A Publication of:
OSU Extension - Fairfield County
831 College Ave., Suite D, Lancaster, OH 43130
and the
BEEF Cattle questions may be directed to the OSU Extension BEEF Team through Stephen Boyles or Stan Smith, Editor
You may subscribe to this weekly BEEF Cattle letter by sending a blank e-mail to beef-cattle-on@ag.osu.edu
Previous issues of the BEEF Cattle letter
Issue # 524
February 7, 2007
Winter Cold Stress on Cattle - Steve Boyles, OSU Beef Extension Specialist and Jeff McCutcheon, Knox County ANR Agent
Factors that create stress during the winter months are cold, wind, snow, rain and mud. The primary effect on animals is due to temperature. All these factors alter the maintenance energy requirement of livestock. Maintenance requirement can be defined, as the nutrients required for keeping an animal in a state of balance so that body substance is neither gained or lost. An interesting thing to note is that while energy requirements increase, protein requirements remain the same.
Some published sources contain nutrient requirements for beef cattle that include guidelines for adjusting rations during winter weather. Even without published sources, competent livestock producers realize the need for more feed during cold weather. Make sure that water is available. If water is not supplied, cattle will reduce feed intake.
Daily dry matter intake of beef cows with respect to temperature
The metabolic response to the stimulus of cold involves practically all the systems of the body. The striated muscles shiver,
the heart beats faster, breathing becomes deeper, urine flow is increased and the sympathetic and pituitary controlled
systems are activated so to elevate biological oxidations (energy expenditure or heat production) in all tissues. The result is
an increase in the cow's requirements for energy. Spring calving cows, and particularly heifers, in poor body condition are at risk for calving problems. The result may be
lighter, weaker calves at birth, which can lead to a higher death loss, and more susceptibility to things such as scours. Animals in poor condition before calving, provide inferior colostrum and lower milk production. This can lead to lighter
weaning weights or fewer pounds of calf to sell. Females that are in less than desirable body condition at calving are slower
to return to estrus. Therefore body condition at calving affects the current calf crop (milk production) and next year's
calving date (rebreeding date). In most years hay and stockpiled forage can adequately provide the needed nutrients, but it can very widely and should be
tested to make sure it is adequate. OSU Extension has a fact sheet on Forage Testing, ANR-2-98, that describes the proper
sampling techniques for various forages and explains the results. Your local Extension Office may also have a test probe
and can help with submitting the sample to a laboratory. There is a range of temperature where cattle are neither too hot nor too cold and their performance is optimal. This
temperature range is called the thermoneutral zone. It is the temperature range where the fewest nutrients are needed to
maintain bodily functions. For cattle the lower temperatures of the thermoneutral zone are shown in Table 1. All of the
critical temperatures listed are effective ambient temperatures, which basically means the wind chill temperature is used if
the cattle are not sheltered. The critical temperatures also take into consideration the insulating ability of the cattle, as
shown by the change between a wet and dry coat. Table 1. Estimated Lower Critical Temperatures for Beef Cattle *
* From Browsen, R. & Ames D."Winter Stress in Beef Cattle" Cattle Producer's Library. CL760. If we have a choice, snow is preferred to a cold rain. We lose what is called "air insulation" in cattle that get wet versus
those that are out in the snow. The air pockets between hair fibers are a source of insulation. We lose this insulation when
hair gets matted down in a cold rain. The result is that the Dry Winter Coat goes from having a critical temperature of 32
degrees F to about 59-60 degrees F. From several studies it is estimated that for every one degree below the critical temperature a cow's energy requirement
(TDN) increases 1 percent. It is also estimated that for every ten degrees below the critical temperature the digestibility of
the ration decreases by 1 percent. This means that when the temperature drops below the critical temperature the cattle need
to be fed better. It may be that more or better hay needs to be fed Example of Effect of Temperature on Energy Needs
Besides cold weather effecting cattle performance producers have another thing to consider during winter, mud. It is less
clear what effect mud has on a cow's energy requirements but it is estimated that it can increase the maintenance
requirement from 7-30%. If cattle have to deal with mud then their ration should also be improved, to help avoid the
consequences listed above. Another tool producers have to help determine if what they are feeding is adequate, besides forage testing, is Body
Condition Scoring (BCS). In the last trimester of pregnancy a cow should have a score of 5,6 or 7 on a 1-9 scale. If a cow is
going down in BCS then the ration is inadequate and should be improved. An additional source of information can be found in OSU Extension publication: Winter Supplementation of Beef Cows
http://ohioline.osu.edu/as-fact/0001.html EDITOR's NOTE: Over the past week, wind chill has probably burned as many calories as the raw cold in Ohio brood cow
herds. The publication under the following link originates from our counterparts in Alberta, and offers valuable
consideration for portable or temporary wind break fences: Portable Windbreak Fences Steve Boyles offers the following article for consideration as a result of a potential situation for frostbite he experienced
this past week. During this cold weather, is at least your bull out of the wind? - Stephen Boyles, OSU Extension Beef Specialist During cold and windy weather, producers need to be aware of the potential for scrotal frostbite in bulls. During normal
winter conditions frostbite is not a common problem with breeding bulls, but prolonged exposure to extreme cold and wind
increases the incidence of frostbite. If frostbite occurs this can cause bull infertility the next breeding season. It can occur
in bulls that don't have adequate dry bedding or protection from the wind. During cold weather, it is a good idea for bulls to have at least protection from the wind. Defects in sperm are proportional
to the severity of the frostbite lesions, testicle adhesions and swelling of the testes. Older bulls, with lower hanging
scrotums are more frequently adversely affected because they are not as able to pull their testicles up close to the body to
keep them warm. Blisters and scabs might be observed about three weeks after the frostbite happens. A scab may appear on the lower portion
of the scrotum as healing occurs. Scabs will fall off in about a month, leaving reddish-pin scar tissue. However, the
absence of a scab does not indicate that frostbite injury has not occurred. Some protective measures such as windbreaks and good bedding during bad weather can help prevent testicle freezing.
