Effect of supplementation of inulin in dietary on lactation performance, rumen fermentation, ruminal microbial profile and metabolites in dairy cows

Abstract

Background Inulin is a kind of fructo-oligosaccharide (FOS) derived mainly from Jerusalem artichoke and chicory tubers, which is also a soluble dietary fiber. Inulin has become a scientifically proven prebiotic product with satisfactory effects in improving the structure of intestinal flora, regulating blood lipid and glycemia, etc., in humans and monogastric. However, unlike monogastric animals, ruminal microbes are the largest microbiota in ruminants. The microflora profile and metabolism activity in the rumen are closely related to the health of dairy cows. This study investigated the effects of inulin on rumen fermentation parameters, ruminal microbiome and metabolites, as well as lactation performance and serum indexes in dairy cows. A total of 16 Holstein dairy cows with similar body condition were randomly divided into two groups (n = 8 per group), with inulin addition at 0 and 200 g/d per cow, respectively. Experiment was lasted for 6 weeks including 1 week of adaptation period and 5 weeks of treatment period. At the end of the experimental period, the milk, serum and rumen fluid were sampled and analyzed. The rumen microbiota and metabolites were analyzed via 16S rRNA sequencing and untargeted metabolomics, respectively. Results The supplementation of inulin (200 g/d per cow) increased the milk yield (P = 0.001), milk protein (P = 0.032), lactose rate (P = 0.004) and the proportion of saturated fatty acids (SFA) in milk (P < 0.001), while decreased the proportion of unsaturated fatty acids (USFA) (P = 0.041). Rumen pH (P = 0.040) and concentration of NH3-N (P = 0.024) were decreased, however, acetate (P < 0.001), propionate (P = 0.003), butyrate (P < 0.001) and lactic acid (LA) (P = 0.043) were increased. The total cholesterol (TC) (P = 0.008) and triglycerides (TG) (P = 0.01) in serum were also reduced. Additionally, the inulin addition elevated the relative abundance of several beneficial symbiotic and short-chain fatty acids (SCFA)-producing bacteria, such as Muribaculaceae (FDR-adjusted P < 0.01), Acetitomaculum (FDR-adjusted P = 0.043), and Butyrivibrio (FDR-adjusted P = 0.036) etc., meanwhile elevated the levels of L-Lysine (FDR-adjusted P = 4.24 × 10− 3), L-Proline (FDR-adjusted P = 0.0158), L-Phenylalanine (FDR-adjusted P = 0.027), etc. By contrast, several pathogens and ruminal bacteria abundant in high-fat diets, such as Escherichia-Shigella (FDR-adjusted P = 0.022), Erysipelotrichaceae__UCG-004 (FDR-adjusted P < 0.01) and RF39 (FDR-adjusted P = 0.042) etc., were decreased along with the reduction of LysoPC (18:1(9Z)) (FDR-adjusted P = 1.03 × 10− 3), LysoPC (16:0) (FDR-adjusted P = 0.0108), LysoPC (18:2(9Z, 12Z)) (FDR-adjusted P = 1.65 × 10− 3) and 8-Methylnonenoate etc. Conclusion The results indicated the supplementation of inulin in dietary can increase the relative abundance of commensal microbiota and SCFAs-producing bacteria, meanwhile, upregulate amino acids (AAs) metabolism and downregulate lipid metabolism in rumen of dairy cows, which might further improve lactation performance and the level of serum lipids.

Effects of Purple Corn Anthocyanin on Blood Biochemical Indexes, Ruminal Fluid Fermentation, and Rumen Microbiota in Goats

“…Chikwanha et al ( 40 ), who showed that polyphenol-rich grape pomace could improve rumen microbial diversity, evenness, and richness in lambs in in vitro fermentation experiments. Wang et al ( 41 ) demonstrated that supplementation of phenolic-rich inulin in the diet could increase the relative abundance of commensal microbiota in dairy cows. It was likely that the microorganisms could improve anthocyanin bioavailability in the gastrointestinal tract, enhancing the gut antioxidant capacity ( 42 ).…”

Effects of supplementary inulin on ewes milk composition and rumen fermentation parameters

“…Adding inulin also increased propionate numerically. Wang et al (2020) showed that adding inulin to the feed of dairy cows increased net energy for lactation (NEl) leading to an increase in milk production. This is achieved by increasing the molar proportion of acetate, the ratio of acetate to propionate and by increasing the molar proportion of propionate in the rumen fluid of Holstein cows.…”

“…Previous reports have reported an improvement in rumen fermentation and increased microbial protein synthesis (Wang et al, 2020(Wang et al, , 2021a and milk protein content upon inulin consumption (Xue et al, 2019). Erasmus et al (1992) reported that feed additives such as probiotics not only increase methionine flow, but also increase the flow of other amino acids into the intestine.…”

“…pH values below 5.9 and 6.0 are reported as harmful for this group of bacteria (Russell and Wilson, 1996;Moharrery et al, 2014). Tian et al (2019) and Wang et al (2020) reported a significant decrease in rumen pH of dairy cows upon intake of 2% inulin supplemented feed and a significant increase in rumen pH due to feeding 200 g inulin per day per dairy cows. An important result of the present study, however, is the numerical increase in rumen pH with a simultaneous increase in rumen VFA production, which can be very positive.…”

“…The use of inulin in ruminant nutrition has been suggested for several years, but it remains a lesser known and even less used component in the animal feed industry (Birmani et al ., 2019). According to a recent study, inulin supplementation of 100, 200, 300 and 400 g per day for each dairy cow has reportedly altered the rumen fermentation process, increased production of rumen propionate, lactic acid and butyrate, improved production traits such as milk production, protein and lactose and reduced somatic milk cells (Wang et al ., 2020). These authors reported that using 300 g of inulin per day could increase the population of beneficial ruminal microorganisms (eg Prevotella , Butyrivibrio , Muribaculaceae , and Bifidobacterium spp.)…”