Non-introgenouH extract matter represents the sui>aJ"s, starch and 

 gums. It is the ])rinci])al source of heat or eiieray and fat for the 

 dair}' animal. 



Fat includes not only the various oils and fats in all gi"ains and 

 coarse fodders, but also waxes, resins and colorino- matters. It is 

 fre(|uently termed etJier extract, because it is that portion of the 

 })lant sohiblc in ether. It serves as a source of heat oi- energy and 

 fat in the body of the animal. 



Carboliydrates is a term which is generally used to include both 

 the fib(u- and the extract matter. 



2. DlGESTIIULlTY OF ( 'aTTLE FeEDS. 



The several groups of nutrients above described, which make up 

 the various cattle feeds, are valuable to the animal only in so far 

 as they can be digested and assimilated. The concentrated feeds 

 are considerably more digestible than the coarse fodders, as a single 

 illustration will show : — 



In the tirst and fourth columns are given the composition of 

 average samples of timothv hay and of gluten feed. In the second 

 and tifth columns are shown the percentages of the dilierent gTou})s 

 which ai'e digestible. Thus, of the 6.3 pounds of })rotein in timothy, 

 48 })er cent are digestible^ or 3 pounds ; and of the 26.2 pounds of 

 protein in 100 pounds of gluten feed, <S5 per cent or 22.3 pounds, 

 ai'e digestible. Excluding the ash, which is not generally taken 

 into account, it is shown that 100 pounds of timothy hay contain 

 about 4S pounds of digestilile or actual food material, and 100 



