During the reproductive period the AA have carried on bacteriological researches in the preputial cavity in eight sardinian rams, without pathological processes, living in eight flocks in the country around Sassari, in order to detect the bacteriological flora. This flora could interfere both with fertility and with conservation of seminal material for artificial insemination. Three withdrawals have been carried on before, during and after the reproduction season. E.coli, P. mirabilis, Staph. epidermidis have been found in the varius examined subjects. The AA stress that the same bacterium which had been isolated in the first withdrawal. Moreover in some subjects the bacteriological flora had increased. The AA stress how these data can be useful in order to control the flock fertility and in order to improve the technology of conservation of seminal material.