A case-control study was conducted in Lusaka Province to retrospectively investigate potential risk factors associated with suspected blackquarter outbreaks in traditionally managed cattle in the Province. Data were collected from farms with suspected cases and from apparently blackquarter or blackquarter-like-disease free farms. The data were analyzed using a logistic regression method. Factors that were associated with an increased risk of suspected blackquarter on the study farms were; (i) the total year of experience in rearing cattle and (ii) the use of rivers, streams and dams as the main source of water for cattle.

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A study has been conducted to compare the three growth curve models for fitting to growth data in wild and laboratory mice. Body weight data from birth to ten weeks of age were taken weekly from two subspecies of mice, Yonakuni wild mouse (Yk, Mus musculus molossinus yonakuni) and laboratory outbred mouse of CF_#1 (Mus musculus domesticus) . The numbers of Yk were 44 males and 45 females, whereas of CF_#1 were 45 males and 45 females. Three growth curve models, namely Gompertz, logistic and Asymptotic models, were used to describe growth patterns within each subspecies-sex subclass. All models were fitted to weight data by Gauss-Newton method of SAS. A criterion based on coefficient of determination (R²) has been used for comparing the three growth curve models. High value of R² indicates goodness of fit attained by the model. Mean R² values in fitting Gompertz model were 0.999 for both subspecies at two sexes, indicating that this model was the best fit to body weight data in mice used.

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Immuno-serological characterizations of feline calicivirus (FCV) field isolates and vaccine strains were examined using neutralizing monoclonal antibodies (MAbs) raised against the F4 strain of FCV and polyclonal antisera. Neutralizing test (NT) with present MAbs showed that 29 isolates and 2 vaccine strains of FCV were divided into 4 groups, but 8 isolates could not be classified into any groups. The results of NT using polyclonal antisera were varied and indicated that the neutralizing activities of these sera were not related to the expression of neutralizing epitopes detected by MAbs used in the present study. These results demonstrated a heterogeneity among FCV isolates circulating concurrently in Japan and the possibility of grouping of calicivirus field isolates using MAbs.

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Between December 23, 1995 and Japnuary 7, 1996, a rapidly spreading outbreak of a bovine respiratory infections occured at 3 dairy farms in Hyogo prefecture, Japan. Clinical symptoms of the infected animals were almost same among 3 farms. Clinical sings of the infected animals recovered 8-10 days after antibiotic treatments. A significant increase of the neutral antibody titers to RS virus were observed and Pasteurella haemolytica was isolated from some animals. Therefore, this outbreak was suspected to be compound infections of RS virus and Pasteurella haemolytica. All 3 farms introduced pregnant heifers from an area in Hokkaido on December 10, 1995 and some of these animals had high antibody titers to RS virus. Therefore, this outbreak might be caused by the introduction of some virus-infected animals from an area in Hokkaido.

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