8 N. H. EXPERIMENT STATION [Bulletin 205 



We have this data for the pure grains and feeds, but 

 because the various proprietary feeds are not standardized 

 there are no data available for them. 



HOW TO USE TABLE NUMBER 3. 



Only the digestible nutrients are of value and so in 

 comparing tv^^o feeds we should compare just the digestible 

 nutrients. Suppose we had a cottonseed meal which ana- 

 lyzed 38 per cent, protein. 



The table shows cottonseed protein to be 84 per cent, 

 digestible. We then would have 84-100 of 38 lbs., or 31.9 

 lbs. of digestible protein per 100 lbs. If a wheat bran 

 analyzed 15 per cent, protein we see from the table that it 

 is 78 per cent, digestible and we would have 78-100 of 15 or 

 11.7 lbs. of digestible protein. The cottonseed meal would 

 have 31.9 lbs. compared with 11.7 in wheat bran. 



HOW TO FIGURE THE COMPARATIVE VALUE OF 

 FEEDS FROM THE CHEMICAL ANALYSIS. 



Because such factors as palatability, digestibility, etc., 

 play an important part in determining the value of feeding- 

 stuffs it is difficult to make an exact comparison of their 

 value from a chemical analysis. The analysis will, how- 

 ever, serve as a very valuable guide. Since the farmer can 

 usually raise carbohydrates cheaper 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 which one dollar will buy. An 

 example is as follows : Feed number 21 sells for $2.70 per 

 100 pounds and is guaranteed protein 9.50 per cent, and fat 

 4.00 per cent. If it contains 9.50 per cent, protein there 

 are 9.5 pounds of protein in 100 pounds of feed costing 

 $2.70. Then one dollar will buy 9.50 divided by 2.70 or 3.5 



