Day 1 2 3 4 5 6 7 8 9 10 11 12 Reference* 0.0 0.0 0.3 0.0 0.0 0.3 0.5 0.6 15.4 1.7 43.3 52.0 Reference se 0.0 0.0 0.1 0.0 0.0 0.1 0.0 0.1 14.9 0.8 14.6 - EasyStrip® 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.7 15.5 1.3 40.9 40.9 EasyStrip® se 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 14.9 0.5 13.8 - Water Consumed 12.0 12.0 12.0 13.2 12.8 14.4 14.4 15.2 14.0 15.2 13.0 18.0 Water se 0.5 0.4 0.6 0.8 1.2 2.4 0.7 0.5 0.6 1.0 0.9 - No. of Cages 5 5 5 5 5 5 5 5 5 4 4 1

Table 2: Summary of daily ammonia (ppm) measured independently after reference gas pre-calibration using an Eagle II® gas monitor*, and as estimated using EasyStrips®. Cages remained closed during the complete study period. Ammonia values were obtained by insertion of the monitor probe or distilled water remoistened strips the same distance into each static cage through the water bottle port. Daily water consumption was measured. Each cage was only monitored until ammonia methods indicated ammonia exceeded 20 ppm. Ammonia is reported in ppm, and water in mL consumed. During the 12 day study period, room temperatures at the cage level averaged 72.3 ± 0.4 °F, and room relative humidity was 52.3 ± 1.2%. Values are expressed as mean ± s. e.