CREATININE RATIOS IN RANDOM SAMPLED AND 24-HOUR URINES OF WHITE-TAILED DEER

We examined assumptions associated with collecting and chemically anal yzing single urine specimens of northern ungulates to assess their phy siological responses to changes in nutrition to validate this techniqu e. We determined the degree to which creatinine ratios of 5 urinary ch aracteristics (urea nitrogen [N], sodium, potassium, calcium, and phos phorus) in single urine specimens, voided at various times of the day, reliably represented their values in 24-hour urines. We used computer simulation to compare data from 24-hour urine pools and random sample s of single urine specimens collected from 12 hand-reared, adult male white-tailed deer (Odocoileus virginianus). Eight and 4 deer were fed high and low nitrogen diets, respectively. Overall, urea N:creatinine and potassium:creatinine exhibited the greatest potential. Specificall y, during B-day spring trials, 90% of the samples of single urine spec imens had mean urea N:creatinine values differing less than or equal t o 19.7 and 12.3% from the mean 24-hour urine values of the high nitrog en and low nitrogen-fed groups. During the summer trials, the differen ce was less than or equal to 14.5 and 27.5% for the high and low nitro gen-fed groups. For potassium:creatinine ratios, 90% of mean values of samples of single urine specimens from the high nitrogen and low nitr ogen-fed groups differed from mean 24-hour urine values by 9.3 and 16. 0% during spring-and by 11.9 and 12.4% during summer. Additional resea rch should examine similar comparisons in deer fed submaintenance diet s.