DISEASES OF DAIRY STOCK.

Press, Volume XLVIII, Issue 14406, 13 July 1912, Page 14

DISEASES OF DAIRY STOCK.

ADDRKSS BY MR,REAKES

Mr C. J. Reakes, chief veterinarian, delivered an interesting lecture at tho National Dairy Show, . Palmerston North, on "'Diseases of Dairy Stock." Mr ficakes congratulated the National Dairy Association and all those engaged in dairying on the very prosperous reason just ended. The industry was steadily improving and progressing and was destitfed to become more prosperous still. He was convinced that the industry had a great future before it. With regard to the question of diseases, he stated that what appeared at. first sight a puzzling disease had oomo under their notice some timo ago. The cows affected showed a gradual and constant wasting, ami got thinner and thinner. The animal appealed to get cramped in its t'orequarters, while there was a slight swelling noticeable on tho ribs. On holding a postmortem examination, they found the swollen ribs very weak at the point where the enlargement existed. They found further, in the course of experiments, that if they gave these cows a treatment of phosphate of iron they recovered, and if the pastures were given a dressing of basic slag the trouble -«a<3 got rid of. The whole trouble was that land which was of an inferior quality in the beginning and which had been in grass for a numbor of years without manure of any kind being applied had become denuded of phosphates. Allusiou was made to a disease sometimes Called foot-rot, and often met with .in cattle running in paddocke where there was a lot ot tall fescue. A small germ called the necrosis bacillus was invariably found in these cases, the function of the germ being to destroy tissues.; Last year 3n experiment had been tried. with ergot ia its ordinary medical form, the cattle being drenched with it. This .however did not give any results' at all, tho animals being entirely unaffected. It was an accepted fact, though, tliat ergot, was liable to lose some of its properties through being kept. It was then decided to try ergot in ite natural condition, and the speaker arranged to get a supply of tal] fescue heads infected Wj'tn ergot. The experiment was carried out at the Wallacevillo laboratory in conjunction with Mr A. H. Reid, F.R.C.V.S., the officer in charge of the laboratory. After two steers had beed fed with this some time they commenced to go back. At first ono leg commenced to swell very considerably, and theii two'others. Subsequently the swelling went down, and the hair began to come off, leaving in its place raw patches. Finally the hoofs commenced to drop off,, and the beast was killed. [ The germ j however, was always present in the soil, and this explained how it was .that gome scientists were Jed astray and put the.whole trouble down to the germ, whereas ergot was the thing that etarted it, though the necrosis bacillus had an important action in producing the worst"conditions. If possible the cattle, especially milk cows and young animals, should not be allowed to graze oav-grass, which was badly ergotieed. Witft regard to contagious mammitis there was, of course a considerable amount about, but so long as they had milking cows about there would always be a number of cases arising from eim?>le causes and not from contagion. Unbrtunately, it was almost impossible for the farmer to tell whether the case is of tho simple form or contagious, and he, therefore, advised them to treat icases as though they were contagious. It had to be remembered, however, that every case was not contagious. The contagious form of, the disease should be watched very carefully, however,, and more particularly should' care be taken where miilking machines <were need, as contagion could easily be carried from one cow to another by the cups. Ho Was hopeful that they ■would bo able to get a satisfactory form of treatment for curiug but up to the present they had not been able to cure it with any injections that had been tried. Alluding to contagious abortion, he stated he had great hopes that it would not again l>o as troublesome as it haa been in"the past. Great care should be taken, however, in dealing with thie. It did not always follow that it had died out; it might make its appearance again at any time, and a careful watch should always be kept for any cases that might appear. The most troublesome disease, however, was tuberculosis. Last year the value of the stock condemned on account of this disease had been very considerable. The troublo was that beforo these animals had been condemned they had been spreading infection among others. Ho would like to point out in this connection that if all the skim nu'lk w;ero pasteurised, instead of this disease costing a large .sum each year, it would not cost one-tenth of tho present cost. In 6ome places where the dairy factories had adopted the system of pasteurisation there had been a noticeable decrease in tubercnlosis in the district, and ho was convinced that if all the factories adopted this system it would pay them handsomely. He_ sincerely hoped that when the next Winter Show came round he would be able to congratulate them on the fact that this disease had been materially checked.