Effect of Whole or Ground Flaxseed Supplementation on Fatty Acid Profile, Fermentation, and Bacterial Composition in Rumen of Dairy Cows

Supplementing flaxseed meal with sucrose, flaxseed oil, or both: Effect on milk enterolactone, ruminal microbiota profile, production performance, and nutrient utilization in dairy cows

Flaxseed is the richest source of secoisolariciresinol diglucoside, which is converted by ruminal microorganisms primarily to the mammalian lignan enterolactone. Our objective was to investigate the effect of diets containing soybean meal or flaxseed meal (FM) supplemented with sucrose, flaxseed oil, or both on milk enterolactone concentration and yield, diversity and relative abundance of ruminal bacterial taxa, ruminal fermentation profile, production performance, milk fatty acid (FA) yield, and nutrient utilization in dairy cows. Sixteen Holstein cows [8 multiparous (4 ruminally-cannulated) and 8 primiparous] averaging (mean ± SD) 134 ± 54.1 DIM and 679 ± 78.9 kg of BW in the beginning of the study were assigned to treatment sequences in a replicated 4 × 4 Latin square design. Each experimental period lasted 25 d with 18 d for diet adaptation and 7 d for data and sample collection. Diets were formulated to contain a 60:40 forage:concentrate ratio and included (DM basis): 1) 8% soybean meal and 23% ground corn (SBM), 2) 15% FM, 10.7% ground corn, and 5% sucrose (FLX+S), 3) 15% FM, 15.4% ground corn, and 3% flaxseed oil (FLX+O), and 4) 15% FM, 10.2% ground corn, 5% sucrose, and 3% flaxseed oil (FLX+SO). Compared with SBM, the concentration and yield of milk enterolactone increased in cows fed the FM diets, but did not differ among FLX+S, FLX+O, and FLX+SO. The relative abundances of the phyla Firmicutes, Verrucomicrobiota, and Actinobacteriota and those of the bacterial genera Lachnospiraceae NK3A20 group, Eubacterium coprostanoligenes group, Anaeromusa-Anaeroarcus, WCHB1-41, and p-251-o5 decreased, whereas Prevotella and NK4A214 group increased when comparing SBM against at least 1 diet containing FM. Furthermore, the relative abundances of Firmicutes and Actinobacteriota and those of Prevotella, Lachnospiraceae NK3A20 group, Eubacterium coprostanoligenes group, Acetitomaculum, Lachnospiraceae unclassified, NK4A214 group, and Anaeromusa-Anaeroarcus changed (increased or decreased) across the FLX+S, FLX+O, and FLX+SO diets. However, all these changes in the relative abundance of the ruminal bacterial taxa were not conclusively associated with the effect of diets on milk enterolactone. Diets did not affect ruminal pH and concentrations of NH3-N and total VFA. Dry matter intake and yields of milk, milk fat, and milk true protein all decreased in cows fed FLX+O or FLX+SO. Yields of milk total odd-chain FA, branched-chain FA, total < 16C FA, and total 16C FA all decreased with feeding FLX+O and FLX+SO. The apparent total-tract digestibilities of DM and OM were lowest in the FLX+S and FLX+O diets, with CP and ADF digestibilities lowest in cows receiving FLX+S or FLX+O, respectively. Urinary excretion of total N was lowest with feeding SBM. Contrarily, diets did not affect the urinary excretion of total purine derivatives. In brief, despite the effect of diets on the relative abundance of several ruminal microbiota phyla and genera, we were unable to conclusively associate these changes with increased milk enterolactone in FM-containing diets versus SBM.

Enhancing Rumen Fermentation and Bacteria Community in Sika Deer (Cervus nippon) through Varying Levels of Dragon Fruit Peel Polyphenolic Extract: An In Vitro Study

