DISEASES IN STOCK.

Otago Witness, Issue 2892, 11 August 1909, Page 9

DISEASES IN STOCK.

; CAUSES OF TUBERCULOSIS. ! ADVICE BY MR REAKES. WELLINGTON, August 4. In an address on diseases of stock at the agricultural conference, the Ghief Veterinarian (Mr G. J. Reakes) made special reference to tuberculosis, and the immediate need of taking steps to repress it. "In view of the proved existence of the disease and the several means outlined whereby the disease was being spread," Mr Reakes said, "I am of opinion that tie following preventive measures are immediately necessary :—(1): — (1) Continuance of the present system of weeding out and slaughtering all noticeably affected animals, doubtful cases to be tested with tuberculin; (2) so dividing the farm into paddocks that each paddock can in. turn be kept for some months clear of cattle altogether. Sheep could be grazed upon these naddocks while the cattle were off them ; (3) the constant maintenance of cleanliness in milking sheds, and, so' far as is practicably possible, holding yards; (4) the pasteurisation of all separated milk and whey at dairy factories and creameries before its removal by farmers for the purpose of feeding calves and pigs; (5) the provision of good winter feed both for cows and young stock, thus enabling them to maintain a high standard of vitality, and giving them a better chance of resisting infectious disease. AH these measures can, without much difficulty, be carried out by the dairy farmer except No. 4, which involves dairy factories and creimeries, and this is a most important measure. I &m satisfied thai it would have an infinitely greater far-reaching effect than would any other. In the case of tubercular germs distributed in paddocks, jards, or milking sheds there^ is no certainty of them invariably getting into the system of other cattle or of pigs, since they are, to a great extent, exposed to the germicidal influence of sunlight and other influences detrimental to them, but in the case of tubercular milk they must gain direct entrance in large numbers into the animal body. The prevalence of tubercular disease among pigs fed upon separated milk or whey demonstrates this fact clearly. Most calves in dairying districts receive the same diet, and though, admittedly, they, as a result of being the porgeny of generations of ancestors many of whom have been the subject of tuberculosis, have more resisting power than have pig.s, with whom tuberculosis is not an inherited disease, yet a large number must contract the disease in their early days, though years may elapse before they exhibit outward manifestation of its presence. As to the effectiveness of pasteurisation of skim milk and whey, there can be no question. In Denmark and in the States of lowa and Minnesota it has been made compulsory by law with good re- ' suits. In this country, where practised, it has proved in every way satisfactory. I know of one dairy factory where last year the skim milk was not pasteurised, '<

■ and the percentage of diseased pigs fed upon it varied in different large batches slaughtered from 59 per cent, to IGO pe_ cent. This year the milk was heated, not thoroughly pasteurised, yet successive large batches of pigs kept in. the sama pens and reared from the same stock under similar conditions as in the previous year, were killed without a singla diseased animal being found, and among those batches in which tubercular pigs were present the highest percentage was 11 per cent. Again, I could name two factories within three miles of each other in one of which the by-pToduct whey i 9 pasteurised and at the other it is not. In the first case a tubercular pig which, has been fed upon whey is a rarity, but; in the other a large purchaser who is under inspection will pot buy the pigs afc all on account of .the number found diseased on slaughter. In the case of other factories where the whey is pasteurised I can obtain no record of tuberculosis among pigs fed upon it. It is greatly to be regretted that, owing to the fact that a factory skim-milk or .whey-fed calf rarely comes under the hands of a Government meat inspector before reaching maturity, we are unable to obtain such clear statistics concerning calves as are available in the case of pigs, but knowing the degree to which cattle are susceptible to tuberculosis, I am quite satisfied that the feeding of calves upon raw skim milk or whey from dairy factories is one of the most potent factors in the spread of tubercular disease in this country, and. moreover, that the pasteurisation of these dairy by-products would be one of the most valuable preventive measures which could be adopted