128 



DESCRIPTION OF FEEDING STUFFS 



ni. STRAW OP CEREALS AND LEGUMES 



Straw is the stems and leaves of cereals and legumes after the 

 ripe seeds have been removed. During the latter stage of the vegeta- 

 tive period of the plants soluble materials are transferred to the 

 seeds, and other parts of the plants are left relatively depleted in 

 feed components. Hence we find that straw is low in protein and 

 fat and in more valuable carbohydrates, although still high in nitro- 

 gen-free extract and likewise high in fiber. Straw from cereals cut 

 at different stages of ripening differs considerably in chemical com- 

 position and feeding value. Kellner gives the following analyses 

 of oat straw cut at three different periods of growth — unripe, ripe, 

 and over-ripe : 23 



Composition of Dry Matter of Oat Straw at Different Periods of Ripening, 



in Per Cent 



Unripe . . . 



Ripe 



Over-ripe 



Crude 

 protein 



10.1 

 4.9 

 4.3 



Fat 



1.9 

 1.2 

 1.4 



Nitrogen- 

 free 

 extract 



50.6 

 48.6 

 36.9 



Fiber 



29.4 



37.8 



'49.8 



Aoh 



8.0 

 7.5 

 7.6 



The amount of net energy yielded in the digestion of straw cut 

 at the usual time is small, and in some cases, like coarse rye or 

 wheat straw, it is not sufficient to maintain an animal at an even 

 body weight. Oat and barley straw is more valuable than the 

 other kinds of straw, and is used as a regular part of the feed 

 rations of horses and fattening cattle, especially in European coun- 

 tries. It is generally cut fine and fed wet, mixed with concentrates 

 or sliced roots. It is fed in this way both for the net nutrients that 

 it supplies and also, perhaps largely, because it is believed to a.ct 

 as a filler and enables animals to digest their grain feed more 

 thoroughly when thus diluted with cut straw. 



The different kinds of cereal straw have, on the average, the 

 following chemical composition : 3 to 4 per cent total protein ; 3G 

 to 39 per cent fiber; 36 to 46 per cent nitrogen-free extract, and 1 

 to 2 per cent fat. 



The digestibility of the dry matter and the nitrogen-free extract 

 is low, viz., 40 to 50 per cent, and that of protein only 20 to 30 

 per cent. The total digestible matter in straw ranges from 37 to 



28 " The Scientific Feeding of Animals," p. 169. 



