Submitted to: Graziers Notebook Series
Publication Type: Other
Publication Acceptance Date: 12/19/2000
Publication Date: 2/1/2001
Citation: Gasbarre, L.C., Stout, W. 2001. Parasite control. Graziers Notebook Series. pp. 16-19
Technical Abstract: Internal parasites reduce efficiency in the production of meat and milk by interfering with nutrient utilization. The use of modern drugs has lessened the number of severe outbreaks in herds, but low to moderate levels of parasites remain in virtually all cattle herds, and continue affect productivity. The parasites live in the gut of cattle, and eggs are passed onto pastures in the feces where they develop to infective forms which are ingested as cattle graze. Transmission rate of the parasites is determined by 2 factors, the number of eggs seeded on the pastures, and the survival of the hatched larvae on the pasture. Survival on pasture is dependent upon a number of factors, but the most important are temperature and available moisture. Parasites have evolved so that environmental conditions that favor the grass growth are also optimal for parasite development and survival. Programs that increase forage utilization also increase parasite transmission and as such should develop a good parasite control plan that reduces parasite transmission on the pasture. Drug treatment programs should stop the build-up of parasites on pastures by e early season treatments. Alternatives to anthelmintic usage are few. Homeopathic treatments are widely used, but scientific analyses have not indicated that they are effective. The greatest promise lies in the use of cattle genetics to control disease, but the utilization of this approach is several years away. For organic producers or others interested in reduced drug usage, it is important that animals passing parasite eggs are not regularly introduced onto pastures. Producers regularly using drugs to control parasites should contact experts at universities or government to develop a comprehensive plan for parasite control.