High seroprevalence of bluetongue virus infection in sheep flocks in West Azerbaijan, Iran.

Bluetongue (BT) is an important disease of ruminant livestock that is currently emerging in previously unaffected regions, most notably extensive portions of Europe. The epidemiology of BT virus (BTV) infection is poorly defined in much of the world, including extensive portions of Asia and the Middle East. Thus, the objective of this study was to describe the distribution and seroprevalence of BTV infection of sheep in West Azerbaijan Province of Iran, and to identify demographic and climatological factors associated with exposure of these sheep to BTV infection. BTV infection was widespread in the province as 400 of 1153 (34.7%) of the sheep sera evaluated contained antibodies to BTV, as determined by competitive ELISA, and 172 of 184 flocks included BTV seropositive sheep (93.5%). Multivariable logistic analyses failed to identify specific demographic or animal management practices that were predictive of BTV serological status of the sheep flocks. The virus serotypes and vector insects that occur within the region remain unknown.

Responses of calves to injections of ACTH and their relationship with growth rate.

A study was made of the effects of exogenous adrenocorticotropin (ACTH) on the levels of blood components in 109 dairy replacement calves and the statistical correlations between these effects and the growth rates of the calves from birth to six months. Blood samples were taken from a jugular vein before ACTH was injected and then at two, four, six and eight hours afterwards, and analysed for plasma cortisol concentration, total white cell counts, packed cell volume, haemoglobin, plasma glucose, sodium, potassium, magnesium and inorganic phosphorus, erythrocyte sodium, potassium and magnesium, serum ionised calcium and total protein and total plasma calcium concentration. The injection of 1.1 +/- 0.02 iu/kg of ACTH intramuscularly resulted in a peak plasma cortisol concentration after two hours which had not returned to normal after eight hours. It also resulted in leucocytosis, lymphopenia, neutrophilia, eosinopenia and hypophosphataemia; the mean changes were repeatable (P < 0.05) in 49 of the calves tested two months later. The weight gains to six months of age could be predicted from the degree of the changes in several blood constituents. Significant partial regression coefficients were found for the change in glucose concentration (0 to four hours), absolute neutrophil count (0 to two hours), absolute lymphocyte count (0 to four hours) and loge absolute eosinophil count (0 to two hours). The multiple regression sum of squares was highly significant (P < 0.0001), and the multiple coefficient of determination was 0.305. It was concluded that the changes in these blood components after an injection of ACTH might be used to predict the weight gains of dairy replacement calves.