GENERAL PROBLEMS IN SWINE HUSBANDRY 615 



Just as in the trials in dry lot, the self -fed pigs ate more corn than 

 those which were hand-fed, and made somewhat more rapid gains. On 

 the average the self-fed pigs ate 4 Ibs. more tankage per 100 Ibs. gain, 

 but took 1 Ib. less corn. This slight difference of 3 Ibs. total feed per 100 

 Ibs. gain in favor of the hand-fed pigs would, however, ordinarily be 

 more than offset by the saving in labor thru self -feeding and by the 

 greater rapidity of the gains. 



It should be pointed out that in all of these trials the hand-fed pigs 

 were fed under the supervision of an experienced feeder. Under average 

 conditions there would be a greater advantage in favor of self -feeding. 



927. Free choice method of self -feeding. When self -fed corn and tank- 

 age, free choice, pigs usually show a surprising ability to balance their 

 own ration. When young, they eat a considerably larger proportion of 

 tankage than they do during later periods. This can not be due to any 

 profound knowledge of their own nutritive requirements and of the 

 chemical composition of these feeds, for if fed other grains and other 

 protein-rich supplements, they will fail at selecting the feeds in proper 

 proportions to make a well-balanced ration. For example, barley is con- 

 siderably richer than corn in protein ; yet pigs self -fed barley and tank- 

 age, free choice, will nevertheless often eat a larger proportion of 

 tankage than if they had been fed corn. Again, if pigs are self-fed 

 grain and allowed to drink all the skim milk or buttermilk they wish, 

 they will take much more milk than needed to balance the ration. On the 

 other hand, if the protein-rich supplement is rather unpalatable, they 

 will not eat enough of it, if it is fed free choice. For instance, when pigs 

 are self -fed corn, linseed meal, and alfalfa hay in dry lot they will not 

 infrequently fail to eat enough of the linseed meal to provide sufficient 

 protein in their ration. (973) From these facts we may agree with 

 Robison of the Ohio Station, who after a thoro study of this matter, 

 states, ' ' There is little question of the fallibility of the appetite of swine 

 in enabling them to choose the feed stuffs or to select the proper pro- 

 portions of the particular feeds before them to most nearly meet their 

 physiological needs. ' ' 



Most fortunately from the practical standpoint, it happens that self- 

 feeding by the free choice plan works out well when corn is fed with 

 tankage or fish meal as the supplement, and also when corn is fed with 

 such mixtures as tankage and linseed meal, or tankage and corn germ 

 meal. (973, 980) As a rule pigs will eat about the proper proportions 

 of these feeds to make a well-balanced ration. Once in a while they will 

 not eat nearly enough protein-rich supplement, or they may occasionally 

 eat so much of the expensive supplement as to make the gains costly. 

 In such cases the free choice plan of feeding had best be discontinued. 

 Instead a suitable mixture may be self-fed or the pigs may be hand-fed. 



In the following chapter the advisability of using the free choice plan 

 of self-feeding is discussed under the various feeds, where data are 



