Saponin rich tropical fruits affect fermentation and methanogenesis in faunated and defaunated rumen fluid

Effect of ethanol extract from Enterolobium cyclocarpum fruit on Leghorn chickens exposed to Eimeria

There are concerns about residues of drugs in meat that are used to prevent coccidiosis in chickens. Natural compounds are an alternative to drugs. Two studies investigated the effect of an extract of Enterolobium cyclocarpum fruits (EEC) in the feed of male Leghorn chickens exposed to Eimeria spp. In the first experiment, the administration of EEC after infection with Eimeria spp. was investigated over 16 days. One thousand chickens were randomly housed in 20 pens of 1 m2 each. The pens were randomly assigned to each treatment. Five treatments were administered, containing 150, 300 and 450 mg/kg of EEC in the feed, the fourth treatment (C) contained 0.5 g/kg of a commercial anticoccidial, and the fifth treatment provided no treatment (WA). The second experiment lasted 18 days. Administration of the EEC began five days before the chickens were infected with Eimeria spp. Four hundred and eighty chickens were randomly allocated to 24 pens of 1 m2. The pens were randomly assigned to each treatment. In the second experiment, the same five treatments were tested and one additional treatment containing 300 mg EEC plus 1 g of polyethylene glycol (PEG)/kg of feed (E300PEG). In the experiment one chickens in the EEC treatments had lower faecal oocyst excretion (OE) on day 14 post infection with Eimeria spp., than chickens in the WA treatment (P < 0.05). A reduction in live weight gain (LWG) was observed in the EEC treatments (P < 0.05). In the second experiment, the excretion of oocysts in chickens from the EEC and E300PEG treatments on day 13 post-infection with Eimeria spp. was the same as in the C treatment and lower than in the WA treatment (P < 0.05). LWG was lower in the EEC treatments than in the C treatment (P < 0.05). However, the Chickens in the E300PEG and C treatments had similar LWG (P > 0.05) suggesting that PEG inhibits the negative effect of EEC tannins on LWG. In conclusion, the addition of EEC to chicken feed reduced both OE and LWG. Treatment with EEC and PEG (E300PEG) reduced the excretion of oocysts without negative effects on LWG.

Effect of Cashew Nutshell Extract, Saponins and Tannins Addition on Methane Emissions, Nutrient Digestibility and Feeding Behavior of Beef Steers Receiving a Backgrounding Diet

The beef industry contributes to greenhouse gas emissions through enteric methane emissions, exacerbating climate change. Anacardic acid in cashew nutshell extract (CNSE), saponins and tannins (ST) are plant secondary metabolites that show promise in methane mitigation via antimicrobial effects, potentially exerting changes in ruminal fermentation patterns. This study examined the impact of CNSE, ST, and their combination on methane emissions, digestibility, intake, and performance of sixteen Angus crossbred steers (347 ± 30 kg) receiving a backgrounding diet (70:30 corn silage: cottonseed burrs). The study used a 4 × 4 Latin square design (4 steers, 4 treatments, 4 periods) with a 2 × 2 factorial arrangement, including the main effects of additive (CNSE or ST) fed individually or combined. Thus, steers received the following treatments: (1) no additive, (2) CNSE only, (3) ST only, or (4) both (CNSEST). Non-supplemented steers registered eight more feedbunk visits/d than ST-steers and spent an extra 10 min/d on the feedbunk. The addition of ST tended to increase dry matter, organic matter, and neutral detergent fiber intake. Additives fed individually reduced CP digestibility. Intake of the carrier containing CNSE only was lesser and coincided with a greater methane yield in that treatment. Digestibility and methane mitigation were improved after CNSEST compared with individual inclusion, suggesting synergistic reactions enhanced methane mitigation effects in fibrous diets without affecting the digestibility of nutrients nor animal growth performance.

Ruminal modulator additive effect of Stryphnodendron rotundifolium bark in feedlot lambs

The study aimed to evaluate the inclusion effects of Stryphnodendron rotundifolium (barbatimão) extracts in substitution of the lasalocid sodium on the ingestive behaviour, intake, ruminal parameters, and digestibility of feedlot lambs. Twenty-four pantaneiro lambs were used, with an average age of 150 ± 4.59 days and an initial body weight of 21.2 ± 3.63 kg. The lambs were distributed in three treatments in an experimental design with randomized blocks. The treatments correspond to the additive supplements: LAS (0.019 g of lasalocid sodium/lamb/d); DGB (1.50 g of barbatimão dried ground bark/lamb/d); DHE (0.30 g of barbatimão dry hydroalcoholic extract/lamb/d). The DHE increased 59.74 min in the time spent for ingestion per day, resulting in an efficiency reduction of dry matter (DM) ingestion (127 g of DM/h of feed). There was a reduction of 1.8 mg/dL in the ammoniacal nitrogen concentration with extract supplementation compared to LAS. The DGB reduced total volatile fatty acids by 48.9% compared to the control treatment. The inclusion of barbatimão extracts (DGB and DHE) reduced 12.05% of ruminal butyrate content. The supplementation of barbatimão extracts replacing lasalocid sodium in the diet of feedlot lambs did not affect intake and caused small changes on ingestive behaviour.

