of these are just stack or load of hay. Results and water contain appreciable damage the lungs, setting the a pasture where they could not
worse cases of what is seen in obtained from testing samples concentrations of nitrate, one scene for infection by micro- locate a water tank. The de-
normal years, but some are collected by grabbing handfuls has to consider the contribu- bial agents. Feedlot and ranch hydrated yearlings developed
unique to periods of extended here and there are unreliable tion from both sources. In operators sometimes use the constipation and/or diarrhea,
drought. since they are likely to miss other words, subtoxic concen- term “dust pneumonia,” but weakness, emaciation, and
aggressive behavior. Some
Nitrate poisoning nitrate “hot-spots” in the hay. trations of NO3 in water com- this is not specific and the con-
It is important to have testing bined with subtoxic concen- dition seen may have nothing died before finding water.
A major risk during peri-
done at a laboratory familiar trations in hay may result in to do with inhaled dust. One Some dehydrated steers that
ods of drought is nitrate (NO3)
with this type of analysis. For- toxicity. way to minimize losses is to found the water drank to ex-
poisoning of adult ruminants.
age nitrate analysis is differ- Horses are resistant to ni- give modified live vaccines for cess, developed convulsions,
Drought stress exacerbates
ent from the similar-sounding trate intoxication. Assuming viruses like BRSV with precon- and died. In another recent
the tendency of many plants
nitrate-nitrogen test on water the hay is good in other re- ditioning shots. By contrast, episode, 130 cattle died in a
to accumulate nitrate, particu-
samples by environmental spects, moderately high NO3 killed products have, in some 48-hour period as a result of
larly oat hay and Sudan grass
laboratories. It is recom- hay can be fed to horses. If the cases, increased the disease salt poisoning.
hybrids that were fertilized in
mended that samples be NO3 concentration is not too severity in BRSV outbreaks. Polioencephalomalacia
anticipation of normal mois-
tested at the Wyoming Depart- high (less than 1.5 percent), it Stressed animals are more sus- (“polio” or PEM) due to high-
ture. While it is a good idea to
ment of Agriculture’s Analyti- can be diluted to acceptable ceptible to infections of all sulfate (more than 2,500 ppm)
test hay before feeding it, it is
cal Services Laboratory in concentrations with clean kinds. It is important to stick water is another disease exac-
especially important during a
Laramie [(307) 742-2984; ac- feed. Feed must be thoroughly with a good vaccination pro- erbated by drought. Sulfate is
drought. Nitrate poisoning
cession forms available online mixed before serving (e.g., gram during a drought. concentrated in stock ponds
impairs the ability of blood to
at www.wyagric.state.wy.us/ using a grinder) otherwise and sinkholes by evaporation
carry oxygen. The result is
aslab/aslab.htm.] It is impor- some cattle may still get a
Blue-green algae so that water sources that
sudden death, which may
tant to understand how results toxic dose. Merely throwing poisoning were previously safe become
strike a large number of adult
are reported since there are out one bale of “bad” and two Blooms of toxic blue- deadly under drought condi-
cattle in a herd at once with-
several ways to express nitrate bales of “good” hay does not green algae leading to cattle tions. Like nitrate poisoning,
out warning. In most cases,
concentration. In fact, one constitute dilution. Fermenta- losses occur on rare occasions the sulfur contents of feed and
cattle are found dead, and
measure of a laboratory’s ex- tion may decrease NO3 con- in the High Plains. Blooms water are additives in causing
treatment is impractical. This
pertise is whether its person- tent somewhat if there is suf- form on bodies of water un- the disease. In spite of its
is one of the more common
nel make recommendations ficient soluble carbohydrate der conditions of heat, stagna- name, it has nothing to do
causes of poisoning confirmed
based upon results and offer present, but most Wyoming tion, eutrophication (high ni- with the infectious disease
by the WSVL in cattle. Lower
more than just a number. forages lack the necessary trogen and nutrients), low flow poliomyelitis in children –
concentrations of dietary ni-
The WSVL uses less than energy to fuel the reaction. rates, and a concentrating polioencephalomalacia is a
trate may also cause abortion.
