Scrophularia striata Extract Supports Rumen Fermentation and Improves Microbial Diversity in vitro Compared to Monensin

Effects of allicin on growth performance, antioxidant profile, and microbiota compared to monensin of growing goats

Allicin is a sulfur-containing compound extracted from raw garlic (Allium sativum L.). We compared the effect of allicin addition on growth performance, serum biochemical parameters, and rumen microbiota of goats compared to monensin. Twenty-four Anhui white goats were assigned randomly to one of three dietary treatments: 1) a basal diet (CON); 2) the basal diet with allicin addition at 750 mg per head per day (AC); 3) the basal diet with monensin addition at 30 mg per kg of diet (MS). Animals were fed for 8 weeks. Results showed the average daily gain, and feed efficiency was increased with allicin and monensin addition. Serum levels of IgG, total superoxide dismutase, and glutathione peroxidase were higher in the AC group than those in the CON and MS groups. The microbiota analysis revealed that monensin addition mainly affected genera related to carbohydrate and protein metabolism, and allicin mainly affected genera related to energy metabolism and intestinal health. In conclusion, allicin could improve growth performance and have advantages over monensin in improving the antioxidant capacity and immune function of goats. Allicin may be a potential alternative to monensin.

Meta-analysis of flavonoids use into beef and dairy cattle diet: Performance, antioxidant status, ruminal fermentation, meat quality, and milk composition

The objective of this study was to evaluate the effects of dietary supplementation with flavonoids (FLAs) on animal performance, diet digestibility, antioxidant status in blood serum, rumen parameters, meat quality, and milk composition in beef and dairy cattle through a meta-analysis. Thirty-six peer-reviewed publications were included in the data set. The weighted mean differences (WMD) between the FLAs treatments and the control treatment were used to assess the effect size. Dietary supplementation with FLAs decreased feed conversion ratio (WMD = -0.340 kg/kg; p = 0.050) and increased (p < 0.05) dry matter intake (WMD = 0.191 kg/d), dry matter digestibility (WMD = 15.283 g/kg of DM), and daily weight gain (WMD = 0.061 kg/d). In blood serum, FLAs supplementation decreased the serum concentration of malondialdehyde (WMD = -0.779 nmol/mL; p < 0.001) and increased (p < 0.01) the serum concentration of superoxide dismutase (WMD = 8.516 U/mL), glutathione peroxidase (WMD = 12.400 U/mL) and total antioxidant capacity (WMD = 0.771 U/mL). A higher ruminal propionate concentration (WMD = 0.926 mol/100 mol; p = 008) was observed in response to FLAs supplementation. In meat, the dietary inclusion of FLAs decreased (p < 0.05) shear force (WMD = -1.018 kgf/cm²), malondialdehyde content (WMD = -0.080 mg/kg of meat), and yellowness (WMD = -0.460). Supplementation with FLAs decreased milk somatic cell count (WMD = -0.251 × 103 cells/mL; p < 0.001) and increased (p < 0.01) milk production (WMD = 1.348 kg/d), milk protein content (WMD = 0.080/100 g) and milk fat content (WMD = 0.142/100 g). In conclusion, dietary supplementation with FLAs improves animal performance and nutrient digestibility in cattle. In addition, FLAs improve the antioxidant status in blood serum and the quality of meat and milk.

Sodium butyrate reduces ammonia emissions through glutamate metabolic pathways in cecal microorganisms of laying hens

