August 2013
Late Summer Parasite Management Strategies in Goats
Dr. Ken Andries
Kentucky State University
With the summer grazing season in full swing, and the weather being experienced in most of the eastern part of the U.S., we need to be sure we are using sound and effective parasite control strategies.
It is also important to remember that most of the products used for parasite control in goats are not labeled for use in goats. Thus, only a practicing veterinarian with a valid veterinarian-client relationship with you can make recommendations for extra-label use of any product.
First, we all know that selective treatment is the recommended method today to preserve the effectiveness of available products and the health of the herd. These methods also allow you to keep records on what animals are most susceptible to parasites and cull those from your herd.
The FAMACHA© system is the simplest to conduct chute-side and has been proven to be effective when done properly. You need to attend a training to know how to conduct this process correctly. Contact your local extension office to find out who can do these trainings in your area or consult with your veterinarian.
You also need to learn about the resistance status of the parasites in your herd. This can be different in each herd so test your animal rather than relying on what someone else tells you. The simplest way to check for resistance is to conduct a fecal egg count reduction test. There are other tests that can be performed as well by specific labs if you choose. More information on checking for resistance can be found on this web site. You should consider changing dewormers only if the one you are using is not effective.
If you are using alternative dewormers you also should check the effectiveness of these products. Results on many of these products have varied between locations and there are some that are advertised that have been shown to not work under production conditions. I recommend that any time you start using any new product or method of control, you check to make sure it is effective in your herd before depending totally on that product or practice.
While it is past planting and establishment time for warm season forages, there are some forage management practices that can be beneficial. Grazing browse can reduce exposure to parasites while giving your pastures some rest. Another practice is keeping the forage height up and rotating
pastures. Rapid rotations with long rest periods tend to help reduce exposure, but these must be managed correctly.
It takes about 14 to 21 days under most conditions for the eggs to hatch on a pasture and the larvae to reach the necessary stage of maturity to be a problem. Some rotation systems place animals back on a pasture about at this time. This can be a disaster for the animals as they are going back at the peak time for re-infection. However, it can take up to 90 days to see reductions in the number of larvae on pasture so it is often not practical to hold them off until the pasture is “clean”.
Making rotations that allow 30 to 45 days of rest, depending on moisture conditions, can allow the forage to grow enough to reduce exposure by allowing the goats to graze above 8 inches. This often reduces exposure as the parasites tend to be concentrated in the lower 4 to 6 inches of the plants. However, goats tend to graze desirable plants and in specific areas lower than the average so some exposure will still occur.
Grazing pastures with cattle or horses after a 14 day rest from goats can reduce parasite loads as these animals are not impacted by the barber pole worm. This type of leader/follower co-grazing system can be effective, but there must be enough rest and forage available for both groups of animals. The cattle can graze the pasture lower than the goats without problems but allow the grass to fully recover before putting the goats back on the pasture.
This is a good time to start preparing for cool season annual plantings and for planning to establish warm season alternative forages. In many areas, late summer and early fall is the time to plant cool season annuals for grazing in the fall and winter. It is also the best time to start preparing a field to plant sericea lespedeza or other warm season alternative forages. Lespedeza and some of the other alternatives have shown to be effective in reducing parasite loads while providing better quality forage for your animals.
One final thing, there is no silver bullet out there for parasites. We will always have some parasite pressure on our animals. The more research that is conducted the more we learn that we need to select for genetic resistance in our herds to parasites. We also need to manage using good grazing practices and not overgraze an area. Insuring that the mineral and protein nutrition of the goats are met also helps reduce problems.
Goats like a variety of plants to graze/browse; we need to give them an opportunity to graze a variety of plant types to keep them healthy. Keep records and cull animals that require excessive care as well as those that do not perform in other ways.