0.5 percent NO3 (measured as The probiotic feed additive wind. Toxic algal blooms lead technical term for breakdown
Hay should be sampled
the nitrate ion) as a “safe” cut- Bova Pro® (FarMor Biochem, to sudden death due to liver of gray matter in the brain,
for nitrate testing after it is cut
off for forage. Many authori- Milwaukee), based upon a pat- damage, shock, and/or central which is what happens in both
and cured. Use a bale corer,
ented Propionibacterium bac- nervous system injury. This is dehydration/salt poisoning
teria, is advertised to decrease a rare cause of loss in Wyo- and sulfate poisoning.
rumen NO3 and blood meth- ming. When losses occur, the Ponds are the biggest
emoglobin concentrations by death toll can be heavy and problem, but well water may
40 to 50 percent. Preliminary sudden. also be high in sulfates. Al-
though PEM is normally a
data looked promising when Dehydration-salt
the product was introduced problem in spring and sum-
poisoning and mer when water consumption
several years ago.
sulfate poisoning is greatest, it may occur in any
Dust and pneumonia (“polio”) season when sulfate concen-
Bovine respiratory disease, High levels of NaCl (com- trations are high or if animals
especially due to bovine respi- mon salt) and/or water depri- are abruptly exposed to high-
ratory syncytial virus (BRSV) vation are hazardous to live- sulfur waters. Clinically, ani-
Three of 130 dead cattle that died of salt poisoning over a 48- and Pasteurella (Mannheimia) stock. Sodium may affect pro- mals become blind and show
hour period in one herd in Wyoming are shown. bacteria, may be more serious duction in sensitive animals, nervous signs such as incoor-

7. UW College of Agriculture Spring, 2003 Page 7
on the high plains
dination and a goose-stepping ing large amounts of dense, and open-mouth breathing in Plants containing high con- The sudden switching of
gait. Testing stock water is poor roughage may cause ex- the absence of coughing centrations of soluble ox- feeds or increases in grains
important to prevent prob- tensive lesions in the mouth shortly after they are turned alates (Halogeton and grease- may lead to rumen acidosis
lems. Cattle develop some tol- and throat, resulting in ab- out on fertilized or irrigated wood) are more toxic when and diarrhea. Drought-related
erance to elevated sulfate wa- scesses of the head region. aftermath. This disease pre- ingested by sheep lacking acidosis is common when
ters if they are introduced to Several episodes have oc- sents a challenge to producers adequate water. Locoweeds short feed inventories neces-
it gradually. There is no cost- curred in which adult animals during periods of drought. remain toxic even in winter sitate more frequent switches
effective method for removing had such severe oral lesions Most ranchers don’t move months. Cattle may consume or when some non-traditional
sulfate from stock water. Haul- that they were unable to swal- cattle to meadows until after more locoweed during a feeds such as baker’s
ing water may be the only low and lost weight or died heavy frosts, which lower the drought. Clinical signs are byproducts or dough (high car-
option on some ranches with due to pus draining into the risk. During a drought this abortion, nervousness, and bohydrate sources) are added
a high sulfate problem. lungs from mouth abscesses. may not be an option. Preven- brisket disease. Pine needle suddenly to rations. The pre-
In one episode, 23 of 150 adult tative strategies include gradu- abortion cases may occur vention of abomasal impac-
Salinity cattle belonging to one pro- ally adapting cattle to a pas- more commonly during tions, rumen acidosis, and
Sodium and sulfate are
ducer developed large, ture over 10 to 12 days, cut- drought as cattle will eat the hazards of unusual feeds cen-
not the only elements concen-
chronic, pus-filled facial swell- ting and windrowing the pas- needles more readily. ters on providing a proper
trated in livestock water sup-
ings. Cattle had large lymph
plies by drought. A number of
nodes due to secondary bac-
different inorganic substances
terial infections. Treatment
cumulatively contribute to the
was unavailing. No foxtail or
property of water referred to
other penetrating plant frag-
as “salinity.” Simply stated, the
ments were found, and the
salinity of a water sample is
owner was adamant that he
what is left after the water is
avoided foxtail stands when
boiled off and organic com-
haying. The owner ran the
pounds are oxidized. Salinity
cattle on an arid creek where
may be indirectly measured as
there were heavy stands of
total dissolved solids (TDS) or
greasewood (Sarcobatus
conductivity. Although the re-
vermiculatus). Due to the
lationship between salinity
drought and lack of forage, the
and disease is not as clear-cut
cattle probably grazed on
as for sodium and sulfur, high-
greasewood and developed
salinity water does not sup-
extensive wounds of the
port productive animals. The These three horses have swelling of the brisket or shoulder area due to pigeon fever.
mouth due to the stiff spines
impact depends upon the
of the plant. Opportunistic bac-
class of animals and their wa- ture before turnout, and ex- Management of plant poi- diet. Rations should be bal-
teria infected the wounds and
ter requirements. For ex- posing less susceptible sonings centers on preven- anced to allow for optimal pro-
created the clinical problem.
