136 



RADIOISOTOPES IN BIOLOGY AND AGRICULTURE 



A respiration apparatus has been described by Kleiber and Edick (23) 

 which allows simultaneous measurements of the metabolic rate and the 

 radioactivity in the expired CO2 of cows injected with C^Mabeled com- 

 pounds. Its unique feature is a face mask that is sufficiently tight yet 

 comfortable enough to be used for 3 hr at a time. Absolute tightness is 

 not essential, since the apparatus operates with open-air circulation. By 

 the use of gas-sampling devices, representative samples of the expired air 



Tenpenny noils for ^ 

 adjusting stanchion ^ ^ ^ 



Tenpenny nails for^ *^ 



keeping stanchion in ^ ^ 

 place 



^Feed box 

 -\^PIywood 



Feces - ^^ ^ 

 containers 



Urine Funnel '^3^>^ 



Fig. 4-13. Schematic diagram of two-unit metabolism stall suitable for sheep, goats, 

 or small calves. [From Sam L. Hansard, C. L. Comar, and M. P. Plumlee, Radio- 

 isotope Procedures with Farm Animals, Nucleonics, 9: 13-25, 38-45 (1951).] 



can be taken to allow measurements of expired C^'*02 at varying times 

 after dosage of the animal. The health or cross-contamination hazard is 

 not a particular problem with farm animals, since they can be maintained 

 out in the open, where the expired C'^ will be diluted in the atmosphere. 

 Sheep, Goats, and Small Calves. Figure 4-13 (17) presents the details 

 of a two-stall metabolism unit which is satisfactory for these animals 

 The procedures for the females are essentially the same as described above 

 for cattle. With the males it is convenient to provide a grille and urine 

 funnel in the stall so that it is not necessary to attach a funnel to the 



