You don’t see them, but they are there, lurking in the grass, waiting for the opportunity infest your bowels and leach off your nutrition. If this thought terrifies you, then you are probably a cow worried about having worms.
Yes, in those peaceful looking pastures are parasites that are hoping to hitch a ride on the nearest bovine to complete their life cycle. There are a number of different species of intestinal worms that can infest cattle, but for the most part they have a similar system of how the reproduce and move from animal to animal.
The worms start life as eggs laid inside an infected cow. They pass out in the manure. In that manure, the eggs hatch into larvae that wriggle away from the manure to nearby grass. When a cow eats that grass, the larvae are ingested, move to the intestines, and their mature into adult worms, ready to lay eggs and start the cycle again.
Worms in cattle cause several different problems. At the minimum end, they make the cattle less efficient, because they take resources away from cows that could go to maintenance and growth, which increases the cow’s environmental footprint. If the amount of worms gets high enough, the cow can suffer clinical effects, such as anemia. Worms also have a negative effect on a beef animal’s immune system, making it more likely that animal will contract pneumonia and other infectious diseases.
Fortunately, we have ways to treat worms. This include oral dewormers, like the kind you might give to dogs or cats, and injectable dewormers. There are deworming products that can be poured on the animal’s back and absorbed, but they are not as effective as the oral or injectable kinds.
Note that worms are only a problem with cattle grazing pasture. Because cattle in confinement are not grazing pasture, they cannot consume more worms. As long as they are successfully dewormed when the arrive at the feedyard, they will not need to be dewormed again.
Worms are gross, but they are an inevitable part of grazing. As ranchers, we do our best to decrease the amount of worms our cows have to deal with, so they can stay healthy and be as “green” as they can be.