Table 2.

Ammonia level^aand urine spot diameter, color,^band edge^ccharacteristics (mean ± 1 SD) on day 1-16 after cage change in cages housing 5 male or 5 female mice

	Male Cages (n = 135)	Female Cages (n = 123)	P
Ammonia	2.7 ± 0.9	2.2 ± 0.9	<0.0001d
Diameter (in.)	3.0 ± 1.2	2.3 ± 1.1	<0.0001d
Color3	1.9 ± 0.7	1.6 ± 0.7	<0.0026d
Edge4	1.5 ± 0.5	1.3 ± 0.5	<0.0058d

^aAmmonia level codes: 1, less than 1 ppm ammonia (color of indicator disk, yellow); 2, 1–25 ppm (light green); 3, 25–50 ppm (medium green); and 4, more than 50 ppm (dark blue).

^bColor codes: 1, light brown; 2, medium brown; and 3, dark brown.

^cEdge codes: 1, diffuse; and 2, distinct.

^dValue significantly (P < 0.01) different between male and female mice.