A study of the justification for intensive tick control in Kenyan rangelands

Abstract

Sixty male weaner cattle at the National Range Research Station, Kiboko, Kenya were placed in four groups of 15 animals under four different tick control regimens for 16 months. The treatment groups were: spraying with acaricide weekly, spraying every three weeks, spraying whenever group mean tick infestations reached more than 200 per animal (once only in the course of the study) and a control unsprayed group. The cattle were weighed monthly. There were no significant differences between the liveweight gains of the groups during a period of severe drought and during the following period of compensatory weight gain. The untreated group gained more weight than the other groups. Cattle died in all groups, but without significant differences between the groups; the long drought and associated malnutrition were the prime cause of death. Rhipicephalus pravus and R pulchellus were the dominant tick species with fewer Amblyomma gemma, Hyalomma truncatum and small numbers of Boophilus decoloratus and R evertsi. These ticks transmit anaplasmosis, babesiosis and cowdriosis in the study area. Total tick counts reached 750 on individual animals but group means rarely reached more than 200 because of high resistance to ticks in some animals. Host resistance ranking within groups was virtually constant throughout the experiment. The study showed that intensive tick control is not required in the semi-arid areas of Africa.

Theileria

“…Reduction in tick populations may be achieved by the "long-interval tick control m e t h o d " or by treatment only during the high tick season (Tatchell et al, 1986). Reduction in tick populations may be achieved by the "long-interval tick control m e t h o d " or by treatment only during the high tick season (Tatchell et al, 1986).…”

A study of the effect of tick infestation on liveweight gain of cattle in the Sudan

“…Management costs would increase the financial burden to the point where there could be no conceivable benefit from intensive tick control. This has been seen elsewhere in Africa (Tatchell et a/., 1986) wherever cattle are immune to TBD, and the only putative benefit to be gained from tick control is in reducing specific tick damage.…”

Concepts and key issues of ethnoveterinary medicine in Africa: A review of its application in Zimbabwe

“…Studies carried out by Kayaa (2000) have also revealed that synthetic dewormers slow the decomposition of manure. The annual cost for importing acaricides has been estimated at US$9.3 million in Zimbabwe (Perry et al, 1990), US$16 million in Kenya (Tatchell et al, 1986), US$10 million in Zambia (Pegram et al, 1988), US$26 million in Tanzania (Kagaruki, 1997) and Uganda (OkelloMarandure 1837…”