Figure 3.

Comparative statistics for carbon dioxide emission, oxygen consumption, and methane emission estimates from an automated head chamber system (AHCS; GreenFeed, C-Lock Inc., Rapid City, SD) between the “gold-standard” [average of all visits ≥ 3 min. visit duration (n = 144 ± 55.01; mean ± standard deviation)] and estimates with 3 visit duration thresholds (≥ 3 min., ≥ 2 min., or ≥ 1 min.) and with randomly selected number of visits (5 to 60, increasing by increments of 5). The statistics reported are Pearson’s Correlation Coefficient (r); the bias correction factor (Cb); Lin’s concordance correlation coefficient (CCC; Lin, 1989, 2000); and the root mean square error (RMSE) expressed as a percent of the “gold-standard”. The horizontal line in the CCC graphs represents the 0.90 thresholds set as excellent agreement between the estimates and the “gold-standard”. Data used in this analysis are from Proctor (2023).