314 



PRODUCTIVE FEEDING OF FARM ANIMALS 



try, but records obtained in Danish pig-feeding trials with about 

 2500 summer- and winter-fed pigs have a direct bearing on this 

 question. The following sumrAary table 22 shows the amount of feed 

 eaten, reduced to a grain equivalent according to the feed-unit sys- 

 tem, and the feed requirements for 100 pounds gain in weight and 

 for each of three groups of pigs — 35 to 75 pounds, 75 to 115 pounds, 

 and 115 to 155 pounds — with averages: 



Feed Required to Fatten Pigs in Winter and in Summer 



Weight 



Grain equivalent 



per day per head, 



pounds 



Winter 



Summer 



Grain equivalent 



for 100 pounds gain, 



pounds 



Winter 



Summer 



35 to 75 pounds 



75 to 115 pounds 



115 to 155 pounds 



Average 



2.66 

 3.96 

 5.26 



3.96 



2.65 

 3.92 

 5.25 



3.94 



371 

 446 

 516 



444 



346 

 397 

 457 



400 



While the pigs ate practically the same amounts of feed in 

 summer and winter, it required 400 pounds to make 100 pounds of 

 gain in summer, against 444 pounds in winter; an increase of 11 per 

 cent. The larger feed requirements in winter are explained by the 

 fact that more body heat is lost by radiation on account of the lower 

 air temperature. The same result was obtained in comparing the 

 feed required by pigs weighing about 70 pounds each, kept in a well- 

 built piggery and in individual hog-houses (Fig. 83), at the Ottawa 

 station. 23 The trial was conducted during 60 days in winter time. 

 In the open winter quarters the pigs ate 526 pounds grain per 100 

 pounds gain, against 366 pounds for those in the piggery, a differ- 

 ence of 44 per cent in favor of the latter quarters. Brood sows in 

 similar colony houses required only 25 per cent more, a figure which 

 corresponds closely to that obtained in trials at the Kansas Agri- 

 cultural College 24 (Fig. 84). 



Feeding for Bacon Production.— Bacon hogs are kept only 

 to a relatively small extent in the United States, but the raising 

 of such hogs and the production of a high quality of bacon are 

 important special industries in Canada and northern Europe, es- 

 pecially in Ireland and Denmark. The bacon found on the market 

 in this country is largely the sides of lard hogs and has an inferior 

 grade of meat. The special breeds of bacon hogs are best adapted 

 to the production of good bacon, having a larger body and legs, less 



22 Copenhagen Station Report 30, 1895 ; Exp. Sta. Record 7, p. 246. 



23 Report, 1904. 



24 Report Prof. Agr., 1883. 



