A composite polyphenol-rich extract improved growth performance, ruminal fermentation and immunity, while decreasing methanogenesis and excretion of nitrogen and phosphorus in growing buffaloes

Effects of coix seed polyphenol extract on rumen fermentation, milk production, fatty acid profile, antioxidant activity, and polyphenol content in dairy goats

The transfer of natural antioxidants from feed to milk has become a research hotspot. Polyphenols are a source of potent natural antioxidants that may play important roles in improving antioxidant activity and milk quality in dairy goats. The aim of this study was to evaluate the effects of polyphenol-rich coix seed extract (CSE) on rumen fermentation, milk production, fatty acid profile, antioxidant activity, and polyphenol content in milk from lactating dairy goats. Forty dairy goats were allocated to 4 treatments, and the treatments containing 0, 1.5, 3.0, or 4.5 g of CSE per kilogram of TMR. The results indicated that the ruminal fluid total VFA level increased linearly and quadratically, the acetic acid concentration and acetate:propionate ratio decreased quadratically, and the propionic acid level increased quadratically with increasing CSE concentration. An increase in dietary CSE linearly and quadratically increased milk production parameters, and quadratically increased milk protein, lactose, and SNF. The concentrations of C18:3n-3, C20:3n-3, and C22:5n-3 in milk were affected by the treatment, and increased quadratically, whereas those of C18:2n-6c, C20:3n-6, and C20:4n-6 decreased quadratically with increasing CSE. An increase in the concentration of CSE in the diet linearly and quadratically increased 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity in plasma and total antioxidant capacity (TAC) and catalase (CAT) activities in milk. The levels of gallic acid, protocatechuic acid, catechin, apigenin, kaempferol, and bergapten in milk were affected by the treatment, and linearly and quadratically increased with increasing dietary CSE levels. Significant positive correlations were detected between TAC, CAT, and DPPH scavenging activity and gallic acid, protocatechuic acid, apigenin, kaempferol, and bergapten, and positive correlations were detected between CAT and DPPH scavenging activity and catechin concentration in milk. In addition, significant positive correlations were detected between DPPH scavenging activity in plasma and TAC, DPPH scavenging activity in milk. Taken together, these findings indicate that dietary supplementation with CSE appears to be a promising strategy for improving the production performance of lactating dairy goats. Overall, the appropriate supplemental level of CSE was 1.5 g/kg in dairy goats under the conditions of the current experiment.

Influence of forage-to-concentrate ratio on the effects of a radiata pine bark extract on methane production and fermentation using the rumen simulation technique

Climate change and food safety standards have intensified research into plant-based compounds as alternatives to dietary supplements in animal feed. These compounds can reduce enteric methane (CH4) emissions and the formation of ruminal ammonia. This study investigated the effects of radiata pine bark extract (PBE) supplementation on CH4 production, ruminal fermentation parameters, and nutrient disappearance using the rumen simulation technique in diets with different forage-to-concentrate (F:C) ratios. The experimental design was a 22 factorial arrangement of two F:C ratios [70:30 (HF) vs 30:70 (HC)], without or with PBE (2% on a DM basis). Two consecutive incubations were conducted during 15 days, with 10 days of adaptation, followed by 5 days of sampling. Use of PBE decreased ammonia nitrogen (NH3-N, P < 0.001) and total volatile fatty acids (VFAs, P = 0.019) concentrations, while it increased acetate (P < 0.001) and propionate (P < 0.001) proportions in both diets. However, CH4 yield [mg/g organic matter (OM) disappeared] tended to be reduced by 33.6% (P = 0.088) only in the HF diet supplemented with PBE. The OM disappearance tended to increase (P = 0.079) with PBE; hemicellulose disappearance increased in HF and decreased in HC diets (P < 0.001), whereas protein disappearance decreased in HF and increased in HC diets (P < 0.001). In conclusion, PBE supplementation reduced NH3-N and VFA concentrations in HF and HC diets, but CH4 yield (mg/g OM disappeared) was only reduced in the HF diet. Additionally, nutrient disappearance was dependent on the F:C ratio of the diet, without adverse effects on ruminal fermentation. Hence, the incorporation of radiata PBE into HF diets could serve as an environmentally friendly additive, potentially offering an alternative use for a forestry industry by-product, while beneficially modulating ruminal fermentation.

