Internal parasites are a problem that every beef producer must face. They are a constant annoyance that can rob a beef operation of its productivity. They impair production by increasing maintenance energy costs, diet digestibility, and immune activity.
Internal parasites, often underestimated, can significantly impact the profitability of beef cattle. Consider this, a beef operation with 100 cows could potentially lose over $ 10,000 annually due to reduced productivity caused by internal parasites. However, research has shown that proper deworming can increase weaning weights by over 30 pounds and pregnancy rates by over 10%. These statistics highlight the potential for increased profitability through effective parasite control, a compelling reason to take action.
Controlling them requires correct planning and proper timing. To maximize efficiency, you need to use the right dewormer at the right time of year. Here are some things to consider when planning your deworming program.
Dangers of internal parasites
The total effect that internal parasites can have depends on several factors. Things like age and even stress levels play a part in infection. Calves are more likely to have them than mature cows, and cows will typically develop a decent immunity to them by around four years of age.
Internal parasites pose a significant threat to cattle health and productivity. Beyond the obvious health problems, they can lead to a severe drain on productivity. The most significant impact is the decrease in voluntary feed intake, which responds to changes in the abomasum. This reduced intake hampers the absorption and digestion of critical nutrients, leading to economic losses estimated to be over $3 billion annually in the livestock industry. This alarming figure should serve as a wake-up call for beef producers to prioritize parasite control.
Though there can be others, four parasites are typically the most common. These include hairworms, Lungworms, Liver flukes, and Coccidia. Each of these parasites has a unique life cycle, specific symptoms to look out for, and different treatment options. Understanding the life cycle of these parasites is crucial for effective control. I reviewed these parasites’ different symptoms and treatment options in a previous post, “Four common cattle internal parasites.”
Understanding the life cycle of internal parasites is crucial for effective control. The main form of transmission for these parasites is that they are present on the grasses that cattle graze. Cattle consume the eggs, and they enter their intestinal tract or abomasum. Parasites lay eggs there, passing through the digestive tract and returning to the environment via manure. These eggs are very resilient and can survive things like extreme temperatures. Kansas State has a paper, ‘Understanding Internal Parasites in beef cattle,’ that provides detailed insights into the life cycle of internal parasites, empowering you with knowledge for effective control.
3 classes of dewormers
While there are many options when it comes to deciding what product to use, what you use depends on several different factors. An important one is which product you used last time. Using the same product all the time can cause resistance to it. Resistance is when the parasites become less affected by the dewormer, thus making it ineffective. This is why it’s crucial to rotate the active ingredients in your deworming program.
Though there are many different brands at your local feed store, typically, they fall into three categories of active ingredients. Benzimidazole, macrocyclic lactones, and imidazothiazoles are the three different types of dewormers. Each type has its own advantages and disadvantages. For instance, macrocyclic lactones are effective against a wide range of parasites. They can be administered in different ways, but they are more expensive. On the other hand, Benzimidazoles are more affordable but may not be as effective against all parasites. Understanding these differences can help you choose the right dewormer for your herd.
- Benzimidazoles: found under the drug names fenbendazole, oxfendazole, and albendazole. The commercial names for them are Safe-Guard, Panacur, Synanthic, aValbazen, Bimectin, and Noromectin.
- Macrocyclic Lactones are found under the drug names eprinomectin, doramectin, ivermectin, and moxidectin. Their commercial names are Eprinex, Eprizero, Ivermectin, Ivomec, LongRange, Dectomax, and Cydectin.
- Imidazothiazoles are found under the drug name levamisole. LevaMed and Prohibit are commercial names.
When to use a dewormer
Most producers apply deworming at a specific time of year. Typically, it happens when they are running the cattle through the chutes, casting, and dehorning. However, doing it this way can cause more problems than it solves.
Regular monitoring and adjusting of your deworming program is key to maintaining its effectiveness. The only natural way to determine the effectiveness of a dewormer is to use a Fecal Egg Count Reduction Test. This test measures the number of eggs present in the pasture before and after administering dewormer. An effective treatment reduces the fecal egg count by 90% or more after treatment. This test is a valuable tool for monitoring the effectiveness of your deworming program. It can help you identify if and when resistance is developing. By staying proactive and adjusting your strategies, you can ensure the health and productivity of your herd.
If, by using the fecal egg count reduction, you find out that your current program is not practical, there are some practices you can use to improve:
Deworming strategies
- Only deworm “high-risk” animals will include younger cattle, ones less than 16 months, and calves.
- Do not deworm by the calendar: Cattle should only be dewormed when they need it. An easy way to determine the parasite load of a herd of cattle is to count fecal eggs together.
- Perform selective non-treatment: To do this strategy; producers should deworm all the animals in the high-risk groups except for the top 10-15% heaviest/best performers.
- Utilize combination treatment: This strategy involves treatments simultaneously with at least two drugs in different classes. An example of this would be using one benzimidazole and one macrocyclic lactone. Using this approach, parasites resistant to one type will likely be susceptible to the other. This susceptibility would significantly reduce the selection pressure for resistance to either drug.
- Avoid under-dosing. This typically occurs when animals are not weighed before treatment, meaning they are given a lower dose than is required for maximum effect. Under-dosing is a severe problem that contributes to the selection of resistance.
- Examine grazing practices: Overstocking and overgrazing force animals to graze closer to manure piles, increasing the risk of parasite exposure. Using rotational grazing and giving pastures enough rest can help break the parasite life cycle and reduce exposure.
Getting the most from your dewormer
Making an excellent internal parasite program takes a little more than just using a dewormer. The timing and application of the drug play a considerable role. How often you use a particular drug is also a significant factor.
You will need to change the specific drug to prevent resistance. Resistance is a natural process where parasites develop the ability to survive exposure to a particular dewormer. This resistance is not due to individual parasites becoming immune but rather the population of parasites becoming less susceptible to the drug. Only after exposure to 1 over time will the parasites develop genetic resistance, so you will need to hit them with something new from time to time.
Now, this means more than just changing the brand of dewormer that you use. As I showed earlier, different brands have the same active ingredient. What you want to do is to change the active ingredient that you use.
