NEWS for North Dakotans
Agriculture Communication, North Dakota
State University
7 Morrill Hall, Fargo, ND 58105-5665
July 30, 1998
What has four hooves and flies? The answer this summer is North Dakota's cattle.
This summer's warm, moist weather has produced a bumper crop of flies and mosquitos, and they're as annoying to cattle as they are to humans, says John Dhuyvetter, North Dakota State University Extension livestock specialist at the North Central Research Extension Center near Minot.
"We've had a number of producers reporting a large buildup of flies around their cattle," Dhuyvetter says. "Research shows that heavy insect infestations can cut calf growth by 15 to 20 percent."
Livestock bothered by flies are extremely uncomfortable and often can be observed bunched together as a form of cooperative protection from the insects. "When they're standing bunched together like that, they're not out eating or drinking like they should be, and that's lost production," Dhuyvetter says.
He notes that many of the region's cattle producers have shifted away from fly control. "Because of the need to rotate products to avoid the development of resistant insect populations, producers began to look at fly control as a nuisance. Also, with low cattle prices, eliminating fly control is an easy cost-cutting measure."
But with this year's insect boom, cattle producers may want to rethink their strategy. Some options to consider:
n Ear tags that have been impregnated by insecticide are still a good option. Ideally they should be changed each year to avoid the development of resistant pests. The use of a single insecticide over the long term creates a favorable environment for the few resistant insects that exist in any population.
n Mass treating cattle with sprays can be effective. Cattle need to be gathered together and the spray needs to be reapplied once a week or even more often in some cases.
n Dust bags and rag oilers are self-service insecticide applicators for cattle. Although they are among the oldest fly control methods, they are still effective if they can be placed where cattle are forced to use them regularly.
n Pour-on insecticide formulations provide good protection against selected insects, and the protection can last up to two months.
n Some insecticide formulations can be mixed in feed to provide protection to cattle and kill insect larvae in manure.
"The method producers use will depend on cost and on how cattle are handled this time of the year," Dhuyvetter says.
Livestock facilities can serve as a potential breeding ground for insects. Dhuyvetter says, "Sanitation probably needs a little more consideration at this time of year. Keeping feed spills and manure scraped up will help keep fly populations down around livestock handling facilities."
###
Source: John Dhuyvetter (701) 857-7682
Editor: Tom Jirik (701) 231-9629