Make sure all the bulls can get out of the wind if you maintain multiple bulls. A wind break fence out in the lot might be
considered if other bulls tend kick one of the other bulls out of the main wind protection area or barn. Bulls being trucked
in cold weather should be protected, since traveling in an open truck creates a serious wind chill factor. Evaluation of possible frostbite damage is best accomplished by a trained veterinarian performing a breeding soundness
examination 45-60 days after the injury occurred. A semen evaluation performed earlier than this period will most likely
indicate poor semen quality and could result in unnecessarily culling a bull that may produce satisfactory semen after
healing has occurred. Feeder Prices Drop - Will They Drop Further? - Brian Roe, Associate Professor AED Economics, Ohio State
University, February 2007 Usually lightweight feeder cattle sell for the lowest prices in October and November, as the flood of spring-born calves
saturate the market and drive down prices. Then, in late winter and spring, as the supply of lightweight feeder calves from
the sparser summer and fall-born calf crops comes to market, prices perk up and hit their annual peak. Unfortunately, for those contrarians - those fall calving herds who count on the late winter price spike to make going
against the grain worth the trouble - this is an unusual year. At the beginning of January, lightweight feeder cattle were
selling at Kentucky auctions for about $17 to $18 less per hundredweight than they were a year earlier and for about $10 to
$12 less than they were during October of 2006. By early February, prices declined by another $4 to $5 and my projections
suggest that prices will continue to decline by another $5 to $10 over the next couple of months. The explanation for the price decline has several obvious reasons - high corn prices, unfavorable western grazing
conditions, and slow movement of cattle into and out of western feedlots due to the fury of winter in the plains. The
swelling of corn prices pre-date the winter weather issues, and are important driver of recent feeder cattle price trends. With
corn prices soaring, lightweight feeder cattle become like Hummer's during an energy crisis - too expensive to fill up. In
case you don't remember, during 1996, when corn averaged $3.60 and spiked near $5.00 per bushel, 300-400 pound feeder
cattle sold for an average of $57/cwt for the year. The good news is that, despite futures prices for corn being around $4 for the next year, 300-400 pound feeder steers are
still trading around $115, which is higher than any price observed prior to 2005. This is considerably lower than the last
two years, however, and the price will likely decline further. Why is it likely to decline? Well, lightweight feeders are still
selling at a considerable price premium compared to heavier feeders. For Kentucky auction steers, the difference in price
between the light (300-400#) and heavy (700-800#) cattle still stands at about $30. In 1995, when corn averaged $2.80, the
premium for lightweights shrunk to $16 and in 1996, when corn averaged $3.60, the premium was a mere $4. Since corn
prices began to soar last fall, the price premium has not shrunk at all. This suggests that the premium for lightweight calves will shrink during the next year. There are two ways the premium
could shrink. The price of heavier feeders could increase (don't hold your breath) or, more likely, the price of lighter
feeders will continue to drop. If fall calving operations have calves ready for market, there may still be a window to market
these in the next month before lightweight prices plunge too much further. Otherwise operators have to consider if they can
add weight to these calves in a more cost effective way than can the back grounders or feedlots that are their typical buyers.
If operators have their own corn, they may consider finishing these animals themselves as the prices for fed cattle have
remained quite strong. Given the high price of corn, however, these operators need to put pencil to paper to determine if
their scarce corn will fetch more marketed through cattle or through the ethanol plant. Fed cattle markets remain strong, and I continue to worry that futures prices for the April and June contracts paint too rosy
of a picture. This market has been moved greatly by the troubling weather events that have mired western feedlots.
