Table 5.

mcrA cDNA relative abundance proportions in the rumen of bulls receiving a control (CTL) or linseed plus nitrate (LINNIT) supplemented diet; only the six most abundant OTUs (clustering at 97% of similarity) are presented, regrouping 99% of sequences.

OTU n°	Affiliation (bootstrap values)	CTL	LINNIT	SEM	Effect treatment
1	Methanobrevibacter (100)	0.58	0.65	0.065	0.41
2	Unclassified Euryarchaeota (100)	0.18	0.13	0.025	0.16
5	Unclassified Euryarchaeota (100)	0.13	0.09	0.04	0.42
6	uncultured_rumen_archaeon (100)	0.07	0.11	0.03	0.31
4	unclassified Methanomassiliicoccaceae (53)	0.03	0.01	–	<0.001
3	unclassified Methanomicrobiales (95)	0.01	0.01	–	0.24

Values are means of eight individual measures; data were analyzed using one-way ANOVA in R. Bootstrap values were computed in mothur following 1,000 iterations.