The aim of this study is to investigate the effect of dragon fruit peel polyphenolic extract (DFPE) on gas production, rumen fermentation, and bacterial communities in sika deer using an in vitro technique. Three treatments with different DFPE levels (DFPE0, base diet; DFPE5, base diet + 5 mg/g DFPE; DFPE10, base diet + 10 mg/g DFPE, respectively; n = 6) were implemented. The phenolic composition of DFPE, gas production (GP), ammonia nitrogen (NH3-N), volatile fatty acid (VFA), and bacteria communities was evaluated after 24 h of incubation. The results showed that GP and NH3-N were reduced by DFPE supplementation. Total VFA, isovaleric acid, and valeric acid were increased (p < 0.05) by the addition of DFPE. No changes (p > 0.05) were observed in pH, acetic acid, propionic acid, isobutyric acid, butyric acid, and the ratio of acetic acid to propionic acid. Additionally, the alpha indexes, including Sobs, Shannon, and Ace, were increased by DFPE supplementation. Moreover, at the phylum level, DFPE supplementation increased (p = 0.01) Bacteroidota but reduced (p < 0.01) Firmicutes. At the genus level, compared to DFPE0, the DFPE10 had increased relative abundances of Rikenellaceae_RC9_gut_group (p < 0.01), norank_f_Muribaculaceae (p = 0.01), Lachnospiraceae_NK3A20_group (p < 0.01), Christensenellaceae_R-7_group (p < 0.01), and NK4A214_group (p < 0.01), decreased relative abundances of Streptococcus (p < 0.01), Oribacterium (p = 0.01), and Enterococcus (p < 0.01). Compared to DFPE0, DFPE5 had no change (p > 0.05) in all bacteria at the genus level except for decreased relative abundance of Enterococcus (p < 0.01). These results indicated that DFPE may be able to be used as a feed additive to enhance fermentation parameters and improve ruminal bacteria communities in Sika deer.

Effect of Garlic Straw with Silage Corn Stalks on Hu Sheep Rumen Fermentation and Microbial Community In Vitro

Garlic, an important economic crop, provides nutrient-rich straw. When appropriately balanced with silage corn stalks, it is a high-quality forage resource. However, studies on the impact of garlic straw with silage corn stalks on Hu sheep's digestive metabolism and rumen microbiota are scarce. In this study, different addition ratios of garlic straw and silage corn stalks were utilized for in vitro experiments. We designed six experimental groups (CON, G0, G20, G40, G60, G80, and G100) based on varying ratios of garlic straw to silage corn stalks. Rumen microbiota was analyzed through 16S rRNA sequencing. Nutrient composition analysis indicated that garlic straw's relative feeding value (RFV) closely resembled that of silage corn stalks. After 24 h of fermentation, dry matter digestibility and in vitro gas production significantly increased, reaching peak values at a 60% addition ratio. Furthermore, volatile fatty acids (VFAs) such as acetic, propionic, and butyric acid exhibited elevated contents, with the highest yields observed at 60% inclusion. At the genus level, Prevotella, Rikenellaceae RC9 gut group, and Succiniclasticum were identified as the dominant bacterial groups. The gas production test showed a significant decrease in the G80 group compared to others. Microbial analysis revealed a higher abundance of Prevotella in G80 compared to G20, offering valuable insights for reducing greenhouse gas emissions from ruminant animals. Finally, this study predicted the impact of garlic straw with silage corn stalks' addition on Hu sheep's metabolic pathways and biological functions of the rumen microbiota. This research highlights the potential for effectively utilizing garlic straw as a feed resource for Hu sheep and proposes a rational proportion for combining garlic straw with silage corn stalks.

Milk production and milk fatty acid profile as a response to feeding dairy cows with flax products during the persistence period

The response of enhanced dietary dairy cows with linolenic-rich sources during the persistence period was studied to determine its effectiveness on some blood constituents, milk yield and milk fatty acid profile. A complete randomized design experiment was conducted in the spring and involved 20 Friesian cows (60 days in milk) that were divided into four groups of five animals by milk production according to different types of flax source in isonitrogenous and isoenergetic rations: a traditional diet with no flax source (CO), a diet contains flaxseed meal (FLM), a diet contains whole flaxseed (FLS) and a diet contains flax oil (FLO). DM intake and DMI% of weight were increased for cows fed FLM. However, Omega-3 intake was reduced for cows fed on CO ration. Although, blood serum metabolites did not differ among treatments (p < 0.05) except serum cholesterol which was increased with FLO cows, and serum total lipid which was reduced with FLM cows. Cows fed on flax product and control peaked in milk production at the same time (8-week post-partum), and cows fed on FLM continued in peak production for a longer period. Using flax products enhanced milk production, cows fed FLM had higher milk yield than those fed CO (20.76 vs.16.32 kg/d), and there was no difference between cows fed FLO (17.87 kg/d) and those fed FLS (18.01 kg/d). Also, energy-corrected milk yield and 3.5 fat-corrected milk yield were increased with cows fed on FLM as compared with cows fed CO ration. Flax products had no significant effect on milk fat and protein %, whereas cows fed FLM had the greatest fat% value (3.35%) and FLS had the greatest protein% value (2.66%). Moreover, fat and protein yield increased significantly in treatment groups compared to the CO group, whereas they were the greatest in FLM g (0.700 and 0.540 kg/d), respectively. Concentrations of omega-3-fatty acids in milk fat were increased by using FLO in the ration; using flaxseed meal enhanced conjugated linoleic acids in milk fat and resulted in the highest omega-6-to-omega-3-fatty-acids ratio. The data suggest that flax seed meals can be used as a fat source in the diet of dairy cows during the persistence period with a good response to milk production and its health properties. Moreover, flax oil should be protected before use in rations to prevent its components from saturation or being changed in the rumen.