Comparison of the effects of alfalfa meal and sorghum distillery residue supplementation on the methane emissions in black-feathered Taiwan native chicken

The issue of global warming, primarily fueled by anthropogenic greenhouse gas emissions, necessitates effective strategies to address methane (CH4) emissions from both ruminants and nonruminants. Drawing inspiration from successful approaches employed in ruminants, this study evaluates the impact of supplementing the diets of Taiwan's native black-feathered chickens with alfalfa meal and sorghum distillery residues (SDRs) on CH4 emissions. Using a respiration chamber the results reveal a significant reduction in CH4 emissions when incorporating either 30% alfalfa meal or 30% SDRs into the chicken diet, demonstrating a 59% and 49% decrease, respectively, compared to the control group (P < 0.05). Considering that alfalfa meal contains saponins and SDRs contain tannins, the study delves into the mechanism through which these components mitigate CH4 production in chickens. Incorporating saponins or tannins shows that groups supplemented with these components exhibit significantly lower CH4 emissions compared to the control group (P < 0.05), with a consistent linear decrease as the concentration of the feed additive increases. Further in vitro analysis of chicken cecal contents indicates a proportional reduction in CH4 production with increasing levels of added saponins or tannins (P < 0.05). These findings suggest that the CH4-reducing effects of alfalfa meal and SDRs can be attributed to their saponins and tannin content. However, caution is warranted as excessive alfalfa meal supplementation may adversely impact poultry growth. Consequently, sorghum distillery residue emerges as a more suitable feed ingredient for mitigating CH4 emissions in Taiwan's native black-feathered chickens compared to alfalfa. Additionally, substituting SDRs for conventional commercial chicken feed not only reduces CH4 emissions but also enhances the utilization of byproducts.

Effectiveness of herbal plants on rumen fermentation, methane gas emissions, in vitro nutrient digestibility, and population of protozoa

Background and Aim

Herbal plants have the potential to reduce the population of metagonic bacteria and protozoa due to the bioactive compound contained in herbal plants. This study aimed to evaluate the effect of herbal plant supplementation on rumen fermentation characteristics, methane (CH4) gas emissions, in vitro nutrient digestibility, and protozoan populations.

Materials and Methods

This study consisted of two stages. Stage I involved determining the potential of herbal plants to increase total gas production (Orskov and McDonald methods) and reduce the protozoan population (Hristov method). Three potential herbs were selected at this stage and used in Stage II as supplements in the palm kernel cake (PKC)-based diet (30% herbal plants + 70% PKC). Proximate and Van Soest analyses were used to determine the chemical composition. In vitro dry matter digestibility (IVDMD), organic matter (IVOMD), and rumen fermentation characteristics were determined using Theodorous method. Conway microdiffusion was used to determine ammonia concentration (NH3). Gas chromatography was used to determine the total and partial volatile fatty acid production.

Results

The results of the first stage showed that seven herbal plants (Moringa oleifera, Rhodomyrtus tomentosa, Clerodendron serratum, Curcuma longa Linn., Urena lobata, Uncaria, and Parkia timoriana) significantly differed in terms of total gas production (p < 0.05). Herbal plants can increase gas production and reduce protozoan populations. The highest total gas production was observed using P. timoriana, M. oleifera, and C. longa Linn. Moringa oleifera plants were the most effective in lowering protozoa population. In Stage 2, the supplementation of herbal plants in PKC-based-diet significantly increased IVDMD, that was ranged from 56.72% to 65.77%, IVOMD that was ranged from 52.10% to 59.54%, and NH3, that was ranged from 13.20 mM to 17.91 mM. Volatile fatty acid partial and total gas production potential and CH4 gas emissions were also significantly different from those of the control (p < 0.05).

Conclusion

Supplementation of M. oleifera, C. longa Linn., and P. timoriana in ruminant diet effectively increased total gas production, IVDMD percentage, and IVOMD, and reduced CH4 gas emissions and protozoa populations during rumen fermentation.

A Review of Effect of Saponins on Ruminal Fermentation, Health and Performance of Ruminants

Saponins are steroid, or triterpene glycoside, compounds found in plants and plant products, mainly legumes. However, some plants containing saponins are toxic. Saponins have both positive and negative roles in animal nutrition. Saponins have been shown to act as membrane-permeabilizing, immunostimulant, hypocholesterolaemic, and defaunating agents in the rumen for the manipulation of ruminal fermentation. Moreover, it has been reported that saponins have impair protein digestion in the gut to interact with cholesterol in the cell membrane, cause cell rupture and selective ruminal protozoa elimination, thus improving N-use efficiency and resulting in a probable increase in ruminant animal performance.

Evaluating the Effects of Some Selected Medicinal Plant Extracts on Feed Degradability, Microbial Protein Yield, and Total Gas Production In Vitro

This study evaluates the effect of 22 crude ethanolic plant extracts on in vitro rumen fermentation of Themeda triandra hay using monensin sodium as a positive control. The experiment was run independently three times at 16 and 48 h of incubation periods using the in vitro gas production techniques. Fermentation parameters were determined at both hours of incubation. Plant extracts influenced gas production (GP) in a varied way relative to control at both hours of incubation, and GP is consistently highly significant (p < 0.0001) at 16 and 48 h. Microbial protein yield (MY) was not significantly affected at 16 h (p > 0.05), but it was at 48 h (p < 0.01). Higher MY was recorded for all treatments except for A. sativum and C. intybus at the early incubation stage (16 h) relative to 48 h of incubation. Compared to the control group at 48 h, all plant extracts have higher MY. After 48 h of incubation, the result shows that plant extracts have an effect on fermentation parameters determined; ruminal feed degradation, gas production, microbial protein yield, and partitioning factor in varied manners. All the plant extracts improve the MY which is the major source of amino acids to ruminants and has significant importance to animal performance. C. illinoinensis, C. japonica, M. nigra, P. americana, C. papaya, and A. nilotica (pods) were the most promising plant extracts, but further study is recommended to validate the in vitro observation in vivo.

