Comparison of 3 methods for estimating enteric methane and carbon dioxide emission in nonlactating cows

Abstract

Among techniques for estimating enteric methane (CH4) emission by ruminants, open-circuit respiration chambers (OC), the use of a gas tracer (SF6), and the GreenFeed (GF) device are the most commonly used. In this study, we compared these techniques in 8 dry cows receiving a diet made of 70% hay and 30% concentrates given in limited and constant amounts, in a 15-wk experiment. Two periods in free stalls for SF6 and GF and in chambers for OC were used; in addition, SF6 was determined in chambers for 1 period. Methane emission (g/d) and CH4 yield (g/kg DMI) were higher (P < 0.0001) for OC than for SF6 and GF (367, 310, and 319 g/d for OC, SF6, and GF, respectively). The difference between OC and GF was related to a difference in post-prandial rate of gas emission. The between-animal coefficient of variation of CH4 emission was higher for SF6 than for OC and GF (20.8, 13.5, and 12.0% on average, respectively). Correlation coefficients between OC and SF6 were high and significant for CH4 emission and CH4 yield (r = 0.782 and r = 0.717, respectively; P < 0.05), but not significant between OC and GF, or between SF6 and GF. Correlation coefficients were highly significant for SF6 determined either in free stalls or in chambers (r = 0.908 and 0.903 for CH4 in g/d and g/kg DMI, respectively; P < 0.01). Carbon dioxide (CO2) emission and CO2 yield were similar for GF and OC (10,003 and 9,887 g/d, 752 and 746 g/kg DMI, respectively); CO2 data obtained with SF6 were lower (7,718 g/d and 606 g/kg DMI; P < 0.0001), but this technique is not relevant for CO2 emission determination. Correlation coefficients between OC and GF were not significant for CO2 emission and CO2 yield. This set of results shows that differences between methods are minor for average values, but that individual correlations may limit their interchangeability for determining gas emissions of individual animals. This study also shows the reliability of GF on-farm determination of CH4 and CO2 emissions for groups of animals.

Interaction between feed use efficiency and level of dietary crude protein on enteric methane emission and apparent nitrogen use efficiency with Norwegian Red dairy cows1

“…The increasing NGR, Ac/Pr, and rumen pH with increasing time postfeeding suggested that if methane emissions were to be influenced by diet fermentation pattern, rumen pH, and VFA profile ( Wolin, 1960 ; Russel, 1998 ), the diurnal pattern of enteric CH 4 emission may not be constant. Recent reports by Danielsson et al (2017) and Doreau et al (2018) clearly indicate this diurnal fluctuation. This is expected because of the differences in rate and extent of fermentation of different dietary components into different VFA.…”

Investigation of intra-day variability of gaseous measurements in sheep using portable accumulation chambers

“…Alternatively, when animal’s gaseous emissions were measured in respiration chambers their CH 4 output was found to range from 14 to 24.6 g/day ( Pinares-Patiño et al, 2013 ; Fraser et al, 2015 ) and 19.0 g/day when measured using the SF 6 tracer technique ( Lassey et al, 1997 ). According to Doreau et al (2018) and Goopy et al (2011) short-term measurements are less accurate at predicting daily CH 4 production when compared with that of long-term measurements such as respiration chambers due to peaks of emissions during and post feeding which can be missed using spot-sampling methods. Furthermore, short-term measurements add additional sources of variation to the overall daily output as stated by Hegarty (2013) .…”

Response to Climate Change: Evaluation of Methane Emissions in Northern Australian Beef Cattle on a High Quality Diet Supplemented with Desmanthus Using Open-Circuit Respiration Chambers and GreenFeed Emission Monitoring Systems

“…This technique has minimal labor input and interference with animal behavior and production [ 21 ]. Previous studies reported minor differences between RC and GEM methods in average CH 4 emission values [ 22 ]. In this study, the comparative effect of four different dietary inclusion levels of Desmanthus on CH 4 emissions was evaluated using GEM in a pen-based experiment imitating a grazing situation.…”