The Southland Times FRIDAY, JUNE 9, 1939. Tuberculin Testing Of Cows

Southland Times, Issue 23839, 9 June 1939, Page 6

The Southland Times FRIDAY, JUNE 9, 1939. Tuberculin Testing Of Cows

TN a letter to The Southland 1 Times, printed yesterday, Dr A. F. Ritchie Crawford drew attention to a question which has a direct bearing on the public health. Stressing the need for a compulsory tuberculin test, he pointed out that only .88 per cent, of the total number of dairy cows in the Dominion were tested last year; yet it was found that 7 per cent, of these were affected by tuberculosis. “If the incidence is the same in those untested,” wrote Dr Crawford, “we have the stupendous number of 131,095 cows suffering from tuberculosis —and their milk is being consumed.” Support for these statements can be found in last year’s report from the director of the live-stock division of the Department of Agriculture. After announcing a slight increase in the incidence of infection among cattle examined at various abattoirs and meatexport slaughterhouses, the director repeated a recommendation which has been made more than once in the past. A more extensive application of the tuberculin test, he said, should be made compulsory. “There can be no denying that the existence of this disease in dairy herds, even though its incidence in New Zealand is low compared with other countries, has a deteriorating effect on the general standard of animal health. ... In the past attention has been drawn to the desirability of tuberculin testing all cows supplying milk for human consumption throughout the Dominion. ' I would again stress this recommendation, which can be regarded as an ... . important public health measure.” I The Minister’s Objection

In face of these figures and the advice of his own departmental expert the Minister of Agriculture, speaking at Dunedin yesterday, declared that universal tuberculin testing is not warranted at the present time. Those who read his remarks will find it hard to feel that Mr Lee Martin realizes how gravely the public health is threatened by the present condition of many dairy herds. His statement that there has been as high as a 60 per cent, reaction to the test is a damaging admission of the need for compulsory testing at the earliest possible moment; but, because he believes that the industry cannot afford “the wholesale culling and slaughterings that would be necessary”, nothing is to be done—and thousands of persons are to go on drinking milk from infected cows. That there are difficulties in the way of universal testing ■will be readily understood. One of them would be the financial outlay involved in any large-scale payment of compensation for infected cows; another, more serious, would be the heavy fall in milk production that would result from extensive culling. A further difficulty mentioned by the director of the live-stock division would be the provision of a staff large enough to carry out the testing. Nevertheless the problem cannot be neglected indefinitely without affecting the standard of public health, which is by no means as high as it should be in a country favoured above most others in the quantity and quality of its food resources.

Is Pasteurization Adequate?

The importance of milk as an essential food is widely recognized in theory and has been given a practical recognition in New Zealand by the distribution of a free daily ration to school children. According to Mr Lee Martin, the Health Department considers that i pasteurization is an adequate safeguard against tuberculosis in milk. This opinion is supported by many experts; but there is an equally strong, if not stronger, body of opinion against pasteurization on the ground that it upsets the chemical constituents of milk through the precipitation of the calcium salts, and reduces its nutritive value. Whatever the truth of this matter, it is certain that milk in its raw state is highly nutritious, and it seems reasonable to believe that the best way of safeguarding its nutritive value is through the careful testing of dairy herds. (There are, in any case, many thousands of consumers whose supplies of milk are not pasteurized.) The complete eradication of tuberculosis in cows might seem to require a long and expensive process of culling from infected herds; but it should be possible to make a beginning by tuberculin testing in special areas, with the intention of establishing tuberculosis-free districts. This measure was advocated by the director of the live-stock division of the Department of Agriculture, and seems to indicate a practicable way of approaching the problem. But if the Government declines to act, the situation must remain largely in the hands of dairymen. A voluntary extension of the present system of testing would do much to check the spread of infection and to preserve the high quality of New Zealand milk.