Microencapsulation of Mitragyna leaf extracts to be used as a bioactive compound source to enhance in vitro fermentation characteristics and microbial dynamics

OBJECTIVE

Mitragyna speciosa Korth is traditionally used in Thailand. They have a high level of antioxidant capacities and bioactive compounds, the potential to modulate rumen fermentation and decrease methane production. The aim of the study was to investigate the different levels of microencapsulated-Mitragyna leaves extracts (MMLE) supplementation on nutrient degradability, rumen ecology, microbial dynamics, and methane production in an in vitro study.

METHODS

A completely randomized design was used to assign the experimental treatments, MMLE was supplemented at 0%, 4%, 6%, and 8% of the total dry matter (DM) substrate.

RESULTS

The addition of MMLE significantly increased in vitro dry matter degradability both at 12, 24, and 48 h, while ammonia-nitrogen (NH3-N) concentration was improved with MMLE supplementation. The MMLE had the greatest propionate and total volatile fatty acid production when added with 6% of total DM substrate, while decreased the methane production (12, 24, and 48 h). Furthermore, the microbial population of cellulolytic bacteria and Butyrivibrio fibrisolvens were increased, whilst Methanobacteriales was decreased with MMLE feeding.

CONCLUSION

The results indicated that MMLE could be a potential alternative plant-based bioactive compound supplement to be used as ruminant feed additives.

Methane mitigation in ruminants with structural analogues and other chemical compounds targeting archaeal methanogenesis pathways

Ruminants are responsible for enteric methane production contributing significantly to the anthropogenic greenhouse gases in the atmosphere. Moreover, dietary energy is lost as methane gas without being available for animal use. Therefore, many mitigation strategies aiming at interventions at animals, diet, and microbiota have been explored by researchers. Specific chemical analogues targeting the enzymes of the methanogenic pathway appear to be more effective in specifically inhibiting the growth of methane-producing archaea without hampering another microbiome, particularly, cellulolytic microbiota. The targets of methanogenesis reactions that have been mainly investigated in ruminal fluid include methyl coenzyme M reductase (halogenated sulfonate and nitrooxy compounds), corrinoid enzymes (halogenated aliphatic compounds), formate dehydrogenase (nitro compounds, e.g., nitroethane and 2-nitroethanol), and deazaflavin (F420) (pterin and statin compounds). Many other potential metabolic reaction targets in methanogenic archaea have not been evaluated properly. The analogues are specifically effective inhibitors of methanogens, but their efficacy to lower methanogenesis over time reduces due to the metabolism of the compounds by other microbiota or the development of resistance mechanisms by methanogens. In this short review, methanogen populations inhabited in the rumen, methanogenesis pathways and methane analogues, and other chemical compounds specifically targeting the metabolic reactions in the pathways and methane production in ruminants have been discussed. Although many methane inhibitors have been evaluated in lowering methane emission in ruminants, advancement in unravelling the molecular mechanisms of specific methane inhibitors targeting the metabolic pathways in methanogens is very limited.

Ruminal fermentation and methane production in vitro, milk production, nutrient utilization, blood profile, and immune responses of lactating goats fed polyphenolic and saponin-rich plant extracts

This study was conducted to evaluate the effect of a composite plant extract (CPE) rich in polyphenolics and saponins from seeds of Dolichos biflorus (horse gram), root of Asparagus racemosus (shatavari), bark of Amoora rohituka (rohitaka), and peel of Punica granatum (pomegranate) on ruminal fermentation and methanogenesis in vitro, milk production, nutrient digestibility, immune response, and blood profiles in lactating Beetal goats fed CPE at 20 g/kg diet. Dose effect of CPE was assessed using different doses (0, 10, 20, 30, and 40 g/kg substrate) to find out an optimum dose for the in vivo study. The in vivo experiment lasted 70 days including a 10-day adaptation period. In the in vitro study, dry matter (DM) and fiber degradability increased linearly (P < 0.05) and methane production and ammonia concentration decreased linearly (P < 0.05) with increasing doses of CPE. Concentrations of total VFA and proportion of propionate increased (P < 0.001) linearly, whereas proportion of acetate and acetate to propionate ratio decreased with a linear effect. Dietary CPE increased milk yield (P = 0.017) and concentrations of protein and lactose (P = 0.045) by CPE, but concentrations of fat and solid not fat in milk were not affected (P > 0.10). Somatic cell counts in milk reduced (P = 0.045) in the CPE-fed goats. Apparent digestibility of DM (P = 0.037) increased significantly and NDF (P = 0.066) tended to increase due to supplementation of CPE. Blood glucose (P = 0.028) and albumin (P = 0.007) concentrations increased, while other liver-marker metabolites and enzyme activities and superoxide dismutase activity were not altered in goats due to feeding of CPE. Concentrations of total amino acids (P = 0.010), total essential amino acids (P = 0.012), and total ketogenic amino acids (P < 0.001) were greater in the CPE-fed goats than the control goats. Cell-mediated immune response improved due to CPE feeding. This study suggests that the CPE rich in both phenolics and saponins could improve ruminal fermentation, milk production, and nutrient utilization in lactating goats with better health status while decreasing methane emission.