ample, lactating dairy cows younger stock (less than 15 tion. Grazing management tein, mineral, energy, and
Coarse feed can also result
may be affected by as little as months old) or sheep to the involves the prevention of roughage contents. Roughage
in abomasal impaction in
1,000 ppm TDS whereas beef pasture first. Ionophores such overgrazing by proper pasture should be of the proper den-
cattle. Heifers in late pregnancy
cattle may tolerate as much as as monensin will prevent or rotation and by reducing sity to allow for optimal gas-
are at most risk due to the in-
5,000 to 7,000. High salinity reduce pulmonary emphy- stocking rates. Weed control trointestinal activity. Unusual
creased nutrient demands of
is more likely to result in pro- sema if fed in advance, but can be attained by proper feeds, while tempting at times,
combining growth and gesta-
ductivity losses than in clini- many cows won’t use the fencing, prudent application should be consciously avoided
tion. Pregnant heifers develop
cal disease and deaths. blocks and they are of no of weed killers, and mowing/ or viewed with skepticism.
bloat, recumbency, and die
value once clinical signs begin. plowing. If herbicides are Sudden feed switches should
Coarse feed with large amounts of black
Keep a close eye on cows for used, beware that some can be avoided. It is helpful to ac-
Poor quality feed can lead fluid in the rumens and impac-
a few days after a change to temporarily increase toxicity climate cattle to new rations
to diseases when nutritional tions in the abomasum.
lush meadows. and/or decrease the palatabil- slowly.
contents are low and/or alter- Pulmonary ity of plants.
nate feeds are abused. Feed- Toxic plants Pigeon fever
emphysema (“cow Unusual feedstuffs
The danger from poison- myositis in horses
asthma”) ous plants is magnified during Feeding of unusual feeds A disease that is unusual
Pulmonary emphysema drought. Overgrazing, aggra- or those of unknown quality for Wyoming except in
with edema (“cow asthma,” vated by poor pasture growth, and composition may be drought years is a bacterial
“grunts,” “fog fever”) is asso- forces animals to seek less tempting to ranchers when infection that most often af-
ciated with an abrupt change palatable, potentially toxic quality feed is scarce. Unusual fects the brisket of horses. It
from dry pastures to mead- plants. Plant populations in or unbalanced rations can lead is called pigeon fever because
ows, especially regrowth pastures tend to change as to mineral and other dietary of the pigeon-breasted appear-
meadows after haying. The drought-resistant weeds begin deficiencies leading to insidi- ance of affected horses.
disease occurs because of high to dominate more desirable ous disease in herds. An ex- The disease is caused by
concentrations of the amino forage plants. Drought stress ample of toxicosis due to an a specific bacterial agent and
acid L-tryptophan in forage. may increase the toxicity of unusual feed involves whey, is probably spread by flies. It
The amino acid is converted some plants such as nitrate- which when used as a supple- is not known how drought pre-
to a toxin in the rumen, caus- accumulating and cyanide- ment may contain toxic quan- disposes horses to this non-
ing an acute reaction in the forming species. Exposure to tities of salt (causing seizures) fatal disease. More than 100
lungs. The result is an acute toxic plants may occur directly or fat (causing bloat). Grazing horses with this disease were
respiratory distress syndrome on the pasture or in poor qual- of turnips has led to
This is the skinned head of a diagnosed in Wyoming in
in a high proportion of the ity feeds obtained from fields polioencepha-lomalacia (PEM)
cow with extensive abscess 2002, most in the months of
formation in the cheeks, herd. Cattle display character- stressed by drought and/or from excessive sulfur. August to November.
probably due to coarse feed. istic breathlessness, distress, overgrown with toxic weeds.

8. Page 8 Spring, 2003 UW College of Agriculture
Trees and shrubs demand special
watering to survive drought
Donna Cuin Trees and shrubs also tree roots. Remember, trees
UW Cooperative Extension need to be watered periodi- evolved in forests where tree
Service, Program Associate I, cally during the winter canopies shaded their roots
Natrona County months. The necessity for day in and day out through-
supplemental water depends out hot summer days.
T rees and shrubs are the
foundation plants in any
landscape whether in a rural
upon the presence or lack of
snow cover, daytime tempera-
tures, and wind. Typically in
Trees and shrubs have
developed over time with de-
caying organic matter cover-
windbreak or an urban setting. Wyoming the recommenda- ing the soil over their roots.
