4. Any person undertaking butterfat testing for a purchaser in a laboratory must keep, and retain for the relevant period, records comprising details of all samples of milk analysed, showing—
(a)the time and date the sample was taken on the holding;
(b)the time and date of his receipt of the sample;
(c)the time and date of the analysis;
(d)the identity of the purchaser concerned;
(e)the identity of the producer concerned (by name or reference number);
(f)the butterfat content of each sample recorded to two decimal places;
(g)the method of analysis used; and
(h)the results of any repeat analyses undertaken.