38 FEEDING ANIMALS. 



carbo-hydrates soluble, or by gelatinizing the contents of 

 the stomach. But these points have not been very much 

 investigated. 



It is found that pectin is increased in roots and fruits by 

 cooking. The process of digestion may perhaps have the 

 same effect. 



FATS. All our fodders and roots contain a small propor- 

 tion of fat, and this is one of the most important of the 

 carbo-hydrates. The fats in plants have, substantially, the 

 same composition as the fats of the animal body. In the 

 analyses which will be given of all these bodies, it will be 

 seen that the fats contain a much larger proportion of 

 carbon and correspondingly less oxygen; and in burning 

 gives out about 2^ times as much heat as starch, sugar, 

 etc., and are estimated to have 2K times the nutritive value 

 of such carbohydrates. 



Fat is found in different fodders about in the following 

 proportions : Average meadow hay 2.5 per cent., best 3 ; 

 clover, very good, 3.2; timothy 3 percent.; turnips and 

 other roots 0.1 to 0.2 ; Indian corn 4 to 7 per cent. ; oats 6.0 ; 

 rye 2.0 ; barley 2.5, etc. ; straw from 1 to 2 per cent. But 

 the seeds, of cotton, flax, hemp, and some other plants, 

 contain from 10 to 38 per cent, of oil. These oil-bearing 

 seeds are put under pressure to extract the oil as an article 

 of commerce, but the residue (oil cake) retains a consid- 

 erable proportion of oil. 



Oil has a great effect in rapid fattening of animals, but 

 they are also able to store up fat from the carbo-hydrates. 



The following table of the analysis of the carbo-hydrates 

 above described will give the reader a correct idea of their 

 composition, and how nearly they approximate to each 

 other : 



