DESCRIPTION OF FEEDING-STUFFS 169 



(2) Chaff and straw. 



During the maturation of a plant the nitrogenous 

 and non-nitrogenous substances are transferred 

 from the green portions of the plant to the seeds, 

 as has already been noticed (p. 152). At this time 

 the stems, haulms, etc. undergo lignification, and 

 after the ripening of the fruit there remains but 

 little protein, fat, and nitrogen-free extract in the 

 straw or chaff, the quantity varying with the 

 completeness of ripening. A good example of this 

 is seen in the following analyses of oat straw at 

 three different periods of ripening 



Unripe . 

 Ripe . 

 Over-ripe 



If the passage of substances from the stem and 

 leaves is entirely or partially prevented in any way, 

 as when the plant is laid by hail, rain, wind, or 

 other causes, or by drought, then a more nutritious 

 straw is obtained, as the above figures show. In 

 consequence of such conditions, the protein content 

 of cereal straw, which as a rule is only 2-3%, can 

 rise to 6% and more. Continued wet weather, on 

 the other hand, causes the formation of a straw poor 

 in protein and rich in crude fibre. 



Manuring has also a distinct, although usually 



