Than cattle leukosis is dangerous to health of the person as consumer of live stock products of what there is an economic damage from this disease, what methods of specific prevention and leukosis treatment – these questions are answered by the publication.
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Cattle leukosis, unfortunately, was widely adopted in our country and causes a notable economic damage to cattle-breeding farms.
The correspondent of the magazine Animal husbandry of Russia addressed to the honored worker of a science of the Russian Federation, the academician of the Russian Academy of Natural Sciences G. Aykazovich – to the leading scientist in the field of a leykozologiya.
- When for the first time in the world leukosis was found?
- Cattle leukosis is revealed for the first time in 1876 in East Prussia on black and motley breed of an ostfrizsky origin. Ignorance of the true reason of emergence of an illness and high genetic potential of this breed promoted free plemprodazhe for increase of efficiency of native animals that led to a wide circulation of leukosis, first of all in countries of Western Europe.
- Whether the reasons of emergence of an illness are known?
- For many years to them referred these or those features of environment, nature of feeding, heredity etc. At last in 1976 the American scientists managed to allocate the activator of an ekzogenny origin which excludes hereditary transfer of an illness at patients with leukosis of cows.
This virus contains in blood leukocytes, and also in milk, sperm, to okoloplodny liquid and is transferred at the every possible veterinary and zootechnical manipulations which are connected with blood and carried out without observance of principles of an asepsis and antiseptics.
In 5-10 % of cases the virus breaks an intraplatsentarny barrier and is transferred from infected mother to a fruit. Numerous cases of infection of animals are known at the joint contents and contact to a source of an infection in shelters, on pastures, and also blood-sicking insects.
- Of what there is an economic damage from this disease?
- The economic damage depends first of all on duration of trouble of herds on this disease and extent of defeat of a livestock of cattle.
Frequent diseases of highly productive animals with short-reception from them of milk and posterity actually destroy a genofund of the best families and lines which were created in each economy of ten years.
Thus, the big damage puts leukosis to breeding farms, breaking selection work, interfering with increase of efficiency of doyny herd, cultivation of valuable young growth for sale.
- Whether there are reliable methods of lifetime diagnostics of an illness?
- It is possible to tell with confidence that at one infectious disease of cattle there are no such authentic methods of early recognition of infectious and pathological process, as at leukosis. It is subdivided into stages. The first, infectious, passes without visible clinical symptoms, is diagnosed by serologichesky methods of researches (READ and IFA). The second – a pathological stage – with gematologichesky changes in peripheral blood. Both these stages are diagnosed with big reliability.
- Than cattle leukosis is dangerous to health of the person as consumer of live stock products?
- The definite answer on this question while isn’t present. But scientific researches show that milk of sick cows contains leykozogenny substances which are hazardous to health of people.
In experiments on a skarmlivaniye of crude milk from sick cows it was possible to lambs and calfs to reproduce leukosis. Existing directive documents milk from patients with leukosis of cows is forbidden to be used for a food of people, it should be fed after boiling to calfs or the pigs being on fatten. The infecting agent which perishes at pasteurization, and existence in it okogenny substances which aren’t neutralized even by boiling is dangerous to the person not.
- Whether there are methods of specific prevention and treatment of leukosis of cattle?
Leukosis virus, as well as the causative agent of AIDS, is localized in blood lymphocytes. To kill this virus, it is necessary to destroy a lymphocyte. It will lead to an immunodeficiency as the protective mechanism of an organism weakens.
The main method at eradication of leukosis of KRS – a vybrakovka. At carrying out protivoleykozny actions in large herds it is necessary to hand over no more than 3 % of sick cows on meat, without allowing development in them tumoral defeats.
(On magazine materials Animal husbandry of Russia).