10 N. H. EXPERIMENT STATION [Bulletin 218 



HOW TO FIGURE THE COMPARATIVE VALUE OF 

 FEEDS FROM THE CHEMICAL ANALYSIS 



Because such factors as palatability, quality of protein, 

 digestibility, etc., play an important part in determining the 

 value of feeding-stuffs it is difficult to make an exact com- 

 parison of their value from a chemical analysis. The 

 analysis will, however, serve as a very valuable guide. 

 Since the consumer can usually grow carbohydrates cheap- 

 er than he can purchase them, he is chiefly interested in 

 buying the concentrated feeding-stuffs for their protein and 

 fat content. 



Feeds may be compared upon the basis of the number 

 of pounds of protein and fat one dollar will buy. An ex- 

 ample is as follows: Feed number 119 sells for $5.25 per 

 100 pounds and is guaranteed protein 12 per cent, and fat 

 3 per cent. If it contains 12 per cent, protein there are 12 

 pounds of protein in 100 pounds of feed costing $5.25. Then 

 one dollar will buy 12 divided by 5.25 or 2.28 pounds of 

 protein and 3 divided by 5.25 or 0.6 pound of fat. Feed 

 number 104 sells for $3.15 per 100 pounds and is guaran- 

 teed 20 per cent, protein and 5 per cent, fat. Then one 

 dollar buys 20 divided by 3.15 or 6.35 pounds of protein and 

 5 divided by 3.15 or 1.6 pounds of fat. 



In buying feed number 104 the consumer received 

 nearly three times as much protein and nearly three times 

 as much fat per dollar as in feed number 119. These fig- 

 ures represent two feeds in the same class which were sold 

 in New Hampshire in December 1924. The state inspec- 

 tor collected one of them in Concord on December 23 and 

 the other in Manchester on December 29. 



In comparing feeds of the same class this method 

 shows fairly accurately their relative value. When feeds 

 of different classes as a cottonseed meal and a hominy feed 

 are compared the digestible protein figures should be com- 

 pared and the carbohydrates and crude fiber must also be 



