448 IOWA DEPARTMENT OP AGRICULTURE 



FORAGE CROPS FOR IOWA SWINE. 



JOHN M. EWARD. 



Hog growing and fattening in the middle west economically centers 

 around corn. 



Our chief problem is to advantageously dispose of our corn; this is 

 done by intelligently supplementing said corn with foods which are 

 efficiently grown or purchased, and which supply the deficiencies of the 

 corn itself. 



Indian Corn is our greatest American swine grain; it is not a com- 

 plete ration, being deficient in a few particulars: 



First, — Loiv in protein. The remedy of course is to supply this ma- 

 terial. 



Second, — The quality of tJic corn protein is somewtiat inferior. Os- 

 borne* and Mendel have shown us that zein which comprises practically 

 58 per cent of the corn proteins, lacks three protein building stones, 

 namely tryptophane, lysine and glycocoll. Unfortunately for corn tryp- 

 tophane is necessary for normal growth and development; fortunately 

 for corn, however, the other 42 per cent of the protein is of seemingly 

 good quality. It is common sense to assume that meat proteins are 

 more efficient pound for pound than vegetable proteins, because having 

 already been built up into animal tissues they are more likely to furnish 

 the initial amino acids or building stones; in practice meat and milk 

 proteins give best physiological results. 



Third, — Deficiency of minerals. Calcium especially is markedly con- 

 spicuous because of its almost entire absence. The significance of cal- 

 cium is apparent when we realize that it comprises practically 40 per 

 cent of the dry ash of bone. Phosphorus, the bone-forming mate of 

 calcium, is of much importance, furnishing as it does 17 per cent or 

 thfereabouts of the material which makes up the dry material of bone 

 ash, and yet corn does not supply enough phosphorus to meet normal 

 requirements of growing swine. 



Fourth, — It shows an acid ash. There is in corn a preponderance of 

 such elements as sulphur, phosphorus and chlorine, as compared to cal- 

 cium, potassium, sodium and magnesium; this comparison being made 

 with normal solutions made up from the different elements. 



Corn is somewhat constipating in character and does not have as much 

 fat possibly as the animal can use to advantage; hence these difficuties 

 need to be overcome. 



Feeds that economically supply the deficiences of corn are the ones 

 advantageously used in the growing and fattening of swine in the Corn 

 Belt. 



*Monthly Journal of Biological Chemistry Vol. XIV, No. 2, March, 1913. 

 Science, Vol. XXXVII, No. 944, January 31, 1913. 



FORAGE CROPS ARE INDISPENSABLE. 



The imperative economic need of green pastures and forages in suc- 

 cessful pork production is emphasized by some six years' investigation 

 involving more than five thousand hogs at the Iowa Experiment Station. 

 In selecting a forage for our conditions, a forage that is suitable to the 



