[Machine milking and udder health: a literature review].

This article reviews the influence of machine milking on udder health. The main risks are transmission and penetration of pathogens during milking. Pathogens can be transmitted via the hands, cloths, and liners. Irregular fluctuations in the vacuum can cause penetration of mastitis pathogens into or through the teat canal. Such fluctuations are caused by air blasts in the milking machine. Machine milking can also cause teat lesions, although only severe lesions give rise to new infections. Preliminary research results on the influence of the frequency and degree of udder evacuation show that the clinical symptoms of mastitis generally decreases as the frequency and completeness of milking increase. It is concluded that machine milking can influence udder health but that the influence strongly depends on the exposure to pathogens and the quality of the milker.