Table 3.

Least squares means for the effect of lubabegron (LUB) dose on cumulative gas emissions and cumulative gas emissions standardized by final BW and HCW for five gases measured from cattle pen enclosures (CPE) over 91 d¹

	LUB (mg·kg−1 DM)						Dose	Significance of contrast
Variable	0.0	1.38	5.5	22.0	SEM	Dose × sex P-value2	P-value2	Control vs. 1.38 mg·kg−1	Control vs. 5.5 mg·kg−1	Control vs. 22.0 mg·kg−1
Unshrunk final BW, kg3	567	583	582	582	19.4	0.916	0.257
HCW, kg	349	364	365	365	11.7	0.865	0.035	0.019	0.014	0.014
NH3
Total emissions, g/animal	7,783	7,093	6,860	6,751	855	0.281	0.052	0.076	0.023	0.013
Standardized by BW, g/kg	13.6	12.1	11.7	11.6	1.19	0.161	0.004	0.009	0.002	<0.001
Standardized by HCW, g/kg	22.3	19.5	18.7	18.5	1.97	0.147	0.001	0.004	<0.001	<0.001
CH4
Total emissions, g/animal	10,466	10,692	10,763	10,476	638	0.712	0.895	—	—	—
Standardized by BW, g/kg	18.4	18.3	18.5	18.0	1.06	0.439	0.858	—	—	—
Standardized by HCW, g/kg	30.0	29.3	29.5	28.7	1.81	0.376	0.601	—	—	—
CO2
Total emissions, kg/animal	720	758	734	755	47.3	0.616	0.302	—	—	—
Standardized by BW, g/kg	1,268	1,299	1,261	1,299	61.3	0.322	0.268	—	—	—
Standardized by HCW, g/kg	2,061	2,081	2,013	2,070	107.8	0.269	0.331	—	—	—
H2S
Total emissions, g/animal	20.6	19.9	20.3	20.0	6.04	0.581	0.975	—	—	—
Standardized by BW, g/kg	0.035	0.033	0.035	0.033	0.0110	0.417	0.905	—	—	—
Standardized by HCW, g/kg	0.057	0.055	0.055	0.055	0.0176	0.379	0.776	—	—	—
N2O4
Total emissions, g/animal	−27.4	−36.8	−36.4	−34.7	10.2	0.279	0.627	—	—	—
Standardized by BW, g/kg	−0.046	−0.062	−0.060	−0.060	0.0154	0.306	0.693	—	—	—
Standardized by HCW, g/kg	−0.075	−0.097	−0.095	−0.095	0.0264	0.311	0.742	—	—	—

¹Emissions were measured from an individual CPE (n = 8) over 15-min sampling periods using calibrated, gas-specific analyzers (Thermo Environmental Instruments (TEI), Waltham, MA). This procedure was continuous so that a maximum of 11 sampling periods were available for determination of daily emission rates/animal for each CPE. Emissions were measured from 0800 hours on day 1 until 0500 hours on day 91.

²If the dose × sex interaction was not significant (P > 0.05), contrasts were constructed to evaluate the main effect of dose for the pooled sexes. Statistical significance for dose was declared when P ≤ 0.05 and tendencies were declared when 0.05 < P ≤ 0.10.

³Unshrunk; initial BW did not differ by dose (P = 0.937; Table 6).

⁴Measured values from CPE were less than the values reported from ambient air, resulting in negative values.