CHEMICAL COMPOSITION OF FEEDING STUFFS 



57 



The results show a decrease in the percentage of water and, 

 therefore, in the succulence of the drop toward maturity. In order 

 to show the changes in chemical composition, the analyses have 

 been calculated to water-free substance, and it is seen that as the 

 plant matures the percentages of ash, crude protein, amides, and 

 fat decrease ; as the stems grow hard and woody, the fiber contents 

 of the plant increase, and the percentages of valuable feed com- 

 ponents decrease in proportion, except that of nitrogen-free extract, 

 which does not change materially. If we now consider the digesti- 

 bility of the different cuttings of alfalfa, we have the following 

 average figures obtained in digestion experiments conducted at 

 Ontario Agricultural College. 7 



There is a decided decrease in the digestibility of the total dry 

 matter and of all components as the plant approaches maturity ; the 

 decrease is especially marked between the second and third cuttings. 

 If the total digestible matter obtained in the three crops be calcu- 

 lated on the basis of the figures just given, it will be found that 

 the amounts of digestible matter secured in the later cuttings 

 are considerably lower than those found in the earlier ones. 

 In the Canadian experiments referred to, the three cuttings 

 averaged the amounts of green alfalfa and digestible matter shown 

 in the table : 



Calculated Yields of Dry Matter and Digestible Matter of Green 

 Alfalfa Per Acre, in Pounds 



There was a decrease of 18.8 per cent, or nearly one-fifth, of the 

 digestible matter during the two weeks interval between the last 

 two cuttings, calculate d on the yields of the second cutting. 



'Report, 1899, p. 37. 



