To test the following claim that if farmers let chickens follow the cows, the parasite problem for cows can be resolved as chickens eat parasites such as fly larvae, an interview is done with Dr. Faries, who is now retired but used to work for the Texas A&M University.
The answer is as follows…
Many species of worm parasites find shelters in the gastrointestinal and respiratory tracts of cows. In the United States, brown stomach worm Ostertagia the Coccidia Eimeria Bovis and the lungworm Dictyocaulus are both clinically and economically important. According to Dr. Faries, who is a retired veterinarian from the Text A&M University, adult horn flies are common parasites on farms where cattle feed on pastures. Dr. Faries says that chickens ranging the pasture with cattle infested with horn flies will scratch and feed on the cattle manure, consuming horn fly larvae and pupae, thus enhancing the drying of scattered manure. This is beneficial for reducing the next generations of adult flies and the level of infestation on pasture cattle. However, this means of horn fly control is effective for pasture cattle without other cattle grazing in adjacent pastures. As a result, the claim that raising chickens on pasture that follow the cattle can indeed help resolve the parasite problems, yet it only solves part of the problem. Other methods need to be taken such as carefully managing the pastures, applying multi-species grazing technics and controlling grazing time of cows.
Corwin, R., & Randle, R. (n.d.). Common Internal Parasites of Cattle. Retrieved November 20, 2014, from http://extension.missouri.edu/p/g2130
Faries, F. (n.d.). Common Cattle Parasites. Texas Agricultural Extension Service, 6(98). Retrieved November 20, 2014, from http://university.uog.edu/cals/people/PUBS/InsLive/L-2333.pdf
Duval, J. (1994, January 1). THE CONTROL OF INTERNAL PARASITES IN RUMINANTS. Retrieved November 20, 2014, from http://eap.mcgill.ca/agrobio/ab370-04e.htm#PREVENTIVE MEASURES
Faries, Floron C., Jr. “Chickens’ Effectiveness in Reducing Cattle Parasites.” E-mail interview. Nov.-Dec. 2014.