Table 4. Average Percent of Labeled Sand Dose Retained by Four Cows Following Oral Administration Days After Dosing 20 um Average Percent Retained + One Standard Deviation 80 um 200 um 450 um 1 75 £8 97 + 1 99 + 1 99 + 0.4 2 23 +7 80 +11 90 + 7 93 + 3 3 8 +6 60 +17 — 69 + 24 76 +18 4 3 +4 46 + 20 54 + 32 62 + 29 5 0.8 + 0.8 34 + 20 43 + 33 53 + 32 6 0.1 + 0.2 24 + 20 34 + 33 4&4 + 36 7 ND 17 + 16 25 + 24 34 + 30 8* ND 9 + 9 15 + 15 20 +17 9 ND 6 + 5 9 + 10 14 + 12 10 ND 4 + 3 7 + 8 10 + 8 11 ND 2 + 2 5 + 6 6 + 6 12 ND 1 + 1 3 + 3 4 + 4 13 ND 0.6 + O.5 1 + 2 3 + 3 14 ND 0.2 + 0.2 0.5 + 0.9 2 + 3 15 ND <O0.1 0.2 + 0.3 1 + 2 16 ND <0.1 *Estimates from grab samples were made after day 7. ND--not detected. . 157 <O.1 <0.1