These plants live the longest tion is to apply water when the The use of organic mulches
and are the most expensive daily temperatures exceed 45 helps to recreate a more natu-
assets in landscape plantings. degrees. Warm winter tem- ral environment. As organic
With long-lasting, severe peratures lead to the loss of matter begins to break down,
drought conditions, trees and snow cover and are usually the presence of fungus will
shrubs should receive the focus brought on by warm Chinook increase, further assisting in
in sustainable landscapes. If winds. Watering is not recom- this break-down process. Trees
water supplies are short, trees near the tips of their growing application is to take the diam- mended during high winds. have lived surrounded by fun-
and shrubs should receive the ends. However, the critical root eter of a tree times the five Summer or winter, trees will gus for centuries. This is why
most attention. mass is within the drip line of minutes needed to get 10 gal- need the same amount of it has become increasingly
Tree roots develop in a the tree. By watering within lons of water flow. Therefore, water in the soil to sustain life. more prevalent for
fashion similar to that of their the drip line, one can create 8-inch diameter trees will However, in the winter, water homeowners and landscapers
above-ground growth. Trees soil moisture for the greatest need 40 minutes of water flow will not need to be applied as to do away with turf grasses
develop approximately 40 majority of the roots. to receive 80 gallons of water. frequently. Watering once a growing over tree roots within
percent of their mass above Moisture applied to turf Most trees will need three month from October through the drip line of trees and
ground and 60 percent below grass associated with trees will waterings per month from April will supply plenty of wa-
ground. This means that there also supply moisture to the April through October. ter to sustain trees. Shrubs
is more living plant tissue be- tree roots below the roots of Shrubs need to be wa- may benefit from watering
low ground dedicated to ab- the turf grass. If watering rows tered approximately once ev- twice per month if conditions
sorbing moisture and gather- of trees in a windbreak, one ery week if there is a lack of warrant watering. Shrubs will
ing nutrients from the soil. should think of it as watering natural precipitation. Estab- also require less water in the
However, the roots tend to the tree area, not the rows of lished shrubs need between 2 winter months than during the
spread farther from the trunk tree trunks. Be sure to spread and 10 gallons per week based growing season. Established
and do not grow to a depth water applications over the upon their size. Small shrubs shrubs will only require 5 to
greater than 18 to 24 inches. entire tree-root areas, rather less than 3 feet tall need 2 to 18 gallons per month during
This translates to a shallow than focusing on areas close 4 gallons of water per week. the winter months. Newly es-
root structure growing close to to each tree trunk. Medium shrubs between 3 tablished trees and shrubs
the soil surface and spreading Water deeply and infre- and 6 feet tall need 5 to 7 gal- may need watering twice per
outwards from the trunk. This quently to create moist soil to lons. Large shrubs more than month depending upon win-
spread can be up to three to a depth of 12 inches. To as- 6 feet tall will need from 8 to ter conditions.
five times the height of a tree. sure survival, a tree will need 10 gallons per week during the Mulch is a garden product
Watering trees at the drip 10 gallons of water per inch growing season. that is almost crucial for suc-
line of tree branches and be- of trunk diameter with each Newly planted trees and cess in growing trees and
yond is recommended. As watering. A typical garden shrubs need additional, shrubs during drought condi-
shown in the above illustra- hose on medium pressure will supplemental water applica- tions. Mulch is typically some-
tion, the finer moisture-gath- supply 10 gallons in 5 minutes tions during their first growing thing organic like shredded shrubs. Grasses tend to have
ering root tissues are at the ex- of run time. Test hoses for ac- season. These plants need to tree bark, chipped tree branch root structures more suited to
treme ends of the tree roots. curacy. The way to calculate expend a great amount of en- material, coconut hulls, or bacterial colonization rather
In order to gather water, the how long to leave water run- ergy to develop a healthy nu- pine branches and needles. than the fungal colonies which
roots need access to water ning for appropriate water trient and water-seeking root There is an extensive list of are preferred by trees.
system in their first year. This other materials that can also Mulched areas will also help
growth requires water and make wonderful mulch for improve the pH acid level of
nutrients from the soil. Due to tree areas. In Wyoming these soil around tree roots.
the dry climate in Wyoming, products can be difficult to use These practices in rural
the water source must be in high-wind-exposure areas, and urban landscape settings
supplemented even in low- but rocks and gravel can pro- will improve success with trees
water-requiring plants until vide alternative sources of soil and shrubs and help to con-
the root system is developed protection. The main purpose serve water during years of
and well established. During for using mulch is to prevent drought. For suggestions on
that first critical year of root soil moisture evaporation. The species and varieties of trees
establishment, small shrubs organic mulches will also and shrubs suited to a particu-
will require 4 to 6 gallons of break down to add nutrients lar area, contact a local Uni-
water per week. Remember to to the soil and improve its versity of Wyoming Coopera-
keep in mind that the soil moisture-holding capacity. tive Extension Service office.
should be kept moist, not wet, Mulches will help in weed pre-
to encourage healthy root vention and in keeping soil
growth. temperatures lower around

9. UW College of Agriculture Spring, 2003 Page 9
Rigidula medic is a new annual legume forage crop being developed by UW at the Torrington Research and Extension Center for grazing in dryland cropping systems.