Ammonia emission is an important problem that needs to be solved in laying hen industries. Sodium butyrate (SB) is considered to have potential for reducing ammonia production because of its ability to improve nitrogen metabolism. In this in vitro fermentation study, we presented a correlation analysis of the metatranscriptome and metaproteome of lay hen cecal microorganisms, in order to identify important proteins and pathways involved in ammonia production reduction due to sodium butyrate supplementation. The results showed that sodium butyrate supplement decreased the production of ammonia by 26.22% as compared with the non-sodium butyrate supplementation (CK) group. The SB group exhibited a lower concentration of ammonium nitrogen (NH₄⁺-N) and a decreased pH. Sodium butyrate promoted the uric acid concentration and lowered the uricase activity in the fermentation broth of laying hens cecal content. Notably, the 'alanine, aspartate and glutamate metabolism' category was more abundant in the SB group. The addition of sodium butyrate increased the expression of glutamate dehydrogenase (GDH) gene in cecal microbiota (e.g., Ruminococcus sp. and Bacteroides sp.) in vitro. The metaproteome analysis results showed that the expression of GDH with NADPH as coenzyme (NADPH-GDH) was up-regulated in cecal microbiota by sodium butyrate supplement. Our results indicate that sodium butyrate can affect glutamate metabolism through regulating the expression of glutamate dehydrogenase in cecal microorganisms, thereby reducing ammonia production. This study reveals that glutamate dehydrogenase-mediated glutamate metabolism play a key role in ammonia emission reduction in laying hen and provide theoretical basis for further developing ammonia production reduction approach.

Remarkable positive effects of figwort (Scrophularia striata) on improving growth performance, and immunohematological parameters of fish

This study was conducted to investigate the effect of figwort on the growth and immunohematological parameters of common carp (14.20 ± 0.53 g). Four experimental diets were developed to feed fish for eight weeks: control, Figw10 (10 g/kg figwort), Figw20 (20 g/kg figwort), and Figw30 (30 g/kg figwort). The results showed that fish fed dietary Figw10 gained more weight (38.25 g) than control (P < 0.05). Regarding immunohematological parameters, fish fed dietary Figw30 had a higher level of white blood cells (31.2 10³/mm³), hematocrit (35.82%), blood performance (14.63), total protein (1.96 g/dL), albumin (0.79 g/dL), globulin (1.17 g/dL), lymphocyte (70.53%), monocyte (3.03%), alternative hemolytic complement activity (ACH50) (147.76 u/mL), lysozyme (62.19 u/mL), and bactericidal activities (135.24) than the control group (P < 0.05). After 14 days of the challenge with Aeromonas hydrophila, the Figw30 treatment had the highest survival ratio (61.76%) compared to the control with 26.46%. Further, after the challenge, fish fed dietary Figw30 had a higher value of immunoglobulin M (42.00 μg/mL), antibody titer (19.23), complement component 3 (296.39 μg/mL), and complement component 4 (97.91 μg/mL) when compared with those fed control diet (P < 0.05). In conclusion, the optimum dosage for providing the best immune response was 30 g/kg in diet.

Supplementing a Clay Mineral-Based Feed Additive Modulated Fecal Microbiota Composition, Liver Health, and Lipid Serum Metabolome in Dairy Cows Fed Starch-Rich Diets

Starch-rich diets are a commonly adopted strategy in order to sustain high milk yields in dairy cows. However, these diets are known to increase the risk of gut dysbiosis and related systemic health disorders. This study aimed to evaluate the effects of supplementing a clay mineral-based feed additive (CM; Mycofix® Plus, BIOMIN) on fecal microbiota structure, fecal short-chain fatty acid (SCFA) fermentation, serum metabolome, and liver health in primiparous (PP, n = 8) and multiparous (MP, n = 16) early-lactation Simmental cows (737 ± 90 kg of live body weight). Cows were randomly assigned to either a control or CM group (55 g per cow and day) and transitioned from a diet moderate in starch (26.3 ± 1.0%) to a high starch diet (32.0 ± 0.8%). Supplementation of CM reversed the decrease in bacterial diversity, richness, and evenness (p < 0.05) during high-starch diet, demonstrating that CM supplementation efficiently eased hindgut dysbiosis. The CM treatment reduced levels of Lactobacillus in PP cows during starch-rich feeding and elevated fecal pH, indicating a healthier hindgut milieu compared with that in control. Butyrate and propionate levels were modulated by CM supplementation, with butyrate being lower in CM-treated MP cows, whereas propionate was lower in MP but higher in PP cows. Supplementing CM during high-starch feeding increased the concentrations of the main primary bile salts and secondary bile acids in the serum and improved liver function in cows as indicated by reduced levels of glutamate dehydrogenase and γ-glutamyl-transferase, as well as higher serum albumin and triglyceride concentrations. These changes and those related to lipid serum metabolome were more pronounced in PP cows as also corroborated by relevance network analysis.

