THE FEEDING STUFFS 



575 



No determinations of the energy values of these samples were 

 made, but it may be fairly assumed that the increasing woodi- 

 ness not only diminished the total amounts of digestible nu- 

 trients contained but also increased the relative expenditure of 

 energy in digestion and assimilation, so that the lesser amount 

 of digestible matter in the more mature samples was probably 

 less valuable per unit than that of the younger samples. 



When the seeds of grasses begin to form, there is a rather 

 rapid transfer of nutritive materials to them from the stalks 

 and leaves. The seeds of the ordinary hay grasses, however, 

 are so small and so well protected by their seed-coats that they 

 either shell out and are lost or largely escape mastication and 

 digestion. Grass harvested after the seeds have formed prac- 

 tically furnishes straw rather than hay. 



680. Maize. A somewhat important exception to the 

 general rule regarding the influence of maturity is observed 

 in the case of maize. While advancing maturity produces its 

 normal effects on the stalks and leaves, such large amounts of 

 easily digestible material are stored up during ripening in the 

 grain, and the latter makes up so large a percentage of the total 

 weight of the crop, that it outbalances the effect of increasing 

 maturity, and the ripe or nearly ripe crop, taken as a whole 

 i.e., as used for silage or as field-cured forage is more di- 

 gestible than at earlier stages of growth. For example, the 

 dry matter of maize forage at three different stages had the 

 following composition and digestibility : 



TABLE 165. COMPOSITION AND DIGESTIBILITY OF MAIZE FORAGE AT 

 DIFFERENT STAGES 



