Ticks and tick-borne diseases plus trypanosomosis are a constraint to cattle rearing in Tanzania. Rufiji district was not known for important ticks infesting cattle because inhabitants were not engaged in keeping livestock. Not only has settlement of pastoralists and cattle in Rufiji increased the number of cattle but also cattle have been the source of bringing in and spreading of ticks. This study investigated tick species that have been introduced and managed to establish themselves in the new livestock farming areas in cattle in Rufiji. Tick distribution study was undertaken in three villages of Chumbi ward seasonally in 2009, 2011, and 2012. The identified ticks were
Ticks and tick-borne diseases and trypanosomosis and tsetse fly are major constraint to cattle rearing in Tanzania. Intensive tick surveys conducted between 1955 and 1961 provide the basic information on distribution of Tanzanian tick species. According to Yeoman and Walker [
Large numbers of indigenous cattle are mostly owned by pastoralists and agropastoralists and account for 98% of cattle population in the country. The grazing land for these animals in areas that is home to many pastoralists is no longer sufficient due to the increase in number of cattle and human population. As a result some of the pastoralists from these areas are currently migrating with their animals opting to settle in other areas of Tanzania where there is an ample grazing land for their animals. Such areas are in the eastern and southern part of Tanzania.
For many years, most areas in eastern Tanzania such as Rufiji district in Coast region have been keeping very few numbers of cattle. This is due to the fact that people living in these areas are not engaged in keeping livestock. Tick surveys conducted by Yeoman and Walker [
Settlement of pastoralists and their animals in some areas of Rufiji district in recent years has not only increased the number of cattle population but also the cattle have been the source for bringing in and spreading ticks of economic importance into the areas. The species of ticks that managed to establish themselves in these new areas together with tsetse fly species present transmit diseases to the animals. In this paper we present results of tick that has managed to establish themselves in the new livestock farming areas of Rufiji in cattle present in the areas.
Rufiji is one of the six districts of Coast region covering an area of about 14,500 sq km. It lies between latitude 7.47–8.03°S and longitude 38.62–39.17°E with overall altitude of less than 500 metres above sea level. The climate is tropical with cool and dry season from June to September and hot and dry season from December to March. Long rainy season lasts from March to May and short rainy season from October to December. Short rains are unpredictable with variation from year to year. The overall mean temperature is 28°C.
Vegetation is characterized by tropical forests and grasslands. The district has Rufiji River which is a prominent feature that divides the district into two halves. Furthermore Kilwa and Rufiji districts border Selous Game Reserve to the western part. Land utilized for grazing is estimated to be 90,000 ha out of 482,430 ha suitable for grazing.
The district veterinary officer (DVO) assisted in providing information about areas where pastoralists from different areas of the country have settled with their animals. Longitudinal study was conducted seasonally in Chumbi ward in 2009, 2011, and 2012 for investigating ticks species. The ward was selected because of high density of cattle introduced from different areas of Tanzania compared to other wards in the district. Chumbi ward comprises three villages namely Chumbi, Kiwanga, and Muhoro.
Ticks were collected from 11 herds. One- to two-month visit intervals were made during the period of rainy season (March–May) and dry season (June–November). During each visit adult ticks were collected from 3-4 head of cattle randomly selected from the herd kraal after the consent was given by each owner in all villages. Collected ticks were preserved in 70% alcohol; however the collected immature stages, nymphs and larvae, were excluded from counting and identification of ticks. The adult ticks were identified in the laboratory according to published keys [
Collected data on identified tick species, season and village were entered into Microsoft excel software where they were coded before being analysed by statistical analysis software (SAS). A two-way ANOVA was conducted to detect the effect of season and village on the tick species. Ticks count was used as dependent variable while village, season, and tick species were used as independent variables. Means were separated at 95% confidence interval and the difference was considered significant at 5% in all statistical tests.
Mean ticks species for the villages of Rufiji district.
The mean catch for
Villages had significant effect on the ticks species collected (
Mean ticks count from villages of Chumbi ward.
Mean tick species caught seasonally in the three villages of Chumbi ward.
Mean tick species caught seasonally.
Seven tick species were encountered in the new cattle settlement areas of Rufiji, namely,
The occurrence of these tick species in some areas of Rufiji district to which no livestock were kept before suggests that the species were introduced in these areas by the infested cattle and other livestock brought in by the pastoralists. It appears now that some of tick species introduced have managed to establish themselves, for instance,
From the present surveys, ticks of cattle appear to be present in the new established cattle settlement areas of Rufiji. It is important for the livestock farmers to be aware and use effective chemicals and drugs to control the vectors. This study indicates that movement of animals in traditional pastoralist system is one of the factors for vector spread and establishment. Hence better land use and planning should be encouraged in order to mitigate factors behind movement of livestock in search of pastures as a result of overgrazing in former areas coupled with poor range land management which cannot support increasing number of cattle in the former pastoralist tradition areas.
The authors declare no competing interests.
Kamilius A. Mamiro, Henry B. Magwisha, Elpidius J. Rukambile, Martin R. Ruheta, Expery J. Kimboka, and Imna I. Malele designed the study. Kamilius A. Mamiro, Henry B. Magwisha, Elpidius J. Rukambile, Martin R. Ruheta, and Expery J. Kimboka carried the field work, Deusdedit J. Malulu analysed the data, Kamilius A. Mamiro, Henry B. Magwisha, and Imna I. Malele wrote the paper, and all authors read and edited the manuscript.
This work was funded by the Ministry of Livestock and Fisheries Development through ZARDEF fund. The authors acknowledge the assistance offered by CVL staff from Parasitology Department. They thank the District Veterinary Officer (DVO) from Rufiji District for support during the surveys.