MINISTERS REPLY.

Pahiatua Herald, Volume XLI, Issue 12430, 24 August 1933, Page 2

MINISTERS REPLY.

MILK GRADING TESTS. MR, VE ALE’S OPEN LETTER. THE VIEWS OF EXPERTS. illectric Telegraph—Press Association HAMILTON, August 22. Sstatements made by Air P. O. V'eale, dairy research chemist, of Hawera, in his recent open letter •riticising various matters connected with the new dairy regulations, vere replied to by the Minister of Agriculture, Hon. C. E. Macmillan, n the course of an address at the mnual smoke concert of suppliers' committees of the New Zealand Comer at ive Dairy Ltd., at damilton to-night. Mr Macmillan said that Mr Veale vas aggrieved that the jiroposal to rive a choice of three tests to be applied when grading milk was debated on the Minister’s casting /ote, and claimed that all the research scientists voted in favour of :he regulation as it now stood included only practical men, i.e., simple laymen. Mr Veale, said the Minister, took particular exception to the fact that die department responsible to the country for the conduct of the infustry exercised four votes, and mplied that they were the votes oi men who had not practised dairy research. That was not correct. Dr. CL J. cceakes, a scientist with long experience in bacteriology, including dairy bacteriology, and Mr A. H Cockayne, who possessed scientific knowledge in a high degree and was well versed in dairy science, accounted for two of the votes. th< other two being Mr W. M. Single ton, the Director of the Dairy Divi si on, whose whole career had been spent in 'milk and dairy problems, and the speaker himself, who had h«id long and intimate connection with dairy factory suppliers’ and companies’ problems. With Mr Singleton (though not voting) was Dr. Moir, a scientist of high repute, whose training included an extended course of three years at the National Dairy Research Institute at Reading, England. MTLK FOR CHEESE-MAKING. “The move to improve the quality of milk for cheese-making,” the Minister continued, “began last year when the regulations prescribed that grading be based upon the curd test—a process by which a sample of each supplier’s milk is made into a curd or uncured cheese. The research scientists said this test was not sufficient in itself to determine what was wrong with milk that did not make a good curd, and that one of the other tests should be prescribed in the event of differential payments being made obligatory. “All scientists are agreed that no one test alone is fully satisfactory, and the curd test was decided upon for testing cheese mi]k because it detects milks which make curds of objectionable flavour or showing gas holes or sliminess, and it may be used for detecting nnlk described as non-acid. By showing a. supplier his own defective curd alongside a good curd the defects are made manifest, and the supplier is then usually so satisfied on the point that improvement is made. This is a gTeat feature in the value of the curd test, as the key of the position as regards clean milk lies in the hands of the suppliers.

LAST YEAR’S REGULATIONS. ‘‘L-;*st year’s regulations, grading milk by the curd test without differential payments, were violently opposed by a small group of cheese factories, but after a year’s trial ho factory can be found sufficiently antagonistic to propose that milk grading should be rescinded. In an endeavour to meet the viecvs of the objecting scientists, and to strengthen the testing method, the new regulations which came into force on August 1, 1933, were made to provide that, while the factory manager must use the curd test, of which he has already had a year’s experience, he must "use with "it either the direct count or the methylene blue test in determining whether milk is to be penalised bv a lower price for second grade. "The direct count implies either having the milk tested in a laboratory or installing a microscope and instruct™i! a man in its use. The methylene blue test requires very little extra expense or scientific knowledge.” The Minister quoted Mr A. T. R. Mattick, head of the bacteriological departmentj National Institute for Research in Dairying, Reading, -England, who writes in the Journal of Dairy Research, 1930, as follows: ‘‘One fact emerges from a consideration of the literature upon the methods at present m use for determining the bacteriological content of milk, viz., no one method is capable of giving exact informa■tmn as to the numbers of living bacteria present.”

GERMAN. ATTITUDE. It was pointed out by Mr Macinillan that at the South German Dairy Research and Experimental fetation, near Munich, the professors regarded the rennet curd as the b? o®* 0 ®* important in judging the suitability of milk for cheese-making. ,lhe unquestioned superiority of the rennet curd test, was established by Aeiier and Berwig, dairy scientists, m 48 experiments in which cheese was made from the same milk which was. judged both by the fermentatest an <3 the rennet curd test Ihe German scientists, after using a set of simple milk quality tests for three years, stated that they -were so impressed with the value of the curd test that m the fourth year they proposed to increase the poi nts allotted to it from ten to fifteen, while no other test was allotted more than five points. For practical purposes this curd" test method, which was not approved of by Mr Veale, of examining milk had undoubtedly stood the test of time, and if conscientiously and regularly used would no doubt help •materially to improve the quality of .the milk used for cheese-making

and consequently tlie quality of cheese exported from New Zealand. STATEMENT IN TEXTBOOK. In his textbook on “Dairy Bacteriology,” said Mr Macmillan, Hammer emphasised the value of the Wisconsin curd test, which was introduced at the end of last century. After describing the method of obtaining the pat of curd he wrote: “If it is solid throughout, shows no sliminess at the surface, and has an agree able; odour, the milk is probably free from organisms that would be objectionable in cheese-making, while gas holes in the curd, .sliminess, objectionable odours, etc., show the presence of organisms that can be expected to cause undesirable conditions in cheese; in some instances the curd is so full of gas holes that it may be spongy. Milk with a very high bacte.riolog : cal count may give a desirable type of curd, and another lot with a low count may give a very undesirable curd, so that the test. is of no value in comparing samples of milk from the standpoint of their keeping quality. “As I have already stated,” Mr Macmillan concluded, “we have to look to the suppliers to bring about the necessary improvement m milk quality. No one test in itself being entirely reliable, the best course has been adopted, by linking up the curd test, as being the tqst affording the best basis for grading and the best object lesson to the supplier, with one of the other two tests.” In liis open letter to the Minister, Mr Veale tendered his resignation from the special dairy committee appointed in March last. Mr Veale stated that he had the step for the reason that, although the committee was set up to confer with and advise the department in the matter of the new dairy regulations, there had been no proper consultation with the committee at all. He alleged that on the contrary there was a strong indication by the Minister and his department that they would not be guided by advice of any kind, particularly scientific.