Effects of different forage proportions in fermented total mixed ration on muscle fatty acid profile and rumen microbiota in lambs

Objective

The objectives of this study were to evaluate the effects of different forage proportions in the fermented total mixed ration (FTMR) on growth performance, muscle fatty acid profile, and rumen microbiota of lambs.

Methods

Thirty 6-month-old small tail Han sheep × Ujumqin lambs with initial body weight (BW) of 27.8 ± 0.90 kg were selected for the test and divided into two groups of 15 sheep in each treatment (three pens per treatment and five lambs per pen) according to the principle of homogeneity. Two isoenergetic and isonitrogenous diets were formulated according to the NRC. The diet treatments were designed as (1) OH treatment containing 25% alfalfa hay and 35% oat hay, and (2) AH treatment containing 35% alfalfa hay with 25% oat hay. The forage-to-concentrate ratio for both diets was 65: 35 (DM basis). Three replicates were randomly selected from each treatment to determine growth performance, fatty acid profile and rumen bacterial communities in lambs.

Results

Results revealed no statistically significant (p > 0.05) differences in dry matter intake and average daily gain between the two diet groups. Cholesterol and intramuscular fat were significantly (p > 0.05) higher in the AH group, while no statistically significant difference (p > 0.05) was found in pH24 value. The muscle fatty acid compositions of lambs were obviously (p < 0.05) influenced by the diet treatments. Compared with the OH group, the C16:1, C17:0, and C20:3n6 contents were higher (p < 0.05) in the AH group, whereas the content of C18:1n9c, C20:1, C18:3n3, and C22:6n3 was obviously (p < 0.05) increased in the OH group. The monounsaturated fatty acid (MUFA) contents were significantly higher in the OH group, whereas no significant differences (p > 0.05) were detected in saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) contents among the two diet treatments. Bacterial composition was generally separated into two clusters based on principal coordinate analysis, and the OH group had a higher Shannon index. The relative abundance at the genes level of the Rikenellaceae_RC9_gut_group was obviously (p < 0.05) increased in the AH group and the relative abundances of Prevotella_1, Fibrobacter, and Bacteroidales_UCG_001_unclassified were obviously (p < 0.05) enriched in the OH group. Integrated correlation analysis also underscored a possible link between the muscle fatty acid compositions and significantly altered rumen microbiota.

Conclusion

Overall, oat-based roughage in FTMR could promote a beneficial lipid pattern in the Longissimus lumborum muscles of lambs. These findings provide a potential insight into diet effects on fatty acid profile and the rumen microbiome of lambs, which may help make decisions regarding feeding.

Feeding incremental amounts of ground flaxseed: effects on diversity and relative abundance of ruminal microbiota and enteric methane emissions in lactating dairy cows

We evaluated the effects of incremental amounts of ground flaxseed (GFX) on diversity and relative abundance of ruminal microbiota taxa, enteric methane (CH₄) emissions, and urinary excretion of purine derivatives (PD) in lactating dairy cows in a replicated 4 × 4 Latin square design. Twenty mid-lactation Jersey cows were used in the study. Of these 20 cows, 12 were used for ruminal sampling, 16 for enteric CH₄ measurements, and all for spot urine collection. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Diets were formulated by replacing corn meal and soybean meal with 0%, 5%, 10%, and 15% of GFX in the diet's dry matter. Ruminal fluid samples obtained via stomach tubing were used for DNA extraction. Enteric CH₄ production was measured using the sulfur hexafluoride tracer technique. Diets had no effect on ruminal microbiota diversity. Similarly, the relative abundance of ruminal archaea genera was not affected by diets. In contrast, GFX decreased or increased linearly the relative abundance of Firmicutes (P < 0.01) and Bacteroidetes (P < 0.01), respectively. The relative abundance of the ruminal bacteria Ruminococcus (P < 0.01) and Clostridium (P < 0.01) decreased linearly, and that of Prevotella (P < 0.01) and Pseudobutyrivibrio (P < 0.01) increased linearly with feeding GFX. A tendency for a linear reduction (P = 0.055) in enteric CH₄ production (from 304 to 256 g/d) was observed in cows fed increasing amounts of GFX. However, neither CH₄ yield nor CH₄ intensity was affected by treatments. Diets had no effect on the urinary excretion of uric acid, allantoin, and total PD. Overall, feeding GFX decreased linearly the relative abundance of the ruminal bacterial genera Ruminococcus and Clostridium and enteric CH₄ production, but no change was seen for CH₄ yield and CH₄ intensity, or urinary excretion of total PD, suggesting no detrimental effect of GFX on microbial protein synthesis in the rumen.

