Last year, farmers lost $21 billion due to the impact of parasites on cattle health and productivity. While worms are common, you can get ahead of them to protect your profitability.
In this post, we cover:
Just a single parasitic worm can create tens of thousands of eggs. With as many as 80% of U.S. cattle having parasites, it’s critical for beef and dairy producers to have a robust deworming strategy to protect the well being and productivity of their herd.
“For the beef industry to meet an expected 14% growth in global meat consumption by 2030, major improvements will be needed in parasite management,” says Tom Strydom, MSD Animal Health global director for parasite management for ruminants.
Unmanaged parasite loads threaten the health and productivity of herds. Cattle impacted by worms can experience:
Clinical disease from parasites
Weakened immune system
Reduced fertility and reproduction
Lower-weight calves
Minimized growth
Diminished milk production
While even severe parasite burdens in cattle are rarely fatal on their own, high worm loads weaken immune function, making them more susceptible to other infections.
With about 90% of worms on the pasture, cattle become infected with worms through grazing. They ingest the larvae in the grass.
Feed bunks and water sources can also become contaminated. Because parasitic worms can live in the digestive tract, their eggs can be found in their feces. This is part of why properly cleaning and sanitizing barns, pens, feed bunks, and water troughs are critical.
Keep in mind that worms can withstand harsh habitats. “Parasite eggs are very resilient and can survive in the environment for long periods of time. This includes surviving drought and winter conditions,” reports Kansas State University.
The most common examples of parasitic worms that impact cattle include:
Cooperia
Haemonchus
Ostertagia
Trichostrongylus
By carefully monitoring your cattle, you can catch signs of worms. Look for:
Digestive impairment, sometimes accompanied by diarrhea
Loss of appetite, which can lead to dramatic weight loss
Listlessness
Substandard coat quality
Because worm infection in cattle typically begins on pasture, your parasite control program should include pasture management. Pair animal health products with grazing management strategies to optimize parasite control in your herd.
About 90% of the worms in your pasture are in the lower four inches of grass. Consequently, Bovine Veterinarian says: “the harder you graze your pastures the more worms your cattle will ingest.”
Overgrazing can lead to excessive parasite loads. Best practice is to wait until your grass is at least four inches tall before allowing cattle to graze.
Pairing dewormer products with grazing management can help you protect your herd and increase your ROI. It's crucial to know the best practices for deworming cattle, including the timing and frequency of dewormer administration, identifying which cattle are most susceptible to worms and whether all cattle should be treated, and understanding the benefits of using multiple dewormers.
Initiating deworming protocols during the nursing calf stage can boost performance and increase weaning weight.
Cattle may be dewormed one to two times a year. Deworm cattle before spring turnout and during fall run.
Cattle under 12 months of age can easily become infected with worms. Calves have yet to build up the robust immune system of older members of the herd.
Bulls are more prone to parasite infections than cows.
About 10% to 20% of your strongest-looking cattle should remain untreated for parasites.
Treat the remaining 80% to 90% of your herd with dewormers. The surviving worms from these treated cattle will not only be drug-resistant but so will their offspring, which means that, over time, the majority of worms will be resistant to deworming treatments.
Leaving at least 10% of the herd untreated reduces the building of a population of drug-resistant parasites. Instead, the worms that remain can be treated effectively with available animal health products.
Dewormer resistance is a growing concern for livestock producers. Since the introduction of anthelmintics, worms have evolved to develop genetic resistance to various deworming compounds.
The macrocyclic lactone drug class is particularly susceptible to cattle dewormer resistance.
While completely eradicating worms may seem like the goal of parasite control, this could actually create super worms that are resistant to drugs. Therefore, the USDA Center for Veterinary Medicine suggests the practice of refugia – not exposing some parasites to a dewormer – to “slow the development of resistance on your farm.”
For the best protection against parasites, producers should use more than one type of deworming product.