Undoubtedly this will have a negative impact of the number and weight of cattle emerging from the west. However, I still
believe that markets have over-reacted. For example, the April contract recent traded around $94.50. My calculations
suggest that, if demand for finished cattle is exactly as strong as last year, the total supply of beef in April (# head times
carcass weight) would have to be 8% below last year. Is an 8% decline in April supplies in the cards? USDA projects supply in the April-June quarter to be 1.5% higher than last
year, though this estimate may not take into account the weather events of the last 4 weeks. Nonetheless, feedlot inventories
for January were at record levels as were the number of cattle on feed for more the 120 days. Even if the recent weather
events move supply from a projection of +1.5% to -5%, I still see prices to be about $5 too high if demand is unchanged
from last year. A similar situation holds for June - USDA projects supply to +1.5%. In order for June prices to meet the
$91 futures prices recently traded on the Chicago Mercantile Exchange, the supply would have to drop to a 5% decrease if
demand is unchanged from last year. Needless to say, I see these recent prices as a good opportunity to hedge feedlot sales
for the spring. Furthermore, I see no such undue optimism in the August, October or December futures prices. Forage Focus: Benefits of Frost Seeding Legumes - Curt Stivison, Fairfield County Soil and Water Engineering
Technician Adding legumes to hay and pasture fields brings at least four benefits and frost seeding is a simple, but effective method.
Broadcasting legume seed on the soil surface as it 'honeycombs' in late winter (February 15 to March 15) allows the seeds
to become covered as the soil freezes and thaws. 1) Higher yields: The total yield of forage per acre is increased. For example, a study conducted at Lexington, Kentucky
compared renovating a fescue pasture using red clover to fertilizing the grass with nitrogen. In this study, adding 6 pounds
of red clover seed to a fescue pasture produced higher yields than fescue fertilized with up to 180 lb N/ac. 2) Improved quality: Adding legumes to grass fields improves forage quality over grass alone. This added quality includes
increases in palatability, intake, digestibility, and nutrient content. The result is improved animal performance. Research
has shown that legumes improve animal growth rates, reproductive efficiency, and milk production. 3) Nitrogen fixation: Legumes get their nitrogen needs from symbiotic bacteria that live in "knots" (nodules) on their roots.
These bacteria are added when the legume seed is inoculated. This "fixed" nitrogen provides the nitrogen needed by the
legumes and also grasses growing with them. Alfalfa usually fixes the most, between 200 and 300 pounds/acre/year, while
annual lespedeza is on the low side with about 75 pounds. Red clovers can fix 100 to 200 pounds of nitrogen/acre/year.
With nitrogen cost at 40 cents a pound that equals 40 to 80 dollars an acre benefit in nitrogen alone. At the recommended
seeding rates of 6 to 12 pounds (depending on conditions) and a cost of 2 dollars a pound, that equals 12 to 24 dollars. 4) More summer growth: Most of the growth of cool-season grasses occurs during the spring and fall. Legumes make more
growth during the summer months than cool-season grasses. Growing grasses and legumes together improves the seasonal
distribution of forages and provides more growth during summer. Controlling grass and weed competition in a new seeding is critical. Many attempts at renovation have failed simply
because grass was allowed to grow and reduce the light, nutrients, and water available to the young legume plants. The
grass must be kept short by grazing or mowing until the new legume plants are 3 to 4 inches tall. Stop grazing if the
animals begin biting off the young legume leaves. Grazing and mowing should be stopped for several weeks to allow the
legumes to become well established. After this, the field should be mowed or grazed on a schedule that will help keep the
particular legumes used in good condition. A rotational grazing system helps keep legumes in the stand longer. Visit the OSU Beef Team calendar of meetings and upcoming events BEEF Cattle is a weekly publication of Ohio State University Extension in Fairfield County and the OSU Beef Team. Contributors include members of
the Beef Team and other beef cattle specialists and economists from across the U.S. All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race,
color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status. Keith L. Smith, Associate Vice President
for Ag. Admin. and Director, OSU Extension. TDD No. 800-589-8292 (Ohio only) or 614-292-1868 Fairfield County Agriculture and Natural Resources
Temp, F
<5
5-22
22-41
41-59
59-77
77-95
>95 intake, % change
1.16
1.07
1.05
1.03
1.02
0.90
0.65
Coat Description
Critical Temperature Summer Coat or Wet
60 degrees F Dry Fall Coat
45 degrees F Dry Winter Coat
32 degrees F Dry Heavy Winter Coat
19 degrees F
Effective Temperature
Extra TDN Needed
Extra Hay Needed (lbs./cow/day)
or, Extra Grain Needed, (lbs/cow/day) 50 F
0
0
0 +30 F
0
0
0 10 F
20%
3.5-4 lbs
2-2.5 lbs -10 F
40%
7-8 lbs
4-6 lbs.
