40 MAINE STATE COLLEGE 



contains a comparatively larger average percentage of nitrogenous 

 material, but is relatively woody. At the same time, if cut in 

 bloom, or soon after, instead of being allowed to stand until so 

 late, it makes a valuable fodder, and one that is superior to the 

 poorer grades of hay from upland grasses. 



DIGESTIBILITY OF HATS FROM GRASSES AND OTHER FODDER PLANTS. 



The hays cut in 1888 on the College Farm, the analyses of 

 which are given on page 38, were submitted to digestion tests, 

 that is, the actual amount of available nutritive material contained 

 in them has been determined by experiments with animals. 



The principles and methods involved in a digestion experiment 

 are explained on pages 90-92 of the Station Eeport for 1888, and 

 are briefly summarized below : 



(1.) Only that portion of the food which is dissolved by the 

 juices of the stomach and intestines and taken into the blood, is 

 available for use in sustaining life or producing growth. 



(2.) The solid excrement or dung is the undissolved or unused 

 portion of the food, therefore : 



(3.) The difference between what the animal takes in as food 

 and excretes in the feces constitutes the dissolved, digested or 

 useful portion. 



A digestion experiment, then, consists simply in feeding an ani- 

 mal a known and uniform daily ration, determining at the same 

 time the composition of the food and the weight and composition 

 of the solid excrement. This has been done by the Station in 

 1888-9 with quite a number of cattle foods, sheep being used as 

 the experimental animals. Eepeated observations have shown 

 that the various classes of ruminants are practically alike as to 

 the manner and extent of their digestive processes, so that what 

 is true for sheep would be true for cows and oxen. (For fuller 

 details of methods used in the digestion experiments see Station 

 Report for 1888, pp. 91-92.) 



The data needed for the calculation of the coefficients or per- 

 centages of digestibility are the following : 



(1.) Composition of food. 

 (2.) Composition of feces. 

 (3.) Weights of food eaten and feces excreted. 

 The composition of the foods is already given on page 38. The 

 other data can be found in the two following tables. 



