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before they die. And again they may take on the cerebral symptoms. They 

 may act like they are crazy, and sometimes they Jump in the air and fall 

 over dead. That depends on the different poisons. The symptoms vary 

 considerably. 



Q. Should the sick hogs be given both treatments when they are 

 vaccinated, both the virus and serum? 



Mr. McDONALD: That depends on circumstances. We always made it 

 a point to give the hogs both treatments, regardless of whether they were 

 sick or well. I can't see where the addition of two cubic centimeters of 

 virus in hogs that already had a quart of virus in them makes any difference. 

 Where you go into a herd that is sick with cholera and take temperatures, 

 which everyone should do to determine the condition of the herd, if you 

 chase the pigs around you are liable to increase their temperatures from 

 excitement. In that case if you give serum alone you would only have a 

 temporary immunity in the hog which later on would come down with 

 cholera and you would blame the treatment for the loss of the pig. 



Q. I would like to ask about the use of minerals. Some of the minerals 

 that are recommended are very expensive. What form would be effective 

 at a moderate price? What do you think about the use of minerals? 



Dr. McDONALD: Well, I guess there are quite a number of hogs that 

 need them. I do not believe, however, that hogs need as much mineral as 

 we have been led to believe they do through the advertisements. I don't 

 think anyone knows exactly what amount of mineral is absorbed by these 

 hogs. There is no doubt but what some of the minerals are beneficial in 

 some cases. As to the price of them, why, that is just a matter of market 

 prices. 



Q. Which are the most essential? That is what I am getting at, 

 leaving out some of the high prices. 



Dr. McDONALD: Well, I think that charcoal, lime and phosphorus 

 are about the essential minerals. 



Q. If pigs are weaned and healthy do you think it is necessary to 

 change their feed at the time of vaccination? 



Dr. McDONALD: From what they have been getting? 



Q. Yes, sir. 



Dr. McDONALD: No, I do not, any more than I would advise that 

 they be kept off of corn for a period of ten days or two weeks. I believe you 

 would get a more permanent immunity where hogs are vaccinated if they 

 are gvien a chance for the serum and virus to work before they are put on 

 full feed. When the government was demonstrating the use of serum and 

 virus in 1913 and 1914 they would not vaccinate in a herd unless the owner 

 would agree to keep them off of corn for at least two weeks. 



Q. There is Just this question in my mind: what is the difference 

 between the virus that the farm bureau uses and the virus that the vet- 

 erinarian uses? The veterinarian claims the farm bureau virus is no good. 



Dr. McDONALD: I don't know, I am sure. All virus is made the same 

 under federal supervision, as I told you before. If there is any difference, 

 it would probably be in the keeping of the virus after it left the manu- 

 facturer for distribution. 



PRESIDENT MANN: One of the great problems that humanity has 

 had for a while besides production of food has been distribution of food 

 and in the past the farmers have rather depended on the city people to solve 

 most of the problems regarding the distribution of food and other problems, 

 but now the farmers know that unless they have a hand in solving those 

 problems that the producer will not get a fair share of the returns. 



Now there are a good many problems relating to marketing. Marketing 

 of the surplus product is an old proposition. The first step in marketing 

 is the haul of the product of the farm over to the local elevator, the stock- 

 yards and distributing points, and I think it is fortunate for agriculture that 

 such strong organizations as the state association and farm bureaus are 

 getting near to the solution of this first step at least, and later the other 

 step will follow in the great problem of the distribution of the product, the 

 marketing. Now they are feeling their way along, but they are doing some 



