Effect of Dietary Chestnut or Quebracho Tannin Supplementation on Microbial Community and Fatty Acid Profile in the Rumen of Dairy Ewes

Impact of oil type and savory plant on nutrient digestibility and rumen fermentation, milk yield, and milk fatty acid profile in dairy cows

Fat supplements are well known for their multiple beneficial effects on ruminant health, reproduction and productivity, and as a source for certain bioactive compounds in ruminant products. On the other hand, numerous phytochemicals have demonstrated the potential to improve rumen fermentation through modifying the volatile fatty acid (VFA) pattern to favour those with greater energy efficiency, boosting microbial protein synthesis, and decreasing methane emission and ruminal ammonia concentration. Savory is an aromatic plant rich in various phytochemicals (mainly carvacrol and flavonoids) that can alter ruminal metabolism of dietary fatty acids, potentially increasing the production of some bioactive compounds such as conjugated linoleic acids (CLAs). This study aimed to investigate combined effects of oil type (fish oil (FO) versus soybean oil (SO)) and the inclusion of savory (Satureja khuzistanica) plant (SP) in the diet on total tract digestibility of nutrients, rumen fermentation, milk yield and milk fatty acid profile in dairy cattle. Eight multiparous lactating Holstein cows were used in a replicated 4 × 4 Latin square design experiment with four diets and four 21-d periods. During each experimental period consisted of 14 days of adaptation and a 7-day sampling period, cows were randomly assigned to one of the four dietary treatments: the diet supplemented with 2% (DM basis) fish oil (FOD) or soybean oil (SOD), the FOD or SOD plus 370 g DM/d/head SP (FODs, SODs, respectively). The experimental diets were arranged in a 2 × 2 factorial design, with the fat sources as the first and SP as the second factor. The FO-supplemented diets had lower dry matter intake (DMI) and higher total tract digestibility than SO-supplemented diets (P < 0.05), and including SP in the diet improved total tract digestibility of dry matter (DM), organic matter (OM), ether extract (EE), and non-fibrous carbohydrates (NFC) (P < 0.05) without negatively affecting DMI. Rumen pH was lower with SO than with FO diets (P < 0.01) and increased with SP inclusion in the diet (P < 0.05). Total protozoa count and ruminal ammonia concentration decreased, and the branched-chain VFA (BCVFA) proportion increased with SP inclusion in the diet (P < 0.05). Milk production, as well as the concentration and yield of milk components (except lactose concentration) were higher with SO than with FO diets (P < 0.05), but these variables remained unaffected by SP. The milk concentrations of both non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) were lower with SO compared to FO diets, and these variables were reduced by SP (P < 0.01). The proportions of both mono- and polyunsaturated FA (MUFA and PUFA, respectively) in milk were higher with FO than with SO diets (P < 0.01), and their proportions increased by SP at the expense of saturated FA (SFA) (P < 0.01). Including SP in the diet increased the proportions of all the milk n-3 FA (C18:3c, C20:5, and C22:6) by 21%, 40%, and 97%, respectively, and those of conjugated linoleic acids (C18:2 (c9,t11-CLA) and C18:2 (t10,c12-CLA)) by 23% and 62%, respectively. There was no interaction between oil type and SP for the assessed variables. Fish oil, despite reducing milk production and milk components, was more effective than soybean oil in enriching milk with healthy FA. These findings also show promise for SP as a feed additive with the potential to improve total tract digestibility, rumen fermentation and milk FA composition.

Effects of Phlorotannins from Sargassum on In Vitro Rumen Fermentation, Microbiota and Fatty Acid Profile

The fatty acid profiles of ruminant-derived products are closely associated with human health. Ruminal microbiota play a vital role in modulating rumen biohydrogenation (BH). The aim of this study was to assess the influence of dietary supplementation with phlorotannins (PTs) extracted from Sargassum on rumen fermentation, fatty acid composition and bacterial communities by an in vitro culture study. The inclusion of PTs in the diet increased dry matter digestibility and gas production, and reduced ammonia-N concentration and pH. PT extract inhibited rumen BH, increasing the content of trans-9 C18:1, cis-9 C18:1, trans-9 and trans-12 C18:2 and reducing C18:0 concentration. 16S rRNA sequencing revealed that PTs caused an obvious change in rumen bacterial communities. The presence of Prevotella decreased while carbohydrate-utilizing bacteria such as Prevotellaceae_UCG-001, Ruminococcus, Selenomonas, Ruminobacter and Fibrobacter increased. Correlation analysis between rumen FA composition and the bacterial microbiome revealed that Prevotellaceae_UCG-001, Anaerovorax, Ruminococcus, Ruminobacter, Fibrobacter, Lachnospiraceae_AC2044_group and Clostridia_UCG-014 might have been involved in the BH process. In conclusion, the results suggest that the inclusion of PTs in the diet improved rumen fermentation and FA composition through modulating the rumen bacterial community.