Feeding dairy cows bakery by-products enhanced nutrient digestibility, but affected fecal microbial composition and pH in a dose-dependent manner

We reported recently that adding bakery by-products (BP) to the diets of dairy cows up to 30% improved performance and rumen pH, but caused major shifts in the nutrient profile and availability, likely modifying nutrient degradation patterns throughout the gastrointestinal tract. The aim of this study was to investigate the effects of the gradual replacement of cereals by BP on the apparent total-tract digestibility (ATTD), the fermentation patterns, and the microbial community in feces of dairy cows. Twenty-four mid-lactating Simmental cows (149 ± 22.3 days in milk, 756 ± 89.6 kg of initial body weight) were fed a total mixed ration ad libitum (fresh feed was offered twice per day) containing a 50:50 ratio of forage to concentrate (dry matter basis) throughout the experiment. The trial lasted 5 wk, whereby the first week was used for baseline measurements, in which all cows received the same diet, without BP. Cows were then randomly allocated into 3 groups differing in the BP content of diets (0% BP, 15% BP, and 30% BP on a DM basis) and fed for 4 wk. Fecal samples were taken for analysis of pH, volatile fatty acids (VFA), and 16S rRNA gene sequencing. The inclusion of BP resulted in an increase of ether extract and sugars, and a reduction of starch and neutral detergent fiber in the diet. Feeding BP linearly increased the ATTD of almost all nutrients resulting in up to 2 kg more digestible organic matter intake (DOMI). Increasing BP level up to 30% increased fecal total VFA concentration and decreased the pH. The proportion of butyrate in feces increased linearly, but the proportion of all other VFA was not affected by BP-feeding. The richness and diversity indices of the fecal microbiota linearly declined by the inclusion of BP. The cellulolytic phyla Fibrobacteres decreased, whereas amylolytic phyla, such as Proteobacteria, increased. Overall, results showed that feeding BP linearly increased ATTD and DOMI, but impaired fecal microbial diversity and pH. In the interest of the optimization of BP inclusion in the dairy cows' feeding, a dietary level between 15 to 30% of BP might be a better compromise than 30% in terms of an enhanced DOMI and performance with still lowered risk of hindgut dysbiosis, but this will require further investigations.

Dietary Supplementation with Sodium Sulfate Improves Rumen Fermentation, Fiber Digestibility, and the Plasma Metabolome through Modulation of Rumen Bacterial Communities in Steers

Six steers were used to study the effects of dietary supplementation with sodium sulfate (Na₂SO₄) on rumen fermentation, nutrient digestion, rumen microbiota, and plasma metabolites. The animals were fed a basal ration with Na₂SO₄ added at 0 g/day (sulfur [S] content of 0.115% dry matter [DM]), 20 g/day (S at 0.185% DM), or 40 g/day (S at 0.255% DM) in a replicate 3-by-3 Latin square design. The results indicated that supplementing with Na₂SO₄ increased the ruminal concentration of total volatile fatty acids, the molar proportions of acetate and butyrate, the ruminal concentrations of microbial protein, SO₄ ^2--S, and S^2--S, and the digestibility of fiber, while it decreased the molar proportion of propionate and the ruminal concentration of ammonia nitrogen. Supplementing with Na₂SO₄ increased the diversity and the richness of rumen microbiota and the relative abundances of the phylum Firmicutes and genera Ruminococcus 2, Rikenellaceae RC9 gut group, and Desulfovibrio, whereas it decreased the relative abundances of the phylum Bacteroidetes and genera Prevotella 1, Prevotellaceae UCG-001, and Treponema 2 Supplementing with Na₂SO₄ also increased the plasma concentrations of amino acids (l-arginine, l-methionine, l-cysteine, and l-lysine), purine derivatives (xanthine and hypoxanthine), vitamins (thiamine and biotin), and lipids (acetylcarnitine and l-carnitine). It was concluded that supplementing the steer ration with Na₂SO₄ was beneficial for improving the rumen fermentation, fiber digestibility, and nutrient metabolism through modulating the rumen microbial community.IMPORTANCE Essential elements like nitrogen and sulfur greatly affect rumen fermentation and metabolism in ruminants. However, little knowledge is available on the effects of sulfur on the rumen microbiota and plasma metabolome. The results of the present trial demonstrated that supplementing the steer ration with sodium sulfate markedly improved rumen fermentation, fiber digestibility, and metabolism of amino acids, purine derivatives, and vitamins through effects on the ruminal microbiome. The facts obtained from the present trial clarified the possible mechanisms of the positive effects of sulfur on rumen fermentation and nutrient utilization.

