MAI^UAL OF CATTLE-FEEDIIS^G. 97 



loss of 2-3 per cent. In this experiment the ^-eight of 

 the food was more than eight times that of the pigeon, 

 and the amount of nitrogen in the food ten times that in 

 tlie animal Taking into account, aLo, the small weight 

 of the anuaal and the duration of the experin^ent, the hy- 

 pothesis of any appreenihle excretion of gaseous nitrogen 

 becomes untenable. The small deficit observed is largely 

 explained by the fact that the animal gained 73 grms. 

 during the experiment, and was found, wiien killed, to be 

 rich in flesh. 



Experiments on Domestic Animals. — The impor- 

 tance of Voit's observations for the founding of a ra- 

 tional theory of feeding, speedily led to experiments on^ 

 agricultural animals, which showed that, as was to be ex- 

 pected, the same law holds good for them. A large num- 

 ber of experiments, in which various domestic animals 

 have received a fodder which experience has shoM'^n to be 

 sufficient to keep them in unaltered condition for long 

 periods, have shown that under these circumstances all the 

 nitrogen of the fodder reappears in the excrements. 



Oxen. — The earliest observations were those of Ilenne- 

 berg, at the Weende Experiment Station, on oxen. His 

 first experiments, in 1858 to 1859 and 1860 to 1861, agreed 

 in the main wdth Yoit's results, but, owing to the com- 

 parative imperfection of the experimental methods then 

 available, considei-able variations were found in particular 

 cases. Further experiments, however, made in 1865,* with 

 improved methods and apparatus, showed that these varia- 

 tions were due to experimental errors, and most abun- 

 dantly confirmed Voit's observations, as the following 

 results show: 



* " Neue Beitrdge zur Begrandung einer Eatxonellen Fiitterung der 

 WiedeikcLuer," p 880. 