Experimental intoxication of Brahman (Bos indicus) heifers with Enterolobium cyclocarpum fruits

Enterolobium cyclocarpum is a poisonous plant distributed throughout the Americas. The E. cyclocarpum fruits have high toxic potential for cattle in Colombia and the clinical signs and pathological lesions are ill-defined. To begin address this issue, twelve Brahman heifers were administered E. cyclocarpum fruits and the evolution of clinical signs were recorded. Blood was collected to establish biochemical and hematological parameters. Animals were euthanized between 4 and 15 days after the initial dose was given, and tissue samples were routinely processed and stained by Hematoxylin-Eosin. The severity of clinical signs and tissue lesions were correlated with the dose of E. cyclocarpum fruits. Clinical signs included fever, tachypnea, sialorrhea, jaundice, tympanism, and diarrhea. Skin lesions were consistent with photosensitization. Hematological and biochemical tests showed increased hematocrit, neutropenia, increased serum fibrinogen, elevated hepatic enzymes and azotemia. Histology revealed panlobular cytoplasmic vacuolization and extensive foci of necrosis in the liver. The skin, fore-stomach, abomasum and intestine revealed microcirculatory, inflammatory and ulcerative changes. Protein casts and tubular epithelium vacuolization were found in kidney. Depending on the toxicosis intensity, it is concluded that E. cyclocarpum fruits may cause two clinical and pathological forms of poisoning in Brahman heifers. First, a severe intoxication at repeated exposition with high (20 g/kg/d) or low (10 g/kg/d) dose that affected the digestive and tegumentary systems and the kidney. Second, a mild to moderate form with a single low dose (10 g/kg/d) that affected in lower grades the same systems/organs.

Nutritional Interventions to Reduce Methane Emissions in Ruminants

Methane is the single largest source of anthropogenic greenhouse gases produced in ruminants. As global warming is a main concern, the interest in mitigation strategies for ruminant derived methane has strongly increased over the last years. Methane is a natural by-product of anaerobic microbial (bacteria, archaea, protozoa, and fungi) fermentation of carbohydrates and, to a lesser extent, amino acids in the rumen. This gaseous compound is the most prominent hydrogen sink product synthesized in the rumen. It is formed by the archaea, the so-called methanogens, which utilize excessive ruminal hydrogen. Different nutritional strategies to reduce methane production in ruminants have been investigated such as dietary manipulations, plant extracts, lipids and lipid by-products, plant secondary metabolites, flavonoids, phenolic acid, statins, prebiotics, probiotics, etc. With the range of technical options suggested above, it is possible to develop best nutritional strategies to reduce the ill effects of livestock on global warming. These nutritional strategies seem to be the most developed means in mitigating methane from enteric fermentation in ruminants and some are ready to be applied in the field at the moment.

Effects of Yucca schidigera Based Feed Additive on In Vitro Dry Matter Digestibility, Efficiency of Microbial Production, and Greenhouse Gas Emissions of Four Dairy Diets

The present study evaluated the effects of a feed additive (synthesized from Yucca schidigera) on some fermentation variables. In the first of two experiments, seven concentrations of the feed additive were evaluated using the in vitro batch culture technique to determine the optimum dose to use in the second experiment. The substrates used were a total mixed ration (TMR) and alfalfa hay. The levels of inclusion were 0 (control), 0.5, 1, 2, 4, 6, and 8 g/head/d. After this initial evaluation, 2 g/head/d was selected for the second experiment. For the second study, four dietary substrates (two corn silages and two TMR; collected from different dairy farms in the Piedmont, North Carolina, area) were used. Incubation times were 3, 6, and 24 h and treatments were 0 (control) and 2 g/head/d of the feed additive. Inclusion of the feed additive did not affect (p > 0.05) in vitro dry matter disappearance. Additionally, the feed additive had no effect (p > 0.05) on short-chain fatty acid concentrations, microbial mass, and efficiency of microbial production. Methane production was reduced by 22.7% with feed additive inclusion. Similarly, lower (p = 0.013; 18%) carbon dioxide concentration was observed in the feed additive treatment. Ammonia and hydrogen sulfite concentrations were similar (p > 0.05) for both treatments. Inclusion of the feed additive at 2 g/head/d decreased methane and carbon dioxide concentrations in most of the diets. The energy saved by reducing the amount of methane produced was not partitioned into valuable products such as short-chain fatty acids and microbial mass.

Crude saponin extract from Sesbania grandiflora (L.) Pers pod meal could modulate ruminal fermentation, and protein utilization, as well as mitigate methane production

The aim of the study was to conduct a basic evaluation of the in vitro effect of crude protein (CP) levels in concentrate and a saponin extract from Sesbania graniflora pods meal (SES) on the kinetics of gas, nutrient digestibility, ruminal fermentation, protein efficiency uses, and methane (CH₄) mitigation. Eight treatments were formed according to a 2 × 4 factorial design in a completely randomized design (CRD). The first factor referred to the levels of CP at 14 and 16% on dry matter (DM) basis in the concentrate diet, and the second factor referred to the levels of SES supplementation at 0, 0.2, 0.4, and 0.6% of the total substrate on a DM basis. The results showed that S. graniflora pod meal contained 21.73% CP, 10.87% condensed tannins, and 16.20% crude saponins, respectively. Most kinetics of gas as well as cumulative gas were not influenced by the CP levels or SES addition (P > 0.05) except gas production from immediately soluble fraction (a) was significantly different by CP levels. Ammonia-nitrogen concentration of incubation at 4 h was significantly difference based on the CP levels and SES supplementation (P < 0.05). Increasing SES levels significantly (P < 0.05) decreased protozoal population. In vitro digestibility of DM and organic matter was not changed by CP levels or SES addition. Butyrate and acetate to propionate ration were decreased, and propionate was increased when increasing SES dose (P < 0.05), while CP levels did not change total volatile fatty acids and molar portions. The ruminal CH₄ concentration was reduced by 44.12% when 0.6% SES was added after 8 h of incubation. Therefore, SES supplementation could enhance protein utilization and improve rumen fermentation particularly lowering CH₄ production.

