Table 1.
Ammonia (NH3, ppm) by gas detector and numerical bedding score (Bedding Score, mean ± SD; range 0–4) by number of cages (n) for group- or singly occupied mouse disposable IVCs at standard conditions (mean 72 °F [22.2 °C]) or thermoneutral conditions (TN, mean 82 °F [27.8 °C]) with diced cellulose or corncob bedding. Control values for ammonia were 0 ppm at all time points.
| Day(s) After Cage Change | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 7 | 14 | 27 | 28–30 | ||||||||
| Bedding Type | Temperature | Occupancy (n of cages) | NH3 | Bedding Score | NH3 | Bedding Score | NH3 | Bedding Score | NH3 | Bedding Score | NH3 | Bedding Score |
| α-Cellulose | Standard | Group ( n = 5) | 0 | 0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 (n = 4); 6 (n = 1)* | 2.4 ± 0.5 | 0 | 3.0 ± 0 (n = 3) |
| Single ( n = 3) | 0 | 0 ± 0 | 0 | 1.0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 3.0 ± 0 | ||
| TN | Group ( n = 2) | 0 | 0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 23 (n = 1); 0 (n = 1)** | 3.5 ± 0.7 | |
| Single ( n = 2) | 0 | 0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 3.0 ± 0 | ||
| Corncob | Standard | Group ( n = 5) | 0 | 0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 3.0 ± 0.7 |
| Single ( n = 3) | 0 | 0 ± 0 | 0 | 1.0 ± 0 | 0 | 2.0 ± 0 | 0 | 2.0 ± 0 | 0 | 3.0 ± 0 | ||
* or **= denotes and describes discrepancy between ammonia gas detector and colorimetric sensor readings
*1 of 5 cages read at 6 ppm by gas detector and had colorimetric score of 3 (corresponds to 50–100 ppm) and 1 of 5 cages read at 0 ppm and had score of 3 (colorimetric read 50–100 ppm) and these cages were removed from study
**1 of 2 cages read at 23 ppm by gas detector and had colorimetric score of 2 (corresponds to 25-50 ppm)