Cattle Weight Gain Hinges on Controlling Parasites

Feb 15, 2020

Tara Jo Bina

Countryside Feed Sales & Nutrition Professional

When it comes to protecting cattle from parasites, there are two types to focus on – internal and external.

Internal parasites, including a number of different worms, live inside the gastrointestinal tract. External parasites, like ticks and flies, live on or around your animals and become an issue when you turn them out to pasture. Although both can cause economic damage, they require different control methods and there are a number of options to choose from. Here’s a look at the steps to take to get a handle on parasites and prevent the weight loss they can cause.


When left untreated, worms can suppress appetite, reduce feed intake and negatively impact the animal’s immune system. In fact, research suggests that producers can lose up to $190 in performance per head over an animal’s lifetime due to harmful internal parasites.1 We offer two dewormers at Countryside Feed – Safe-Guard® and Ivomec® Pour-On.

Safe-Guard® is a feed-through product that goes directly to the gut, killing worms where they live. According to product research, results prove 90 percent reduction in fecal egg counts.2 Ivomec® Pour-On is a topical product that controls 33 species and stages of internal and external parasites, including lice. Both products can provide excellent control, but talk with your local Countryside Feed representative before choosing one over the other to make sure it’s the best fit for your operation.


Most active in the spring, ticks that carry Anaplasma transmit the blood parasite to cattle through their bite, causing Anaplasmosis. In addition to killing adult cattle, this infectious disease can also cause abortions, decreased weight gain and bull infertility. The incubation time for the disease to develop varies from 3 weeks to more than three months.

An effective way to protect cattle from Anaplasmosis is to feed them a chlortetracycline (CTC) product like Aureomycin® year-round in their feed or mineral mix. Available at Countryside Feed in both granular and meal form, it’s also effective against a wide range of respiratory and enteric diseases, it controls Pasteurella and treats bacterial enteritis caused by E. coli.

Another thing you can do is control tick populations in your pastures, which is best achieved by implementing a pasture-burning program. In addition to reducing tick numbers, performing a controlled burn offers a host of other benefits, such as the elimination of invasive species in favor for more desirable, native plants.

Horn Flies
Horn flies can cause the most economic damage of all parasites, as they stay on or around an animal for their entire lifespan, typically only leaving to lay their eggs in fresh manure. There can be hundreds or even thousands of horn flies on every animal in your herd and their bites cause stress, prompting your cattle to go off feed and spend energy trying to dislodge them. If left unchecked, this can lead to a significant reduction in weight gain.

While it isn’t possible to totally eliminate horn flies, you can limit them to around 200 per animal with one of the following methods:
  • Mineral additives offer excellent protection for as long as they’re mixed in your feed. We carry Altosid® IGR at Countryside Feed, which is a high quality feed-through insect growth regulator that stunts the horn fly life cycle in the pupal stage, preventing the emergence of biting adult flies.
  • Ear tags are another effective way to keep fly populations down. Generally they offer 90 days of protection, so you’ll need to retag cattle about halfway through the season to keep them protected.

Mineral additives and ear tags cost about the same per head, per season. With the weight they help cattle build, these fly control products always pay for themselves – even in a poor market. When beef prices are strong, fly control is a no-brainer.

If you have questions about selecting the right parasite control measures for your beef operation, please call your local Countryside Feed nutritionist. As mentioned earlier, some choices are better than others depending on your operation, so we’re always here to help you make the right selection for your cattle. 

1 Economic analysis of pharmaceutical technologies in modern beef production, John D. Lawrence and Maro A. Ibaruru, Iowa State University, 2007.

2 1992. World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) methods for the detection of anthelmintic resistance in nematodes of veterinary importance. Vet Parasitol. 44, 35-44. 2. 2006 The detection of anthelmintic resistance in nematodes of veterinary importance. Vet. Parasitol. 136, 167-185

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