Drenching calves early in the season is a crucial practice that can significantly impact the health and productivity of your herd. The first drench given to calves should not be viewed merely as a treatment for the animals themselves, but rather as a strategic measure to prepare the paddocks for the entire season. By administering a highly effective drench early on, you can reduce the larval build-up of parasites on the pasture. This proactive approach helps to minimise parasite challenges and worm burdens later in the season, ensuring that you are always ahead of the parasite problem as you move into summer and autumn.
When it comes to selecting a drench, a triple combination drench is currently the most effective option available. This type of drench contains three different drugs, each targeting internal parasites in distinct ways. The advantage of using a triple combination drench is that it can effectively kill parasites that may be resistant to one or even two of the drugs. This comprehensive approach not only controls parasites in the presence of single or multiple drug resistance but also helps to slow the development of resistance to these critical drugs. By using a product with three different active ingredients, you can kill more worms and reduce the likelihood of resistance developing on your farm. However, this strategy is contingent upon maintaining adequate refugia.
Refugia refers to the portion of a parasite population that is not exposed to a particular drug treatment. Maintaining refugia is essential for slowing the development of drug resistance. If you do not treat some of your animals, the parasites they carry do not become resistant, thus creating refugia. However, not treating animals can lead to poor growth rates, reduced productivity, clinical disease, and even death in severe cases. Therefore, it is crucial to strike a balance between optimising productivity and maintaining enough refugia. This can be achieved through careful monitoring, using the right drench, and seeking advice from your vet, as a one-size-fits-all approach is often inadequate.
By following these guidelines and working closely with your vet, you can ensure that your drenching program is effective, sustainable, and beneficial for the long-term health and productivity of your herd.