Timing is Key to Spring Pest Control Program for Pasture Cattle
Implementing an insect pest control program is just part of doing business at most modern dairies and cattle feeding operations. An integrated pest management program should address insect breeding areas as well as the pests actually on cattle. Management of manure, feed spillage, and general sanitation practices, and use of fly predators, fly baits, and premise sprays can be integrated with individual animal treat-ments to help control pest populations.
But what about cow-calf or stocker operations where cattle are managed on pasture? Asked to recommend spring pest control measures for pasture cattle, University of Nebraska Veterinary Entomologist Roberto Cortinas says insecticides are the most viable tools for reducing pest populations and their negative effects on animal performance.
“But there are no set rules for choosing a type of insecticide or method of application,” states Cortinas. “It just depends on the operation, the economic threat insect pests present, what kind of control the producer expects, and what the producer is willing or able to do about it. Topical applications (sprays and pour-ons), self-applicators (backrubs, face-mops, and dust bags), and insecticide ear tags can provide control when used properly. They all have advantages and disadvantages.”
Cortinas says timing is important, regardless of the type of product used. Implementing fly control measures too early isn’t cost effective, and being late won’t deliver the desired results.
“My advice is to monitor herds for flies and implement controls after flies appear but before populations reach economic threshold levels. And to address the resistance issue, I advise changing each year to a product with a different chemical compound.
”Producers should also consider treating cattle for internal parasites, and roundworms in particular, in the spring. According to Texas AgriLife Extension Veterinarian Floron (Buddy) Faries, the best time to deworm cattle is when larvae are developing in the lining of the stomach and intestines, during spring and fall.
Together with their own veterinarian, producers can design a strategic deworming program incorporating timely removal of the parasites and pasture management aimed at reducing op-portunities for cattle to become reinfested by ingesting worm larvae in contaminated pastures. Ideally, dewormed cattle should be moved to a clean pasture immediately after treatment, particularly if an oral dewormer is used. However, ivermectin dewormers persist longer in an animal’s system, offering some extended protection against reinfestation.
Faries says there are times when spring deworming may not be cost-effective, as in the wake of drought conditions. For effective transmission of larvae to cattle, pastures must experience at least three weeks of ample moisture and soil temperatures over 55 degrees. If these conditions did not occur, Faries says cattle aren’t likely to benefit from deworming.
“But when the timing is right for deworming, it is cost-effective,” adds Faries. “That’s particularly true for young cattle which are more susceptible to depressed performance due to a worm burden.”