TUBERCULOSIS 197 



separate stable — preferably on a different farm. They must not 

 be watered at the same tank as healthy cattle, nor fed from 

 common mangers. The danger m allowing tuberculous and non- 

 tuberculous cattle to associate in the open air, is less than in a 

 stable; but this disease undoubtedly spreads in the open air. 



Accredited herd plan. — Every stockman should know about 

 the accredited herd plan. 



This is a common movement over the United States by which 

 state and federal authorities are cooperating to free breeding 

 herds from tuberculosis. 



Such herds are officially published as tuberculosis-free and 

 the owner receives a certificate to this etfect from his state and 

 the federal government. 



Requirements of the ])lan at the present time are, in general, 

 two negative annual tests or three negative semiannual tests of 

 the entire herd. 



The owner first signs an application and agreement ; his herd 

 is tested (at public expense, in some states), until it becomes 

 accredited. Thereafter it must be regularly tested each year by 

 a private veterinarian at the owner's expense. This veterinarian 

 must have passed a certain official examination. 



The advantages to the breeder of being on this list are obvi- 

 ous: advertising and reputation, shipment interstate, advance 

 compliance with laws and regulations concerning sale of pure- 

 bred cattle for breeding purposes, and aiding in eradication of 

 the disease at the fountain source of dissemination. 



There is, as a rule, more tuberculosis among pure bred cattle 

 tlian among grades, and the general movement of the pure bred 

 is from herd to herd whereas the grade moves from farm to 

 killing floor. 



Fortunately, the prevalence of tuberculosis among pure-bred 

 cattle is now being reduced and the near future may see the 

 figures reversed as between pure-bred and grade cattle. 



The following figures will give the student an appreciation of 

 the volume of this new movement for accredited herds. On Feb- 

 ruary 1, 1922, there were 12,157 accredited herds in the United 

 States; 104,467 herds which had had the first negative test; 

 18,956 on waiting lists and a total of nearly 143,449 under joint 

 state and federal supervision, ^linnesota leads in clean herds 

 at this date (February 1, 1922) with 1310 accredited herds and 

 2256 other herds with first clean test. 



