MEASURING THE USEFULNESS OF FEEDS 51 



age crude protein content of wheat from the northern plains states is 

 13.5 per ct., wheat from the Atlantic states contains only 11.7 per ct. and 

 that from the Pacific states but 9.9 per ct. crude protein. The 

 same extended study shows that climate exerts little or no influence on 

 the chemical composition of corn, providing the crop matures, the aver- 

 age for the various sections showing no appreciable difference in content 

 of the several nutrients. Grindley of the Illinois Station 9 has shown 

 that samples of corn and wheat from the same region may vary 10 per 

 ct. and sometimes even more in their content of protein or fat. The 

 nitrogen-free extract is less variable, while fiber shows still larger 

 differences than protein or fat. The same general tendencies as to local 

 variations hold with the other cereal grains. 



Obviously, the amount of moisture in grain or any other feed directly 

 affects the amount of nutrients it furnishes. Of the cereals, corn 

 commonly varies most in water content. Therefore separate averages 

 are given in Appendix Tables I and III for dent corn of the various 

 grades, based on the percentage of water contained. 



The roughages are even more variable in composition than the cereals, 

 owing to the fact that, besides climate, their composition is often greatly 

 influenced by the stage of maturity, the manner of curing, and the 

 moisture content. Analyses of corn fodder and corn stover show a 

 water content ranging from over 50 per ct. in field-cured material in wet 

 seasons down to 10 per ct. or less in arid regions or where cured under 

 cover in a dry season. To show the difference in nutritive value of these 

 extremes it may be stated that corn fodder or stover containing 10 per 

 ct. water will carry 80 per ct. more nutrients per 100 Ibs. than a sample 

 of the same forage containing 50 per ct. water ! To overcome this error 

 so far as possible, separate averages are given for very dry and for 

 ordinary field-cured samples of these feeds in Appendix Table I. 



The general rule that immature plants contain a much larger pro- 

 portion of crude protein than when mature is well illustrated by analyses 

 of samples of alfalfa cut at various stages of maturity by Dinsmore at 

 the Nevada Station 10 and cured until they were somewhat drier than 

 normal hay. The dried alfalfa cut when 3 inches high, a stage at which 

 it is often grazed, carried 34.6 per ct. crude protein and only 43.4 per ct. 

 total carbohydrates. As the crop matured the protein content of the 

 hay therefrom decreased and the carbohydrates increased, till the sample 

 cut when seed was beginning to form contained only 14.1 per ct. crude 

 protein, while the carbohydrates had increased to 68.1 per ct. Immature 

 plants usually contain much more water than the same plants when more 

 mature. On account of such wide differences in composition the authors 

 have, wherever possible, given in Appendix Table I the averages for 

 roughages at different stages of growth. (See averages for corn fodder, 

 timothy hay, Kentucky bluegrass, red clover, etc.) 



111. Bui. 165. "Nev. Ept. 1907. 



