A survey on bacterial mastitis in the cows from the traditional farms located in the suburb of Tabriz city, Iran

Mastitis is one of the most critical problems for dairy cattle worldwide. The purpose of this study was to determine whether mastitis is caused by bacteria in the dairy cows of traditional farms. In this randomized clinical trial, 54 Holstein cows with clinical mastitis (from October 2020 to September 2021) were selected from the traditional farms located in the suburbs of Tabriz city. All cows were subjected to sampling during four seasons according to the National Mastitis Council (NMC) guidelines and the collected samples were rapidly sent to the Veterinary faculty’s microbiological laboratory for bacterial cultures. The distribution of mastitis was evaluated according to the stage of lactation, parity, season, and types of bedding system. The results were as follows: E. coli 39%, Streptococcus uberis 21%, Streptococcus agalactia 7%, and Staphylococcus aureus 33%. The results of this study showed that parturition, increased number of parity, wet and rainy seasons, as well as sawdust and cow manure bedding are among the risk factors for mastitis. In conclusion, in traditional farms, unlike industrial farms, environmental mastitis has more importance than contagious mastitis. Regarding the presence and shedding of E. coli microorganisms in the milk, this should be highlighted as a concern for public health.