Mitragyna speciosa Korth Leaf Pellet Supplementation on Feed Intake, Nutrient Digestibility, Rumen Fermentation, Microbial Protein Synthesis and Protozoal Population in Thai Native Beef Cattle

This experiment evaluated the use of Mitragyna speciosa Korth leaf pellets (MSLP) on feed intake and nutrient digestibility in Thai native beef cattle. Four Thai native beef cattle steers were randomly assigned according to a 4 × 4 Latin square design to receive four dietary treatments. The treatments were as follows: control (no supplementation), MSLP supplement at 10 g/hd/d, MSLP supplement at 20 g/hd/d and MSLP supplement at 30 g/hd/d, respectively. All animals were fed a concentrate mixture at 0.5% body weight, while urea lime-treated rice straws were fed ad libitum. Findings revealed that feed intakes were increased by MSLP, which also significantly increased the digestibility of dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF). Ruminal total volatile fatty acid (TVFA) concentration and propionate (C3) proportion were increased (p < 0.05) with MSLP supplementation, whereas ruminal ammonia-N (NH3-N), plasma urea nitrogen (PUN), acetate (C2), C2:C3 ratio and estimated methane (CH4) production decreased (p < 0.05). Total bacterial, Fibrobacter succinogenes and Ruminococus flavefaciens populations increased (p < 0.05) at high levels of MSLP supplementation, while protozoal populations and methanogenic archaea reduced (p < 0.05). Supplementation of MSLP also increased the efficiency of microbial nitrogen protein synthesis. Supplementing beef cattle with MSLP 10−30 g/hd/d significantly increased rumen fermentation end products and nutrient digestibility by mitigating protozoal populations and estimated CH4 production.

Polyphenols for Livestock Feed: Sustainable Perspectives for Animal Husbandry?

There is growing interest in specialized metabolites for fortification strategies in feed and/or as an antioxidant, anti-inflammatory and antimicrobial alternative for the containment of disorders/pathologies that can also badly impact human nutrition. In this context, the improvement of the diet of ruminant species with polyphenols and the influence of these compounds on animal performance, biohydrogenation processes, methanogenesis, and quality and quantity of milk have been extensively investigated through in vitro and in vivo studies. Often conflicting results emerge from a review of the literature of recent years. However, the data suggest pursuing a deepening of the role of phenols and polyphenols in ruminant feeding, paying greater attention to the chemistry of the single compound or to that of the mixture of compounds more commonly used for investigative purposes.

Decrease of Greenhouse Gases during an In Vitro Ruminal Digestibility Test of Forage (Festuca arundinacea) Conditioned with Selenium Nanoparticles

