Parasites are just a part of raising cattle on pasture, but there are management strategies beef producers can use to limit infestation and minimize economic impact on production. No beef producer wants their cattle overrun with worms and susceptible to disease, reduced gain or death.
The goal with parasites is to keep them under the economic threshold of the cow. Here are five tips to help your cattle keep nutrients focused on gain instead of wasting nutrients on parasites.
1. Rotate Pastures
Parasitic lifecycles go from eggs in manure to larvae. According to Penn State Extension, it can take parasites as little as six days to go from eggs to L3 larvae that infect cattle. Therefore, subdividing and rotating pastures every four to six days is an ideal strategy for staying ahead of the parasite lifecycle. Ensure animals have enough pasture to graze for that period.
If this strategy does not work for your operation, and you must rotate entire pastures, remember that parasitic larvae can survive as long as 120 days when weather conditions are cool and wet. If weather conditions become hot and dry, parasites can die quickly. Therefore, do not return cattle to the same field for 60-120 days depending on the weather. This will lower the infestation of cattle since eggs will hatch and have no animals to infect and complete their life cycle.
2. Avoid Overgrazing
Another strategy to prevent and manage parasitism is leaving 4-5 inches or more of pasture grass when animals rotate fields. Infective parasitic larvae can only travel up the first 2-3 inches of a grass blade. If cattle can avoid having to graze this low, they will be less likely to get infected. Allow cattle to graze on taller pasture grasses when possible and avoid overstocking fields so animals are not required to graze on infected remnants of grass.
3. Graze Mixed Species
Many parasites are species-specific. Meaning, cattle parasites cannot live in horses and sheep parasites cannot live in cattle. According to North Carolina State University, mixed species grazing can help lessen the parasite load on pastures. This can work in a couple of ways. Mixed species can graze the same pastures at the same time, or different species can graze pastures on rotation. Whichever strategy producers choose, mixing species will help lighten the parasite load because there are fewer larvae consumed by one species.
It's recommended that cattle be paired with goats or sheep and horses be paired with goats.
4. Use Dewormers Responsibly
As beef producers, you may have a quarterly deworming schedule or maybe even every six months in warmer and wetter areas of the country. However, many producers have seen their standard deworming programs become less and less effective.
Kansas State University recommends that extra attention be put on the dosing of dewormers to help reduce parasite resistance. Dewormers are most effective when dosed properly by weight. Underdosing can increase the likelihood of resistance. Using weigh scales in chutes can help avoid this.
Discussing deworming protocols with your veterinarian is critical. When possible, it is recommended to administer dewormers strategically to infected animals only to reduce parasite resistance.
5. Incorporate Natural Parasite Mitigants
As parasite resistance increases, natural alternatives are being researched to help keep parasites at bay.
The properties of essential oils make them another possible tool for managing parasite loads. It’s been documented in research trials that parasites find essential oils and their properties irritating, possibly helping prevent attachment to the gut wall in a host. Additionally, because larvae are much more vulnerable than adult worms, essential oils may help suppress larvae numbers in the intestines when essential oils are continuously present in the diet. Tannins, or other anti-nutritional factors of specific plants, have also been shown to help deter parasites when grazed or fed to ruminants.
Another way to naturally manage parasites is to increase dung beetle populations. Dung beetles will help eat and bury the manure of cattle including the parasitic eggs in their feces. Beef producers can buy dung beetles and seed their pastures with them to help lower parasite infections. Dung beetles can also help with fly control.