The germs of hog cholera may be carried on the boots of visitors, by pigeons or dogs. It can only be combatted by vaccination of healthy hogs, quarantining of all sick hogs, burning of all dead hogs and disinfection of premises.
Three methods of vaccination are in use:
(1) The injection of an anti-cholera serum, which makes the hog immune only a few months or weeks.
(2) The simultaneous treatment whereby the serum used in (1) and the defibrinated blood or virus from a diseased hog are injected together. This treatment renders the hog immune for life.
(3) In the combination method, serum alone is used first, and ten days later the simultaneous treatment is administered. This method is seldom used. The services of a skilled veterinarian should be secured to vaccinate hogs.
Feeds and feeding. Protein, fats, and carbohydrates are the three classes of nutrients found in feeds. These, in addition to mineral matter and water, furnish material for the maintenance and growth of the pig. Proteins furnish the material for the production of muscle. Fats and carbohydrates provide fuel for heating the body and giving activity to the muscles. An excess of food nutrients, especially fats and carbohydrates, is stored in the body as fat. The mineral matter goes into the production of bone.
All feeds do not contain these nutrients in the same proportions. Some feeds, like corn, are deficient in protein, while others, like tankage, contain a large percentage of protein.
15. A Self-Feeder
From the foregoing it is easily seen that the problem of the hog raiser is to use a combination of feeds which will provide the proper proportions of the various nutrients. While the pigs are young, bone and muscle producing foods are especially necessary. Toward maturity the percentage of fat producing foods may be increased.