Nutritional Aspects of Ecologically Relevant Phytochemicals in Ruminant Production

This review provides an update of ecologically relevant phytochemicals for ruminant production, focusing on their contribution to advancing nutrition. Phytochemicals embody a broad spectrum of chemical components that influence resource competence and biological advantage in determining plant species' distribution and density in different ecosystems. These natural compounds also often act as plant defensive chemicals against predatorial microbes, insects, and herbivores. They may modulate or exacerbate microbial transactions in the gastrointestinal tract and physiological responses in ruminant microbiomes. To harness their production-enhancing characteristics, phytochemicals have been actively researched as feed additives to manipulate ruminal fermentation and establish other phytochemoprophylactic (prevent animal diseases) and phytochemotherapeutic (treat animal diseases) roles. However, phytochemical-host interactions, the exact mechanism of action, and their effects require more profound elucidation to provide definitive recommendations for ruminant production. The majority of phytochemicals of nutritional and pharmacological interest are typically classified as flavonoids (9%), terpenoids (55%), and alkaloids (36%). Within flavonoids, polyphenolics (e.g., hydrolyzable and condensed tannins) have many benefits to ruminants, including reducing methane (CH4) emission, gastrointestinal nematode parasitism, and ruminal proteolysis. Within terpenoids, saponins and essential oils also mitigate CH4 emission, but triterpenoid saponins have rich biochemical structures with many clinical benefits in humans. The anti-methanogenic property in ruminants is variable because of the simultaneous targeting of several physiological pathways. This may explain saponin-containing forages' relative safety for long-term use and describe associated molecular interactions on all ruminant metabolism phases. Alkaloids are N-containing compounds with vast pharmacological properties currently used to treat humans, but their phytochemical usage as feed additives in ruminants has yet to be exploited as they may act as ghost compounds alongside other phytochemicals of known importance. We discussed strategic recommendations for phytochemicals to support sustainable ruminant production, such as replacements for antibiotics and anthelmintics. Topics that merit further examination are discussed and include the role of fresh forages vis-à-vis processed feeds in confined ruminant operations. Applications and benefits of phytochemicals to humankind are yet to be fully understood or utilized. Scientific explorations have provided promising results, pending thorough vetting before primetime use, such that academic and commercial interests in the technology are fully adopted.

Sustainable impact of pulp and leaves of Glycyrrhiza glabra to enhance ruminal biofermentability, protozoa population, and biogas production in sheep

The aim of this study was to evaluate the effect of pulp and leaves of Glycyrrhiza glabra to reduce the ruminal biogas production in sheep. Five experimental diets of two levels of Glycyrrhiza glabra pulp (GGP) and Glycyrrhiza glabra leaves (GGL) at 150 and 300 g/kg dry matter (DM) were assessed for biogas production and fermentation parameters. Diets were control (diet without GGP or GGL), GGP15 (diet contains GGP at 150 g/kg DM), GGP30 (diet contains GGP at 300 g/kg DM), GGL15 (diet contains GGL at 150 g/kg DM), and GGL30 (diet contains GGL at 300 g/kg DM). Inclusion of 150 and 300 g/kg GGP and 300 g/kg GGL decreased (P < 0.0001) asymptotic biogas production (A), fermentation rate (μ), biogas production at 24 h of incubation (GP24), apparent degraded substrate (ADS), in vitro organic matter disappearance (OMD), and metabolizable energy (ME). Microbial protein biomass (MP) was improved (P = 0.003) by GGP15, GGL15, and GGL30 versus control. Total VFAs (P = 0.003), acetate (P = 0.009), and butyrate (P = 0.002), CH4 (mmol and mL/g OMD), CO2 (mmol and mL/g OMD) (P = 0.0003 and P = 0.0002, respectively), were decreased in GGP15, GGP30, and GGL30 diets versus control. Acetate to propionate ratio (Ac/Pr) was decreased (P = 0.038) in GGL30 diet compared to other diets. Replacing GGP and GGL with alfalfa reduced NH3-N concentration (P = 0.022), total protozoa (P < 0.0001), Isotricha spp. (P = 0.047), Dasytricha spp. (P = 0.067), subfamilies of Entodiniinae (P < 0.0001), and Diplodiniinae (P = 0.06). Results suggested that inclusion of dietary GGL at 150 g/kg dry matter positively modified some rumen parameters such as microbial protein production, protozoa population, and NH3-N concentration, which may be useful economically in ruminant animals and decreasing of environmental pollution.

