624 IOWA DEPARTMENT OF AGRICULTURE 



ference of 65 cents. Strikingly it is shown that for such mature hogs, 

 the self feeder for short feeds is relatively very profitable. Other feeding 

 records show that these old sows had more judgment as regards the 

 amount of supplement they should have, if any, than their feeder, ex- 

 perienced and first class though he was. 



Old sows, weighing from 300 to 500 pounds, just through suckling 

 litters (if not too thin), make very economical gains on corn alone. This 

 is in marked contrast to the heavy requirements of young pigs, for 

 supplement. 



A peculiar development has been manifested in our self feeder investi- 

 gations. The indications are that less protein supplement is required 

 along with corn when pigs are self fed than when they are hand fed. 

 It seems that growing and fattening swine require a certain definite 

 amount of protein, which must be supplied somehow, or the gains will 

 be inhibited and the total consumption of feed decreased through a lack 

 of appetite^this probably being the direct result of lack of protein, 

 principally. Now we know that corn contains about 10 per cent of protein 

 on the average, hence the pig which eats the most corn is getting the 

 most protein. When pigs are self fed, they are enabled to eat more corn 

 than when hand fed, hence they come nearer supplying the minimum of 

 proteins necessary, and hence the reason why they do not suffer so much 

 from protein starvation as do hand fed, corn alone, pigs. This is a very 

 practical point in the economical production of pork, and it is one of 

 which we have been unfamiliar until the recent developments in our 

 "cafeteria" investigations brought it to light. 



It is somewhat difficult in presenting a new proposition such as the 

 "Iowa system of self feeding swine," to avoid giving a wrong impres- 

 sion. In order to guard against misconceptions which might arise from 

 a study of the, let us trust not too enthusiastic, contents of this paper, 

 there is appended some self feeder or "free will" don'ts, which may 

 help to simplify the method: 



1. Don't think that the hog likes hash (a mixture of feeds) any 

 better than you do. He enjoys the "free will" choice method most hearti- 

 ly. 



2. Don't use the self feeder for all classes of hogs. 



3. Don't self feed if you want to grow your pigs along slowly. 



4. Don't self feed if you do not want rapid gains. 



5. Don't fail to provide sufficient self feeder trough space, because 

 swine that stand around waiting for their turn to eat are wasting 

 energy (feed) as compared to when lying down. Encourage the fatten- 

 ing hogs to lie down most of the time. 



6. Don't expect the self feeder to save all the work. 



7. Don't self feed pregnant sows excepting early in the breeding sea- 

 son, unless you mix bulky feeds — of which ground alfalfa is the best 

 of all under corn belt conditions — with grain (a mixture of forty pounds 

 of ground corn, fifty-six pounds of ground alfalfa, and four pounds of 

 tankage should be well adapted to the self feeder scheme of carrying 

 brood sows). Regulate the fatness of the gilts or sows by increasing or 

 decreasing the proportion of corn iri the mixture. 



