Authors: H.J. Schuiling, C. Benfalk, J.A.M. Verstappen-Boerekamp, R. Ferwerda- van Zonneveld, K. Bos, M. Gustafsson
In several European countries there is a demand that milk producers with automatic milking systems (AMS) must clean the milking system three times a day. Cleaning an AMS reduces possible milking time as well as consuming considerable amounts of hot water and detergents. Therefore, it is important to acquire greater knowledge during practical conditions to better understand the consequences of less frequent cleaning.
This study was carried out on 13 Dutch and 9 Swedish farms during a period
of 4 month. All AMS brands were included in the study, the two investigated
treatments were cleaning with 8 and 12 hours intervals. Milk quality was
analysed for total bacterial count (TBC), coliform count (CC), psychrotrophic
count (PC) and thermoduric count (TC). The AM-systems were tested before and
after each period of cleaning with one of the two cleaning frequencies. If
necessary the systems were adjusted to the demands set by the manufacturer. To
ensure that milk cooling and cleaning have been done correctly during the
sampling period, in the Swedish farms the temperature was monitored in the
milk pipe and in the bulk tank.
In both countries the difference for TBC was significant for the two different
cleaning frequencies, even though the difference is small. In the Netherlands
also a significant difference was obtained for the other groups of bacteria.
In some farms, probably depending on type of AM-system and on management, the
TBC is low in all cases, with no difference between two and three times
cleaning per day.
Depending on the payment system for milk quality, the number of coliform
bacteria when two system cleanings per day are performed can be above the
level for first quality milk. It is suggested that the less frequent change of
filters could attribute to this.
When AM-systems have a sanitary design, are optimised for cleaning, are well maintained and controlled, a good milk quality can be achieved with two system cleanings per day. This will reduce consumption of water, energy and chemicals and will increase the milking capacity. But defects in the construction or in the procedures will show sooner and will have a larger effect on milk quality.
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© Animal Sciences Group -
Wageningen UR. Last update:
20-02-2008 10:03. |
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