Udder health in herds with automatic milking

Many Swedish farms with an automatic milking system (AMS) have experienced a rise in somatic cell counts (SCC) after the robot introduction. The calculated herd SCC, based on monthly milk recording samples, is the most objective marker for udder health at herd level. A multivariable regression analysis of the association between herd level SCC and herd factors showed that there was a significant statistical association (P<0.001) between robot milking and elevated herd level SCC. The statistical model predicted the SCC to be 8% higher than in corresponding production with conventional milking. Streptococcus agalactiae has been suspected as a main cause but this is unlikely since a national bulk tank PCR-screening in 2010 estimated the prevalence of S. agalactiae in Swedish AMS to 4.9%. A large number of herd investigations have pointed out the same four most common reasons: (1) Poor cow traffic, leading to long and uneven milking intervals; (2) Incomplete milkings were not followed up on a daily regular basis; (3) Ineffective and sparse systemic wash; and, (4) No possibility to segregate healthy cows from those with chronic contagious mastitis. Practical experiences from Swedish AMS have shown certain management procedures to be of great importance to reduce SCC: (a) access to feed and water at least 23 hours a day and no overstocking in any part of the barn; (b) correct settings for every cow in relation to days in milk) and milk yield; (c) routine for monitoring causes of all incomplete milkings twice daily; (d) milk all cows at least two times a day; and, (e) protect the fresh cows during transition and introduction in the barn.