Recent Advances in Measurement and Dietary Mitigation of Enteric Methane Emissions in Ruminants

Abstract

Methane (CH4) emission, which is mainly produced during normal fermentation of feeds by the rumen microorganisms, represents a major contributor to the greenhouse gas (GHG) emissions. Several enteric CH4 mitigation technologies have been explored recently. A number of new techniques have also been developed and existing techniques have been improved in order to evaluate CH4 mitigation technologies and prepare an inventory of GHG emissions precisely. The aim of this review is to discuss different CH4 measuring and mitigation technologies, which have been recently developed. Respiration chamber technique is still considered as a gold standard technique due to its greater precision and reproducibility in CH4 measurements. With the adoption of recent recommendations for improving the technique, the SF6 method can be used with a high level of precision similar to the chamber technique. Short-term measurement techniques of CH4 measurements generally invite considerable within- and between-animal variations. Among the short-term measuring techniques, Greenfeed and methane hood systems are likely more suitable for evaluation of CH4 mitigation studies, if measurements could be obtained at different times of the day relative to the diurnal cycle of the CH4 production. Carbon dioxide and CH4 ratio, sniffer, and other short-term breath analysis techniques are more suitable for on farm screening of large number of animals to generate the data of low CH4-producing animals for genetic selection purposes. Different indirect measuring techniques are also investigated in recent years. Several new dietary CH4 mitigation technologies have been explored, but only a few of them are practical and cost-effective. Future research should be directed toward both the medium- and long-term mitigation strategies, which could be utilized on farms to accomplish substantial reductions of CH4 emissions and to profitably reduce carbon footprint of livestock production systems. This review presents recent developments and critical analysis on different measurements and dietary mitigation of enteric CH4 emissions technologies.

Dietary supplemental plant oils reduce methanogenesis from anaerobic microbial fermentation in the rumen

“…Daily methane produced (per unit of fermented OM) from ruminal fermentation was decreased by more than 20% when the basal diet was supplemented with any of the plant oils examined. The depressing effect of supplemental plant oils on methanogenesis cannot be attributed to a general inhibitory effect on ruminal fermentation, as the indicators of the extent of degradation (dietary OM rumen digestibility, production of fermentation gas or daily VFA output) were not affected by any of the supplemental plant oils 7 . Additionally, not only the total daily amount of methane generated was reduced, but also the concentration of methane in the fermentation gas, reinforcing the idea that supplemental plant oils may exert a rather specific effect on methanogenesis.…”

Effects of berry seed residues on ruminal fermentation, methane concentration, milk production, and fatty acid proportions in the rumen and milk of dairy cows

“…The amount of energy lost as methane in ruminant animals may account for 6 to 12% of gross energy intake, or 8 to 14% of digestible energy intake (Czerkawski, 1969;Johnson and Ward, 1996). For mitigation of methane production in ruminants, it is crucial to develop a strategy that decreases methane-producing microbial activities and proliferation without limiting beneficial rumen function (Foiklang et al, 2016;Patra, 2016). Berry seed residues were considered as potential factors for modulating rumen microflora populations responsible for methanogenesis.…”

Is rumination time an indicator of methane production in dairy cows?

“…As far as inexpensive, less time-consuming methods for CH 4 records are concerned, some innovative techniques have been proposed (see Patra, 2016), such as the sniffer gas concentration methods (Garnsworthy et al, 2012;Lassen et al, 2012). This is a noninvasive technique that can be installed inside the integral feed 11075 bins of automatic milking systems (AMS) or concentrate feeders, where it continuously measures CH 4 concentration during milking, and several hundred measurements can be made in a very short time (Lassen and .…”