Lower blood lipid level from the administration of plant tannins via altering the gut microbiota diversity and structure

Twenty-four Tan sheep were randomly assigned into 4 groups to study the capability of tannin supplementation (0.5% in dietary DM) to lower blood lipid levels mediated through the gut microbiota. The control (NC) group was offered a basic diet, while the 3 treatment groups were the TA group, which received supplementary tannic acid (TA); GSPE group, which received supplementary procyanidins (GSPE); and the TA + GSPE group, which received supplementary TA and GSPE, besides being supplied with the basic diet for 8 weeks feeding. At the end of the experiment, the serum glucose, insulin, lipids, and cytokines were measured, and the short-chain fatty acids (SCFAs) in the colon were tested by GC/MS. Moreover, the jejunal and colonic microbiota were detected by 16S rRNA sequencing. Significant reductions in serum triacylglycerol, cholesterol, and high density lipoprotein were found in all treatments. The total SCFAs decreased, while the iso-acids were significantly increased in the TA and TA + GSPE groups. The sheep showed noticeably lower MCP-1 and higher COX-2 levels in the GSPE group than that in the NC group. IL-6 was increased in the sheep fed with TA. The tannins still caused a noticeable shift in the colonic microbiota, with significant increases in the abundances of Adlercreutzia and Oscillospira. Ultimately, it was found that the diet with low levels of tannin could reduce blood triacylglycerol and cholesterol in sheep significantly by affecting the composition of the gut microbiota.

Utilization of Mao (Antidesma thwaitesianum Muell. Arg.) Pomace Meal to Substitute Rice Bran on Feed Utilization and Rumen Fermentation in Tropical Beef Cattle

This experiment was conducted to investigate the effects of replacing rice bran with mao pomace meal on feed intake, digestibility, and rumen fermentation in beef cattle. Four crossbred (50% Brahman × 50% Thai native) beef cattle with an initial body weight of 195 ± 13 kg and 16 months of age were used in a 4 × 4 Latin square design. The dietary treatments included four levels of RB replacement with mao pomace meal at 0, 33, 67, and 100% in concentrate diets. Rice straw was used as a roughage source, fed ad libitum. Replacement of mao pomace meal with rice bran did not affect (p > 0.05) the intakes of concentrate, rice straw, and total dry matter intake. Ether extract intake decreased linearly when increasing the levels of mao pomace meal (p < 0.01). The experimental diets had no effect (p > 0.05) on the digestibility of fiber and crude protein, while dry matter, organic matter, and ether extract digestibility decreased linearly in the group of mao pomace meal replacing rice bran (p < 0.05). Increasing levels of mao pomace meal in concentrate diets did not alter rumen pH, ammonia−nitrogen, or total volatile fatty acid concentration (p > 0.05). The proportion of propionate increased linearly (p < 0.05), whereas acetate and the acetate to propionate ratio decreased linearly (p < 0.05) when replacing rice bran with mao pomace meal. Moreover, the proportion of propionate was greatest, while acetate was lowest when mao pomace meal was included at 100% in the concentrate diet. In conclusion, the replacement of rice bran with mao pomace meal in a diet could enhance the efficiency of rumen fermentation. Nonetheless, it reduced the digestion of nutrients in tropical beef cattle.

A Bayesian Network Meta-Analysis of Complications Related to Breast Reconstruction Using Different Skin Flaps After Breast Cancer Surgery

BACKGROUND AND OBJECTIVES

As the incidence of breast cancer rises, the number of mastectomy surgeries surges, so does the importance of postoperative breast reconstruction. The implementation of autologous flap restoration methods is becoming prevalent, although which is the best flap remains controversial. As a result, we performed a Bayesian network meta-analysis to compare the eight most common flap in the reconstruction processor of breast cancer surgery. Our findings may help surgeons decide which skin flaps to use for breast reconstruction.

METHODS

We searched PubMed, Medline, Embase, and the Cochrane library for relevant literature. For our Bayesian network meta-analysis, we scrutinized 37 papers and evaluated the postoperative complications of eight commonly used breast reconstruction procedures. We also registered this study on PROSPERO, with the number CRD42021251989.

