70 



EXPERIMENT STATION EECORD, 



As regards the influence of the character of feed consumed, it was found that 

 the digestibility of the dry substance, protein, fat, and carbohydrates, of a 

 ration consisting of clover hay and ground corn may be increased for steers by 

 decreasing the proiK^rtion of clover hay. The same constituents of a ration 

 consisting of clover, ground corn, and linseed-oil meal 1:4:1 are more digestible 

 for steers than those of rations consisting, respectively, of clover hay and 

 ground corn 1:1, 1:3, or 1 : 5. 



As regards the influence of the amount of feed consumed, it was found that 

 the dry substance and carbohydrates of a ration consisting of clover hay and 

 ground corn 1 : 1 were most digestible for steers when the ration was given in 

 amounts just sufficient for maintenance, and gradually became less digestible 

 as the size of the ration was increased above the maintenance requirements. 

 The dry matter and carbohydrates of the remaining rations were also most 

 digestible for steers when the rations were given in amounts just suSicient for 

 maintenance, but in these cases there was practically no difference between the 

 coefficients for the heavier rations. In none of these four rations did the 

 amount of feed consumed significantly influence the digestibility of the protein 

 and fat. 



Coefficients of digestibility of some common rations for swine, W. Dietrich 

 and H. S. Grindley {Illinois Sta. Bui. 110 {1914), pp. 165-201, fig. 1; abs. pp. 

 Jf). — In two sets of digestion trials, a pair of year-old barrows, a Berkshire and 

 a Yorkshire in the first experiment and two Berkshires in the second, were fed 

 during 6- to 8-day periods on various combinations of feeds and amounts of 

 feeds. The coefficients of digestibility as determined directly by these experi- 

 ments are shown in the following table : 



Average coefficients of digcstibiUti/ nf nitious hji smne. 



It is concluded that " the coefficients of digestibility obtained for a single 

 feed by calculation from the data obtained for a combination of feeds are not 

 reliable, especially when the single feed has been fed in comparatively small 

 quantities. By this method of calculation all of the difference between the 

 values for the single feed and the corresponding values for the combined feeds 

 is credited to the single feed, whereas it is probable that in the combined ration 

 each feed exerts an influence upon the digestibility of the other." 



As regards the influence of one ration upon another, " the results of these 

 experiments indicate that the coefficients of digestibility of one feed or ration 



