CATTLE FOODS NATURAL PRODUCTS 



225 



increase of fiber as the plant approaches ripeness is well 

 illustrated by analyses made at the Connecticut Experi- 

 ment Station of a sample of timothy grass cut at different 

 periods of growth : 



TABLE XLV. COMPOSITION OF DRY SUBSTANCE (PER CENT) 



These analyses show that the changes are not con- 

 fined to an increase of fiber. The relative proportions of 

 ash and protein grow less as the plant matures. An 

 examination of the nitrogen-free extract would prob- 

 ably show an accompanying decrease of the soluble 

 carbohydrates. 



The combined effect of these changes is to cause the 

 plant to harden in texture and become less palatable and 

 more difficult of mastication. 



310. Age decreases digestibility. The digestibil- 

 ity is naturally affected by age. Three American diges- 

 tion experiments with timothy hay cut in bloom or 

 before show an average digestibility of the organic mat- 

 ter of 61.5 per cent, the average from four experiments 

 with timothy cut when past bloom being 55.4 per cent. 

 Doubtless the increase in dry matter when timothy 

 stands beyond the period of full bloom no more than 

 compensates for the decrease in digestibility. Using 

 the average coefficients of digestibility and the average 

 yields, as given in this connection, the yield of digestible 

 o 



