• 28. The effect of phenotypically ranking beef cattle for residual methane output on daily methane emissions, intensity and animal productivity

      Smith, Paul E.; Waters, Sinéad M.; Kenny, David A.; Kirwan, Stuart F.; Conroy, Stephen; Kelly, Alan K.; European Union; 16/RD/ERAGAS/1RUMENPREDICT-ROI2017; 818368 (Elsevier BV, 2021-04)
      Beef cattle ranked as having low residual methane output had lower emissions intensity and similar overall productive performance as their high emissions ranking contemporaries. The concept of residual methane output is proposed as an appropriate trait to more equitably identify animals on the basis of low emissions beef production
    • Sward type alters the relative abundance of members of the rumen microbial ecosystem in dairy cows

      Smith, Paul E.; Enriquez-Hidalgo, Daniel; Hennessy, Deirdre; McCabe, Matthew S.; Kenny, David A.; Kelly, Alan K.; Waters, Sinéad M.; FACCE ERA GAS; Irish Dairy Levy Trust; European Union; et al. (Springer Science and Business Media LLC, 2020-06-09)
      The performance of ruminant livestock has been shown to beneft from the enhanced nutritive value and herbage yield associated with clover incorporation in the grazing sward. However, little research to date has been conducted investigating the efects of mixed swards containing white clover on the composition of the rumen microbiome. In this study, the rumen microbial composition of late lactation dairy cows grazing perennial ryegrass only (PRG; n=20) or perennial ryegrass and white clover (WCPRG; n=19) swards, was characterised using 16S rRNA amplicon sequencing. PERMANOVA analysis indicated diet signifcantly altered the composition of the rumen microbiome (P=0.024). Subtle shifts in the relative abundance of 14 bacterial genera were apparent between diets, including an increased relative abundance of Lachnospira (0.04 vs. 0.23%) and Pseudobutyrivibrio (1.38 vs. 0.81%) in the WCPRG and PRG groups, respectively. The composition of the archaeal community was altered between dietary groups, with a minor increase in the relative abundance of Methanosphaera in the WCPRG observed. Results from this study highlight the potential for sward type to infuence the composition of the rumen microbial community.