Comparison of the effect of various chemical stabilizers and lyophilization cycles on the thermostability of a Vero cell-adapted rinderpest vaccine.

The thermostability of a rinderpest vaccine produced on Vero cells was evaluated using a variety of chemical stabilizers and lyophilization protocols. Three stabilizer preparations and three lyophilization schedules were examined using accelerated stability testing at 37 degrees C. The vaccine preparation exhibiting the greatest stability at 37 degrees C was tested at three additional temperatures, 42, 45 and 56 degrees C, and an Arrhenius plot was constructed from the data. The stability of the reconstituted vaccine produced with the two most efficacious stabilizers was examined using three different diluent preparations. The stabilization method and high Vero cell virus batch titers resulted in a lyophilized vaccine which maintained the minimum required dose of log10 2.5 TCID50 tissue culture infectious dose for more than 20 weeks at 37 degrees C.

Appropriate animal health information systems for nomadic and transhumant livestock populations in Africa.

Nomadic and transhumant livestock comprise the normative mode of production in the arid and semi-arid regions of Africa. By adopting management practices with high human labor and informational input, pastoral societies have adapted to innately high environmental variability. The Western veterinary model, which developed under sedentary conditions of production, has been unable to address herd health problems in African pastoral regions. By soliciting the participation of pastoral people, however, it is possible to develop an animal health information system that is technically appropriate, economically viable and socially acceptable. The organizational structure of appropriate information systems can furnish the framework for animal health delivery under pastoral conditions.

Clinical, serologic, and pathologic changes in calves with experimentally induced Trypanosoma brucei infection.

In 7 calves inoculated with Trypanosoma brucei and observed for 105 days, the minimal clinical signs were occasional lethargic periods associated with parasitemia. Rectal temperatures increased by postinoculation day (pid), 10, remained moderately high until PID 50 to 60, and then returned to base line. Moderate anemia occurred between PID 15 and 25. Slightly increased lymphocyte count with relative decrease in neutrophil count was found in 3 calves. Monocytosis of minimal degree occurred 14 days after parasitemia. Trypanosome counts of low level and irregular frequency were found throughout the infection. The average number of trypanosomes in blood was approximately 1,000/ml. Antibody titers, as determined by the indirect immunofluorescent antibody method, appeared on PID 22 and stayed at moderate levels. The immunoglobulin M first increased at PID 5 and remained high (av 216% of base line value) throughout infection, but immunoglobulin G was never increased. Histopathologic study revealed proliferative changes in the lymph nodes and spleen characteristic of humoral antibody (B-cell) response. Mononuclear cell infiltration (lymphocytes and plasma cells), eosinophols, and edema were common in the lymph nodes, spleen, liver, heart, brain, hypophysis, testes, kidney, skeletal muscle, adrenal gland, pancreas, and uterus.

Bovine trypanosomiasis: effect on the immune response of the infected host.

Yearling cattle were inoculated with a recently isolated field strain of Trypanosoma congolense. Dinitrophenylated ovalbumin, a bacteriophage, or bovine parainfluenza-3 virus injected into the cattle during the first 5 weeks of infection resulted in peak serum antibody titers lower but not much lower than those produced by noninfected cattle. Primary and secondary antibody responses of inoculated cattle required more time to reach peak titers. Peripheral blood lymphocyte concentrations decreased to 42% of preinfection base-line value 1 1/2 weeks after the onset of T congolense infection and thereafter plateaued at less than 75% of base-line value. Lymphocyte cultures prepared from infected and noninfected cattle gave no marked differences in [(3)H]thymidine uptake after stimulation with phytohemagglutinin or pokeweed mitogen. Differences in lymphpocyte responsiveness were not noticed in one-way mixed lymphocyte culture reactions, using mitomycin C-treated lymphocytes from noninfected cattle as stimulator cells.

Elephants in Thailand: determinants of health and welfare in working populations.

The Asian elephant (Elephas maximus) has played a prominent role in Thai history and society. However, in the face of modernization, elephant handlers have been struggling to justify their continued ownership. As a result, working elephants may still encounter situations in which their health and welfare are jeopardized. This study developed both a survey instrument and a visual assessment to describe and evaluate the health and living conditions of elephants encountered in a variety of work and living situations. These situations were found to be significantly associated with whether or not an elephant received proper husbandry or was in good body condition. These results may prove valuable in predicting the welfare of elephants according to work and living situations.