G John Rowlands

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In this, the first of a series of papers on the epidemiology of bovine trypanosomiasis in the Ghibe valley, southwest Ethiopia, the tsetse populations and their relationships to the prevalence of trypanosome infections in cattle are described. The tsetse challenge to cattle at two sites sites in the area was estimated as the product of tsetse relative(More)
A longitudinal study was carried out in the coastal lowlands coconut-cassava agro-ecological zone of Kaloleni Division, Coast Province, Kenya between June 1990 and December 1991 to estimate disease incidence and cause-specific case-fatality risk in an average of 120 cattle in 26 small-holder dairy herds kept in two grazing-management systems. East Coast(More)
A cross-sectional study was carried out from July to September 1989 in Kaloleni Division, Coast Province, Kenya to estimate the prevalence of vector-transmitted diseases in small-holder dairy cattle and to identify the risk factors associated with different management systems. One hundred and thirty of the 157 herds with dairy cattle in Kaloleni Division(More)
Short-term associations between disease and milk yield were studied in 1594 lactations occurring between 1977 and 1982 in 732 Friesian, Ayrshire and Holstein crossbred cows. Statistically significant differences in milk yield between one week before and one week after clinical diagnosis were observed for ketosis (5.1 kg/d), hypomagnesaemia (4.1 kg/d),(More)
In the Ghibe valley, south-west Ethiopia, a tsetse control trial using deltamethrin-impregnated targets was started in May 1990. The mean relative density of the main vector, Glossina pallidipes, fell from 2.1 flies per trap per day in the 12 months prior to introduction of tsetse control to 0.41 flies per trap per day in the 12 months after tsetse control(More)
A method is described for calculating new infection incidence from monthly field data collected between April 1994 and February 1998 from an average of 770 Ethiopian Highland Zebu cattle maintained under traditional management in the Ghibe valley, southwest Ethiopia and exposed to a high challenge with drug-resistant parasites. Each month cattle with a(More)
Studies on seasonality and population dynamics of ticks on indigenous cattle and their crosses (calves) were carried out in Buruli Ranching Scheme, Nabiswera, Luwero district of Uganda on three treatment groups of animals: group 1 (twice a week dipping), group 2 (once a month dipping) and group 3 (no tick control). During this study, four major species of(More)
During 1977 a survey was undertaken by practising veterinary surgeons of the incidence of different lesions causing lameness in dairy cattle. Forty-eight veterinary practices participated and they treated 7526 cases of lameness in 1821 herds. The average incidence of lameness among all cows was 5.5 per cent and the annual incidence among practices ranged(More)
The effect of teat washing and drying on bacterial numbers in bulk milk was compared with that of no teat preparation in eight commercial herds over one year. Using in-line milk samplers, milk was collected at various points during its passage through the milking plant and the samples were used to establish the relative significance of the sources of(More)
A statistically derived disease reaction index based on parasitological, clinical and haematological measurements observed in 309 5 to 8-month-old Boran cattle following laboratory challenge with Theileria parva is described. Principal component analysis was applied to 13 measures including first appearance of schizonts, first appearance of piroplasms and(More)