Non-tick stock-specific index for assessing resistance of zebu cattle to Rhipicephalus appendiculatus Neumann (Acarina: Ixodidae)

A quantitative index of resistance to ticks, which had been derived from results of artificial infestation of East African zebu cattle with a Rusinga Island (Lake Victoria) stock of Rhipicephalus appendiculatus, was tested for consistency using three additional tick stocks—from a laboratory (Muguga), Intona (Trans Mara) and Ukunda (Kenya coast). Results from all the stocks gave similar indices when compared with corresponding values for the Rusinga stock, confirming both the validity of the mathematical function and of the use of any local stock of the tick species for assessing the resistance of cattle to R. appendiculatus.