Enteric Methane Emissions and Animal Performance in Dairy and Beef Cattle Production: Strategies, Opportunities, and Impact of Reducing Emissions

Abstract

Enteric methane (CH4) emissions produced by microbial fermentation in the rumen resulting in the emission of greenhouse gases (GHG) into the atmosphere. The GHG emissions reduction from the livestock industry can be attained by increasing production efficiency and improving feed efficiency, by lowering the emission intensity of production, or by combining the two. In this work, information was compiled from peer-reviewed studies to analyze CH4 emissions calculated per unit of milk production, energy-corrected milk (ECM), average daily gain (ADG), dry matter intake (DMI), and gross energy intake (GEI), and related emissions to rumen fermentation profiles (volatile fatty acids [VFA], hydrogen [H2]) and microflora activities in the rumen of beef and dairy cattle. For dairy cattle, there was a positive correlation (p < 0.001) between CH4 emissions and DMI (R2 = 0.44), milk production (R2 = 0.37; p < 0.001), ECM (R2 = 0.46), GEI (R2 = 0.50), and acetate/propionate (A/P) ratio (R2 = 0.45). For beef cattle, CH4 emissions were positively correlated (p < 0.05–0.001) with DMI (R2 = 0.37) and GEI (R2 = 0.74). Additionally, the ADG (R2 = 0.19; p < 0.01) and A/P ratio (R2 = 0.15; p < 0.05) were significantly associated with CH4 emission in beef steers. This information may lead to cost-effective methods to reduce enteric CH4 production from cattle. We conclude that enteric CH4 emissions per unit of ECM, GEI, and ADG, as well as rumen fermentation profiles, show great potential for estimating enteric CH4 emissions.

Global Warming and Dairy Cattle: How to Control and Reduce Methane Emission

“…Methanogens are found in various sites inside the rumen, including the epithelium, biofilms, protozoa, and fungus [ 92 ]. Saliva lysozyme plays a crucial role in the rumen microbiota by limiting the proliferation of Gram-positive bacteria.…”

“…In the rumen microbial ecology, ciliate protozoa are major H2 producers that play an important role in interspecies H 2 transfer and CH 4 emissions. Protozoa have been shown to have a strong correlation with CH 4 emissions, which suggests that protozoa could be a potential target for CH 4 mitigation [ 92 , 93 , 94 ]. Reduced neutral detergent fiber from forage (NDF) and increased concentrate intake may be associated with a lower rumen pH.…”

“…An analysis of lactating of Holstein–Friesian, Jersey, and cannulated dairy cows fed a high-quality dairy feed supplemented with silage or high-quality fodder performed by Min et al showed that milk production has a significant relationship with methane production [ 92 ]. The relationship between milk production and methane production in a grain-based diet was not meaningful, but a significant difference was found when comparing CH 4 emissions per kg in cattle given grain- and forage-based diets (R2 = 0.38 − 0.40).…”

Impact of orange essential oil on enteric methane emissions of heifers fed bermudagrass hay

“…Methane measurements were carried out in two open-circuit respiration chambers with an internal volume of 9.97 m 3 . Each chamber was equipped with a steel feeder (90 cm length, 70 cm height, and 50 cm width), automatic bowl-type waterer (20 cm diameter), fan (30 cm diameter), air conditioner (12,000-BTU), and dehumidifier.…”

“…Methane (CH 4 ) emitted by ruminants is a substantial GHG source. Given that CH 4 is a short-lived GHG, reducing its emissions is important for mitigating the adverse effects of climate change ( 2 , 3 ). The development of effective CH 4 mitigation strategies that do not adversely affect animal performance is important, especially in tropical countries where livestock plays an important role in ensuring food security and contributes to poverty reduction.…”