title: The effects of the brown ear-tick, Rhipicephalus appendiculatus, on milk production in dairy cattle.
abstract: The effect is reported of artificially controlled levels of infestation with adults of Rhipicephalus appendiculatus on the milk yield of twenty commercial Bos taurus dairy cattle on a high plane of nutrition and eighteen crossbred B.taurus x Sanga cattle on a lower plane of nutrition on the highveld of Zimbabwe. The results showed no significant effect on milk yield of infestations averaging twenty engorging ticks per animal per day, despite severe ear damage in some animals. They indicate that milk production of dairy cattle under commercial management is not sensitive to infestation with R.appendiculatus. The results have important implications for management of ticks in Africa, but need to be interpreted within the context of the control of tick-borne diseases.
authors.affiliation: Veterinary Research Laboratory, Causeway, Zimbabwe.
authors.forename: R A
authors.initials: RA
authors.lastname: Norval
authors.forename: R W
authors.initials: RW
authors.lastname: Sutherst
authors.forename: J D
authors.initials: JD
authors.lastname: Gibson
authors.forename: J D
authors.initials: JD
authors.lastname: Kerr
authors.forename: L M
authors.initials: LM
authors.lastname: Thorne
authors.forename: A
authors.initials: A
authors.lastname: Ellenhauge
mesh_terms: D000818:Animals; D002417:Cattle / Q000469:parasitology*; D005260:Female; D007774:Lactation; D013984:Tick Infestations / Q000662:veterinary; D013987:Ticks; D015030:Zimbabwe