490 HORSE. SWINE AND POULTRY DISEASES 



The hog is an animal that is ordinarily incased in a thick 

 layer of fat, which is a poor conductor of heat and in which the 

 circulation of blood is very meager. Over the fat a skin is stretched 

 in which the circulation of the blood is relatively small, and this 

 skin, unlike that of a man or a horse, does not take a prominent 

 part in regulating the bodily temperature through the agency of 

 radiation and perspiration. The covering of a hog may be re- 

 garded rather as an excellent means for preventing the escape of 

 heat from, than for regulating the temperature of, the body ; hence 

 we have conditions that probably permit of a more rapid production 

 than escape of heat. If we bear this in mind we see how urgently 

 necessary it is that hogs should be kept very quiet for some time 

 before and throughout the duration of a tuberculin (temperature) 

 test. 



Normally it seems that fat hogs have a higher temperature 

 than lean ones, and that a higher temperature induced by exer- 

 cise or some other temporary cause persists longer in fat than in 

 lean hogs. These general remarks are based on numerous obser- 

 vations of hog temperatures made in the 'Course of the last ten years 

 on other hogs than those included in the tuberculin tests presented 

 in this article. 



In these experiments each hog was placed in a rectangular 

 crate about twelve hours before the first temperature was taken, 

 and remained in this confinement continuously until the tubercu- 

 lin test was completed. The reason for confining the hogs during 

 the tuberculin test was to keep them as quiet as possible, and to 

 prevent increases of temperature incident to physical exertion and 

 nervous excitement. The crates were large enough to permit the 

 hogs to get up and down easily, narrow enough to keep them from 

 turning around, and short enough to prevent too much move- 

 ment backward and forward. The dimensions found to be satis- 

 factory for hogs ranging in weight from 50 to 150 pounds are 

 (interior measurement): Length, 4 feet; width, 1 foot 2 inches; 

 height, 2 feet. 



In the forward end of each crate a small trough for feeding 

 and watering was fastened securely to the floor. The tops of the 

 crates were fastened at the forward or head ends with hinges and at 

 the rear with hasps and staples. At first an attempt was made to 

 have a door at the rear end of each crate, to let down when the 

 attendant was required to approach the hog to insert the ther- 

 mometer into its rectum; but this arrangement was abandoned 

 because it was found to be much easier to reach the hog from above. 

 the material used in the construction of the crates was miscella- 

 neous pieces of rough lumber 1 inch thick, wire nails, hinges, hasps, 

 and staples. The only tools required were a hatchet and a saw. 

 Without the use of crates of the kind described, or some equally 

 satisfactory means of restraint, it is difficult, if not impossible, to 

 obtain reliable temperature records of hogs. 



The extreme need of quiet is very well illustrated by the tem- 

 perature of 17 hogs, taken at noon on one day after they had been 



