TTIE DIGESTIBILITY OF FEEDING STUFFS. 505 



of concentrated feeding- stuffs this presents no difficulty. Previous to 

 the beginning of the experiment the concentrated feeding stuffs should 

 be thoroughly mixed, and tbe daily rations for each animal weighed 

 out in separate vessels or in paper bags, an average sample being taken 

 for analysis; or tbe rations may be weighed out each day, a subsample 

 of constant amount (200 gm.) being taken each day, and these sub- 

 samples kept in a bottle for analysis. 



With roots and tubers the matter is somewhat more difficult. These 

 vary widely in composition, and undergo changes from partially drying 

 and also as a result of respiration. In case of these it is decidedly 

 preferable to take samples daily after the roots have been cut up. The 

 same applies to green fodders, silage, distillery refuse (slump), and 

 similar feeding stuffs. 



The samples taken daily are immediately dried at a low temperature, 

 and mixed later. If the differences in the feeding stuff can not be 

 equalized by mixing, it is advisable to continue the experiment for a 

 longer time than stated above. 



In the case of coarse fodders, as hay and straw, the method of pro- 

 cedure is as follows: If the experiments are to be made with sheep, or 

 only a single experiment with steers, a sufficient quantity of the fodder 

 for the trial is cut fine, mixed thoroughly on a tight floor, spread out in 

 a thin even layer (2 to 3 in. thick), and small samples taken from 

 about 20 different parts of the layer. These samples are mixed, spread 

 out in a circle, and segments of this circle taken from different parts, 

 which when united make several kilograms. This serves as the sample 

 for analysis. Samples which are taken by hand from a large heap of 

 coarse fodder do not represent the average of the material. The ration 

 for each day of the experiment is weighed out previous to the experi- 

 ment in tightly woven bags, samples being taken for the determination 

 of water. 



If, on the other hand, it is the intention to use a coarse fodder in a 

 long series of experiments with steers or horses, the separate wagon 

 loads as they are delivered are spread out in layers in the mow, small 

 samples being taken of each portion or forkful, so that from 10,000 lbs. 

 of hay 300 to 500 lbs. of samples would be taken. These samples are 

 cut in a fodder cutter, and sampled as described above. In this way it 

 is possible to determine the average composition of coarse fodder, as 

 the following illustration will show: In August, 1894, 12,500 lbs. of 

 hay was delivered at the agricultural experiment station at Mockern, 

 the average samples of which, taken as described above, contained 1.6 

 per cent of nitrogen and 46.16 per cent of carbon in dry matter, and 

 yielded 4,430 calories of heat per gram when burned in the calorimeter. 

 Thirteen months later, when about 2 tons of the hay remained, another 

 sample was taken which was found to contain 1.583 per cent of nitrogen 

 and 40.10 per cent of carbon, and to yield 4,415 calories of heat. 