The Festuca arundinacea Schreb. is one of the most used forage grasses due to its duration, productivity, great ecological breadth, and adaptability. Livestock has been criticized for its large production of greenhouse gases (GHG) due to forage. The advancement of science has led to an increase in the number of studies based on nanotechnologies; NPs supplementation in animal nutrition has found positive results in the fermentation of organic matter and the production of fatty acids and ruminal microorganisms. The objectives of this study were (1) to evaluate the in vitro digestibility of forage containing selenium (Se) nanoparticles (NPs), and to identify the specific behavior of the ruminal fermentation parameters of F. arundinacea Schreb. and (2) quantify the production of greenhouse gases (total gas and methane) (3) as well as the release of bioactive compounds (phenols, flavonoids, tannins, and selenium) after fermentation. Three treatments of SeNPs were established (0, 1.5, 3.0, and 4.5 ppm). The effects of foliar fertilization with SeNPs son digestion parameters were registered, such as the in vitro digestion of dry matter (IVDM); total gas production (A_{total gas}) and methane production (A_CH4); pH; incubation time(to); the substrate digestion rate (S); t_Smax and the lag phase (L); as well as the production of volatile fatty acids (VFA), total phenols, total flavonoids, and tannins in ruminal fluid. The best results were obtained in the treatment with the foliar application of 4.5 ppm of SeNPs; IVDMD (60.46, 59.2, and 59.42%), lower total gas production (148.37, 135.22, and 141.93 mL g DM^-1), and CH₄ (53.42, 52.65, and 53.73 mL g DM^-1), as well as a higher concentration of total VFA (31.01, 31.26, and 31.24 mmol L^-1). The best results were obtained in the treatment with the foliar application of 4.5 ppm of SeNPs in the three different harvests; concerning IVDMD (60.46, 59.2, and 59.42%), lower total gas production (148.37, 135.22, and 141.93 mL g DM^-1), and CH₄ (53.42, 52.65, and 53.73 mL g DM^-1), as well as a higher concentration of total VFA (31.01, 31.26, and 31.24 mmol L^-1). The F. arundinacea Schreb. plants fertilized with 4.5 ppm released-in the ruminal fluid during in vitro fermentation-the following contents: total phenols (98.77, 99.31, and 99.08 mgEAG/100 mL), flavonoids (34.96, 35.44, and 34.96 mgQE/100 g DM), tannins (27.22, 27.35, and 27.99 mgEC/100g mL), and selenium (0.0811, 0.0814, and 0.0812 ppm).

The effect of ensiled paulownia leaves in a high-forage diet on ruminal fermentation, methane production, fatty acid composition, and milk production performance of dairy cows

BACKGROUND

The use of industrial by-products rich in bioactive compounds as animal feeds can reduce greenhouse gas production. Paulownia leaves silage (PLS) was supplemented to dairy cows' diet and evaluated in vitro (Exp. 1; Rusitec) and in vivo (Exp. 2, cannulated lactating dairy cows and Exp. 3, non-cannulated lactating dairy cows). The study investigated the PLS effect on ruminal fermentation, microbial populations, methane production and concentration, dry matter intake (DMI), and fatty acid (FA) proportions in ruminal fluid and milk.

RESULTS

Several variables of the ruminal fluid were changed in response to the inclusion of PLS. In Exp. 1, the pH increased linearly and quadratically, whereas ammonia and total volatile fatty acid (VFA) concentrations increased linearly and cubically. A linear, quadratic, and cubical decrease in methane concentration was observed with increasing dose of the PLS. Exp. 2 revealed an increase in ruminal pH and ammonia concentrations, but no changes in total VFA concentration. Inclusion of PLS increased ruminal propionate (at 3 h and 6 h after feeding), isovalerate, and valerate concentrations. Addition of PLS also affected several populations of the analyzed microorganisms. The abundances of protozoa and bacteria were increased, whereas the abundance of archaea were decreased by PLS. Methane production decreased by 11% and 14% in PLS-fed cows compared to the control in Exp. 2 and 3, respectively. Exp. 3 revealed a reduction in the milk protein and lactose yield in the PLS-fed cows, but no effect on DMI and energy corrected milk yield. Also, the PLS diet affected the ruminal biohydrogenation process with an increased proportions of C18:3 cis-9 cis-12 cis-15, conjugated linoleic acid, C18:1 trans-11 FA, polyunsaturated fatty acids (PUFA), and reduced n6/n3 ratio and saturated fatty acids (SFA) proportion in milk. The relative transcript abundances of the 5 of 6 analyzed genes regulating FA metabolism increased.

CONCLUSIONS

The dietary PLS replacing the alfalfa silage at 60 g/kg diet can reduce the methane emission and improve milk quality with greater proportions of PUFA, including conjugated linoleic acid, and C18:1 trans-11 along with reduction of SFA. Graphical abstract of the experimental roadmap.