Betaine Modulates Rumen Archaeal Community and Functioning during Heat and Osmotic Stress Conditions In Vitro

Rumen archaea play an important role in scavenging ruminal hydrogen (H₂) and thus facilitate rumen fermentation. They require optimum temperature and osmolality for their growth and metabolism; however, a number of external factors may put archaea under heat and osmotic stress. Betaine is an osmolyte, molecular chaperone, and antioxidant; therefore, it bears potential to combat against these stressors. In this in vitro study, three betaine levels, namely, 0 (control), 51 (low), and 286 (high) ppm, were used. Each of these was subjected to two temperatures (39.5 and 42°C) and two osmolality conditions (295 and 420 mOsmol kg^-1) with n = 6 per treatment. Sequencing analyses of the solid phase (which use solid materials containing primarily fibrous materials of low-density feed particles) and the liquid phase (rumen fermenter liquid) using 16S rRNA revealed that more than 99.8% of the ruminal archaea in fermenters belong to the phylum Euryarchaeota. At the genus level, Methanobrevibacter was the most prevalent in both phases, and Methanosaeta was only detected in the liquid phase. The genera Methanobrevibacter and Methanobacterium both showed a positive correlation with methane (CH₄) formation in the liquid and solid phases, respectively (P < 0.05). Heat stress increased the relative abundance of genus Methanimicrococcus at the expense of candidate archaeal genus Vadin CA11 (P < 0.05). In the solid phase, osmotic stress significantly reduced the Shannon and Simpson indices of diversity, and relative abundance was higher for Methanobrevibacter at the expense of Methanimicrococcus. In the liquid phase, osmotic stress increased not only the abundance-based coverage estimator (ACE) and singles parameters of diversity but also the relative abundances of Methanosphaera and Methanobacterium. The overall decrease in all gas parameters and estimated metabolic hydrogen ([2H]) utilization was observed during osmotic stress conditions (P < 0.05). Betaine enhanced the diversity of solid phase archaea as indicated by the increase in ACE and singles during heat stress, and only a high dose improved all diversity parameters in the liquid phase during osmotic stress (P < 0.05). Thus, betaine alleviates the effects of heat stress and osmotic stress on the archaea community.

Physicochemical stressors and mixed alkaloid supplementation modulate ruminal microbiota and fermentation in vitro

The drop of ruminal pH and heat are common physicochemical stressors challenging ruminal microbiota, nutrient digestion and cattle performance. We characterized the ruminal microbiota and digestive activity in response to different pH (6.0 and 6.6) and temperature (39.5 and 42 °C), as well as established the effective dose of alkaloid supplementation (0, 0.088 and 0.175% of feedstock DM) to modulate ruminal fermentation under these conditions. The acidotic condition decreased microbial diversity and abundances of minor bacterial families whereas most of the highly abundant families like Lactobacillaceae, Prevotellaceae, and Bifidobacteriaceae thrived under the stress. Abundances of all three methanogenic archaea taxa detected increased with heat, as did methane production. However, while Methanomassiliicoccaceae benefited from the low pH, Methanomicrobiaceae diminished and methane production decreased. The low dose of alkaloid addition shifted the fermentation to more propionate and less acetate and the high dose decreased methane and ammonia concentration under the low pH. In conclusion, physicochemical stressors shape the microbial community and function. Mixed alkaloid supplementation facilitates the activity of rumen microbial community under acidotic stress.

