cellosis control is vaccination before the disease strikes rather than test and slaughter after the disease has taken its toll. The Department is requested to restudy this question for further consideration at next year's hearing."

In response to this request, the Department has conducted a comprehensive and critical review of all phases of this program with special reference to the role of vaccination in the control and eradication of the disease.

In 1941, Brucella abortus, strain 19 vaccine, developed by Department scientists, was introduced as a part of the cooperative State-Federal brucellosis eradication program. This proved to be a valuable adjunct to the program in providing a useful degree of resistance to brucellosis in otherwise susceptible animals. Vaccination has been found to be effective in lowering infection rates in all breeds of cattle but has had little effect on reducing the number of infected herds. Although calfhood vaccination is effective as a means of controlling the disease, research and field studies indicate that brucellosis in dairying and range areas cannot be eradicated by vaccination alone. However, this procedure served a useful purpose in reducing high infection levels to a point where eradication is practicable and can be accomplished through the application of other eradication tools. When available procedures are applied in an appropriate manner, no difficulty is being experienced in eradicating brucellosis.

Other procedures include brucellosis milk ring test (BRT), an effective means of detecting dairy herds having brucellosis by testing milk and cream at dairy plants, and market cattle testing (MCT), a screening procedure for beef herds. Both procedures eliminate down-the-road testing otherwise required to determine the brucellosis status of herds. Cattle affected with brucellosis in herds located by these screening procedures are removed for slaughter. The objective of the cooperative program is eradication of brucellosis which would not be possible by the use of vaccination alone. However, calf vaccination is an essential tool in the total eradication effort.

The vast majority of the livestock owners support the eradication program as evidenced by the fact that 82 percent of the counties in the United States enjoy the benefits of modified certified brucellosis area status.

EXPLANATORY NOTES

Brucellosis eradication

Three more States become modified-certified.-During fiscal year 1963, the States of Missouri, Kansas, and California achieved statewide certification by reducing infection to not more than 1 percent of cattle and 5 percent of herds. This brings the total of certified States to 34, including Puerto Rico and the Virgin Islands. In the current fiscal year, Kentucky has been added to the growing list of modified-certified States.

In fiscal year 1963, 167 counties were certified, bringing to the total number more than 82 percent of all counties in the United States certified. Additional counties are being added to the modified-certified list at a substantial rate. Favorable legislation enacted in several States in 1963 is resulting in increased activity. As of June 30, 1963, 85 percent of all counties in the United States were working to eradicate brucellosis, with many individual farms and ranches in the remaining counties also participating.

After reaching modified-certified status, the States move into the certified brucellosis-free area phase of the eradication program, the phase in which eradication is completed. Certified brucellosis-free status is granted when all cattle in a specified area are free of infection. Seven new States and the Virgin Islands have entered this phase of the program since the beginning of fiscal year 1963. As of June 30, 1963, 18 States, plus Puerto Rico and the Virgin Islands, had one or more brucellosis-free areas. During fiscal year 1963, 74 counties and 1 Indian reservation were added to the free area list. As of June 30, 1963, a total of 192 counties had certified brucellosis-free status.

The State of New Hampshire has maintained its brucellosis-free status for over 3 years without difficulty, thus demonstrating the effectiveness of the available tools and procedures being used to eradicate the disease.

The following table sets forth a comparison of certification of areas during fiscal years 1962 and 1963:

Milk ring and market cattle testing activities.-Increased emphasis is being placed on use of the milk ring test for dairy herds and on the market testing of beef herds as techniques for screening sources of infection. Many States now conduct the milk ring test four times per year. Through these methods, outbreaks of brucellosis are detected very early, usually before the disease can spread to other herds, and efforts can be concentrated in herds most likely to contain infected animals. Only 1.2 percent of all herds ring tested in 1963 were classified as suspicious which is an indication of the effectiveness of this method for checking on infection in dairy herds.

Approximaely 2.5 million animals were blood tested at stockyards, packing plants, and other concentration points during fiscal year 1963 as part of the market cattle testing activities. Of these, over 62,000 showed evidence of brucellosis. The States reported an overall efficiency of 95 percent in tracing these animals to the herds from which they originated. When infection was found in the herds of origin, more than 10 percent of the animals tested were infected. Tracing infected animals to herds of origin is proving to be one of the most effective tools in the eradication program. As long as areas and herds are adequately represented in the market cattle testing program, continued certification of areas is assured without extensive on-farm or on-ranch tests

Vaccination of calves continues to increase.-Over 7 million calves, representing more than 55 percent of all eligible heifer calves in the United States, were vaccinated against brucellosis during fiscal year 1963. This is an increase of 5 percent over 1962, and represents substantial induced resistance against brucellosis in the cattle population.

Swine brucellosis eradication activities increase.-California is making good progress in the validated brucellosis-free area program to eradicate brucellosis in swine with 17 of 58 counties having eradicated swine brucellosis. There is also increasing nationwide interest in eradicating swine brucellosis. Over 1,100 herds throughout the United States are established as validated brucellosis-free herds.

Federal-cooperators financing.—A distribution by State of Federal and cooperators funds in fiscal year 1963 and other data relating to the program is shown in the following tables: