Rumen Methane Emission, Relation to Global Warming and Strategies to Ameliorate

Abstract

Abstract

Ruminant animals are on a continuous symbiotic association with surroundings. They acquire their own protozoa and bacteria directly from the surrounding post-partum to establish rumen function; in addition they need food, water and air thereafter. On contrast animals need to exhaust gas and expel urine and faeces to surroundings   Ruminant are also in symbiotic relation with microbes, they provide microbes with food, and water for them to grow, reproduce and perform rumen fermentation. On the other-hand ruminant animal will get benefits from the best quality protein (microbial protein), manufactured by microbes to get their requirements from energy and protein for their growth, production and reproduction. As a result of continuous microbial fermentation, the accumulation of methane and other gas will remain. As due to methane high greed ability to absorb environmental heat which amounted to 84 x than ability of CO₂. One ton of methane can emit heat by about 28x compared to same weight of CO₂. As due to this, it was expected that air temperature will reach 1.8 - 4 C° by year 2050. The consequence of that the whole of the globe will get more warm. The estimated total GHG emitted from livestock activities globally was about 6490 Tg CO₂.eq, of which 26% from microbial rumen fermentation. The total contribution of different ruminant in methane emission globally (million ton CO₂ eq.) was 2495 for beef, 2128 for dairy cows and 747 for sheep. Based on unit of animal product the emission was   (kgCO₂ eq): 30/kg beef, 25 / kg sheep meat and 3 / kg milk. The amount of methane emitted will depend on type of animal, its size, productivity, health, type of management (confined, or on range), type of food and quality, resistance to disease and parasites, adaptation to surroundings...etc. Amelioration of methane emission from ruminant activities becomes a priority for all countries due to negative effect on global warming. Some strategies have been applied to mitigate such effects: 1. manipulation and improvement of the existent situation on level of animals (reduce numbers, increase productivity, rumen manipulation, feed additives and new micro-organisms. 2. manipulation of feed and nutrients by adding lipids, essential oils, enzymes, ionophores, Tannins, Saponines, Algae, Fungi, concentrates, low fibers, non-conventional feeds. 3. Use recent advances in genetic and biotechnology to select for better genes allow for low methane emission, high heat tolerant animals, high disease and parasite resistant animals. It is still more practical and easier strategically under our local conditions to look closely to the animal and feed and try to end up with high efficient animal that can depend on whatever feed available and able to be converted to edible food.