508 EXPERIMENT STATION RECORD. 



it can be let down upon the floor, and lias cleats nailed across it at right 

 angles to facilitate placing the animal in the stall or removing it. The 

 stall lias an opening on one side, closed by a sliding door, through which 

 the drinking water can be introduced in a square vessel. A bottle is 

 placed underneath the stall into which the urine tube empties. 



In experiments with pigs the harness for collecting the feces and 

 urine has often been omitted, as pigs are in the habit of depositing the 

 dung regularly in a particular place in the pen, and may readily be 

 made to deposit it in a receptacle provided for the purpose. But if a 

 sufficiently narrow stall of slats is used the feces bag and urine funnel 

 can be used on pigs, and this is considered preferable. 1 



SAMPLING THE FECES. 



The feces voided during a period of U4 hours are first weighed, 

 pulverized, and thoroughly mixed. Aliquots of about 100 gm. are 

 weighed out in flat dishes, dried at 60° C, and then kept at the tem- 

 perature of the room until they are practically constant in weight (air 

 dry). The moisture is determined in these air-dry samples, and for 

 this purpose the samples from several days may be mixed. 



THE KIND OF ANIMALS FOR EXPERIMENT. 



The kind of animals to be used for experimental purposes will depend 

 principally upon the object of the experiment. There is little doubt 

 that the various kinds of farm animals do not differ very much in their 

 ability to digest concentrated feeding stuffs, and the digestion coeffi- 

 cients obtained for concentrated feeding stuffs with sheep may be used 

 in calculating practical rations for cattle and even for horses. 



But with coarse fodders the case is different. It is known definitely 

 that coarse fodders are more thoroughly digested in the complicated 

 stomach and intestines of ruminants than in the simpler digestive 

 apparatus of horses and swine. There is believed to be no considerable 

 difference in this respect between the different kinds of ruminants, 

 especially between cattle and sheep. The average digestion coefficients 

 obtained in experiments with sheep agree approximately with those 

 obtained with steers for coarse fodders of the samekiud but of different 

 origin. Hence, it appears to be immaterial from the standpoint of 

 practice whether the coefficients of digestibility obtained with sheep or 

 with steers are used in calculating rations, especially as in practice the 

 content of crude nutrients in coarse fodders is only estimated approxi- 

 mately. Under these conditions, as the experiments with sheep are 

 simpler, more convenient, and cheaper, most experiment stations have 

 chosen sheep very largely for such experiments. 



The digestibility with different kinds of ruminants is not entirely 

 uniform, as is shown by some parallel experiments made incidentally 



1 A description of such a stall is given in Jour. Landw., 33 (1885), p. 154. 





