10 Feeds and Feeding. 



per ct. of plant protein is nitrogen (^'^Vi6=6.25). From the table 

 we learn that pasture grass contains 3.5 lbs. of crude protein per 

 100 lbs,, while dent corn contains over 10 lbs., and red clover* hay 

 still more. 



12. Fiber. — The woody portion of a feeding stuff is determined 

 by boiling a sample thereof successively in weak acid and alkali 

 and washing out the dissolved matter. That which remains is 

 termed fiber. Fiber consists mostly of cellulose and is the woody 

 portion of feeds. The grains of Indian corn contain only 2.2 per ct. 

 of fiber, while clover hay yields nearly 25 per ct. 



13. Fat. — A sample of the pulverized dried fodder is treated with 

 ether, wliich dissolves the fats, waxes, resins, chlorophyll or green 

 coloring matter, and similar substances. This, most properly called 

 ether extract in works on plant analysis, is for convenience termed 

 fat in this work. The ether extract of seeds is nearly all true fat 

 or oil, while that of the leaves and stems contains chlorophyll, wax, 

 etc. By the table, mangels are shown to yield only 0.2 lb. of fat per 

 100 lbs., while corn carries 5 lbs., the extract in this case being 

 true fat. 



14. Nitrogen-free extract. — The nitrogen-free extract, expressed 

 in the tables in this book as N-free extract, embraces the substances 

 that are extracted from the dry matter of plants by treatment with 

 weak acids and alkalies under standard conditions, less the crude 

 protein, fat, and ash. It is determined by difference and not by 

 direct analysis. The total dry matter in a feeding stuff minus the 

 sum of the ash, crude protein, fiber, and fat, equals the nitrogen- 

 free extract. It embraces the sugars, starches, pentoses, non- 

 nitrogenous organic acids, etc., of the plant. 



15. Carbohydrates. — The nitrogen-free extract and fiber together 

 constitute the carbohydrates. 



The methods of analyzing and grouping plant substances now em- 

 ployed by chemists are, in many particulars, unsatisfactory. In 

 time they will work out a more rational classification of the food 

 substances of plants, but for the present we have nothing better 

 than what is here given. 



In discussing feeding stuffs it is often desirable to differentiate 

 between those of coarse, bulky nature and others more condensed 

 and usually more nutritious. Accordingly the terms "concentrate" 

 and "roughage" employed in the first edition of the work are re- 

 tained since they are now widely recognized and used. 



