Climate Change and Goat Production: Enteric Methane Emission and Its Mitigation

SIMPLE SUMMARY: Given that goats are considered more climate resilient than other ruminant species, research efforts are therefore needed to understand goat productivity during exposure to high ambient temperatures. Heat stress can affect the digestion and rumen fermentation pattern of goats, which contributes to the reduction in production performance in goats. Diet composition, breed and environmental stresses are common factors which negatively influence rumen function and enteric methane (CH(4)) emission. There are three mechanisms by which enteric CH(4) can be reduced: targeting end product of digestion to propionate, providing alternate hydrogen sink and selectively inactivating rumen methanogens. The various strategies that can be implemented to mitigate enteric CH(4) include nutritional interventions, management strategies and application of advanced biotechnological tools. ABSTRACT: The ability of an animal to cope and adapt itself to the changing climate virtually depends on the function of rumen and rumen inhabitants such as bacteria, protozoa, fungi, virus and archaea. Elevated ambient temperature during the summer months can have a significant influence on the basic physiology of the rumen, thereby affecting the nutritional status of the animals. Rumen volatile fatty acid (VFA) production decreases under conditions of extreme heat. Growing recent evidence suggests there are genetic variations among breeds of goats in the impact of heat stress on rumen fermentation pattern and VFA production. Most of the effects of heat stress on rumen fermentation and enteric methane (CH(4)) emission are attributed to differences in the rumen microbial population. Heat stress-induced rumen function impairment is mainly associated with an increase in Streptococcus genus bacteria and with a decrease in the bacteria of Fibrobactor genus. Apart from its major role in global warming and greenhouse effect, enteric CH(4) is also considered as a dietary energy loss in goats. These effects warrant mitigating against CH(4) production to ensure optimum economic return from goat farming as well as to reduce the impact on global warming as CH(4) is one of the more potent greenhouse gases (GHG). The various strategies that can be implemented to mitigate enteric CH(4) emission include nutritional interventions, different management strategies and applying advanced biotechnological tools to find solution to reduce CH(4) production. Through these advanced technologies, it is possible to identify genetically superior animals with less CH(4) production per unit feed intake. These efforts can help the farming community to sustain goat production in the changing climate scenario.