Rumen microbiota and dietary fat: a mutual shaping

Abstract

Summary Although fat content in usual ruminant diets is very low, fat supplements can be given to farm ruminants to modulate rumen activity or the fatty acid (FA) profile of meat and milk. Unsaturated FAs, which are dominant in common fat sources for ruminants, have negative effects on microbial growth, especially protozoa and fibrolytic bacteria. In turn, the rumen microbiota detoxifies unsaturated FAs (UFAs) through a biohydrogenation (BH) process, transforming dietary UFAs with cis geometrical double‐bonds into mainly trans UFAs and, finally, into saturated FAs. Culture studies have provided a large amount of data regarding bacterial species and strains that are affected by UFAs or involved in lipolysis or BH, with a major focus on the Butyrivibrio genus. More recent data using molecular approaches to rumen microbiota extend and challenge these data, but further research will be necessary to improve our understanding of fat and rumen microbiota interactions.

Effect of partially replacing a barley-based concentrate with flaxseed-based products on the rumen bacterial population of lactating Holstein dairy cows

“…; Enjalbert et al . ). In the present experiment, the 4% increment in dietary unsaturated fatty acids was not accompanied by a decrease in the abundance of these genera.…”

“…; Enjalbert et al . ) or production performance has been acknowledged, the impact of such strategies on the broad ruminal bacterial communities of dairy cows in vivo is yet to be clearly elucidated.…”

“…However, dietary fat (Enjalbert et al . ) or tannins (Vasta et al . ) may have detrimental effects on bacterial taxa within the rumen or may negatively affect animal production performance (Vasta et al .…”

“…Furthermore, the inclusion of dietary tannins in ruminant rations may be an effective approach for mitigating the biohydrogenation of polyunsaturated fatty acids (Vasta et al 2009). However, dietary fat (Enjalbert et al 2017) or tannins (Vasta et al 2010) may have detrimental effects on bacterial taxa within the rumen or may negatively affect animal production performance (Vasta et al 2010). Nonetheless, most studies evaluating these dietary strategies for mitigating fatty acid biohydrogenation have not determined effects on the broad bacterial community structure of the rumen of lactating Holstein cows.…”

Role of diverse fermentative factors towards microbial community shift in ruminants

“…Fat supplements, which contain unsaturated fatty acid, given to ruminants to modulate rumen activity could have negative effects on the growth of microbes such as protozoa and fibrolytic bacteria (Enjalbert et al . ). In the study of Abubakr et al .…”