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Ingenious Device For Bloat Control

A new long-acting device for control of bloat, developed in Australia, will be tested on both sides of the Tasman in the coming spring. Its inventor. Dr R. H. Lahy, of the Commonwealth Scientific and Industrial Research Organisation, has recently been discussing the proposed trials with scientists of the Department of Scientific and Industrial Research and the Department of Agriculture. The device is a large plastic capsule containing a jellied form Of pluronic antibloat material, which is gradually released in the rumen over a period of several weeks. In preliminary trials in Australia last year, it gave satisfactory control of bloat for 32 days after administration. The capsule, constructed as a hinged cylinder, is inserted into the cow's throat by means of a tube. The hinges are made of rubber, so tensioned that when the capsule reaches the rumen it opens out, and is then too large to be regurgitated by the animal. The capsule retains this larger shape until some time after its contents are exhausted. Then the corrosion of a tiny metal trigger permits the hinges to part, and the separate halves of the capsule can be readily regurgitated. Interviewed in Palmerston North, Dr Laby said the New Zealand trials would be more detailed than those in Australia. Here, the studies will he made not only of the degree and duration of bloat control achieved, but also of any possible effects of the capsules on animal health or on milk production and quality.

In Palmerston North, the testing will be done by the Applied Biochemistry Division of the D.S.I.R. in collaboration with Massey University and the Dairy Research Institute. These tests will involve about 50 animals at a time. At Ruakura, the Department of Agriculture. will conduct trials on a larger scale. Dr Laby’s interest in bloat began in 1985 when he was seconded to the then Plant Chemistry Division of the D.S.I.R. in Palmerston North. During his 14 months there he studied the concentrations of surface-active chemicals in rumen foams. Then he went back to Australia to investigate the significance of his findings. His first experiments in construction of what he calls "variable-geometry devices” were in October, 1968. These capsules were tested in cows in April. 1969, and were mechanically successful. Last spring, three trials of the capsules packed with slow-release pluronics were conducted. “The last of these was the most successful,” said Dr Lahy, “because we were solving technical problems as we went along. “In this most successful trial, the capsules we used were 6in long and Hin in diameter. In the 50 treated animals there was no bloat at all in the first 11 days, whereas untreated animals bloated severely. From the eleventh day to the thirtysecond day. some bloat occurred in the test animals, but in only one case was it severe enough to require treatment.” Dr Laby said he thought the most practical use of the capsules would he to aim at reducing bloat to an acceptable level rather than eliminating it completely. He is

at present working on new systems, based on the same principle, which he hopes will give such control for as long as 50 days.

He said the economics of these devices had still to be worked out. “We haven't even settled on the final design yet,” he said, “so this is a thing that still has to be costed.” But he added that in the preliminary trials, the 11day complete control was achieved with only a fifth of the daily dose that is required in twice-daily drenching. “So there you have a potential saving that you can use to build the casing,” he said.

If the forthcoming tests confirm the preliminary results. the advantages of the system will extend beyond the conventional scope of bloat control. Sustained-release devices, requiring stock to be treated only once in several weeks, would make bloat control possible for beef breeders as well as dairy farmers. Moreover, Dr Lahy looks forward to other possible applications of the “vari-able-geometry devices.” The next one to he looked at will he sustained infusion of magnesium into the rumen with a view to controlling grass tetany in cattle. Another, which may he investigated later, is the administration of anthelmintics for control of worms in sheep.

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Permanent link to this item

https://paperspast.natlib.govt.nz/newspapers/CHP19700626.2.52

Bibliographic details

Press, Issue 32333, 26 June 1970, Page 9

Word Count
713

Ingenious Device For Bloat Control Press, Issue 32333, 26 June 1970, Page 9

Ingenious Device For Bloat Control Press, Issue 32333, 26 June 1970, Page 9