Evaluation of fecal fermentation profile and bacterial community in organically fed dairy cows consuming forage-rich diets with different particle sizes

Organic cattle farming encourages the use of forage-rich diets, and the reduction of particle size has been suggested as an approach to improve forage utilization and enhance nutrient intake of cows. However, reducing forage particle size increases passage rate, as well as the flow of potentially fermentable nutrients out of the rumen, and the consequences for hindgut fermentation have not been evaluated yet. This study evaluated the effects of decreasing dietary forage particle size on the fecal short-chain fatty acid (SCFA) profile and the bacterial community structure of dairy cows fed forage-based rations. Twenty-one organically fed lactating Holstein cows (4 primiparous and 17 multiparous; mean and standard deviation 703 ± 65 kg body weight, 135 ± 104 days in milk) were divided into 2 groups and fed 1 of 2 diets for 34 d. Diets contained 20% concentrate and 80% forage (dry matter basis), and were fed either as a control with a forage geometric mean particle size of 52 mm (CON; 11 cows) or as a diet with the forage particle size reduced to a geometric mean size of 7 mm (RED; 10 cows). Fecal samples were collected at the end of the experiment, and samples were immediately frozen at -20°C. Samples were analyzed for SCFA, and the fecal bacterial community was evaluated using 16S rRNA sequencing. Data showed that the concentration of total SCFA was not affected by treatment, but the proportion of propionate, a key glucogenic precursor in cattle, tended to be greater for RED (13.3 and 13.8 ± 0.1%, respectively). The predominant bacterial phyla, including Firmicutes (58.0 ± 0.7%), Bacteroidetes (26.9 ± 0.4%), and Verrucomicrobia (4.0 ± 0.4%), were not affected by forage particle size. Family Lachnospiraceae increased in relative abundance when the RED diet was fed (12.1 and 13.9 ± 0.5% for CON and RED, respectively), and genera Acetitomaculum (1.1 and 1.8 ± 0.2%), Turicibacter (0.7 and 0.9 ± 0.1%), and Ruminobacter (0.1 and 0.4 ± 0.1%) increased in relative abundance when RED was fed. In addition, relative abundance of some fecal bacterial taxa was correlated with major fecal SCFA and pH. Reducing the particle size of forages, from 52 to 7 mm geometric mean particle size, maintained fecal concentration of total SCFA and tended to enhance propionate concentration, without risk of dysbiosis. Thus, results suggest that reduction of forage particle size represents an effective approach to optimizing forage utilization while maintaining hindgut fermentation and fecal bacterial diversity in dairy cows fed forage-rich diets.

Betaine addition as a potent ruminal fermentation modulator under hyperthermal and hyperosmotic conditions in vitro

BACKGROUND

Climatic and dietary shifts predispose ruminal microbes to hyperthermal and hyperosmotic stress, leading to poor fermentation and subsequently adverse effects on ruminant productivity. Betaine may function as substrate, osmolyte, antioxidant, and methyl donor for microbes. However, its effect depends on the extent of microbial catabolism. This study revealed the ruminal disappearance kinetics of betaine and its dose effect on ruminal fermentation during thermal and osmotic stress using a rumen simulation technique.

RESULTS

Three different betaine doses were used: 0, 50, and 286 mg L^-1 ; each was assigned to two incubation temperatures (39.5 and 42 °C) and two osmotic conditions (295 and 420 mOsmol kg^-1 ). Betaine disappeared rapidly within the first 6 h of incubation; however, the rate was lower during hyperosmotic stress (P < 0.05), the stress condition that also suppressed the overall fermentation and degradation of organic nutrients and decreased the bacterial diversity (P < 0.001). During hyperosmotic stress, betaine shifted the fermentation pathway to more propionate (P < 0.05). Betaine counteracted the negative effect of hyperthermal stress on total short-chain fatty acid concentration (P < 0.05) without affecting the composition. Both stress conditions shifted the bacterial composition, but the effect of betaine was minimal.

