summarized in table 6. Corbett et al. (1960) 
found that 4 to 6 days were required for excre- 
tion of chromic oxide in feces to equilibrate 
with intake of chromic oxide administered in 
shredded paper once daily. Similar observa- 
tions have been made in more recent studies 
on chromic oxide paper (Green et al. 1966) 
and chromic oxide-cellulose mixtures (McCann 
and Theurer 1967). 
Since fecal output (percent of actual) is 
TABLE 6.—Percent recovery of chromic oxide administered in shredded paper or on cellulose 
Percent recovery *? 
Days 
Indicator form, Number Time of to Total 
feeding method, and kind Time of dose grab equili- _collec- Grab 
and forage type of animal Cr.03 sample brate tion sample Investigator 
A.M. P.M. A.M. P.M. 
Shredded Paper: 
Hand fed: 
Grass hay __ 4 sheep LOSOOh so ce ete dee cee ee peer 4-6 98.6 sath Corbett et al. 
(1960) 
DO oe ole 4 sheep 10:00 : _. 10:30 4:30 Ba 101.8 102.3 ~— do. 
Dose eeses- 6 steers G00 2a tee 6:30 _.--3- 96.8 93.2 Green et al. 
(1966) 
Doct 22s 6 steers 6:00" - 25222 T3200" 9 2seaes 4 97.6 113.1 do. 
(every other day) 
DOiMésis.4 2852 3 steers twice GWiICG.* pee SORE Ere pes 100.1 a Hye Streeter 
daily daily (1966) ° 
Freshly cut 3 steers 
grass. do. dos 9 )* wesw. pees Ded 99.5 ae do. 
Grazing: 
Pasture ____ 3 sheep 8:00 4:00 8:40 4:40 =e 97.9 100.9 Soa et al. 
19 
DOf 2 2-2 3 sheep 8:00 ase BsdOy * ie sare er 99.7 105.8 ~— do. 
S000 6 a ee Ee 2 4:40 Sis Sar 12.2 
8:00 222226 8:40 4:40 ae BOs 89.8 
Pasture + 3 steers 9:00 4:30 9:00 4:30 Bye 94.2 98.9 do. 
hay. 
Pasture ____ 2 steers 9:00. sence ° Con- > Con- Le 94.4 ° 93.0 Cowlishaw & 
tinuous’ tinuous Alder (19638) 
Native range 6 steers 6:00 6:00 * Con- * Con- ae 90.6 > 83.1 Streeter ; 
(2 trials). tinuous tinuous (1966) 
Native range 5 heifers 5:00 BOO Slo eee Eee 89.6 Seow: do. 
(3 trials). 
Cellulose 
Mixture * 
Hand fed: 
Alfalfa hay 8 steers Ts00) © st222 1304 te 4 81.8 95.8 McCann & 
(2 trials). Theurer 
(1967) 
Meadow hay 2 steers twice twice 8:00 4:00 Bess Bes 81.0 Bohman et al. 
daily daily (1967) 
Grazing: 
Native 12 steers do. do. twice twice Pere 99.8 97.0 do. 
range daily daily 
(2 trials) 
Native 
range + 
supple- 
ment 
(3 trials) 16 steers do. do. do. do. 100.7 103.8 = do. 
Native 4 steers 7:00! © soee ee 12007 tie ee ee 76.2 80.5 Galt et al. 
range. (1968) 
* Adapted from investigator’s data where not given directly. 
* Based on fecal concentration and on concentration necessary for complete recovery; or on recl 
mated fecal output. 
* Refers to composite collection of fecal “pats” from the ground. . 
* Chromic oxide powder was mixed with Solka Floc (The Brown Co., Berlin, N.H.). 
°Unpublished Ph.D. Dissertation, University of Nebr., Lincoln, Nebr. 
° Unpublished data. University of Ariz. and Rocky Mountain Forest 
footnote 11, p 117, Galt, H. D., Theurer, B., and Martin, S. C. 1968. 
116 
procal of esti- 
& Range Exp. Sta., Tucson, Ariz.; see 
