Alternatives for methane emission mitigation in livestock systems

Abstract

Human activities are contributing to Global Climate Change through the production of Green House Gases (GHG), which result in increased air, land and ocean temperatures and extreme changes in precipitation in regions of low and high rainfall. The most important GHG's are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). It is estimated that 18 % of the annual GHG emissions come from different types of livestock and that 37% of CH4, with higher global warming potential (23) relative to CO2 (1), comes from fermentation processes in ruminants. It is possible that in the future beef and milk exports from producing countries is subject to bans if cattle systems do not comply with measures to reduce GHG. There are several alternatives available and being researched to reduce enteric CH4 emissions from cattle that range from manipulating diet composition, supplementing feed additives (i.e. ionophores, organic acids, halogenated compounds, oils) and selection of forage plants of high quality and containing secondary metabolites (i.e. tannins and saponins) to animal breeding, immunization and genetic transformation of rumen microorganisms. Results show that inhibition of enteric CH4 emission is possible through the use of ionophores, organic acids and oils. The use of ionophores can result in resistance of rumen microbes and as a result the effect is short term. The high cost of organic acids makes it unlikely that there direct supplementation in ruminant diets is economically viable. However, organic acids are present at relatively high concentrations in the leaf tissue of plants and attempts should be made to select and breed forages with higher levels of these compounds. It is argued that a more efficient strategy to reduce enteric CH4 in ruminants is through selection of grasses of high quality (i.e. high concentration of water soluble carbohydrates), of forage legumes containing secondary metabolites like tannins and of fruits/plants containing saponins, provided that they do not affect intake and digestibility. Improved nutrition of cattle through feeding high quality forages can result in high animal performance and in reductions of CH4 emitted per unit of dry matter intake and per unit of product.

Climate Change Impact on Livestock: Adaptation and Mitigation

“…Wright et al ( 2004 ) developed two vaccines, VF3 (based on three methanogenic strains 1Y, AK-87 and ZA-10) and VF7 (based on seven methanogens), that produced a 7.7 % reduction in methane emissions from sheep, despite targeting only a minority (20 %) of methanogens present within these host animals. Researchers believe that anti-methanogenic vaccines will only yield the short-term reductions in methanogens and/or methanogenesis, due to the possible proteolytic degradation and low persistence of host antibodies in rumen (Cook et al 2008 ;Lascano and Cárdenas 2010 ). They also created a vaccine based on fi ve methanogens ( Methanobrevibacter spp.…”

Overview on Adaptation, Mitigation and Amelioration Strategies to Improve Livestock Production Under the Changing Climatic Scenario

“…Researchers believe that anti-methanogenic vaccines will only yield the short-term reductions in methanogens and/or methanogenesis, due to the possible proteolytic degradation and low persistence of host antibodies in rumen (Cook et al 2008 ;Lascano and Cárdenas 2010 ). Vaccination of sheep with entodinial or mixed protozoa antigens reduced protozoa, and the released IgG antibodies against rumen protozoa remained active and continued to bind the target cells up to 8 h (Williams et al 2008 ).…”

Review of substances/agents that have direct beneficial effect on the environment: mode of action and assessment of efficacy

“…Consequently, should it reach watercourses, it would not be expected to bind to sediments. It is potentially hazardous and may be toxic to ruminants and humans (Lascano and Cárdenas, 2010). Liver and kidney effects have been seen in animals after single exposures.…”