1G8 Maintenance Hatioiis and Sfairit L'l/idcah nts 



Wc liavo alroafly soon tliat tliis estimate of ITcnneberf; and Stohmann 

 and WolfT is unsupported by the practical examples given. Considera- 

 tions of later calorimetry experiments support the conclusion that the 

 above estimate is much in excess of the normal maintenance require- 

 ments of oxen. Kellner' fed an ox of 718 kg. on 9 kg. average 

 meadow hay per day for 15 days. During this period the animal 

 lost about 1 lb. weight a day, so the diet was evidently just under 

 maintenance. For a 1000 lbs. ox this diet works out at 12 lbs. hay 

 a day (about). The estimate of G-35 lbs. starch equivalent for main- 

 tenance of Wood and Yule corresponds to 14 lbs. meadow hay, which 

 agrees well with this experiment. An isolated experiment, however, 

 is a dangerous basis for conclusions, and this becomes more evident 

 when the figure quoted by Murray of 17,320 cals.^ as the energy require- 

 ment for maintenance of an ox of 038-1 kg. is con.sidered. This 

 figure is derived from an experiment conducted by Kellner on an 

 "ox B," whose energy requirements for maintenance were extra- 

 ordinarily high owing to its uneasiness and general restlessness in the 

 calorimeter and while under experiment. So unsatisfactory a subject 

 did tliis ox prove for experimental purposes that Kellner^ himself 

 omitted it when making the average on which Wood and Yule's graph 

 is based. 



A notable advance in the state of our knowledge with regard to 

 the maintenance requirements of oxen was made when Kiihn', in a 

 series of painstaking and careful experiments with seven. oxen extending 

 over a period of seven years, came to the conclusion that the main- 

 tenance requirements of grown oxen are satisfied with a ration containing 

 •7 lb. digestible protein and O-G lbs. digestible nitrogen-free extract 

 per 1000 lbs. live weight per day. 



In these experiments, a coarse fodder formed the sole source of the 

 availal)le energy (meadow or clover hay and oat straw) and the experi- 

 ments included both determinations of digestibility and the total 

 metabolism of nitrogen and carbon including the excretion of methane. 



The death of Kiihn left the investigation in the hands of Kellner', 

 who, as a result of experiments with two oxen A and B and combining 

 some of Kiihn's earlier results, came to the conclusion that an ox of 



• Kellner, Landw. Vcnmchs. SUit. 1898, 50, p. 24.'). 



- ({oodwin, Sclenlific Feeding of Aninmls ( Kellner" .s), p. .'>(•. 



'■> Kellner, Landto. Versueh.t. Stat. ISitl!, 47. •27.'">: 50. 2".{. footnote. 



' Kiihn. Lnndw. Vermiclm. Stat. lS!t4, 44, SriT-.W!. 



■'■ Kellner, Landw. l'<T.««rA,s-. Stat. ISllfi. 47 27r\ 



