Table 7.

Summary of statistical measures to assess the adequacy of proposed models using regression between observed (Y) and model predicted (X) enteric methane emission (EME) of lactating dairy cows.

Item	Proposed Model 1
	Animal		Diet		Animal + Diet
	I	II	I	II	I	II
Observed EME (Y), g/d	390.50	383.75	436.32	424.44	437.65	441.43
Predicted EME (X), g/d	394.39	384.47	451.04	424.81	452.64	450.79
Mean bias (Y − X), g/d	−3.89	−0.72	−14.72	−0.34	−14.99	−9.36
n 2	85	76	27	29	21	20
Intercept (β0)	−21.34	27.19	−393.78	−37.38	−57.70	10.61
Slope (β1)	1.04	0.93	1.84	1.09	1.09	0.96
p-value (H0, β0 = zero and β1 = 1)	0.80	0.75	0.37	0.85	0.29	0.59
(R2)	0.38	0.55	0.08	0.66	0.62	0.65
MSEP 3, (g/d square)	3664.88	2778.46	3809.82	1808.71	2008.72	1656.60
Root MSEP, g/d	60.54	52.71	59.39	42.53	44.82	40.70
Partition of MSEP, %
Error due to mean bias	0.41	0.02	5.92	0.01	10.71	5.03
Error due to slope not equal to 1	0.11	0.75	1.62	1.21	1.05	0.38
Random error	99.48	99.23	92.45	98.78	88.24	94.58
CCC 4 (0 to 1)	0.53	0.72	0.08	0.78	0.72	0.79
r 5 (0 to 1)	0.61	0.74	0.28	0.81	0.78	0.81
Cb 6 (0 to 1)	0.87	0.98	0.28	0.96	0.92	0.98

¹ Full equations for models are specified in Table 6. ² Dataset from 35 experiments of 35 peer-reviewed papers (Table 3). Number of observations was different in models since some inputs are not reported in all studies. ³ Mean squared error of prediction. ⁴ CCC = concordance correlation coefficient (CCC = r × C_b). ⁵ r = correlation coefficient estimate (precision). ⁶ C_b = bias correction factor (accuracy).