Effects of Dietary Capsaicin and Yucca schidigera Extracts as Feed Additives on Rumen Fermentation and Microflora of Beef Cattle Fed with a Moderate-Energy Diet

Capsaicin (CAP) and Yucca schidigera extract (YSE) are two types of plant extracts that can change rumen fermentation. This study was conducted to investigate whether supplementation of beef cattle diets with CAP and YSE for 90 days would affect rumen fermentation and microflora. Forty-five healthy Angus steers (initial body weight = 510.54 ± 41.27 kg) were divided into three groups: control (CON), CAP, and YSE. Ammonia nitrogen (NH3-N) and total volatile fatty acid (TVFA) concentrations were significantly higher in the YSE group than in the CON group and significantly lower in the CAP group than in the CON group. At the phylum level, YSE increased the relative abundances of Bacteroidota and Patescibacteria and reduced that of Bacillota. At the genus level, CAP and YSE both increased the relative abundances of genera subordinate to Bacteroidota and decreased the relative abundances of genera subordinate to Bacillota. Our study shows that YSE and CAP have different effects on rumen fermentation and microflora after long-term supplementation.

Effect of Flaxseed Supplementation on Milk and Plasma Fatty Acid Composition and Plasma Parameters of Holstein Dairy Cows

The objective of this study was to determine the effect of whole flaxseed and ground flaxseed supplementation on the composition of fatty acids in plasma and milk, particularly the content of omega-3 polyunsaturated fatty acids (n-3 PUFAs). Thirty Holstein dairy cows were randomly assigned to three treatment groups. Cows were fed a total mixed ration without flaxseed (CK), 1500 g of whole flaxseed (WF), and 1500 g of ground flaxseed (GF) supplementation. There were no differences observed in dry matter intake, milk yield, energy-corrected milk, and 4% fat-corrected milk (p > 0.05). Compared with the CK group, the contents of α-linolenic acid (ALA), eicosatrienoic acid, and eicosapentaenoic acid increased in the plasma and milk WF and GF groups, and the content of docosahexaenoic acid and total n-3 PUFA was higher in GF than the other groups (p < 0.001). The ALA yield increased to 232% and 360% in WF and GF, respectively, compared to the CK group. Compared with the WF group, GF supplementation resulted in an increased milk ALA/ALA intake ratio (p < 0.001). Flaxseed supplementation increased the activity of GSH-Px and decreased the concentration of MDA in milk (p < 0.001). Plasma parameters did not differ among the treatments (p > 0.05). This result indicated that compared with the WF group, GF supplementation in the diet showed higher efficiency in increasing the total n-3 PUFA levels and the milk ALA/ALA intake ratio, and decreased the ratio of n-6 PUFAs to n-3 PUFAs in milk.

Comparisons of Corn Stover Silages after Fresh- or Ripe-Corn Harvested: Effects on Digestibility and Rumen Fermentation in Growing Beef Cattle

