10 



FEEDS AND FEEDING 



Chemical composition of typical feeding stuffs, from Appendix Table I 



15. Water. To determine the amount of water in a feed the chemist 

 places a small quantity of the material, finely divided, in a dish and as- 

 certains its weight. It is then dried in an oven at a temperature of 212 

 F. for several hours and again weighed. The difference between the first 

 and last weights represents the amount of water in the sample. Volatile 

 compounds, such as some of the substances which give various plants 

 their characteristic odors, are also driven off by this heating, but the 

 weight of such compounds is generally insignificant. 



From the second column of the table we learn that even such "dry" 

 feeds as corn, oats, wheat, and wheat bran contain 9 Ibs. or more of water 

 per 100 Ibs. of the feeding stuff. Timothy and clover hay contain still 

 more water, and such succulent feeds as pasture grass, corn silage, and 

 mangels are largely water. 



16. Ash, or mineral matter. The chemist next burns the sample and 

 finds the weight of ash, or mineral matter, which is left. From the 

 third column of the table we learn that 100 Ibs. of corn or wheat con- 

 tain less than 2 Ibs. of ash. Oats, with their strawy hulls, and wheat 

 bran, consisting of the outer coats of the wheat grain, carry more ash. 

 The hays and straws are higher in ash than such grains as corn or wheat, 

 due to the accumulation of mineral matter in the leaves during growth, 

 to earthy matter washed upon the growing plants by rain, and to dust 

 settling on the roughage before it is housed. Such foreign material is not 

 really plant ash, but of necessity is reported as such. Owing to their 

 high water content, the ash in 100 Ibs. of fresh grass, silage, and mangels 

 is low. 



