Comparative study of tick burdens in Gudali and Wakwa cattle under natural infestation in the subhumid highlands of Wakwa, Cameroon. Preliminary observations

Abstract

The relative resistance to different cattle ticks of Gudali and Wakwa cattle with different levels of Brahman breeding, grazed on natural pastures in the subhumid tropics of Wakwa, Cameroon, was assessed using pasture tick infestations. The basic design consisted of 5 young bulls of each breed from different sire herds. Tick populations were observed in Gudali and Wakwa bulls over a period of four weeks when the climate was thought to be highly favourable for the free-living stages of ticks. Counting of adult, larval and nymphal ticks was carried out in the morning of each counting day on the body surface of cattle after restraining them. Ticks were identified by species and sex. Repeated measures analysis of variance technique was used to account for time trends and breed differences. Results showed that Wakwa cattle carried slightly more ticks than Gudali cattle. However, this difference was not statistically significant. Significant within breed differences in tick counts suggested that selection for resistance to ticks, particularly Amblyomma variegatum, can be effective within each breed. The tick species recorded by order of decreasing abundance were Amblyomma variegatum, Rhipicephalus lunulatus and Hyalomma spp. It was clear from this study that long-term investigations would be necessary to ascertain the extent of the differences in tick counts between these two breeds of cattle and to assess the biological mechanisms of resistance to Amblyomma variegatum as well as to estimate the heritability of tick resistance.