MEASURING THE USEFULNESS OF FEEDS 55 



vary in fuel value. Owing to the expense of obtaining analyses, it is out 

 of the question for any but the most extensive feeders to have their 

 particular feeds analyzed, just as only the large manufacturer can afford 

 to have samples of coal analyzed to determine their fuel value before 

 purchasing. With the cereals and the roughages the general feeder must, 

 therefore, rely on that average given in tables of digestible nutrients or 

 net energy which corresponds most closely in his judgment to the feed 

 at hand. In purchasing commercial concentrates, now sold in vast 

 quantities everywhere, it is fortunately possible in most sections of 

 the country to secure standard brands, whose composition is fully guar- 

 anteed by the manufacturer. (Chapter XI) 



