MEASURING THE USEFULNESS OF FEEDS 49 



of any feeding stuff vary in feeding value, the same as different 

 samples of coal 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 manu- 

 facturer 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 con- 

 centrates, sold in vast quantities everywhere, it is now fortunately 

 possible in most sections of the country to secure standard brands, 

 whose composition is fully guaranteed by the manufacturer. (Chap- 

 ter XI.) 



QUESTIONS 



1. What are digestion coefficients and liow are they found in a digestion trial? 



2. In a digestion trial a steer ate in one day 25 lbs. of red clover hay con- 

 taining 86.4 per ct. dry matter, 12.5 per ct. crude protein, 25.2 per ct. fiber, 38.3 

 per ct. nitrogen-free e.vtract, and 3.3 per ct. fat. During tlie same day he voided 

 in the feces 8.9 lbs. dry matter, 1.3 lbs. crude protein, 2.9 ll)s. fiber, 3.3 lbs. nitro- 

 gen-free extract, and 0.4 lb. fat. Find the digestion coefficients for dry matter 

 and the various nutrients. 



3. Define nutritive ratio and show how it is calculated. 



4. Describe a respiration apparatus. 



5. Define available energy and net energy. 



6. Thru what diflTerent means is energy lost when a cow eats corn meal? 



7. Why may considerable straw be fed advantageously to an idle horse but not 

 to one at hard work? 



8. What factors influence the composition of feeds? 



9. Discuss the value for stock of (a) grinding grain, (b) cutting hay, (c) 

 soaking feed, (d) cooking feed. 



10. How is the value of forage aflFected by curing; by ensiling? 



11. What factors affect the digestibility of feeds? 