RESULTS

A total of 21,184 patients were included in this Bayesian network meta-analysis from 37 different studies. The results demonstrate that TRAM flaps are more prone to complications such as hernias in the abdominal wall and blood flow problems. Hematoma and seroma are more likely to follow LDP flaps. Combining LDP flaps with a prosthetic or autologous adipose tissue does not enhance the risk of postoperative problems appreciably. Fat liquefaction are relatively common in DIEP.

CONCLUSIONS

After breast reconstruction, several skin flaps can be employed as clinical choices. TRAM flaps are not recommended for patients with a weak abdominal wall structure, although LDP flaps or SIEA flaps can be considered instead. We do not advocate LDP flaps for patients who have had breast surgery because of the higher risk of hematoma or seroma, but DIEP flaps or LAP flaps can be utilized instead. We do not propose DIEP flaps for individuals who are at a higher risk of postoperative fat liquefaction, but LDP flaps or SIEA flaps can be used instead. However, this Bayesian network meta-analysis has limitations, and further randomized controlled trials are needed to confirm its findings.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Anti-nociceptive Activity of Quebracho tannin Extract on Pain Induced by Formalin and Writhing Tests in Mice

Background: Based on positive role of the tannins for pain relief, there is no report for possible antinociceptive activity of the Quebracho tannin. Objectives: This study aimed to determine the anti-nociceptive activity of the Quebracho tannin extract (QTE) on pain in mice. Materials and Methods: For this purpose, 340 mice were used for formalin and writhing tests each including 4 experiments with 4 sub-groups. In experiment 1, mice were injected with saline, QTE (100 mg/kg), QTE (200 mg/kg), QTE (400 mg/kg), and morphine (5 mg/kg). In the second experiment, injections included saline, QTE (400 mg/kg), naloxone (2 mg/kg), and QTE + naloxone. Experiments 3 and 4 were similar to experiment 2, except that mice injected were with NG-nitro arginine methyl ester (L-NAME, 10 mg/kg) and cyproheptadine (4 mg/kg) instead of naloxone. Then, formalin (1%) was injected, and time spent for licking the injected paw was recorded until 30 minutes following injection in the first and second phases. Finally, injections in 4 experiment groups were the same, and animals were intraperitoneally injected with acetic acid, and contractions were recorded in the writhing test category. Results: According to the results, QTE (100, 200, and 400 mg/kg) decreased pain in the injected paw (P=0.001) and inhibited the pain response by 59.37% (P=0.001). Moreover, the injection of naloxone + QTE significantly decreased pain in the injected paw (P=0.021). Eventually, the injection of the L-NAME + QTE significantly reduced the anti-nociception effect of the QTE on the formalin test (P=0.031) and writhing contractions (55.75%, P=0.033). Conclusion: These findings suggested anti-nociceptive properties of the QTE mediated by opioidergic and nitrergic systems.

Supplementation of Aloe vera extract in lactating goats' diet: effects on rumen fermentation efficiency, nutrient utilization, lactation performance, and antioxidant status

The present work was conducted to investigate the effects of supplementing Aloe vera extract on rumen fermentation efficiency, nutrient utilization, lactation performance, and antioxidant status of goats. Twenty-four crossbreed lactating goats (Alpine × Beetal) were divided into three experimental groups (AV0, AV2, and AV4). AV0 had no supplementation, groups AV2 and AV4 received ready to feed aqueous extract of Aloe vera at 20 and 40 g/kg dry matter intake, respectively, along with basal diet and experiment lasted for 100 days. Average DMI did not vary (P > 0.05) among treatment groups; however, the metabolic bodyweight of AV4 was significantly lower (P < 0.05) than the AV0 and AV2 groups (AV0 = AV2 > AV4). Intake and digestibility of DM, OM, CP, NDF, ADF, and EE were unaffected (P > 0.05) by Aloe vera supplementation. The milk production, yield of milk fat, protein, lactose, and solid not fat (SNF) of goats in the AV4 group were significantly higher (P < 0.05) than other groups (AV4 > AV2 = AV0). The activity of superoxide dismutase and catalase enzymes and levels of plasma ferric reducing total antioxidant power were high (P < 0.01) in the Aloe vera supplemented group (AV4 = AV2 > AV0). There was no significant difference (P = 0.979) in the pH, acetic acid (P = 0.449), and butyric acid (P = 0.864) concentration of the rumen liquor among the treatment groups. The propionic acid concentration was similar between AV2 and AV4 and significantly higher (P = 0.024) than the AV0 group (AV4 = AV2 > AV0). Moreover, C2:C3 values were significantly lower (P = 0.037) in the AV4 group compared to the control (AV0). Thus, Aloe vera supplementation enhanced milk yield, propionic acid production, and antioxidant status without affecting nutrient utilization; however, results were better in the AV4 group. The inclusion of Aloe vera at 40 g/kg of DMI would improve the rumen fermentation efficiency, lactation performance, and overall health status of the dairy goats.

