The Effect of the Introduction of Automatic Milking Systems on Milk Quality

Changes in milk quality after the introduction of automatic milking systems on 28 Dutch dairy farms were examined and observations were compared with milk quality characteristics on two groups of farms milking either two (49 farms) or three times (28 farms) per day in a conventional milking parlor.Milk quality data were collected from January 1996 until March 1998.The farms with an automatic milking system are pioneers and cannot be considered representative of Dutch dairy farms.After the introduction of the automatic milking system, a statistically significant increase in total bacterial plate count and in free fatty acids was observed.Total bacterial plate count, free fatty acids, and freezing point were higher on farms using the automatic milking system than in the other two groups of farms.Somatic cell counts did not change after the introduction of the automatic milking system, but were already rather high in herds using the automatic milking system compared with the other groups of farms.The introduction of automatic milking systems used in the study resulted in a decrease in milk quality compared with conventional systems.(Key words: automatic milking system, free fatty acids, total bacterial plate count, somatic cell count) Abbreviation key: AM = automatic milking, BAB = spores of butyric acid bacteria, FP = freezing point, TPC = total bacterial plate count, 2× = farms milking two times a day, 3× = farms milking three times a day.