Agriculture News: Flies around early and in high number

By Keenan Bishop Published:

 

We keep talking about how everything seems to be 2-3 weeks early this year. In the case of weeds and pests they also seem to be greater in numbers. Flies are always a problem on livestock and controlling them can sometimes be a challenge.

Horn flies

Horn flies are the ones found on the back and sides of the animal facing towards the ground. Horn fly control can mean an additional 12 to 20 pounds of weight per calf over the summer months and can result in less weight loss per nursing cow as well.

Horn fly numbers can be kept below the 100 fly per side treatment threshold with a variety of methods so factors such as cost, convenience, physical layout, and animal movement between pastures should be considered when designing a control program. 

Since the flies spend most of their time on their host, they are an easy target for insecticide treatments, with dust bags and ear tags providing the most consistent control. The goal is to get fly populations lower than 100 flies per animal.

Producers should be aware that some flies, being a recurring nuisance, have developed resistance toward certain insecticides over the years. To prevent horn fly resistance, producers may want to rotate annually the type of chemical they use, only treat cattle with more than 200 flies and those that are 1-year-old or less, and remove ear tags after fly populations begin to decline in the fall.

Face flies

There is no good information on the number of face flies needed per animal to cause an economic loss. These flies are very annoying but even heavy infestations do not seem to reduce the rate of weight gain. Face flies can carry pinkeye from animal to animal in the herd but outbreaks of this disease occur even when there are no face flies around. 

Closely resembling a house fly, they feed off moisture from the animal’s face, including tears, saliva, blood and mucous. In addition, their bites can make cattle more susceptible to pinkeye.

“While not the sole factor in pinkeye outbreaks in herds, the face fly can play an important role,” Townsend said. “It is a strong flier, and its irritating feeding abrades the eye, which allows it to pick up the pathogen from an infected animal and to transfer it to an uninfected one.”

Unlike the horn fly, face flies spend little time on an animal, as they jump from one to another until they get sustenance. 

“While elimination of face flies is not a practical goal, it is possible to reduce their numbers,” Townsend said.

He added, in some cases, impregnated ear tags have reduced populations by 70 percent. Dust bags and back rubbers with fly flips also allow producers to effectively control flies when placed in areas where the animal has to rub against them to get to food or water.

Field Day July 12

Get your meal tickets now for the 54th annual Farm-City Field Day set for 9 a.m.-2 p.m. Thursday, July 12 at the farm of Sherman and Gail Peyton, 739 Colston Lane. They are free and available at the Farm  Bureau Offices  on Wilkinson Blvd. and in Prevention Park.

 

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