620 FEEDS AND FEEDING 



seems best adapted to his conditions and suits his fancy, and then be 

 sure to secure and to maintain vigorous, well-bred animals of that breed. 



Assertions were formerly often made that razorbacks, or the semi- wild 

 swine of the South, were immune to hog cholera and made very eco- 

 nomical gains. In trials by Carlyle at the Wisconsin Station 35 neither 

 of these claims proved true. Statements that the mule foot breed is 

 immune to hog cholera are also unfounded. 



The length of the intestines in modern domestic hogs is apparently 

 longer in proportion to body length than in wild hogs. This indicates 

 that the improved hog can digest his food more thoroly than his 

 ancestors, and also that he can eat a larger quantity of food for his size. 

 Cuvier 36 reported many years ago that the total length of the intestines 

 of the wild boar was 9 times the body length ; in the domestic boar, 13.5 

 times ; and in the Siam boar 16 times the body length. Henry 37 found 

 the average length of the intestines of 39 fattening hogs to be about 21 

 times the body length. 



934. Dressing percentages. Hogs dressed ''packer style" with the 

 head off, and also the leaf fat, kidneys, and ham facings removed, will 

 usually range in dressing percentage from 66 to 75 per ct., or even more 

 in the case of very fat barrows. On the average the dressing percentage 

 of the swine slaughtered at the large packing plants is about 68 to 70 

 per ct. "When hogs are dressed shipper style, with heads on and without 

 the leaf fat, kidneys, and ham facings being removed, the dressing per- 

 centage will usually range from 73 to 85 per ct. or more, depending on 

 the age of the hog and the degree of fatness. 



935. Barrows vs. sows. It is commonly believed that barrows will 

 make a little more rapid and economical gains than open sows, due to 

 the restlessness of the sows during the oestrum periods. Up to the usual 

 market weights there is, however, apparently no appreciable difference 

 in the gains of gilts and barrows. This is indicated in experiments 

 carried on during several years by Morrison, Bohstedt, and colleagues at 

 the Wisconsin Station. 38 In these trials pigs were fed well-balanced 

 rations, either in dry lot or on pasture. The trials were usually begun 

 when the pigs weighed 50 to 70 Ibs., and they were carried to market 

 weights of 200 Ibs. to 225 Ibs. In these experiments 601 barrows gained 

 on the average 1.28 Ibs. a head daily, while the average gain of 469 gilts 

 was 1.26 Ibs. The slightly more rapid gains of the barrows were, no 

 doubt, due to the fact that somewhat more gilts than barrows were 

 retained for breeding stock and not fattened for market in the experi- 

 ments. Thus the barrows in the trials tended to average a trifle better in 

 individuality than the gilts. 



85 Wis. Rpt. 1903. 



M Darwin, Animals and Plants under Domestication. 



37 Wis. Rpt 1889. 



""Unpublished data compiled by DuRant and Heebink. 