Levels of the Enterolobium cyclocarpum pod in feedlot diet on growth performance, ruminal fermentation and biogas production of lambs-hair

Enterolobium cyclocarpum (Ec) is a native legume that grows from southern Mexico to South America; its seeds are traditionally used for feeding ruminants. The objective of this study was to evaluate the addition of Ec pods in diets of hair lambs and their effect on the productive variables, ruminal fermentation and in vitro production of methane (CH4) and carbon dioxide. Thirty male lambs fed diets containing 0% (Ec0), 20% (Ec20) and 40% (Ec40) based on dry matter were evaluated. The addition of Ec40 in the integral diet of the lambs did not affect the growth performance. The pH of the ruminal fluid did not show differences between the treatments. The addition of Ec40 increased propionate and decreased acetate. Protozoa decreased in 47 and 59% with Ec20 and Ec40, respectively; while the population of cellulolytic bacteria decreased with Ec40. In vitro degradability of dry matter was lower in 8.8% with the inclusion of Ec40 in diets. The novelty of the study was that Ec40 diet decreased the ruminal methane production.

Combination Effects of Plant Extracts Rich in Tannins and Saponins as Feed Additives for Mitigating in Vitro Ruminal Methane and Ammonia Formation

The objective of this experiment was to test the effects of combining plant extracts rich in tannins and saponins at varying proportions on in vitro ruminal methane and ammonia formation. Tannins were extracted from Swietenia mahogani leaves and saponins from Sapindus rarak fruits with various solvents. The extracts obtained with the most efficient solvents (tannins: 75% water and 25% methanol; saponins: pure methanol) were then used in vitro. The treatments consisted of two substrate types (high-forage (HF) or high-concentrate (HC) diets) and five extract combinations (tannins: saponins, 1:0, 3:1, 1:1, 1:3, and 0:1) added at 2 mg/mL in incubation liquid. In vitro incubation was performed in four runs, with each treatment being represented with two replicates per run. The addition of plant extracts rich in tannins and saponins, either individually or in combination, decreased the methane proportion of total gas in both the HF (p < 0.05) and HC (p < 0.05) diets. The effects of the plant extracts rich in tannins and saponins were generally additive in mitigating methane emissions. Favorable associative effects between the extracts were observed in the ammonia concentration, both in the HF (p < 0.001) and HC (p < 0.01) diets and in the methane proportion of total gas, with a 1:3 mixture of tannins and saponins added to the HC diet (p < 0.05).

Role of Secondary Plant Metabolites on Enteric Methane Mitigation in Ruminants

The rumen microbiome plays a fundamental role in all ruminant species, it is involved in health, nutrient utilization, detoxification, and methane emissions. Methane is a greenhouse gas which is eructated in large volumes by ruminants grazing extensive grasslands in the tropical regions of the world. Enteric methane is the largest contributor to the emissions of greenhouse gases originating from animal agriculture. A large variety of plants containing secondary metabolites [essential oils (terpenoids), tannins, saponins, and flavonoids] have been evaluated as cattle feedstuffs and changes in volatile fatty acid proportions and methane synthesis in the rumen have been assessed. Alterations to the rumen microbiome may lead to changes in diversity, composition, and structure of the methanogen community. Legumes containing condensed tannins such as Leucaena leucocephala have shown a good methane mitigating effect when fed at levels of up to 30–35% of ration dry matter in cattle as a result of the effect of condensed tannins on rumen bacteria and methanogens. It has been shown that saponins disrupt the membrane of rumen protozoa, thus decreasing the numbers of both protozoa and methanogenic archaea. Trials carried out with cattle housed in respiration chambers have demonstrated the enteric methane mitigation effect in cattle and sheep of tropical legumes such as Enterolobium cyclocarpum and Samanea saman which contain saponins. Essential oils are volatile constituents of terpenoid or non-terpenoid origin which impair energy metabolism of archaea and have shown reductions of up to 26% in enteric methane emissions in ruminants. There is emerging evidence showing the potential of flavonoids as methane mitigating compounds, but more work is required in vivo to confirm preliminary findings. From the information hereby presented, it is clear that plant secondary metabolites can be a rational approach to modulate the rumen microbiome and modify its function, some species of rumen microbes improve protein and fiber degradation and reduce feed energy loss as methane in ruminants fed tropical plant species.

Effect of the addition of Enterolobium cyclocarpum pods and Gliricidia sepium forage to Brachiaria brizantha on dry matter degradation, volatile fatty acid concentration, and in vitro methane production

The purpose of this study was to determine the in vitro fermentation and methane (CH₄) production in the grass Brachiaria brizantha (B) alone or when mixed with Gliricidia sepium forage (G) and/or Enterolobium cyclocarpum pods (E). Theses substrates were incubated in the following proportions: B100 (B100%), B85E15 (B85% + E15%), B85G15 (B85% + G15%), B85GE15 (B85% + G7.5% + E7.5%), and B70GE30 (B70% + G15% + E15%). Dry matter degradation (DMD), volatile fatty acid (VFA) concentration, and CH₄ production were measured at 12, 24, and 48 h of incubation. Experimental design was a randomized complete block. At 48-h incubation, DMD ranged between 46.5 and 51.2% (P = 0.0015). The lowest cumulative gas production (CGP) was observed in B85E15 and B85G15 (160 mL CGP/g organic matter, on average). At 48 h, B85G15 and B100 produced 28.8 and 30.2 mg CH4/g DMD, respectively, while B85E15 or the mixtures, 33.5 mg CH₄/g DMD, on average (P ≤ 0.05). B85E15 and B70G30 had the highest concentration of total VFA (P ≤ 0.05). Results showed that B85E15 and B70GE30 favor DMD and increased total production of VFA and CH₄ at 48 h. Supplementing livestock feed with legume forages and pods allows improves the nutritional quality of the diet and the fermentation patterns.

