350 IOWA DEPARTMENT OF AGRICULTURE 



the old hogs all survived except the old sow left untreated as check. In 

 the experiment of suckling pigs part of each litter was treated and part 

 left untreated. In two litters eleven pigs received treatment. These all 

 lived. In the same lot eight were left untreated and all died. We had the 

 same result in two or three other herds where young pigs were treated. 

 One of the questions I am asked at the present time is whether we can 

 successfully vaccinate young pigs. I will say that you can if they receive 

 a sufficiently large dose. They require a larger dose in proportion to the 

 older shoats. 



I will mention one other herd and that was one in which the owner 

 wished to try one of the commercial vaccines. We had very little serum 

 left at that time but he wanted me to come over and try the government 

 serum along beside the commercial vaccine which he had bought in Chi- 

 cago earlier in the season. I vaccinated sixteen. All survived. Of thir- 

 ty-one treated with the commercial vaccine only six lived. He didn't 

 have very much faith after that in commercial vaccine. 



I will not stop to give you a summary of all the herds treated but I 

 will say that when we began treatment in a herd in which disease had 

 just appeared we practically saved all of the treated animals. We saved 

 all except those actually sick when we began and in some cases we even 

 saved some of those. You can look them up in the reports. All of our 

 experiments will bear me out when I say that if you go into a herd at- 

 tacked by cholera early that you can save practically all of the animals 

 not sick at the time of treatment. If you go in later, the same holds true 

 but of course there is a much larger per cent already sick. The only 

 way to tell definitely how many of the herd are sick is to take the tem- 

 perature. 



We found also that where we vaccinated the herd early before any of 

 them were sick that the disease did not appear later. In the experiment 

 where we wished to learn whether we could stamp out disease by vac- 

 cinating around the sick herd we found that the disease did not spread 

 and we have reason to suppose that we did a great deal toward prevent- 

 ing the spread of the disease. By treating with hyper immune serum at 

 the first outbreak you can stamp out the disease and I do not believe 

 there is any necessity of the disease extending over the country as it has 

 in the past. We have found that we can vaccinate hogs of all ages. We 

 gained also some idea with regard to the dose. We have fixed a standard 

 dose. 



Since 1907 we have made other experiments and the different states 

 in co-operation with us have made the serum and gotten the same re- 

 sults as our bureau has obtained. Since 1907, the main work has been to 

 assist the different states in getting started. Secretary Wilson and Dr. 

 Melvin thought the field was too great for the bureau to manufacture 

 sufficient serum for the farmers of the United States so they endeavored 

 by all the assistance they could give to have each state take up the work 

 itself and I am very glad to say that most all of the swine growing 

 states have done this. The different state experiment stations or veteri- 

 nary boards were invited to come to Ames to find out what we had done. 



