672 EXPERIMENT STATION RECOBD. [Vol. 37 



condition than in ttie previous test. In a palatabiiity test conducted for 12 

 days on the plan of the previous year the silage mixtures were preferred by 

 the animals in the following order: Alfalfa-molasses (20:1), alfalfa-molasses 

 (10:1), alfalfa and corn chop (10:1), alalfa and rye (2:1), alfalfa and 

 sweet-sorghum stover (6:1), and alfalfa alone. Very little difference was 

 shown between the first five mixtures. In a few cases the alfalfa and sorghum 

 stover seemed to be preferred to the alfalfa and corn chop and alfalfa and rye 

 silage. The poor quality of the sorghum stover accounts for the fact that the 

 alfalfa and sorghum stover silage was not relished at times. The cattle ate very 

 little of the alfalfa silage alone. 



No attempt was made either year to determine the feeding value of the 

 different mixtures used. A study of the chemical composition of the silages 

 shows that both years those containing the highest percentage of acid were 

 most palatable to the cattle, with the exception of rye alone. 



Sudan grass silage, C. K. Francis and W. G. Friedemann (Oklahoma Sta. 

 Bui. 115 (1917), pp. 8, figs. 2). — This bulletin gives results of experiments on 

 the preservation of Sudan grass silage in a steel silo. The Sudan grass was 

 cut when about one-sixth of the plants had reached the milk stage. The com- 

 position is given of Sudan grass hay as compared with other hays and of 

 Sudan grass silage and corn silage. It is notetl that the composition of Sudan 

 grass silage is very similar to that of corn silage, except that the former 

 averages about 33 per cent in fiber and the latter about 23 per cent. 



Temperature records taken at several depths in the silo show that the maxi- 

 mum temperature was reached in about 21 to 30 days and that no great in- 

 creases occurred thereafter. It is stated that the Sudan grass silage was fed 

 to the college sheep and, " while proving a good feed. It did not appear to be 

 relished by the animals so well as the corn silage, but quite as well as that 

 made from other grain sorghums, and was relishe<l much more in this form 

 than as cured hay." 



A study of methods of estimation of metabolic nitrogen, E. B. Fobdes. 

 C. E. Ma.vgei-s, and L. E. Morgan {V. S. Dcpt. .\gr.. Jour. Agr. Research, 9 

 (1911), No. 12. pp. ^05-411). — In the work reported, carried on at the Ohio 

 EJiperlment Station, a basal ration of corn alone was fed to each of five pigs 

 during the first period and nitrogenous supplements added to this com ration in 

 subsequent periods. In selecting the supplements an endeavor was made to 

 choose foods the protein of which would probably be entirely digestible. Milk, 

 blood albumin, and commercial dried egg albumin were used. 



The analytical methods compared were the acid-pepsin method, the acid- 

 pepsin and alkallne-pancreatin method, and the alcohol, ether, hot-water, and 

 cold-lime water method suggested by Jordan.' In the first two methods it is 

 assumed that by the use of digestive enzyms the nitrogen which has been 

 digested, absorbed, and returned to the feces may be separate<l from the indi- 

 gestible nitrogen, and that there is no further digestion during thp course of 

 the estimation of that part of the protein which escape<l digestion in the alimen- 

 tary tract of the experimental animal. It is noted that there is no means of 

 pro\ing the truth of this assumption. The experimental methods are described. 



The results show that the apparent digestibility of corn, based on the total 

 nitrogen of the feces, is about 75 per cent. The results of the acid-pepsin 

 method make it appear that the real digestibility is about 92 per cent, and the 

 pepsin-pancreatin method, about 96 per cent. Jordan's method yielded appre- 

 ciably lower figrures, averaging 86 per cent. The results of the acid-pepsin 



*Mnlne Sta. Rpt. 1888, pp. 196, 197; abs. in U. S. Dept. Agr., Office Expt. SUs. Bui. 2 

 (18!)1), pt. 2, p. 60. 



