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Biomedical subjects

H Alushula

Publications and source records attributed to H Alushula.

5 recordsLinked to original sources

The effect of trypanosomosis on pregnancy in trypanotolerant Orma Boran cattle.

A study was undertaken to investigate the influence of trypanosomosis on the outcome of pregnancy in trypanotolerant Orma Boran (Bos indicus) exposed to natural tsetse challenge in an area of Kenya infested predominantly with Glossina pallidipes. Of 73 pregnant Orma heifers, 58 (79.5%) produced live calves at term, 13 (17.8%) aborted and 2 (2.7%) died of trypanosomosis. Of the 71 surviving animals, 22 (31%) were infected with Trypanosoma vivax , 21 (29.6%) T. congolense, and 26 (36.6%) had mixed infections with T. vivax and T. congolense. These results suggest that in areas of high trypanosomosis risk reproductive function is affected even in trypanotolerant cattle, and that both T. vivax and T. congolense can be responsible for the abortions observed in the field. It is suggested that maintenance of pregnancy in the face of trypanosome challenge was dependent on individual variation among the Orma cattle, but as challenge increased beyond the limits of effectiveness of trypanotolerance, disruption of pregnancy occurred.

Journal Article↗

Failure of chemoprophylaxis against bovine trypanosomiasis on Galana Ranch in Kenya.

The duration of prophylaxis provided by 1 mg kg-1 bodyweight of homidium bromide was compared with that provided by 1 mg kg-1 bodyweight of isometamidium chloride in a 12 month field trial involving 90 Boran cattle exposed to trypanosome challenge on Galana Ranch in Kenya. Weekly trypanosome prevalences of over 30% were observed during 4 of the 12 months. During these periods of heavy challenge, parasites were detected 2-3 weeks after administration of both homidium bromide and isometamidium chloride. Both prophylactic drugs were administered, on a group basis, eight times over the 12 month trial and in addition individual infections were also treated with diminazene aceturate. Isometamidium chloride provided slightly longer periods of prophylaxis than homidium bromide, 28.4 days compared with 25.4 days. There was a highly significant difference in the productivity of the two groups during a period of poor grazing. 27% of the isometamidium chloride herd died from a severe wasting condition with substantial liver damage evident on post mortem. The condition was not observed in the homidium bromide herd. The surviving animals in the isometamidium chloride herd had a mean annual weight gain of 24 kg less than that recorded in the homidium bromide herd.

Animals↗

Homidium bromide as a chemoprophylactic for cattle trypanosomiasis in Kenya.

Homidium bromide was used in a strategic chemoprophylactic regime to control trypanosomiasis in Boran cattle in Kenya. Trypanosome infection rates in cattle receiving homidium bromide prophylaxis were compared with those in control cattle which received no prophylaxis but were treated with diminazene aceturate when infected. Homidium bromide was administered twice during the year after which no infections were detected for periods of nineteen weeks and seventeen weeks respectively. The drug sensitivity of the infecting trypanosomes is believed to be a major factor in determining the duration of prophylaxis.

Animals↗

A simple epidemiological method for animal trypanosomiasis to provide relevant data for effective financial decision-making.

The epidemiology of bovine trypanosomiasis on Galana Ranch, Kenya was studied for one year (July 1980--June 1981), using measurements from an experimental population of 3 types of Boran cattle. The results were applied to the estimated ranch population at risk, and an attempt was made to measure the potential economic loss due to trypanosomiasis. The potential losses in beef production due to trypanosomiasis in the ranch population at risk at Galana were estimated at around K.Shs. 8900/km2, when the stocking rate was 14.2 Tropical Livestock Units per km2. The estimated potential loss in the total population at risk was approximately K.Shs. 5 million (around US$ 700,000 at 1981 values). These losses can be minimised by good management techniques based on accurate epidemiological information. Results indicated that Orma-type Boran steers are more resistant to trypanosomiasis than Galana-type Boran steers. Although both types showed similar mortality rates, untreated Orma animals which survived showed a similar growth performance to animals maintained under 3-month Samorin prophylaxis. Untreated Galana Borans lost 14% of their body weight when compared with animals maintained under 3-month Samorin. Also, 30% of the untreated Orma Borans never showed trypanosomes in their blood over the study period, while all corresponding Galana Borans showed parasites; this resulted in a lower measured attack rate in Orma cattle. In 1982, a combination of treating only those animals under trypanosome attack, relating the timing of chemotherapy to measured increased trypanosome attack, and the increased utilisation of the trypano-tolerant Orma Borans resulted in an annual saving of around US$ 110,000 in control costs and an increased land usage of approximately 5%.

Age Factors↗