VARIOUS FACTORY BY-PRODUCTS 189 



the premises, which may seriously affect the quality of the milk 

 produced and the health of the animals. 



Dried brewers' grains can be kept indefinitely and transported 

 from the place of manufacture like other commercial feeds. They 

 contain, on the average, 20 per cent digestible protein, 32 per cent 

 digestible carbohydrates, and 6 per cent digestible fat, against 11.9 

 per cent, 42.0 per cent, and 2.5 per cent, respectively, for the same 

 components in wheat bran ; the two feeds, therefore, contain similar 

 amounts of total digestible components. The brewers' grains have 

 the advantage of containing about twice as much digestible protein 

 and fat as wheat bran, but contain 10 per cent less carbohydrates. 

 Dried brewers' grains form an excellent feed for cattle and horses, 

 and may be fed to the former in similar quantities as wheat bran or 

 small grains, while the rations for horses may consist of one-third to 

 one-half of the dried brewers' grains, the balance being made up of 

 corn and oats. Dried brewers' grains will prove cheaper than oats 

 and quite as satisfactory, especially for hard-worked horses in need 

 of-an extra amount of protein. 9 



Malt sprouts are the tiny dried germs of barley that have been 

 allowed to grow to about one-fourth inch in length. They form a 

 light, bulky, and somewhat dusty feed, containing about 26 per 

 'cent protein (of which one-fourth to one-third is in amide form), 

 12 per cent of fiber, and less than 2 per cent fat. On account of 

 its tendency to dustiness, the feed is either fed mixed with other 

 concentrates or with silage, or is moistened before being fed out. 

 It is especially valuable as a dairy feed, and may be given in amounts 

 of two to three pounds daily per cow ; on acccount of bitter principles 

 contained therein (betaine and choline), most cows object to the 

 feed at first, but soon learn to like it. It is a common feed in the 

 dairy sections of the country, and, as a rule, forms a relatively 

 cheap source of protein. 



Dried distillers' grains are the dried residues obtained in the 

 manufacture of alcohol and distilled liquors from cereals. The 

 ground grains are treated with a solution of malt, thus converting 

 the starch into sugar (maltose) ; by the addition of yeast, the sugar 

 is changed into alcohol, which is distilled over, leaving a very 

 watery residue, called distillers' slop; this is dried in especially- 

 constructed driers and sold as dried distillers' grains. The dis- 

 tillers' grains consist of the hulls, germ, protein, and carbohydrates 

 of minor nutritive value, and make a very rich and valuable feed 



8 Massachusetts Bulletin 94. 



