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June 2014
Pine bark and other natural dewormers for  small ruminants



Dr. Byeng Ryel Min
Tuskegee University

Gastrointestinal (GI) parasites (especially Haemonchus contortus and Eimeria spp.) present the greatest danger to the goat and sheep industry in the United States. In the past, sheep and goat producers relied heavily on anti-parasitic drugs. Unfortunately, GI parasites have become increasingly resistant to many of the anthelmintics.

Alternative methods of GI parasite control for animals raised primarily on forages are vital for the sustainability and profitability of sheep and goat farms in the United States. Consequently, alternative, sustainable, and affordable methods of parasitic control are required. There is also a need to examine plant-based alternatives to control coccidiosis in livestock because there are no FDA approved drugs to treat coccidiosis in small ruminants.

Recently, it has been reported that a natural dewormer distributed by Hoegger’s Goat Supply (Fayetteville, GA) and contains a mixture of dried plant materials including wormwood, gentian, fennel, psyllium and quassia was not supported by scientific data. However, research has shown that legumes such as Sericea lespedeza (Lespedeza cuneata) contain condensed tannin (CT) with anti-parasitic properties.

The anti-parasitic properties of CT have been demonstrated to reduce GI parasitic infection in goats in Oklahoma and Georgia and in sheep in Louisiana. Researchers at Tuskegee University found potential benefits of pine bark (PB) supplementation on anti-parasitic effects and improved feed efficiency. PB is one of the abundant forest by-products in the southern United States and contains 11 to 13 percent CT on a dry matter basis.


Research demonstrates that goats fed on a 30% PB-containing diet (Fig. 1) have up to 30 percent fewer worms in a total mixed ration (TMR), as well as lower instances of fecal egg count and fecal coccidian oocyst count. Feeding PB diet (30% PB powder mixed with TMR diet) reduced both male (64 percent) and female (59 percent) worm counts (drug resistant parasites) compared with the control (without PB) diet.


In addition, mean dry matter intake, feed efficiency, average daily gain, and cold carcass weight were also greater for goats fed the PB powder-containing  diets. On-farm research with six


local farmers also has shown that goats on a PB powder diet (30% PB powder mixed with TMR diet) had 74 percent lower fecal egg counts (Fig. 2) and 5 percent better animal weight gain compared to control diets during three-month trials. Ground PB as a feed ingredient has the potential to improve animal performance while decreasing internal parasites and coccidian infection.

Thus, developing plant-based alternatives such as PB and other natural resources for GI parasites control would be expected to have a greater impact on the goat and sheep industries. This will allow development of Best Management Practices to prevent or treat coccidiosis and GI parasites in ruminant livestock. Ultimately, by raising sheep and goats primarily on forage, farmers can reduce feed costs.

More research is needed to: study the direct mechanisms of tannins and parasite interactions; look for ways of validating the anti-parasitic plants of sheep and goats production systems; and to continue testing the effectiveness of alternative natural dewormers for use in ruminants.

This research has enabled goat production to be a more sustainable and low-cost enterprise by mitigating internal parasites and coccidian infections of grazing animals, thus enhancing overall meat production, protecting animal and human health, increasing producer profits, and providing a stable and safe food supply.

Figure 2.  Fecal egg counts of goats fed pine bark powder containing TMR diet at six farms

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