SIXTH ANNUAL YEAR BOOK — PART IV. 281 



where corn is fed alone, it is not generally an economical feed; the 

 grains are small and a large amount of feed is required to make a given 

 gain. The judicious use of other feeds to supplement corn will often 

 effect a saving in excess of their actual value. 



To get the greatest value from the corn fed, it should be combined 

 with nitrogenous mill feeds, (bran, linseed oil meal, gluten meal, gluten 

 feed, etc.), with dairy by-products (skim milk, butter milk, and whey), 

 or with pasture, preferably on animal forage plants such as rape, sorg- 

 hum, oats, wheat, rye, peas, and combinations of these. 



The variety made possible by the use of supplementary feeds not 

 only makes a more healthful and effective ration economically but as 

 a general rule the effect on the quality of the pork produced is bene- 

 ficial. All these factors are worthy the more careful consideration from 

 the pig feeder. 



To give concrete illustrations of tnese points, I will refer in more 

 detail to the results which have been obtained by investigators at our 

 American Experiment Stations. 



You are all more or less familiar with the relative importance of 

 those constituents of feed which produce blood, bone, and muscle in 

 the animal body, and those which produce fat and supply the princi- 

 pal part of the warmth or energy needed; the former being the nitroge- 

 nous compounds, termed protein, and the latter the carbohydrates and 

 fat, commonly called the carbonaceous compounds. Oil meal, bran, 

 packing house by-products, peas, and dairy by-products are examples of 

 nitrogenous pig feeds; shorts, corn, wheat, and rye are carbonaceous 

 ones. Grains like oats and barley occupy a middle ground. As we 

 will observe later the effect of a feed on the quality of the carcass may 

 be of more importance than its nitrogen or carbohydrate composition. 



A further point of importance, especially in feeding young animals 

 is the mineral composition of the feed. This is represented by lime, 

 phosphoric acid, and several minor substances. Mineral content or ash 

 is very important for the proper development of bone, and corn is, 

 unfortunately, low in ash. 



THE USE OF NITROGENOUS CONCENTRATES. 



Among the most valuable feeds to supply protein and mineral mat- 

 ter in a corn meal ration are the by-products of packing houses, beef 

 meal and tankage. These products are prepared from products which 

 were formerly wastes; those suitable for animal feed are made largely 

 from scraps of meat, fat, and bone and have been cooked by steam. 

 They are high in ash, protein and fat, but low in carbohydrates. Tank- 

 age has been found to lessen very materially the amount of grain 

 required to make a given gain, and it also increases the gains made. 

 Tankage-fed pigs handle better and their coats are in better condition 

 than those on corn meal alone. The amount of tankage fed should 

 not exceed one-fifth the entire ration, and smaller amounts will proba- 

 bly be found more satisfactory. A ration of ten parts of a mixture 

 of equal parts of corn meal and shorts and one part tankage was found 

 to be particularly valuable by the Indiana Station. The Iowa Station 