Equal in quality to alfalfa, the new crop (shown here on April 15) will regenerate from soil seed if given adequate fall moisture or will maintain viability for another year.
Alternative crops can help
during drought emergencies
Jim Krall age or that lack a market struc- consideration that could lead pastures with such crops as tions on the production of al-
Professor, UW Department of ture. Type III: Crops that are to additional narrowing of the forage turnips. ternative emergency forages.
Plant Sciences lacking both a market and a choices is the potential effect To get the best out of win- These can be found at the Web
production package but which of herbicide carryover from a ter wheat, it takes 1.8 pounds site www.uwyo.edu/CES/
D rought is on everyone’s
mind. Regardless of
whether it is for irrigated crops
have potential for both.
Among the first type are stand-
bys such oats, barley, and
previous crop. Do not under
estimate this, especially dur-
ing dry periods.
and 1 pound of nitrogen and
phosphorus, respectively, to
produce a bushel of grain.
plantsci.htm.
For summer annual crop-
ping, corn, although not an
or dryland agriculture, the spring wheat. In the Type II What is the weather going Consider split applications alternative crop in the region,
search is on to find an alterna- category would be crops like to do? Many producers have between fall and spring and an is an example of a crop that
tive crop or practice that will safflower, Niger thistle, canary planted irrigated winter application of 15 to 30 pounds offers some alternative prac-
help get the most out of low- grass, flax, and amaranth. wheat. The crop has a lower of nitrogen at flowering to tices for short-water years.
water conditions. In effect, an Type III crops would be milk- water use, but the peak water boost grain protein if there will Consider lower populations,
alternative on crop dryland is weed, canola, and hemp. use is early (April 15 to July be a premium for protein. reduced fertility, or short-sea-
anything other than winter Grouping crops by season 5), which is important if there There are good pest manage- son hybrids, but remember it
wheat. For irrigated areas, it is is another way of narrowing is a concern about late-season ment packages available for is important to get the crop
anything other than corn, dry the choices. There are cool- irrigation water availability. this crop, but careful monitor- started right away with a shot
beans, sugar beets, and alfalfa. season grasses like winter Grain yield potential can run ing of insects, foliar diseases, of water if needed.
Searching for more than wheat, spring wheat, oats, up to 120 bushels per acre and weeds is important. The Each new crop has its own
these crops is critical because triticale, and barley and cool- under the best irrigated con- University of Nebraska offers set of production parameters
not all alternative crops have season broadleaf crops like ditions, and with average wa- an irrigated winter-wheat pro- and market challenges. There
a production package or a peas, canola, crambe, and len- ter 80 bushels per acre is rea- duction guide at its Web site may yet be a proso millet con-
market to fit Wyoming. David tils for spring and early sum- sonable. One can still get a at www.ianr.unl.edu/pubs/ tract to be had, but producers
Baltensperger of the Univer- mer production. There are crop of 60 bushels per acre fieldcrops/g1455.htm. Con- may end up looking to forages.
sity of Nebraska Panhandle warm-season grasses such as under stressful irrigated con- cerning a second crop of bras- If so, check the University of
Research Center breaks alter- corn, sorghum, sudangrass, ditions. With a normal year sicas or warm-season grass Wyoming Web site at
native crops into three catego- sorghum-sudangrass hybrids, and secured irrigation water, forage, there is less to go by, www.uwyo.edu/ces/Drought/
ries. Type I: Crops which pro- proso, and forage millets and one can plant a second crop but this does not mean there Drought_Main.html as well as
ducers know how to grow, that a few warm season broadleaf of brassica forage pasture or is not information available. the University of Nebraska Web
have an established market, alternatives like some forage one of the warm-season grass University of Wyoming Profes- site at www.panhandle.unl.edu/
but that may not fit current bassicas, sunflower, safflower, forage crops. In New Zealand sor Dave Koch of the Depart- drought/html/rural.html for
economics. Type II: Crops that and chickpea for summer and producers plant a large num- ment of Plant Sciences has more information on drought
are short of a production pack- early fall production. A further ber of annual forage brassica produced extension publica- and drought strategies.