Hydrogen and methane emissions from beef cattle and their rumen microbial community vary with diet, time after feeding and genotype. Issue 3 (14th August 2014)

• Record Type: Journal Article
• Authors: Rooke, John A.; Wallace, R. John; Duthie, Carol-Anne; McKain, Nest; de Souza, Shirley Motta; Hyslop, Jimmy J.; Ross, David W.; Waterhouse, Tony; Roehe, Rainer
• Is Part Of: British journal of nutrition. Volume 112:Issue 3(2014)
• Page Start: 398
• Page End: 407
• Publication Date: 2014-08-14
• Subjects: Nutrition -- Periodicals; 572.4
• DOI: 10.1017/S0007114514000932
• Languages: English
• ISSNs: 0007-1145

Abstract

<abstract abstract-type="normal"> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>The aims of the present study were to quantify hydrogen (H<sub>2</sub>) and methane (CH<sub>4</sub>) 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<sub>4</sub>) and H<sub>2</sub> emissions were measured individually in indirect respiration chambers. H<sub>2</sub> emissions (mmol/min) varied greatly throughout the day, being highest after feed consumption, and averaged about 0·10 mol H<sub>2</sub>/mol CH<sub>4</sub>. Higher H<sub>2</sub> emissions (mol/kg DM intake) were recorded in steers fed the mixed diet. Higher CH<sub>4</sub> emissions (mol/d and mol/kg DM intake) were recorded in steers fed the mixed diet (<italic>P</italic>< 0·001); the AAx steers produced more CH<sub>4</sub> on a daily basis (mol/d, <italic>P</italic>< 0·05) but not on a DM intake basis (mol/kg DM intake). Archaea (<italic>P</italic>= 0·002) and protozoa (<italic>P</italic>< 0·001) were found to be more abundant and total bacteria (<italic>P</italic>< 0·001) less abundant (<italic>P</italic>< 0·001) on feeding the mixed diet. The relative abundance of <italic>Clostridium</italic> cluster IV was found to be greater (<italic>P</italic>< 0·001) and that of cluster XIVa (<italic>P</italic>= 0·025) lower on feeding the mixed diet. The relative abundance of <italic>Bacteroides</italic> plus <italic>Prevotella</italic> was greater (<italic>P</italic>= 0·018) and that of <italic>Clostridium</italic> cluster IV lower (<italic>P</italic>= 0·031) in the LIMx steers. There were no significant relationships between H<sub>2</sub> emissions and microbial abundance. In conclusion, the rate of H<sub>2</sub> production immediately after feeding may lead to transient overloading of methanogenic archaea capacity to use H<sub>2</sub>, resulting in peaks in H<sub>2</sub> emissions from beef cattle.</p> </abstract>