Effect of herbal feed additives containing saponins on rumen fermentation pattern

Macrotyloma uniflorum (kulthi) seeds, Asparagus racemosus (shatavari) roots or Acacia concina (shikakai) pods were supplemented to total mixed rations (TMR) @ 0-3% (on DM basis) to assess the impact of herbal feed additives (HFAs) on the in vitro rumen fermentation pattern. The saponin content and 2, 2-diphenyl-1-picrylhydrazyl- hydrate (DPHH) antioxidant activity was highest in A. racemosus than other HFAs. But total phenols, non tannin phenols, true tannins, condensed tannins, vitamin C and flavanoid contents were highest inM. uniflorum and lowest in A. concina. The dose/level of supplementation of HFAs, irrespective of their nature did not affect net gas production (NGP) and availability of metabolizable energy (ME) from TMR, but digestibility of nutrients and partitioning factor (PF) decreased in comparison to the unsupplemented group. The total and individual volatile fatty acids (VFAs) production; and acetate to propionate ratio was improved when the TMR was supplemented with HFAs at 1% level. The methane and ammonia-N production was depressed at 2% level as compared to control group. Irrespective of the dose, the total VFAs, acetate, and propionate production was higher while ammonia-N decreased in M. uniflorum supplemented TMR than other HFAs supplemented groups. Methane production from the TMR was comparable in the diet supplemented with different HFAs, however, diet supplemented with M. uniflorum resulted in lower methane production. Amongst the tested HFAs, M. uniflorum was a richer source of most of the bio-active compounds. Based on in vitro fermentation parameters, M. uniflorum supplemented to TMR @ 2% gave the best results.

Effects of pomegranate peel extract on ruminal and post-ruminal in vitro degradation of rumen inoculum of the dairy cow

This experiment was carried out to study the effect of water extracted pomegranate peel extract (PE) on ruminal protein degradation and post-ruminal digestion in the dairy cow. PE was added at six levels of total phenolics (g/kg of the basal diet); 3.75 (PE1); 4.4 (PE2); 5.05 (PE3); 5.70 (PE4); and 6.35 (PE5). Rumen degradable crude protein (rdCP) decreased with PE addition (L < 0.0001), but total CP degradability (tdCP) was not affected. Compared to PE0, PE2, and PE3 diets showed higher (L = 0.054, Q = 0.029) digestibility of bypass CP (dBCP). Increasing levels of PE resulted in a decrease in proteolytic bacteria numbers (p < 0.0001). At PE4 and PE5 levels, total VFA and acetate concentrations linearly decreased compared to PE0. PE inclusion lowered the acetate:propionate ratio (L = 0.0001) and Ammonia-N production after 24 h (L = 0.0008) of incubation. The total number of protozoa, genera Dasytricha and Isotricha, and subfamilies Entodiniinae, Diplodiniinae, and Ophrioscolecinae decreased with increasing dietary PE concentration (p < 0.0001). The results suggest that all levels of PE addition reduce the protozoal population and Ammonia-N concentration. All PE levels slowed down protein degradation in the rumen but PE2 and PE3 showed the greatest effect.

Effects of Tea Saponin Supplementation on Nutrient Digestibility, Methanogenesis, and Ruminal Microbial Flora in Dorper Crossbred Ewe

Simple Summary

Greenhouse gas emissions are a serious cause of global warming and climate change, and have become a common focus for all countries. Methane has been proven the second most commonly occurring greenhouse gas. Ruminants have been blamed for substantially contributing to methane emissions. Supplementation with tea saponin (TS) effectively decreased methane emissions and nitrogen emissions. It is not only beneficial for environmental protection, but also has potential economic benefits.

Abstract

Two experiments were conducted using Dorper × thin-tailed Han crossbred ewes. In experiment 1, eighteen ewes were randomly assigned to two dietary treatments (a basal diet, or the same basal diet supplemented with 2.0 g tea saponin (TS)/head/day) to investigate the effects of TS supplementation on nutrient digestibility and methane emissions. In experiment 2, six ewes with ruminal cannulae were assigned to the same two dietary treatments as in experiment 1 to investigate the effects of TS supplementation on rumen fermentation and microbial flora. TS supplementation increased the apparent digestibility of organic matter (OM) (p = 0.001), nitrogen (N) (p = 0.036), neutral detergent fibre (NDF) (p = 0.001), and acid detergent fibre (ADF) (p < 0.001). Urinary N (p = 0.001) and fecal N (p = 0.036) output were reduced, and N retention (p = 0.001) and nitrogen retention/nitrogen intake (p = 0.001) were increased. Supplementary TS did not decrease absolute methane emissions (p = 0.519) but decreased methane emissions scaled to metabolic bodyweight by 8.80% (p = 0.006). Ammonia levels decreased (p < 0.001) and total volatile fatty acid levels increased (p = 0.018) in response to TS supplementation. The molar proportion of propionate increased (p = 0.007), whereas the acetate:propionate ratio decreased (p = 0.035). Supplementation with TS increased the population of Fibrobacter succinogenes (p = 0.019), but the population of protozoans tended to decrease (p = 0.054). Supplementation with TS effectively enhanced the apparent digestibility of OM, N, NDF, and ADF, and decreased methane emissions scaled to metabolic bodyweight.

