Abstract: To assess the association of the incidence of clinical mastitis in dairy cows with the milk yield, lactation period and season, the prevalence of clinical mastitis in five dairy farms in Baoding area of Hebei Province was investigated. The results showed that higher incidence of dairy cow clinical mastitis was observed in 90 to 150 days of lactation, and the incidence was increased with the extension of lactation period. Clinical mastitis was found more frequent in dairy cows with higher milk yield. Higher incidence of clinical mastitis in the surveied dairy farms was observed in autumn comparing to the other seasons.

Key words: Baoding City, dairy cow clinical mastitis, incidence