May 2013
Farm & Field

Fly Control is a Must in These Economic Times


Horn fly levels in excess of 200 fly per animal threshold results in economic losses. Conveniently and safely control horn flies with SWEETLIX feed-through fly control products!

Excessive fly populations can literally suck the profits out of your cattle. Biting flies reduce weaning weights, lower milk production and spread disease. In today’s economic environment, it is more important than ever to keep fly populations in check to maximize efficiency and profitability.

Horn flies are the most economically significant fly with which cattlemen need be concerned. The irritation and blood loss caused by biting horn flies reduces calf weaning weights by 12-14 pounds. Average daily gain in yearling steers can be reduced as much as 30 pounds during a grazing season. Horn flies also cause lowered libido in bulls, resulting in reduced reproductive efficiency.

Adult horn flies are dark gray and about half the size of the housefly. The lifecycle is completed in 8-45 days depending on temperature and humidity. Horn flies tend to rest quietly on the backs and shoulders of cattle until disturbed (photo above). Horn flies rarely leave their hosts except to lay eggs, to move to other cattle in the herd or when cattle enter buildings. Most feeding occurs along the underline of the animal and results in scabby, often bleeding, sores. Each fly may feed from 10-38 times each day! Grazing time is disrupted, resulting in significantly reduced weight gains and daily production.

The methods to control horn flies are many and varied, but most rely upon chemical control.

Pesticide-infused ear tags have been widely utilized with success. However, this method requires the labor and stress of handling cattle twice – once to apply the ear tags and another to remove these tags. Failure to remove ear tags as recommended leads to development of pesticide resistance and reduces the overall success of this method over time.

Sprays and pour-on pesticides can also be effective; however, they also require extra labor and handling of cattle. Another point is that they offer short-term control (one month or less). Therefore, in order for this method to offer optimum control, cattle must be handled and treated monthly throughout fly season. Additionally, there is the fact the applicator must handle these chemicals and the associated safety issues therein.

Some utilize backrubs laced with pesticides and oil. This method yields mixed results. It is difficult to get all cattle within the herd to properly utilize these rubs on a consistent basis. Additionally, labor is required to properly maintain these rubs to make sure they are not dislodged and maintain effective levels of pesticides.

One of the most convenient and effective methods of horn fly control involves self-fed mineral supplements and blocks. These supplements contain active ingredients interrupting the horn fly lifecycle, effectively reducing the overall population of horn flies. Self-fed fly control requires no additional labor and no cattle handling, unlike the previously mentioned methods. Just provide self-fed mineral supplementation to cattle as you normally would.

SWEETLIX branded blocks or minerals contain either Rabon oral larvicide or Altosid IGR, which conveniently and effectively control horn flies. Both active ingredients disrupt the horn fly lifecycle to prevent future generations of flies. Neither Rabon nor Altosid have slaughter withdrawal times and can be fed to all classes of cattle including nursing brood cows and calves. Additionally, Rabon is labeled for use in horses.

For best results, start feeding SWEETLIX branded fly control products at least 30 days before the projected last frost and 30 days after the first frost. In some areas, these dates will overlap. Horn flies emerge when average daily temperatures reach 65 degrees for a period of at least two weeks. Be sure to provide at least one mineral feeder or block per 10-20 head. Locate mineral feeders or blocks where cattle congregate (near watering, loafing or shade areas, etc.). Increase or decrease the number of mineral feeders or change locations if necessary to adjust for proper consumption. Remember, neither Rabon nor Altosid will kill adult flies. Use of approved adulticides will be necessary to eliminate adult fly populations when Rabon- or Altosid-containing supplements are introduced after adult horn fly infestation is already established.

Selected SWEETLIX fly control supplements available through your local Quality Co-op include:

SWEETLIX Pest-A-Side Block

SWEETLIX Rabon Molasses Pressed Block

SWEETLIX EnProAl Rabon Supplement

SWEETLIX 6% CopperHead ROL

SWEETLIX 6% CopperHead IGR

SWEETLIX 4% CopperHead IGR

These represent just a few of the many SWEETLIX supplement products available through your local Quality Co-op. Visit or call 1-87SWEETLIX to learn more.

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In summary, horn flies represent a costly drain on profitability. Fly control is a must in these trying economic times in order to maximize efficiency and profitability. Your local Quality Co-op can offer many tools for effective fly control, including the convenient, self-fed SWEETLIX fly control options previously listed.