Herbal additives influence in vitro fermentative attributes and methanogenesis differently in cattle and buffalo

So as to ascertain the fermentation behaviour and methane-inhibitory efficiency of herbal additives, an in vitro gas-production study was conducted in two different sources of rumen liquor, using six herbal additives, viz. Boerhovia diffusa, Holarrhena antidysentericum, Solanum nigrum, Trigonella foenum-graecum, Withania somnifera and Woodfordia fruticosa. Each of the six herbal additives was subjected to in vitro evaluation at 2.5%, 5.0% and 7.5% levels of supplementation. Further, the runs were replicated using rumen-liquor inoculum sourced from cattle and buffalo, so as to explore the variation, if any, between the two species. The results indicated that there was a significant (P < 0.05) effect of both the source of inoculum and the level of supplementation on various parameters related to substrate degradation and methane production. The degree of inhibition of methane production was significantly (P < 0.05) higher with buffalo than with cattle rumen inoculum accompanying improved substrate degradation and microbial biomass production. The methanogenesis was increased when H. antidysentericum and S. nigrum were used in buffalo rumen liquor; however, these two herbal additives elicited maximum inhibition of methane production when used in cattle inoculum. When compared irrespective of inoculum, W. somnifera, W. fruticosa and B. diffusa were significantly (P < 0.001) more effective in reducing methanogenesis; however, supplementation of the B. diffusa significantly (P < 0.001) reduced the substrate-degradation attributes. Further, the degree of methane inhibition increased linearly with an increasing dose level of the additives. Overall, it is concluded that of the six herbal additives, W. somnifera and W. fruticosa were most effective in terms of optimisation of substrate degradation and inhibition of methanogenesis in vitro.

In vitro ruminal fermentation characteristics and utilisable CP supply of sainfoin and birdsfoot trefoil silages and their mixtures with other legumes

The extensive protein degradation occurring during ensiling decreases the nutritive value of silages, but this might be counteracted by tannins. Therefore, silages from two legume species containing condensed tannins (CT) - sainfoin (SF) and birdsfoot trefoil (two cultivars: birdsfoot trefoil, cv. Bull (BTB) and birdsfoot trefoil, cv. Polom) - were compared for their in vitro ruminal fermentation characteristics. The effect of combining them with two CT-free legume silages (lucerne (LU) and red clover (RC)) was also determined. The supply of duodenally utilisable CP (uCP) in the forages was emphasised. The legumes were each harvested from three field sites. After 24 h of wilting on the field, the legumes were ensiled in laboratory silos for 86 days. Proximate constituents, silage fermentation characteristics, CT content and CP fractions were determined. Subsequently, silage samples and 1 : 1 mixtures of the CT-containing and CT-free silages were incubated for 24 h in batch cultures using ruminal fluid and buffer (1 : 2, v/v). Each treatment was replicated six times in six runs. The effects on pH, ammonia and volatile fatty acid concentrations, protozoal counts, and total gas and methane production were determined. uCP content was calculated by considering the CP in the silage and the ammonia in the incubation fluid from treatments and blanks. Statistical evaluation compared data from single plants alone and together with that from the mixtures. Among treatments, SF silage contained the least CP and the most CT. The non-protein nitrogen content was lower, favouring neutral detergent soluble and insoluble protein fractions, in the SF and RC silages. Absolute uCP content was lowest in SF and SF mixtures, although the ratio to total CP was the highest. In comparison with LU, the ammonia concentration of the incubation fluid was lower for SF, RC and BTB and for the mixture of SF with LU. The total gas and methane production was similar among the treatments, and the total volatile fatty acid production was decreased with the CT-containing legumes. Protozoal count was increased with the mixtures containing LU and either SF or BTB compared with single LU. In conclusion, compared with the other legumes, SF and RC have similar advantages as they show limited proteolysis during ensiling. In addition, SF supplies more uCP relative to total CP. The CT-containing legumes also differed in their effect on ruminal fermentation and ammonia formation, probably because of their different CT contents. Thus, SF and its mixtures appear promising for improving the protein utilisation of ruminants.

The impact of feeding a supplement based on aloe and Manuka honey on milk yield from dairy cows

An Aloe vera and manuka honey commercial supplement (Cow and Calf Formula, DairyCare Ltd, NZ) was fed to approximately 40% of a commercial New Zealand herd with over 1000 cows in lactation following spring calving (August) until the end of lactation (April the following year). The 5 ml of supplement was added automatically to the feed for the treatment group via transponder identification units during at milking. At peak lactation (until October) there was a 5.5% increase (11.76 versus 12.41 litres per milking for control and treated cows respectively; P < 0.001) in yield for the supplemented cows, and over the whole season there was a 4.7% milk yield increase (8.12 versus 8.50 litres per milking for control and treated cows respectively). Data from December and January (high summer) showed no significant increase in milk yield, which was due to a major drought in the area and loss of grazed forage intakes. From these results, it was considered that that the Aloe vera and manuka honey, acting either separately or in synergy, resulted in more nutrients being available for milk production.

