180 HOG CHOLEKA 



Several points that contribute to the success of 

 maintaining an immune herd remain to be men- 

 tioned. Especially in large herds it is a good 

 practice to mark each pig at the time it is immun- 

 ized so that it can be positively identified. Other- 

 wise we are likely to miss an occasional pig or lit- 

 ter, and if these untreated animals subsequently 

 contract hog cholera, we are called to account for 

 deaths for which we are in no way responsible. 

 We should also suggest to the breeder the advan- 

 tage of breeding several sows near the same time, 

 so that a considerable number of pigs can be im- 

 munized at one time. In addition to economy in 

 immunizing this practice enables the breeder to 

 provide foster mothers for pigs farrowed by sows 

 which on account of death or disease incident to 

 parturition are unable to nurse their litters. 



It is important that pigs shall grow steadily and 

 rapidly from birth until the time when simultane- 

 ous treatment is administered. Influences that re- 

 tard growth usually lower resistance as well and 

 we are thus compelled to maintain the immunity 

 of poorly nourished pigs with serum alone much 

 longer than is necessary in handling thrifty pigs. 

 Any suggestions that will aid the breeder to grow 

 pigs rapidly during the first three months of their 

 lives will be greatly to his advantage. 



Handling feeding hogs. A common practice 

 on farms in many parts of the country, more par- 



