Frequent rains this spring and summer have led to lush, fertile pastures. Grass isn’t the only thing that has flourished with the timely rains though. Parasites reproduce more rapidly in warm, humid weather, too, increasing the risk of economic loss.
- Internal parasites are a significant problem in pastured cattle. Female worms lay eggs which are passed to the environment through the manure. The eggs hatch into larvae and then climb blades of grass while they are still wet with dew. Cattle ingest the larvae as they graze, and the parasites develop into adults to complete the life cycle.
- Cattle on dry lots or in confinement rarely battle internal parasites, since grass contact is minimal to non-existent. However, confinement cattle are more exposed to external parasites such as lice and mites, so a pour-on dewormer will be especially beneficial.
- Roundworms are the most devastating group of internal parasites, infecting the abomasum (true stomach) or intestines. Some roundworms suck blood and cause anemia, while others only damage the lining of the intestinal tract. Roundworms are becoming increasingly resistant to dewormers, making control more challenging.
- All internal parasites rob nutrients from the animal, thus decreasing feed efficiency, growth rate and milk production if the animal is lactating. Weight loss, diarrhea, a “pot-bellied” appearance, and a long, scraggly hair coat are the most obvious signs. Severe parasitism leads to fluid retention, especially under the jaw, brisket and/or abdomen. Parasites are easily diagnosed by a fecal floatation run by your veterinarian.
- Young cattle are often the most seriously affected, as they don’t have the fat reserves to cope with nutrient deprivation. Dewormers yield 3-4 times a return on investment due to increased growth rate and feed efficiency, which makes deworming pastured cattle one of the most cost-effective and beneficial decisions you can make.
- There are many commercially available dewormers, several of which are effective on both internal and external parasites. Consult the dewormer label to see which specific parasites are targeted, and speak with your veterinarian to decide the best choice for your operation.
Do you have questions or comments about parasites and/or dewormers? Feel free to add it to this post.