Evaluation of criteria of trypanotolerance

Evaluates teh criteria for trypanotolerance including three related characterstics, v.z. the ability to control parasitaemia, the ability to control anaemia, and the ability to develop an effective immune response

Evaluation of a field test for trypanotolerance in young N'Dama cattle

Evaluates components of a short term test for trypanotolerance criteria in N'Dama post-weaners exposed to a medium natural trypanosome challenge in Gabon; compares the effectiveness of different measures of control of development of anaemia; and measures the post-test recovery of packed red cell volume (PCV) values following treatment with a trypanocidal drug

Measurement of trypanotolerance criteria and their effect on reproductive performance of N'Dama cattle

Evaluates in detail how environmental and stress factorts affect trypanosome infection in N'Dama cows and their calves, the linkages with curative drug treatment given under the management regime prevailing, the linkages with anaemia control as measured by packed red cell volume (PCV), and the resultant influences on animal performance. Major findings were that over the period from calf birth to weaning, while calves and their dams grazing together had similar numbers of trypanosome infections detected, the Trypanosoma vivax : T. congolense rations were very different: 1:0.7 in calves and 1:2.8 in cows. This indicated that some ability to control the development of parasitaemia following T. vivax infection might be being acquired, from weaning onwards. Table 1 summarizes the data on trypanosome infection, curative drug treatment, PCV value and performance trait levels in the 458 pre-weaner calves, the 458 lactating cows and the 1028 cow-year reproduction records available over the 5-year period. These are the actual overall infection rates recorded, the levels of curative drug treatments required and the PCV values, calf growth and cow calving rates achieved

Selection in trypanotolerant cattle breeds in Africa

Presents results of experiments to determine phenotypic & genotypic relationships of the abilities to control parasitaemia, resist anaemia or develop an immune response with animal performance in terms of daily weight gain, maintenance of packed cell volume levels and disease prevalence in trypanotolerant N'Dama and Sahiwal/Ayrshire cattle at three locations in Africa. Assesses heritability of each trypanotolerance-inducing characters

Comparative performance of trypanotolerant and more susceptible cattle breeds exposed to trypanosomiasis in Gabon

Reports the influence of breed and animal age on the prevalence, species and intensity of trypanosome infection and the effects of the infections on the blood packed cell volume (PCV) of N'Dama, Nguni and crossbred cattle. Presents the effects of trypanosome infection, PCV level and lactational status on reproductive performance and liveweight of N'Dama cattle. Compares the mortalities of different breeds exposed to trypanosomiasis risk

Glossina fusca group tsetse as vectors of cattle trypanosomiasis in Gabon and Zaire

The significance of Glossina fusca group tsetse flies as vectors of cattle trypanosomiasis was examined using biconical traps to survey tsetse populations at one site in Gabon and two sites in Zaire. Mean trypanosome infection rates in G. tabaniformis Westwood over the study period ranged from 8.9 - 17.7 percent at the two sites. The mean infection rate in G. nashi Potts was 6 percent. Up to 49 percent of bloodmeals of G. tabaniformis were from cattle. Trypanosome prevalence in cattle where G. tabaniformis appeared to be the main vector was 9.5 percent and 5.4 percent at the Mushie and OGAPROV ranches respectively. A highly significant positive correlation was found between tsetse challenge and trypanosome prevalence in N'Dama cattle across sites. Tsetse challenge was defined as the product of tsetse relative densities, trypanosome infection rates in the flies and the proportion of feeds taken by them from cattle. Thus G. tabaniformis can be an important vector of pathogenic Trypanosoma species in cattle

Determination of tsetse challenge and its relationship with trypanosome prevalence in trypanotolerant livestock at sites of the African Trypanotolerant Livestock Network

Reports the determination of tsetse challenge at sites of the African Trypanotolerant Livestock Network and its relationships with trypanosome prevalence for the period 1984-1986. Lists the Network sites with trypanotolerant cattle or sheep together with the tsetse species detected. Discusses tsetse species captured, tsetse relative density, trypanosome infection rates and infection types in tsetse, and tsetse challenge and trypanosome prevalence in trypanotolerant livestock

Determination of tsetse challenge and its relationship with trypanosome prevalence in livestock within the African Trypanotolerant Livestock Network

Determines the tsetse challenge and its relationship with trypanosome prevalence in livestock at eleven sites within the African Trypanotolerant Livestock Network. Includes tsetse species, their distribution, habitats, and relative density; trypanosome infection rate; and frequency of vivax and congolense - type infection; also shows the overall tsetse challenge determined from the product of relative density; and tsetse challenge and trypanosome prevalence for trypanotolerant and other cattle herds