MAINTENANCE THE ENERGY REQUIREMENTS 293 



ported in which the net energy required for maintenance, i.e., 

 the fasting katabolism, has been determined. 



Respiration experiments upon sheep have been made by 

 Henneberg and Stohmann l in 1867-1868 on two animals, by 

 Henneberg, Fleisher and Mliller 2 in 1872 upon two animals, 

 by Hagemann 3 in 1899 on one animal, and by Kellner 4 upon 

 one animal. With the exception of the third, these were bal- 

 ance experiments with a Pettenkofer apparatus and included 

 no direct determinations of energy so far as reported. The 

 third investigation comprised a digestion and metabolism 

 experiment in which the energy of the feed and the visible ex- 

 creta was determined directly and also 42 determinations 

 of the pulmonary respiration with the Zuntz type of apparatus. 

 (299). 



In addition to the foregoing respiration experiments there are 

 a number of digestion experiments by Wolff in which the 

 live weight of the animals was approximately maintained, 5 and 

 Henry 6 reports a series of experiments by Carlyle and Klein- 

 heinz with breeding ewes in which various mixed rations pro- 

 duced an average daily gain of 0.16 pound per head in animals 

 averaging 145 pounds in weight. 



In these experiments the metabolizable energy of the rations 

 may be computed approximately from the digestible organic 

 matter in the manner described in Chapter XVII (774). In 

 the respiration experiments a correction for the gain or loss by 

 the animal may be made as in the case of Kellner's experiments 

 on cattle (381), while an approximate correction for the gain in 

 the live weight experiments may also be made. 



The results, computed per 100 Ib. live weight, are shown in 

 Table 49. 



383. Net energy in maintenance rations of sheep. As al- 

 ready stated, no direct determinations of the net energy re- 

 quired for the maintenance of sheep are on record and only 

 unsatisfactory data are available for computing it from the 

 metabolizable energy of maintenance rations. For the fore- 



1 Neue Beitrage, etc., pp. 68-286. 



2 Jahresber. Agr. Chem., 16-17 (1873-74), II, 145. 



3 Arch. (Anat. u.) Physiol. ; 1899, Suppl., p. 138. 



4 Die Ernahrung. landw. Nutzt., 6th Ed., p. 422. 



5 Compare U. S. Dept. of Agr., Bur. Anim. Indus., Bui. 143 (1912), pp. 4Q-5 1 - 



6 Feeds and Feeding, loth Ed., p. 482. 



