Ratchaneewan Khiaosa-Ard and Qendrim Zebeli*
Institute of Animal Nutrition, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
* Author of correspondence; Email: firstname.lastname@example.org
Owing to microbial hydrolysis of nutrients in the rumen, ruminants are relatively efficient animals for livestock production considering that they can utilize low-quality feeds including industrial by-products. On the other hand, however, they also contribute to global warming because of their methane emission from the enteric fermentation. The methane emission not only affects the environment but also represents the loss of consumed energy. Thus, mitigating enteric methane emission may improve animal production efficiency as well as contribute to alleviate the impact of ruminants on climate change. This review focuses on various achievements of the last years which have expanded our knowledge regarding mitigation of enteric methanogenesis and its potential contribution in improving cattle production efficiency. The article also discusses the role of nutrition and rumen metabolism on gut and host’s health status as well as on enhancement of product quality of cattle products. The improvement of quality of ruminant products relies mainly on improving their fatty acids composition toward health-promoting polyunsaturated fatty acid profile such as omega-3 fatty acids and conjugated linolenic acids. Plant secondary compounds appear to possess multi-beneficial effects that when fed to ruminants can beneficially modify rumen metabolism, contributing to methane mitigation, gut health, food safety and quality. However, identification of active compounds for use as feed additives in ruminant production and understanding their mode of specific actions remain a big challenge for research.
Key words: rumen metabolism, enteric methane, feed efficiency, milk quality.