June 17, 1918 Digestibility of Corn Silage, Velvet Beans, and Alfalfa 617 



for by the increased quantity of feed. We must therefore conclude that 

 in general, so far as the feeds we are studying are concerned, the combi- 

 nation with other feeds has a depressing effect on digestion. This does 

 not necessarily follow for all the individual nutrients. 



It is evident from a study of the tables that, so far as the average 

 apparent digestion coefficients of silage are concerned, nothing is especially 

 abnormal or noteworthy. It is true that the nitrogen (crude protein) 

 digestion presents some irregularities when fed in combination with other 

 feeds, but when fed alone these irregularities are not out of the ordinary. 

 The amoimt of nitrogen in com silage is so small that variations are 

 likely to occur. Ash digestion also not only shows considerable irregu- 

 larity at times but frequently shows a negative coefficient. This same 

 condition has been noted in previous digestion experiments. 



The apparent coefficients obtained for velvet-bean meal are of special 

 interest on account of the relatively few digestion trials that have been 

 made with this comparatively important feed. From our results it is 

 seen that, as a whole, this feed is rather highly digestible; and when fed 

 alone approximately 84 per cent of the dry matter is digested. The 

 apparent digestibility of none of the nutrients averaged less than 58 

 per cent. 



The apparent digestion coefficients for alfalfa hay present no marked 

 irregularities. They do show the same general decline as a result of 

 combination and quantity of feed. This decline amounts to over 10 

 per cent from feeding alone to the combining of all three feeds in Ration 

 VII, where the total quantity of dry matter consumed was greater than 

 in any other ration. 



Thus, these results show no great variations from what might havje 

 been expected. While it is true that from an economic standpoint we 

 are interested in that combination of feeds which will give the greatest 

 digestibility for all the nutrients of the rations, these results do show no 

 marked decline as a result of food combinations. If marked declines 

 existed, their presence would be magnified by the determination of 

 digestion coefficients by difference, but here we have no marked varia- 

 tions from the normal and can therefore conclude that the combining of 

 these feeds has resulted in no marked increase or decrease in apparent 

 digestion coefficients. 



When rations that contain silage, velvet-bean meal, and alfalfa hay 

 are fed, the tendency seems to be to lower the digestibility of the whole 

 slightly below the calculated digestion coefficients. There are indications 

 also that sHghtly better use is made of the feeds fed when the ration is 

 made up of silage and one of the protein feeds than when both the protein 

 feeds are fed, and that the most complete digestion takes place with 

 silage and alfalfa rather than with the silage and velvet-bean meal, 

 although the difference is small. 



