Influence of the storage period between sampling and analysis on total bacterial count in milk

Every month, only one official milk-testing result is available from between 1000 and 1200 milk producers instead of the two required. Of the missing results, one part originates from milk-collection centers where milk delivery takes place every other day and sampling is performed manually, and is therefore attributable to the time delay between sampling notification and milk delivery. Extending the maximum time allowed between sampling and commencement of the analysis from 30 to 36 hours would provide an easy and cost-effective method to solve this problem. The increase in the number of samples with results above the maximum permitted limit would be slight: In the present study, the percentage increased from 1,397 % at 30 hours to 1,468 – 2,648 % at 36 hours, representing a rise of 0,07 – 1,25 %. This can be accepted as a justifiable drawback as it would affect very few producers and only those whose milk at 30 hours contains bacterial counts close to the official limit. The overall discrimination would probably be even lower as the increased time span would not necessarily affect both monthly samples and therefore, after calculation of the monthly geometric mean as required by the public-law milk quality control, the results may well remain within the limits set.

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