The Importance of Flavonoids in Ruminant Nutrition

Recent scientific reports indicated that flavonoid could affect the rumen volatile fatty acids production along with a reduction in rumen methane concentration which resulted in improvement of performance and production. Flavonoids as polyphenolic compounds are powerful antimicrobials and antioxidants with anti-inflammatory and immune system benefits. Flavonoids can also promote the growth and development of animals as well as improve the quality of animal products. Therefore, these compounds are widely used as feed additives in animal production instead of antibiotics. Base on the research findings, addition of the flavonoids to ruminate diets could suppress methane production without influencing rumen microbial fermentation, fatty acid production and performance of beef or dairy cattle. Flavonoids are capable of the improvement of volatile fatty acids production together with a reduction in both rumen ammonia concentration and methane production which are considered as desirable changes in rumen environment. Also, the positive effect of flavonoids on rumen microbial fermentation and nutritional stress such as bloat or acidosis have been well demonstrated. Many factors such as chemical structure, absorption, its distribution and elimination determine the bioavailability of flavonoids. Isoflavones and flavanols seems to have lower bioavailability, whereas higher bioavailability of proanthocyanidins in ruminants were reported. Incorporation of flavonoids into dairy/beef products may provide a novel way to increase quantity and quality of future products of dairy farming.