G. Christodoulopoulos, Χ. Κaratzias, Ν.Roumbies, Α. Papasteriadis

This research describes an outbreak of avitamonosis A in a herd of dairy cows in the area of Thessaloniki, during the sring of the year 1995. The main clinical sign observed were bindnessm reproductive abnormalities, pacental retentions and births of stillborn, weak and blind calves. The diagnosis was confirmed by measuring the plasma levels of vitamin A and total carotens. The levels of vitamin A and total carotens in blood plasma and the used feeds were compared with corresponding levels of 3 other healthy herds each one which used different feeds. By these means, the role of cornsilage, alfalfa hay and pasture grass, in order to maintain sufficient vitamin A levels, is investigated and discussed.