Fatty acid metabolism in lambs supplemented with different condensed and hydrolysable tannin extracts

Five groups of lambs (n = 9 each) were used to test the effect of plant extracts rich in hydrolysable (HT) or condensed tannin (CT) on animal performance, fatty acid composition of rumen content, liver and meat. The control group (CO) received a concentrate-based diet without tannins supplementation. The other groups received the same diet as the control lambs plus 4% chestnut (CH) and tara (TA) extracts as a source of HT and mimosa (MI) and gambier (GA) extracts as a source of CT. One-way ANOVA was used to assess the overall effect of dietary treatments, tannins supplementation (CO vs. CH+TA+MI+GA) and the effect of tannin type (HT vs. CT: CH+TA vs. MI+GA) on animal performance, rumen content, liver and intramuscular FA. Dietary CH negatively affected animal performance. The rumen content of the different groups showed similar levels of 18:3 c9c12c15, 18:2 c9c12, 18:2 c9t11, 18:1 t11 and 18:0, whereas 18:1 t10 was greater in CO. Also, 18:1 t10 tended to be lower in the rumen of HT than CT-fed lambs. These data were partially confirmed in liver and meat, where CO showed a greater percentage of individual trans 18:1 fatty acids in comparison with tannins-fed groups. Our findings challenge some accepted generalizations on the use of tannins in ruminant diets as they were ineffective to favour the accumulation of dietary PUFA or healthy fatty acids of biohydrogenation origin in the rumen content and lamb meat, but suggest a generalized influence on BH rather than on specific steps.

Correlation of Breed, Growth Performance, and Rumen Microbiota in Two Rustic Cattle Breeds Reared Under Different Conditions

The use of rustic cattle is desirable to face challenges brought on by climate change. Maremmana (MA) and Aubrac (AU) are rustic cattle breeds that can be successfully used for sustainable production. In this study, correlations between two rearing systems (feedlot and grazing) and the rumen microbiota, the lipid composition of rumen liquor (RL), and the growth performance of MA and AU steers were investigated. Bacterial community composition was characterized by high-throughput sequencing of 16S rRNA gene amplicons, and the RL lipid composition was determined by measuring fatty acid (FA) and the dimethyl acetal profiles. The main factor influencing bacterial community composition was the cattle breed. Some bacterial groups were positively correlated to average daily weight gain for the two breeds (i.e., Rikenellaceae RC9 gut group, Fibrobacter and Succiniclasticum in the rumen of MA steers, and Succinivibrionaceae UCG-002 in the rumen of AU steers); despite this, animal performance appeared to be influenced by short chain FAs production pathways and by the presence of H₂ sinks that divert the H₂ to processes alternative to the methanogenesis.

Polyunsaturated fatty acid, volatile and sensory profiles of beef from steers fed citrus pulp or grape pomace

The present study compared the effects of feeding dried grape pomace (DGP) or citrus pulp (DCP) at 150 g/kg dry matter compared to a control diet on major polyunsaturated fatty acids (PUFA), volatile and sensory profiles of beef. Feeding DGP or DCP diets to Angus steers for 90 d increased the proportions of C18:2n-6, C20:4n-6, C18:3n-3, total conjugated linoleic acid (CLA), n-3 and n-6 PUFA in muscle. Control-fed beef had greater concentrations of C18:1n-9, total aldehydes, ketones, and alcohols compared to DCP and DGP. Feeding DGP and DCP diets produced less tender beef than control. Overall, finishing steers on diets containing DGP or DCP compared to control increased proportions of total CLA, n-3 and n-6 PUFA, and reduced concentrations of aldehydes, ketones, and alcohols, but did not affect beef sensory attributes except for a slight reduction in tenderness.