Both waxy corn stover after fresh- (CF) and ripe-corn (CR) harvested are important byproducts of corn cropping system and have 20 d difference in harvest time. The study aimed to investigate the effects of prolonging harvest time on the nutritive value of corn stover silage by comparing CF with CR silages. In vitro ruminal experiment was firstly performed to investigate substrate degradation and fermentation of CF and CR silages. The CR diet was formulated by replacing 50% forage of CF silage with CR silage on a dry matter (DM) basis. Fourteen crossbred steers (Simmental × Limousin × local Chinese) aged 13 months with an average weight of 318.1 ± 37.1 kg were selected and randomly allocated into two dietary treatment groups. Although the CR silage had greater DM and fiber contents than CF silage, it did not alter in vitro degradation (p > 0.05), but with lower molar percentage of propionate and acetate to propionate ratio (p < 0.05). The cattle fed CR diet had a higher DM intake and lower fiber digestibility with reduction in 18S rRNA gene copies of protozoa and fungi and 16S rRNA gene copies of Fibrobacter succinogenes (p < 0.05). Further 16S rRNA gene amplicon analysis indicated a similar diversity of bacteria community between CR and CF treatments (p > 0.05). Few differences were observed in the abundance of genera larger than 1% (p > 0.05), except for the reduction in abundance of genera Ruminococcaceae_NK4A214_group in CR treatment (p < 0.05). In summary, prolonging 20 d harvest time of corn stover silage increases the forage fiber and DM content, which promotes feed intake with decreased fiber degradation, although rumen fermentation and growth performance are not changed in growing beef cattle.

Biohydrogenation Pathway of α-Linolenic Acid in Rumen of Dairy Cow In Vitro

The t9,c12,c15-C18:3 as an isomer of α-linolenic acid (c9,c12,c15-C18:3; ALA), has been recently detected in milk, but has not been found in the rumen. This study hypothesized that it may be a biohydrogenation product of ALA in rumen and aimed to explore whether it was present in the rumen and help to understand the rumen biohydrogenation mechanisms of ALA. The in vitro experiment included two treatments, a control check (CK group) with 50 µL ethanol added, and ALA group with 50 µL ethanol and 2.6 mg ALA (ALA addition calculated by 1.30% of dry matter base of diet); each sample of fermentation fluid had the composition of C18 fatty acids analyzed at 0, 0.5, 1, 2, 3, 4, 5, and 6 h. The results showed that no t9,c12,c15-C18:3 was detected in the CK group, but ALA addition increased the concentration of t9,c12,c15-C18:3 in fermentation fluid. The content of t9,c12,c15-C18:3 peaked 1 h after fermentation, then declined gradually. At 1 h, no t9c12c15-C18:3 was detected in the fermentation fluid of the CK treatment. The results suggested that ALA converted to the isomer t9,c12,c15-C18:3 through biohydrogenation in the rumen. The addition of ALA can also increase the concentration of t9,c12-C18:2, c9,t11-C18:2, c12-C18:1, t11-C18:1, t9-C18:1, and c6-C18:1 in fermentation fluid. It was concluded using an in vitro experiment that t9,c12,c15-C18:3 was a product of rumen biohydrogenation of ALA.

Effect of Flaxseed Supplementation in Diet of Dairy Cow on the Volatile Organic Compounds of Raw Milk by HS-GC-IMS

Flaxseed supplementation in diet of dairy cow can effectively enhance the production of ω-3 polyunsaturated fatty acids (n-3 PUFA) in raw milk, which further give rise to the changes of volatile organic compounds (VOCs). In this study, we used headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) to investigate the VOCs in milk from cows fed three different diets (CK: supplemented with 0 g/d flaxseed; WF: 1,500 g/d whole flaxseed and GF: 1,500 g/d ground flaxseed). A total of 40 VOCs including three acids, six esters, 11 aldehydes, seven alcohols, 13 ketones were identified in all the raw milk samples. Compared with GF supplementation, suppling with WF could influence more compounds in raw milk (GF: five compounds; WF: 22 compounds). Supplementation with WF could increase the concentration of nonanal, heptanal, hexanal, which could cause the occurrence of off-flavors, and reduce the concentration of hexanoic acid (monomer; M), 2-hexanol, ethanol (M), 2-heptanone (dimer; D), 2-pentanone (M), 2-pentanone (D), acetoin (M) in raw milk. GF supplementation in diet could reduce the 2-pentanone (M), 2-pentanone (D). In addition, principal component analysis (PCA) based on the signal intensity of identified VOCs indicated that it is possible to distinguish between the CK and WF milk. However, GF milk could not be distinguished from CK milk. The results demonstrate that compared with GF milk, WF supplementation in diet of dairy cows could increase fishy (heptanal) cardboard-like (pentanal) flavor in milk and decrease sweet (hexanoic acid, 2-heptanone), fruity (ethyl butanoate, ethyl hexanoate, 2-heptanone) flavor which may lead the milk less acceptable. In conclusion, compared with WF, GF supplementation in diet of dairy cow showed higher increase in n-3 PUFA in raw milk, and less influence in VOCs of raw milk and this study might provide theoretical supports for the production of milk rich in n-3 PUFA.