Dairy Cattle, Face Fly and Horn Fly Control with Guardian Ear Tags, 1983

Guardian 5 and 7.5% (flucythrinate) ear tags were evaluated for face fly and horn fly control on dairy cattle. May through Sep. 1983, in Montgomery Co., Va. Herds and treatments in Test A were as follows: (1) Guardian 5% ear tags applied to 27 nonlactating Holstein cows 3 Jun.; (2) Guardian 7.5% ear tags applied to 31 nonlactating Holstein cows 3 Jun.; (3) standard Ectrin 8% ear tags applied to 59 Holstein heifers 25 May; and (4) an untreated herd of 15 nonlactating Holstein cows. All Guardian 5% and 7.5% treated cows received two tags per animal. The Guardian herds were monitored for 10 weeks, and the Ectrin herd for 11 weeks. Herds and treatments in Test B were as follows: (1) Guardians 7.5% improved design ear tags applied 16 Aug. to same herd as # i, Test A.; (2) Guardian 7.5% improved design ear tags applied 16 Aug. to same herd as #2, Test A; (3) standard Ectrin 8% ear tags existing on same herd as #3, Test A and (4) untreated herd, same as #4, Test A. All Guardian treated cows received two improved design tags per animal; all remaining tags from Test A were removed. All herds in Test B were monitored for 5 additional weeks. Herds in Test A and were maintained in separate pastures and all were situated within ca. 2 miles of each other. Weekly face fly and horn fly estimations were made by the same person on 10 adult animals per herd. Numbers of face flies were estimated on the face and head and horn flies on one side of each animal.