566 IOWA DEPARTMENT OF AGRICULTURE 



METHODS OF RESTRAINING HYPERIMMUNES. 



The Iowa State laboratory employes crates to restrain the immunes 

 during the process of hyperimmunization for the quick and slow subcu- 

 taneous methods. Three different sized crates are used to handle hogs 

 weighing from one hundred to three hundred pounds. For the intraven- 

 ous method, we have found the crate impracticable and place them on 

 the table. For the intraperitoneal method, we suspend them by the pos- 

 terior limbs. 



The crate is composed of two sections, the division line dividing the 

 crate into upper and lower halves with a trough in the upper section 

 which the hog rests in while being treated. The two halves of the crate 

 are firmly coupled together by means of hooks. After crating the hog, 

 ropes are placed on the front feet drawing the ropes up and over the 

 outside of the upper half of the crate through the division line of the 

 upper and lower section. The ropes are now tightened so that the front 

 feet are drawn from the floor of the crate to the division line separating 

 the upper and lower section, and the two ropes firmly tied together on 

 top of the crate. The crate is now turned upside down which places the 

 immune on his back in the upper section with his front feet firmly tied 

 down; the lower section is now uncoupled and removed and the posterior 

 limbs tied to the corners of the crate, and the hog is firmly held while the 

 treatment is being administered. We have found this a most satisfactory 

 way of handling our immunes for quick and slow subcutaneous methods 

 of hyperimmunization. 



REHTPERIMMUNIZATION. 



Rehyperimmunization is often employed to save time and money in 

 the production of serum and can be used regularly if the demand for 

 serum does not necessitate the killing of the hyperimmune at the fourth 

 bleeding. It consists in retreating the hyperimmune one or two days 

 after the fourth tail drawing, with one half the amount of virulent blood 

 primarily used to hyperimmunize him as in the quick and slow subcu- 

 taneous or peritoneal methods, it would require only five cubic centi- 

 meters per body weight. In the intravenous method, two and one-half 

 cubic centimeters per body weight is sufficient. 



The Iowa State Laboratory employs this practice of rehyperimmuniz- 

 ing on all fit suhjects; the one requisite being length of tail. This en- 

 ables us to obtain seven tail drawings, four before rehyperimmunizing 

 and three after, beside the final carotid drawing. 



BLEEDING OF HYPERIMMUNES. 



Ten days after hyperimmunizing, we take the first tail drawing and 

 repeat this every seven days for two successive times and the fourth 

 drawing the hog is killed by bleeding from the carotid, but if we wish to 

 rehyperimmunize, the fourth tail drawing is taken and in one or two 

 days the hog may be rehyperihimunized. Then in ten days, the fifth tail 

 drawing is taken and at intervals of one week the sixth and seventh 

 are drawn, and one week later the eighth drawing is taken from the caro- 

 tid artery, and the animal killed. 



