Abstract
Fluorotic lesions were studied in cows and calves on farms belonging to 2 agricultural companies. From company HP 3 calves, 4 heifers and 2 cows were examined and from the other (B), 12 bull-calves. The material consisted of a carcass from 1 dead calf and skull, metacarpus and kidneys from slaughtered animals. The F content of feed and water samples was determined. In HP material extensive enamel defects and strong wear were found in the deciduous incisors. Fluorotic lesions in calves were not described previously. One calf had osteoporosis. In the rest of the material osteosclerosis and subperiosteal bone apposition and tubular atrophy in the kidneys were seen. Kidney lesions were not observed previously in bovine fluorosis. Dark furrows and enamel defects appeared in the teeth of the heifers and the cows. In the skeleton osteosclerosis and subperiosteal bone apposition were found. Microscopically the skeleton showed signs of repair. The F content of the skeleton varied between 135 and 300 ppm in the ash. In water samples 1.5-4.0 ppm of F were found. The mineral supply used contained 300-500 ppm of F. The fluorosis in these animals was caused by a combination of the F of the water and the mineral supplement. Considering the microscopic picture and the low skeletal F level, the lesions in the bull-calves of company B were interpreted as fluorosis in a process of repair. The ingested fluorine in these animals was reduced during the fattening period.