Understanding and reducing methane emissions in ruminants UNFCCC

Understanding and reducing methane emissions in ruminants UNFCCC, Bonn 2007 Dr. Tommy Boland University College Dublin, Belfield, Dublin 4, Ireland

Irish situation n Ireland is obliged to limit GHG emissions to 13% above 1990 levels between 2008 and 2012 n Enteric fermentation from ruminants accounted for 13. 49% of GHG emissions in 2004 (EPA, 2006), accounting for over 53% of Irish agricultural emissions n In the governments strategy to reach our GHG target, the equivalent to a 10% reduction in our national herd would meet the required reduction in CH 4 from livestock n Grassland based ruminant production systems

Options n n Reduce animal numbers Increase animal productivity n n Concentrate composition Basal forage n n Increase concentrate proportion of the diet Increase energy efficiency of the animal Grass vs legume Proportion of grass in the diet Forage quality Methane inhibition

Dietary oils n n Methane emissions reduced by 23% per kg DMI by feeding 350 g/d (4. 8% DMI) coconut oil (Lovett et al. , 2003) Methane emissions reduced by 20% per kg DMI by feeding 250 g/d (2. 8% DMI) coconut oil (Jordan et al. , 2006 a) Methane emissions reduced by 37% per kg DMI by feeding 6% DMI of soya oil (Jordan et al. , 2006 b) Cost and sustainability an issue

Livestock number (‘ 000) change in Ireland 1990 2005 % change 90 -05 Total cattle 6100. 5 6330. 2 6191. 7 +1. 5% Total sheep 5863. 7 5056 4257 -13. 8%

Increased productivity/animal – dairy cows

Effect of age at slaughter on lifetime methane production 16. 5 % reduction in lifetime emissions and 12% reduction in emissions per kg carcass by going from a 30 to 25 month slaughter

Energetic efficiency n Selection for energetically efficient ruminants may lead to inherent improvements in ruminal fermentation processes and consequent reductions in methane (Herd, 2002) n Methane production negatively correlated with animal efficiency n Increased animal energetic efficiency decreases slaughter age and hence lifetime emissions

Energetic efficiency Feed efficiency – considerable genetic variation n Access to national pedigree test centre n Individual intake data n NFE (net feed efficiency) n RFI (residual feed intake) n Methane emissions measured at 6 -9 months and on forage based and grass based diets n Repeatability measured across a number of diet types n

Basal forage n Legumes vs grass n Fresh vs ensiled n Stage of maturity at grazing n Malic acid inclusion at 7. 5% of DMI to a 9% reduction (P < 0. 05) in CH 4 emissions per kg DMI led

Methane inhibition n Halogenated methane analogues n Statins n Individual fatty acids n Probiotics Rumen fermentation, methane production and microbial community structure analysis

Understanding methane formation in the rumen n Optimisation of mitigation practices and new strategies can be proposed for testing n In vitro gas production n Artificial rumen n In vivo studies n Change in microbial community structure

Future scenario n Short term n n Based on low methane feeding and management systems Long term Development/identification of rumen fermentation modifiers n Breeding of forages for reduced methane emissions n Breeding of animals for reduced methane emissions n