Fats or Oils 89 



portion of such an extract from seeds, while material 

 so derived from hay, straw and other coarse fodders 

 also contains a considerable amount of wax, chlorophj'll 

 and other substances. Tables that show the compo- 

 sition of feeding stuffs have a column which is some- 

 times designated "ether -extract," and sometimes "fats 

 or oils.'' The former is the more accurate term, be- 

 cause the compounds which it is the intention to de- 

 scribe are often no more than half fats or oils. The 

 real value of the "ether -extract " from different feed- 

 ing stuffs is partly determined, therefore, by its source. 

 When it is all oil, or nearly so, it is worth much more 

 for use by the animal than when it is made up to quite 

 an extent of other bodies. 



The proportions of fat or oil in feeding stuffs vary 

 within wide limits. In general, seeds and their by- 

 products contain more than the coarse foods, the differ- 

 ences in the percentages of actual oil being greater 

 than is indicated by the ether- extract. Straws natu- 

 rally have less oil than the hays. But little is found 

 in the dry matter of roots and tubers. Among the 

 cereal grains and other more common farm seeds, corn 

 and oats show the largest amounts, the proportion in 

 dry matter being from five to six in one hundred, while 

 wheat, barley, rye, peas, and rice contain much smaller 

 percentages, wheat having about 2 per cent, and rice 

 sometimes not over one -fifth of 1 per cent. Agri- 

 cultural seeds that are especially oleaginous are cotton- 

 seed, flaxseed, sunflower seeds, and the seeds of many 

 species belonging to the mustard family, such as rape. 

 Peanuts, cocoanuts and palm nuts are also very rich in 



