36 SCIENTIFIC FEEDING OF ANIMALS 



just quoted about i lb. less organic matter was 

 digested when the largest ration was given. It is 

 easy to see that by the consumption of large quanti- 

 ties of food the passage through the alimentary 

 canal is more rapid, although this organ possesses 

 a certain extensibility, and so digestion may not be 

 perfect. When large quantities of easily digestible 

 food are consumed it is possible that the intestine 

 is not able to cope with it, and so some of the 

 nutrients escape unabsorbed. Over-feeding of ani- 

 mals for these and other reasons is to be avoided. 



3. The one-sided addition of digestible carbo- 

 hydrates to a food causes, under certain conditions, 

 a greater or less depression of digestibility. This 

 fact has been constated by numerous experiments 

 on ruminants and pigs. One of these, with an ox, 

 may be quoted. It was found that after the addi- 

 tion of 1-66 kilos of dry starch to a daily ration 

 of 9 kilos meadow hay, the digestion of the crude 

 protein decreased by 63 grams (28 grams =1 oz.), 

 the nitrogen-free extract by in grams, and the 

 crude fibre by 133 grams. When the quantity of 

 added starch was raised to 2-87 kilos, then a decrease 

 of 120 grams crude protein, 252 grams nitrogen-free 

 extract, and 167 grams crude fibre was found in the 

 amounts digested. This depression of digestibility, 

 due to the starch, was also observed when other 

 carbohydrates, such as sugar or cellulose, were 

 added to the hay. Similarly, when foods rich in 



