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10. For whatever reason, pasteurisation is very generally undertaken in America as part of the system of distributing milk to urban consumers, This is brought out in the following table (table 2):-
TABLE 2.
►
The extent of pasteurisation in cities in the United States in 1924 and 1930.
Percentage of cities in which the percentage of pasteurised milk was—
Number of cities
Population of reporting. 90 to 100.
50 to 100.
10 to 50.
0 to 10.
cities.
500,000 and over 100,000 to 500,000 75,000 to 100,000... 50,000 to 75,000
1924. 1930. 1924. 1930. 1924. 1930. 1924. 1930. 1924. 1930.
1825822
I
9
25,000 to 50,000
10,000 to 25,000
100.0 90-9100-01100.0 0.0
0.0 37 56 56.8 53-6 91.9 96-4 8-1 3.6 19 13 26.3 50.0 73.6 84.6 15.8 15.4 25
20.0 40.5 80-0 77-8 12.0 22.2 60 56 20.0 30.4 80.0 105 92 12-4 17.4
0.0 0.0 0-0
0.0
10.6
0-0
8.0
0-0
80-4 13-3 17.8
5.0 1.8
Under 10,000
73 79
5.5 11.4
45.7 41.1
55.4 31.4 33-7 2.9 10-9 25.0 27.4 12.0 2.7 63.0
(ii) The eradication of bovine tuberculosis in the United States of America.
11. In 1917 the federal government initiated a campaign for the eradication of tuberculosis from livestock in the United States. The tuberculosis eradication division of the Bureau of Animal Industry was then set up with a programme of—
(1) the eradication of the disease from pure-bred herds of cattle;
(2) the eradication of the disease among swine;
(3) the eradication of the disease in circumscribed areas.
In 1928 two more items were added to this programme, namely―
(4) the eradication of avian tuberculosis among fowls; and
(5) the eradication of Johne's disease (which is also known as para-
tuberculosis).
12. Emphasis is placed upon the eradication of tuberculosis from pedigree cattle, as such cattle are particularly liable to be moved from one herd to another. The method of eradication is the periodic testing of the herd with tuberculin and the removal of reacting cattle. When two successive annual tests or three successive semi-annual tests are completed in any herd without the discovery of a reactor, the herd receives a certificate of freedom from tuberculosis from the state and federal authorities, which is valid for one year.
Such herds are known as accredited herds. Owners entering the scheme sign an undertaking to co-operate with the authorities and agree to keep their herds for the purposes of dairying or breeding. Restrictions are placed upon the entry of animals into herds which either have received a certificate or are in process of qualifying for one. Broadly speaking, animals may not be introduced into such herds unless they originate from an accredited herd or are subjected to adequate isolation and testing.
13. The area plan of eradication, which is not confined to pure-bred cattle, was first put into operation a few years after the accredited herd plan. The area for the purposes of the plan is generally a county, but may be a smaller unit, for example, a township. Testing under the scheme begins
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in any area when 90 per cent. of the owners of herds or the owners of 90 per cent. of the cattle in the area have agreed to co-operate with the authorities. When the testing of the herds of the voluntary entrants has been completed, and the reactors have been slaughtered, the movements of cattle which have not been tested are subjected to severe restrictions, the effect of which is to prohibit their removal from the premises on which they are situated. In this way recalcitrant owners are induced to co-operate. When the incidence of tuberculosis has been reduced to not more than one-half of one per cent., the area is declared to be a modified accredited area. A general retest of all cattle in such an area takes place every three years.
14. The testing of cattle under both the accredited herd plan and under the accredited area plan is undertaken by veterinary officers of the federal or state government, or of the county in question. Animals reacting to the test are generally consigned to public stockyards for slaughter. Exceptional animals, however, and animals in heavily infected districts may sometimes be segregated from healthy stock, the former sometimes on farms set aside by the state government or by associations of pedigree cattle breeders. Compensation is paid for reacting cattle slaughtered. The actual terms of compensation vary, being determined by the different local regulations in force, but are in every case based upon a valuation of the animal before slaughter. The federal government makes a contribution to this compensa- tion based upon the following rules:
-
(1) no payment shall exceed one-third of the difference between the
appraised value of an animal and the salvage value;
(2) no payment shall exceed the amount paid or to be paid by the state,
county or municipality;
(3) in no case shall any payment be more than 35 dollars for any grade
animal, or more than 70 dollars for any pure-bred animal; and
(4) no payment shall be made unless the owner has complied with all
lawful quarantine regulations.
The distribution of the loss occasioned by slaughter is of interest. The average valuation of all cattle slaughtered since 1919 has been 107-96 dollars, of which 30.78 dollars has been recovered from the sale of the carcase, leaving a net loss of 77.18 dollars. This has been borne in the following manner: by the state governments 31-99 dollars, by the federal government 20:42 dollars, leaving 24.77 dollars to be borne by the owner of the animal. At present, owing to the low price of cattle, the figures are very considerably less.
15. Partly, no doubt, on account of the high compensation paid, but also as a result of the increasing insistence in municipal milk regulations on freedom from tuberculosis in herds supplying milk for urban consumption, eradication has made substantial progress in the United States. To-day, 1,577 counties out of a total of 3,073 are modified accedited areas, and over 34 million animals are under supervision by the tuberculosis eradication division. Six surveys of the incidence of bovine tuberculosis in the United States have been carried out by the Department of Agriculture, and these show a remarkable diminution in its incidence in recent years. The estimated percentage of cattle infected with tuberculosis has been as follows in the years named:-
1922
1924
1926
1928
1930
1932
4.0
3-3
2-8
2-0
1-7
1.4
It is confidently anticipated that the operation of the measures now in force will reduce the incidence of the disease to a very low level and will prevent any danger of its subsequent recrudescence. These successful results have not been achieved without considerable expense. In the last ten years
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