Hydrogen and methane emissions from beef cattle and their rumen microbial community vary with diet, time after feeding and genotype

Abstract

The aims of the present study were to quantify hydrogen (H 2 ) and methane (CH 4 ) emissions from beef cattle under different dietary conditions and to assess how cattle genotype and rumen microbial community affected these emissions. A total of thirty-six Aberdeen Angus-sired (AAx) and thirty-six Limousin-sired (LIMx) steers were fed two diets with forage:concentrate ratios (DM basis) of either 8:92 (concentrate) or 52:48 (mixed). Each diet was fed to eighteen animals of each genotype. Methane (CH 4 ) and H 2 emissions were measured individually in indirect respiration chambers. H 2 emissions (mmol/min) varied greatly throughout the day, being highest after feed consumption, and averaged about 0·10 mol H 2 /mol CH 4 . Higher H 2 emissions (mol/kg DM intake) were recorded in steers fed the mixed diet. Higher CH 4 emissions (mol/d and mol/kg DM intake) were recorded in steers fed the mixed diet (P, 0·001); the AAx steers produced more CH 4 on a daily basis (mol/d, P, 0·05) but not on a DM intake basis (mol/kg DM intake). Archaea (P¼ 0·002) and protozoa (P,0·001) were found to be more abundant and total bacteria (P,0·001) less abundant (P,0·001) on feeding the mixed diet. The relative abundance of Clostridium cluster IV was found to be greater (P,0·001) and that of cluster XIVa (P¼ 0·025) lower on feeding the mixed diet. The relative abundance of Bacteroides plus Prevotella was greater (P¼ 0·018) and that of Clostridium cluster IV lower (P¼ 0·031) in the LIMx steers. There were no significant relationships between H 2 emissions and microbial abundance. In conclusion, the rate of H 2 production immediately after feeding may lead to transient overloading of methanogenic archaea capacity to use H 2 , resulting in peaks in H 2 emissions from beef cattle.

Impact of adding nitrate or increasing the lipid content of two contrasting diets on blood methaemoglobin and performance of two breeds of finishing beef steers

“…Basal diet and treatment effects Feeding diets containing a high proportion of cereals has been shown to reduce enteric CH 4 production compared with forage-based diets (Johnson and Johnson, 1995;Moss et al, 1995;Mc Geough et al, 2010;Rooke et al, 2014). This strategy is attractive, in that accompanying improvements in animal performance and efficiency has been demonstrated (Lovett et al, 2003;Mc Geough et al, 2010).…”

Global beef cattle methane emissions: yield prediction by cluster and meta-analyses

“…MitiGate currently contains data from 412 sheep, beef and dairy cattle publications. The eight largest published beef MY datasets with all data needed for metaanalyses are from Herd et al (2014), Richmond et al (2015), Rooke et al (2014), McGinn et al (2009), Eugène et al (2011), Fitzsimons et al (2013), Boadi et al (2004) and Velazco et al (2014). Most of these datasets were missing from the MitiGate database at the time of our study, but were included in the metaanalysis presented in the current paper.…”

Methane emissions from two breeds of beef cows offered diets containing barley straw with either grass silage or brewers’ grains

“…The methodology for measuring emissions using respiration chambers has been previously described in Rooke et al (2014). Briefly, six indirect open-circuit respiration chambers were used (No Pollution Industrial Systems Ltd, Edinburgh, UK).…”

“…Rooke et al (2014) examined CH 4 emissions from crossbred Limousin and crossbred Aberdeen Angus, and found no difference between these breeds in CH 4 yield whether expressed per level of DMI or GEI. Troy et al (2015) compared two breeds of finishing beef steers (purebred Luing and crossbred Charolais) and reported no differences between breeds in CH 4 whether expressed as g/day, g/kg DMI or kJ/MJ GEI.…”