CONCLUSION

Despite its rapid ruminal disappearance, betaine modulated microbial fermentation in different ways depending on stress conditions, indicating the plasticity of the betaine effect in response to various kinds of physicochemical stress. Although betaine did not affect the abundance of ruminal microbiota, the enhanced fermentation suggests an improved microbial metabolic activity under stress conditions. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Antidiabetic and protective effects of Scrophularia striata ethanolic extract on diabetic nephropathy via suppression of RAGE and S100A8 expression in kidney tissues of streptozotocin-induced diabetic rats

Background The present study was conducted to examine the antidiabetic effects of Scrophularia striata ethanolic extract and to evaluate its effects on oxidative stress markers and RAGE and S100A8 gene expressions in the kidney of type 1 diabetic rats. Methods A total of 36 rats (weight 200-250 g) were randomly assigned into six groups as follows: Cnt, Cnt + S. striata 100, and Cnt + S. striata 200 that received normal saline, 100 mg/kg bw, and 200 mg/kg bw of ethanol extract of S. striata, respectively; and group Dibt, Dibt + S. striata 100, and Dibt + S. striata 200 that received normal saline, 100 mg/kg bw, and 200 mg/kg bw of ethanol extract of S. striata, respectively. Type 1 diabetes was induced in rats by a single injection of streptozotocin (55 mg/kg bw). After 60 days of treatment, biochemical factors and oxidative stress markers (superoxide dismutase [SOD] and malondialdehyde [MDA]) were measured using spectrophotometric methods. RAGE and S100A8 gene expressions were analyzed using real-time polymerase chain reaction. Results Diabetes significantly impairs serum and urine fasting blood glucose (FBG), lipid profile, creatinine, urea, and albumin parameters. After the treatment with S. striata extract, these parameters are close to the normal range. It was shown that the S. striata extract significantly decreased the kidney expression levels of RAGE and S100A8 genes and improved oxidative stress markers (SOD and MDA) in the kidney tissues when compared with the diabetic control group. It was also found that the beneficial effects of the S. striata were dose dependent. Conclusions The ethanolic extract of S. striata has beneficial antidiabetic effects. Moreover, by reducing RAGE and S100A8 gene expressions and by improving oxidative stress, S. striata might be used as adjuvant treatment for diabetic complications.

A nutritional and rumen ecological evaluation of the biorefinery by-product alfalfa silage cake supplemented with Scrophularia striata extract using the rumen simulation technique

BACKGROUND

By-products of the food production chain are gaining importance as feedstuffs for ruminants. Alfalfa silage cake (AC) is an unexploited biorefinery by-product rich in fiber. The aim of this study was to test AC, using an in vitro rumen simulation technique (Rusitec), for its suitability as a fiber source for cattle. Three diets with similar crude protein (CP) content were formulated; they contained the biorefinery by-product AC, the original alfalfa silage (OA), or a fiber-rich hay. As fibrous feedstuffs are known to promote ruminal methanogenesis, we additionally tested a plant extract of Scrophularia striata (60 mg g^-1 dry matter) for its methane mitigation and antimicrobial properties.

RESULTS

Diets containing AC displayed lower nutrient degradability, with the largest difference in CP degradation (P < 0.001). Sequencing of microbial DNA revealed several effects of the diet and of the addition of S. striata extract, but no inhibitory effect on methanogens. Likewise, methane production, which, in general, is lower with AC and OA diets, was not inhibited by S. striata extract, while the short chain fatty acid (SCFA) profiles were unaffected.

CONCLUSION

Although CP degradation of the AC diet was lower, degradation of the fiber fractions was similar among diets. According to the present results, AC can be used as fibrous feedstuff for ruminants. Supplementation with S. striata extract did not inhibit methane formation. © 2019 Society of Chemical Industry.