FEEDING STUFFS S 



in wheat bran, rye bran, malt sprouts, and in most oily seeds (flax seed), 

 and oil cakes ; in animal feeding stuffs like skim milk, whey, meat, cock 

 chafer or May bug, in most vegetables, and in all spices (seeds). Sour 

 grasses (reeds and sedges) corn cobs, and all leached feeding stuflfs, such 

 as hay and roughage that have been wet with rain, beet and potato pulp, 

 brewers' grains and American meat meal (tankage), are deficient in 

 potash salts. 



Most feeding stuffs contain a very low percentage of sodium salts, 

 hence the desirability of adding common salt to rations. Sodium salts 

 are more abundant in certain tubers and roots as well as in the young 

 growth of forage plants or hay. The same may be said of chlorin. 



All clovers are usually rich in lime salts, which is true also of the better 

 sorts of meadow grasses, the straw of legumes and the hulls of buck- 

 wheat. On the other hand, the straw of the various species of grains 

 and chaff, all root crops, distillery slops, the cereals, legume seeds and 

 malt sprouts are deficient in lime salts. 



Magnesium salts are abundant in the grains, grasses and clovers. Most 

 other feeding stuffs contain magnesium salts in sufficient quantity. The 

 salts of iron are usually present in sufficient quantity in most feeding 

 stuffs. 



The following are usually rich in phosphoric acid : Good green forage 

 and hay, all seeds, bran and malt sprouts, some oil cakes, also milk and 

 meat. Phosphoric acid occurs chiefly in organic compounds. Other feed- 

 ing stuffs, and especially straw and flour made from the various grains, 

 beets and beet pulp, contain little phosphoric acid. 



III. Albuminous Substances; Protein 



The combustible portion of the dry matter, the organic material, in- 

 cludes the proteids, fats and carbohydrates. According to their properties 

 and their physiological action these are divided into two groups, the 

 nitrogenous bodies or albuminous substances and the fats and carbo- 

 hydrates which latter contains no nitrogen. Fats and carbyhydrates are 

 composed entirely of carbon, hydrogen and oxygen. They therefore con- 

 tain no nitrogen whatever. They have similar physiological actions and 

 may be substituted for each other. The proteids, on the other hand, con- 

 tain nitrogen in addition to carbon, hydrogen and oxygen. The proteids 

 may take the place of carbohydrates, but the latter cannot be substituted 

 for the proteids. 



Since nitrogen occurs only in the proteids, but not in the fats and carbohydrates, 

 and since it is present in more or less constant proportions (average 16 per cent), it 

 is used in the quantitative determination of proteids in feeding stuffs. Kjeldal's 

 method for the determination of proteids is used almost exclusively at the present 

 time and is as follows : 



Place one or two grams of dry feeding stuff (10 to 20 grams of fluid material) 

 in a combustion flask (Fig. 1) of high fusibility, add 20 cc. of concentrated sulphuric 

 acid (to which there should usually have been added 200 to 250 gm. of phosphoric 

 anhydrid per liter) and one drop of mercury, as oxygen carrier. The flask, set at 

 an angle, is heated until the solution has become completely colorless. Combustion 

 is usually complete in the course of three hours. The nitrogen which is present 



