H. E. AVOODMAN 147 



digestibility ol: the com silage and dry corn fodder, the most marked 

 difference being in the case of the ether extract, as would be anticipated. 

 Both stored fodders are somewhat less digestible than the green fodder, 

 although it is of interest to note that in the case of the crude fibre, the 

 percentage digestibility shows an increase in the case of both the silage 

 and the dried corn fodder. It is also noteworthy that drying and ensiling 

 do not appear to depress the digestibihty of the nitrogen-free extract to 

 any marked extent. 



General Arrangement of Experiment. 



For the purpose of the digestion trials, a plot of about 1600 square 

 yards was measured off from a large field of oats and tares situated on the 

 Howe Hill Experimental Farm at Cambridge. Within the hmits of the 

 experimental plot, the growth of the crop was, to the eye, of a reasonably 

 uniform character. 



In order to bring out in the sharjaest manner possible any differences 

 in the digestibilities of the three types of foodstuff', it was decided that 

 the experiment should consist of three main periods in which ample 

 rations of the green forage, hay and silage, unmixed with concentrates, 

 should be fed successively and their respective digestibihties determined 

 directly. In the earlier work on oat and tare digestibihty, doubt was felt 

 as to the desirability of keeping the sheep for a period of three weeks on 

 an acidic food Uke silage alone, and the possibihty of digestive disturb- 

 ance was avoided by feeding a smaller ration of silage together with a 

 basal ration consisting of meadow hay and a httle linseed cake. This 

 procedure necessitated the carrying out of digestibility measurements on 

 the basal ration and the calculation of the silage digestibihty by difference. 

 In this experiment, however, no difficulty was encountered in main- 

 taining the sheep during the three weeks of experiment on an ample 

 ration of silage alone. The quahty of the silage was good and the sheep 

 from the outset consumed the ration quite readily without suffering the 

 slightest discomfort. Indeed, it was noteworthy that less difficulty was 

 experienced with the feeding during the silage period than in the green 

 fodder and hay periods. When the green fodder was introduced into the 

 diet, one of the sheep showed at first a tendency to be shghtly "blown," 

 but by judiciously cutting down the amount fed for some days, this 

 difficulty was overcome and a very satisfactory trial was obtained. In 

 the hay period, one of the sheep displayed an inabihty to consume the 

 entire ration, and consequently the digestibihty of the hay was deter- 



