8 N. H. EXPERIMENT STATION. [Bulletin 200 



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. For this reason there is a decided ad- 

 vantage in purchasing the pure grains, although it must be said 

 that there are a number of reliable firms placing good compounded 

 feeds upon the market. 



HOW TO USE TABLE NO. 3. 



Only the digestible nutrients are of value and so in comparing 

 two feeds we should compare just the digestible nutrients. Suppose 

 we had a cottonseed meal which analyzed 38 per cent protein. The 

 table shows cottonseed meal 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 cotton- 

 seed meal would then 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 feedstuffs it is difficult 

 to make an exact comparison in their value from a chemical analy- 

 sis. The analysis will, however, 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 concen- 

 trated feedstuffs 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 118 sells for $3.50 and is guaranteed 

 protein 12.00 per cent, fat 4.00 per cent. If it contains 12.00 per 

 cent protein there are 12 lbs. of protein in 100 lbs. of feed costing 

 $3.50. Then one dollar buys 12 divided by 3.50 or 3.4 lbs. of 



