Farm hygiene and teat cleaning requirements in automatic milking

Abstract

Within hygiene management in dairying effective teat cleaning before milking is a precondition to ensure high quality of raw milk. The teat cleaning efficiency of Automatic Milking (AM) systems was investigated applying different methods. All brands currently used in practice were included: DeLaval, Insentec, Lely Industries, Fullwood, Prolion/Gascoigne Melotte and Westfalia Landtechnik GmbH. Significant differences in teat cleaning efficiency of different brands were determined (p < 0.05), showing the necessity to improve teat cleaning efficiency of at least two brands. Variation between individual farms was of significant influence on teat cleaning efficiency with differences between the 3 farms working with the same AM system (p < 0.05). Also of influence was the initial contamination of teats before cleaning. These results indicate that farm management is important to ensure low teat contamination levels. High coliform counts in bulk tank milk exceeding 100 cfu/ml suggested insufficiencies of teat cleaning on 8 farms, although in some cases these were accompanied by high counts of thermoduric bacteria indicating failures in system cleaning. On 18 farms with AM systems management aspects with regard to teat cleanliness were studied by means of a questionnaire based interview with farmers and a checklist on the actual hygiene status of barns. The outcome was compared to teat contamination measured by determination of TBC (total bacterial counts) and ATP (adenosine-tri-phosphate) from teat swabs taken before teat cleaning. AM specific management factors associated with high teat contamination were: replacement of teat cleaning device less than twice per year, moderate/poor status of the teat cleaning device, average milking frequency per day < 2.5 and no selection of cows for robot acceptance (p < 0.10). Factors not directly related to AM involved contamination of cubicles: less than one cubicle per cow, cows lying on alleys present in the herd, addition of fresh bedding material less than twice per day, no selection of cows for udder health, moderate/poor status of bedding material and moderate/poor status of claws were significantly related to high teat contamination. Additional factors like the general impression of the robot, cleaning frequency of the milking box, status of teat cups and the use of cow brushes in the stable were probably more closely related to the general attitude of the farmer towards hygiene than to teat cleanliness.