The links between supplementary tannin levels and conjugated linoleic acid (CLA) formation in ruminants: A systematic review and meta-analysis

A systematic review and meta-analysis were conducted to predict and identify ways to increase conjugated linoleic acid (CLA) formation in ruminant-derived products to treat human health issues with dietary tannins. The objective was to compare and confirm the effects of dietary tannins on CLA formation by analyzing in vitro and/or in vivo studies. We reported the results of the meta-analysis based on numerical data from 38 selected publications consisting of 3712 treatments. Generally, via multiple pathways, the CLA formation increased when dietary tannins increased. Concurrently, dietary tannins increased Δ⁹ desaturation and the CLA indices in milk and meat (P < 0.05 and P < 0.001, with average R² values of 0.23 and 0.44, respectively), but they did not change the rumen fermentation characteristics, including total volatile fatty acids (mmol/L) and their acid components. In vitro observations may accurately predict in vivo results. Unfortunately, there was no relationship between in vitro observations and in vivo results (R² < 0.10), indicating that it is difficult to predict CLA formation in vivo considering in vitro observations. According to the statistical meta-analysis results regarding animal aspects, the ranges of tannin levels required for CLA formation in vitro and in vivo were approximately 0.1–20 g/kg dry matter (DM) (P < 0.001) and 2.1–80 g/kg DM (P < 0.001), respectively. In conclusion, the in vivo method was more suitable for the direct observation of fatty acid transformation than the in vitro method.

Effects of Chestnut Tannin Extract, Vescalagin and Gallic Acid on the Dimethyl Acetals Profile and Microbial Community Composition in Rumen Liquor: An In Vitro Study

The addition of polyphenol extracts in ruminant diets is an effective strategy to modulate rumen microflora. The aim of this in vitro trial was to study the effects of chestnut tannin extract (CHT), vescalagin (VES) and gallic acid (GAL) on dietary fibre degradability and on the dimethyl acetals (DMA) profile and microbial community composition of rumen liquor. Four diets (basal diet; basal diet plus CHT; basal diet plus VES; basal diet plus GAL) were fermented for 24 h using ewe rumen liquor. At the end of the fermentation, the microbial communities were characterized by sequencing the 16S rRNA gene. The DMA profile was analyzed by gas chromatography. Chestnut tannin extract did not affect fibre degradability, whereas VES and GAL showed a detrimental effect. The presence of CHT, VES and GAL influenced the concentration of several DMA (i.e., 12:0, 13:0, 14:0, 15:0, 18:0 and 18:1 trans-11), whereas the composition of the microbial community was marginally affected. The inclusion of CHT led to the enrichment of the genera Anaerovibrio, Bibersteinia, Escherichia/Shigella, Pseudobutyrivibrio and Streptococcus. The results of this study support the hypothesis that the activity of CHT is due to the synergistic effect of all components rather than the property of a single component.

Invited review: Plant polyphenols and rumen microbiota responsible for fatty acid biohydrogenation, fiber digestion, and methane emission: Experimental evidence and methodological approaches

The interest of the scientific community in the effects of plant polyphenols on animal nutrition is increasing. These compounds, in fact, are ubiquitous in the plant kingdom, especially in some spontaneous plants exploited as feeding resources alternative to cultivated crops and in several agro-industry by-products. Polyphenols interact with rumen microbiota, affecting carbohydrate fermentation, protein degradation, and lipid metabolism. Some of these aspects have been largely reviewed, especially for tannins; however, less information is available about the direct effect of polyphenols on the composition of rumen microbiota. In the present paper, we review the most recent literature about the effect of plant polyphenols on rumen microbiota responsible for unsaturated fatty acid biohydrogenation, fiber digestion, and methane production, taking into consideration the advances in microbiota analysis achieved in the last 10 yr. Key aspects, such as sample collection, sample storage, DNA extraction, and the main phylogenetic markers used in the reconstruction of microbial community structure, are examined. Furthermore, a summary of the new high-throughput methods based on next generation sequencing is reviewed. Several effects can be associated with dietary polyphenols. Polyphenols are able to depress or modulate the biohydrogenation of unsaturated fatty acids by a perturbation of ruminal microbiota composition. In particular, condensed tannins have an inhibitory effect on biohydrogenation, whereas hydrolyzable tannins seem to have a modulatory effect on biohydrogenation. With regard to fiber digestion, data from literature are quite consistent about a general depressive effect of polyphenols on gram-positive fibrolytic bacteria and ciliate protozoa, resulting in a reduction of volatile fatty acid production (mostly acetate molar production). Methane production is also usually reduced when tannins are included in the diet of ruminants, probably as a consequence of the inhibition of fiber digestion. However, some evidence suggests that hydrolyzable tannins may reduce methane emission by directly interacting with rumen microbiota without affecting fiber digestion.