An organic lamb producer evaluated four substances that had been suggested by articles or by other producers to serve as possibly effective anthelmintics in lambs. Although the producer utilized grazing management and other measures to manage internal parasites, she found that parasite load was high in ewes during lambing and lactation, as well as in offspring, and was looking for effective worming methods to complement other management strategies.
The four materials tested were a commercial herbal wormer, garlic, diatomaceous earth, and pyrethrum. Te evaluate efficacy of the worming materials, fecal samples were monitored and weights of gain in the test animals was recorded.
All test groups of lambs showed presence of roundworm at the beginning of the trial, and a higher level of roundworm presence at the end of the trial. The study failed to show any effectiveness of the tested alternative wormers. The study was useful to the producer in that it showed the need to systematically assess the usefulness of any alternative wormer, and test their effectiveness objectively.