152 SCIENTIFIC FEEDING OF ANIMALS 



water in fresh plants decreases with growth, whilst 

 the dry matter increases, also that the components 

 of the latter alter in certain directions. During the 

 development the amounts of crude protein, proteins 

 and non-proteins, and also the mineral substances 

 regularly decrease, whilst the crude fibre increases. 

 In the early stages of growth the plant takes up a 

 lot of nitrogenous food and converts it gradually 

 into protein, whilst at a later period the production 

 of nitrogen-free substances predominates. The 

 higher the plant grows so much greater are the 

 demands made upon the supporting powers of the 

 stem, and it becomes richer in crude fibre. For 

 this purpose a part of the nitrogen-free extract is 

 converted into crude fibre, and in it from the time 

 of flowering chemical changes take place which 

 result in the formation of incrusting materials, 

 which make the fibre woody. After flowering 

 there is also a movement of nitrogenous and nitro- 

 gen-free substances from the green organs of the 

 plants to the seeds and fruits, whereby the percent- 

 age composition of the stem and leaves in crude 

 fibre is increased. In the case of root crops the 

 materials formed during the first year in the green 

 parts of the plant pass into the roots, or tubers. 



As the degree of lignification stands in a certain 

 relation to the digestibility of fodder plants it is 

 clear that the older plants must contain a smaller 

 quantity of digestible material than do the younger. 



