Monday, November 13, 2006 - 10:50 AM
71-6
Use of forages as a natural method of controlling parasitic nematodes of livestock.
Parasitic nematode diseases are common in grazing livestock. Haemonchosis, caused by the blood-feeding activity of Haemonchus contortus, is widespread in the tropics, subtropics, and warmer temperate regions and is a primary constraint to economic production of livestock, particularly small ruminants (sheep and goats). Historically, ethno-veterinary medicine has been used to reduce effects of parasitic infections in animals throughout the world, and this practice is still common with resource-poor farmers in Africa, India, Asia , and other regions. In areas where chemical anthelmintics are readily available, there has been a world-wide increase in anthelmintic resistance in gastrointestinal nematodes (GIN), and this is fueling renewed interest in use of medicinal plants to control parasites in commercial settings. Despite a large amount of anecdotal information on plants with activity against parasitic nematodes, there are relatively few scientific reports on this subject. A number of different plant extracts have been tested for in vitro activity against parasites, but in-vivo data are often lacking. There is growing evidence that condensed tannin (CT) – containing forages in fresh and dried forms can have anti-parasitic properties, and recent studies with the CT legume sericea lespedeza [Lespedeza cuneata (Dum.-Cours.) G. Don.] have been very promising, although the mechanism of action is still uncertain. Other naturally-occurring plant compounds may also have natural anthelmintic properties. Plant structure and its interaction with feeding behavior of different livestock species can greatly affect rate of exposure to infective GIN larvae, although controlled studies in this research area are lacking. Use of plants to control parasitic infection in animals is promising, but additional research is needed on efficacy, mechanisms of action, and practical application.
Recorded presentation