210 The Feeding of Animals 



tion of a sample of timothy grass cut at different 

 periods of growth: 



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 pala- 

 table. The digestibility is naturally affected. Three 

 American digestion experiments with timothy hay cut 

 in bloom or before show an average digestibility of the 

 organic matter 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 digesti- 

 bility. Using the average coefficients of digestibility 

 and the average yields, as given in this connection, the 

 yield of digestible organic matter would be in full 

 bloom, 2,306 pounds, and when out of bloom or nearly 

 ripe, 2,350 pounds. If one considers the decrease in pala- 

 tableness the advantage is with the earlier cut hay. 



