Chute N The Bull

Heat stress can greatly impact cattle producers through decreased milk
production and subsequent calf growth, decreased reproductive
performance in cows and bulls, and decreased stocker and feeder
performance. It has been estimated that heat-related events in the
Midwest have cost the cattle industry over $75 million in the past 10
years. As summer approaches, make preparations to reduce the risk of
heat stress in your cattle.
The ideal temperature range for beef cattle is between 41° F and 77° F.
When temperatures exceed this, cattle are at risk of heat stress. Many
environmental factors affect the potential for heat stress, including
relative humidity, wind speed, solar radiation, ground cover, access to
water, diet, shade and nighttime temperatures. In addition, individual
animal characteristics can contribute to heat stress. These include hide
color, breed, health, adaptation, hair coat length and disposition. When
a combination of these factors and ambient temperature cause an animal's
heat load to exceed its ability to dissipate that heat, heat stress
occurs.
Identifying Heat Stress
When heat stressed, cattle exhibit many physical and behavioral changes.
Heat-stressed animals will have increased body temperatures, increased
water consumption, decreased feed consumption and decreased weight
gains. These changes may be subtle and difficult to recognize or
impractical to measure. Fortunately, there are many signs of heat stress
that are easy to recognize. The most obvious are cattle congregating in
shady areas or standing in ponds, and decreased grazing activity. You
may also notice cattle panting. According to the USDA's Agricultural
Research Service, more than 90 breaths per minute is an indication of
heat stress, and a respiration rate over 110 indicates a dangerous heat
stress level.
Tools are available to help producers identify conditions that are
potentially dangerous for cattle. The Livestock Weather Hazard Guide
provides guidelines that indicate the potential of heat stress at
different temperatures and relative humidity.
Another way to monitor heat stress conditions in your area is the Heat
Stress Forecast. The USDA has developed a Web site that reports heat
stress forecasts for the central United States. These forecasts provide
a more accurate prediction because they account for wind speed and solar
radiation in addition to temperature and humidity. This Web site can be
found at: www.ars.usda.gov/Main/docs.htm?docid=17130.
Managing Heat Stress
Provide fresh, clean water to cattle at all times. Water intake
increases during times of heat stress, so make sure that piped water can
refill tanks fast enough to keep up with cattle demand. If ponds are the
only source of water, monitor water quality throughout hot, dry periods.
Be sure that cattle have adequate shade. If shade is limited, heat
stress can be compounded by animals crowding together.
If possible, avoid working and transporting cattle during periods of
heat stress. If cattle must be worked or rotated to a new pasture, do it
as early as possible in the morning.
Heat stress can also affect the reproductive performance of cows and
bulls so plan your breeding season to avoid the hottest months. Keep in
mind that heat stress can impact semen quality for up to eight weeks.
Be prepared by planning now for heat stress. As hot weather approaches,
monitor the Heat Stress Forecast or use your local conditions with the
Livestock Weather Hazard Guide to determine the potential for heat
stress in your cattle. You can find this and past articles on the web
at www.mycountrytractor.com for your reference. Extension programs
serve of all ages regardless of socioeconomic level, race, color, sex,
religion, disability, or national origin. The Texas A&M University
System, U.S. Department of Agriculture, and the County Commissioners
Courts of Texas Cooperatings serve of all ages regardless of
socioeconomic level, race, color, sex, religion, disability, or national
origin. The TeAgriculture, and the County Commissioners Courts of Texas Cooperating




Thank you,
Tommy Neyland
County Extension Agent
Texas Agrilife Extension Service
P.O. Box 188
Centerville, Texas 75833
903.536.2531 phone
903.536.3804 fax

Chute N The Bull

Every spring, our thoughts turn from calving season to breeding season, green grass, rainy days and warmer temperatures. But with the growing pastures and pleasant temperatures come some disadvantages as well - fly season is upon us.

Flies will be abundant by the time this News and Views article hits your mailbox. At the time of writing this article in late March, I already have noticed a large number of flies on livestock. If you have not already started a fly control program for this year, you are probably already behind the curve. With the early spring rains, 2008 promises to be favorable for insects.
Cow

Flies are a nuisance for humans, but an even greater nuisance for livestock. Additionally, flies can spread disease, from anaplasmosis to pink eye. They are also responsible for a tremendous amount of lost production in the form of decreased weight gain or lower milk yields. Rather than eating, cattle will spend time stomping and tail-swishing, lying down, standing in groups or in the middle of a stock pond.

It doesn't take a large number of flies to have an impact on your cattle's production. As few as 100 to 200 flies per side is enough to impact stocker gains by 50 pounds during the summer. This is greater than or comparable to the weight gain achieved through a growth implant program. If you can see more than a hand-sized patch of flies on each side, typically behind the shoulders, of your cattle, there are enough to be a problem.

There are many methods of fly control. Some of the more common methods are: pour-on, sprays, rubs or dusters, ear tags, feed-through additives and biological control. Some methods work better than others and each has its place. Using a combination of methods will afford you the most effective control. Also, remember to change the class or family of chemical you use periodically to reduce resistance.
The following are a few thoughts on the various control methods:

Pour-ons and sprays provide a good initial kill with two to six weeks' residual. Sprays will typically wear off faster. Rainfall or cattle lingering in stock tanks reduces the duration of protection.

Rubs and dusters are an effective method of control once the cattle associate the use of the applicator apparatus to a reduced insect load. It is best to place the applicator next to mineral feeders, water sources or an area that will force the cattle to rub up against it. Additionally, the chemical will need to be recharged once every one-two weeks or after a rain.

Ear tags are a very effective season-long treatment, but remember to cut the tags out at the end of the season. Leaving the tags in builds resistance to the chemical. Change the active ingredient from year to year. If you used a synthetic pyrethroid this year, change to an organophosphate or organochlorine tag next year.

Feed additives are effective in stopping the fly life cycle. But one of the biggest obstacles is ensuring consistent and adequate intake of the product to have effective control.
Biological control in the form of fly wasps, sometimes called fly predators, is also effective. Some feedlots have started using this method as the fly wasps are considered a natural, nonchemical method of control. Since they are weak fliers, the wasps must be placed in areas of high manure concentration, i.e., feedlots or horse stables. They do not reproduce so they have to be replenished monthly during the fly season.

Remember to follow label directions and applicable withdrawal times prior to slaughter. Getting in control of your fly problem will make your cattle more comfortable and your wallet happier. You can find this and past articles on the web at www.mycountrytractor.com for your reference. Extension programs serve of all ages regardless of socioeconomic level, race, color, sex, religion, disability, or national origin. The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperatings serve of all ages regardless of socioeconomic level, race, color, sex, religion, disability, or national origin. The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating


Thank you,
Tommy Neyland
County Extension Agent
Texas Agrilife Extension Service
P.O. Box 188
Centerville, Texas 75833
903.536.2531 phone
903.536.3804 fax