Ruminal fermentation, methanogenesis and nitrogen utilization of sheep receiving tropical grass hay-concentrate diets offered with Sapindus saponaria fruits and Cratylia argentea foliage

The effects of supplementing a tropical, low-quality grass hay (Brachiaria dictyoneura) with legume foliage (Cratylia argentea) or fruits of the multipurpose tree Sapindus saponaria on ruminal fermentation, methane release and nitrogen (N) utilization were evaluated. Six Swiss White Hill lambs were used in a 6 ✕ 6 Latin-square design with a 3 ✕ 2 factorial arrangement of treatments with measurements of energy metabolism being conducted using open-circuit respiratory chambers. Treatments consisted of three basal diets, either grass alone or legume: grass ratios of 1: 2 or 2: 1. These basal diets were supplemented (1: 3) with a control concentrate or with a concentrate containing 250 g/kg dry matter of S. saponaria fruits. The apparent total tract digestibilities of organic matter (OM) and neutral-detergent fibre (NDF) were reduced and the proportionate crude protein (CP) losses through faeces were increased (P 0·01) by supplementation with S. saponaria, and digestibilities of OM and NDF were linearly reduced (P 0·001) with increasing legume proportion. Body energy retention, however, was similar in all diets. Along with CP intake, the proportionate CP losses through faeces decreased (P 0·001) with increasing legume proportion which was associated with improved (P 0·001) body protein retention and reduced (P 0·1) fat retention. Ruminal fluid ammonia concentration was not significantly affected (P > 0·1) by the inclusion of S. saponaria in the concentrate, but increased linearly (P 0·001) as dietary legume proportion was elevated. Supplementation with fruits of S. saponaria increased (P 0·01) total bacteria count, and decreased (P 0·001) total ciliate protozoa count by more than proportionately 0·50. Daily methane release was reduced (P 0·01) by S. saponaria supplementation in all basal diet types. Although being not clearly affected on a daily basis, methane release relative to body protein retention decreased linearly (P 0·05) with increasing legume proportion. The fact that interactions were mostly non-significant (P > 0·05) indicates that supplementation with S. saponaria fruits is a useful means to reduce methane emission from sheep given both tropical grass-based and grass-legume-based diets. Likewise, including legumes in N-limited tropical diets seems to represent an environmentally friendly way to improve animal productivity.

Effect of replacing oat fodder with fresh and chopped oak leaves on in vitro rumen fermentation, digestibility and metabolizable energy

AIM

A study was conducted to evaluate the effect of replacing oat fodder (OF) with fresh oak leaves (FOL) or chopped oak leaves (COL) on rumen fermentation and digestibility through in vitro gas production technique (IVGPT).

MATERIALS AND METHODS

Nine different diets were prepared by mixing OF with oak leaves (either FOL or COL) in different ratios (100:0, 75:25, 50:50, 25:75, and 0:100). The rations were evaluated through Hohenheim IVGPT with 200 mg substrate and 30 ml of buffered rumen liquor. All the syringes were incubated at 39°C for 24 h in buffered rumen liquor of cattle. After 24 h, the total gas production was recorded, and the contents were analyzed for in vitro methane production, protozoa no. and ammonia-N.

RESULTS

Chopping (p<0.01) reduced the tannin fractions as well as non-tannin phenol. Increase in levels of oak decreased total gas production, methane, organic matter (OM) digestibility, and metabolizable energy (ME) values. The polyphenol content of the substrate did not show any significant difference on the protozoal count.

CONCLUSION

In vitro studies revealed that the addition of oak leaves reduced the methane production and ammonia nitrogen levels; however, it also decreased the OM digestibility and ME values linearly as the level of the oak leaves increased in the diet. Chopping was effective only at lower inclusion levels. Further studies, especially in vivo studies, are needed to explore the safe inclusion levels of oak leaves in the diet of ruminants.

Effects of supplementing rare earth element cerium on rumen fermentation, nutrient digestibility, nitrogen balance and plasma biochemical parameters in beef cattle

The objectives of the trial were to investigate the effects of supplementing rare earth element (REE) cerium (Ce) on rumen fermentation, nutrient digestibility, methane (CH4 ) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged at 14 months, with initial liveweight of 355 ± 8 kg and fitted with permanent rumen cannulas, were used as experimental animals. The cattle were fed with a total mixed ration (TMR) composed of concentrate mixture and corn silage. Four levels of cerium chloride (CeCl3 ·7H2 O, purity 99.9%), that is 0, 80, 160 and 240 mg CeCl3 /kg DM, were added to basal ration in a 4 × 4 Latin square design. Each experimental period lasted 15 days, of which the first 12 days were for pre-treatment and the last 3 days were for sampling. The results showed that supplementing CeCl3 at 160 or 240 mg/kg DM increased neutral detergent fibre (NDF) digestibility (p < 0.05) and tended to increased acid detergent fibre (ADF) digestibility (p = 0.083). Supplementing CeCl3 at 80, 160 or 240 mg/kg DM decreased the molar ratio of rumen acetate to propionate linearly (p < 0.05). Supplementing CeCl3 at 160 or 240 mg/kg DM decreased total N excretion, urinary N excretion and increased N retention (p < 0.05), increased excretion of total urinary purine derivatives (PD) (p < 0.05) and decreased CH4 /kg DMI (p < 0.05). In conclusion, supplementing CeCl3 at 160 or 240 mg/kg DM in the ration of beef cattle increased the digestibility of NDF, decreased the molar ratio of rumen acetate to propionate, increased N retention and microbial N flow and decreased CH4 /kg DMI.

Comparison of the effects of lanthanum, cerium and praseodymium on rumen fermentation, nutrient digestion and plasma biochemical parameters in beef cattle

The objectives of the trial were to compare the effects of supplementing rare earth elements (REE) lanthanum (La), cerium (Ce) and praseodymium (Pr) on rumen fermentation, nutrient digestion, methane (CH4) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged 12 months, with initial average liveweight of 333 ± 9 kg and fitted with rumen cannulas, were fed with a basal ration composed of concentrate mixture and maize silage. Animals received a basal ration without adding REE (Control) or three treatments, i.e. supplementing LaCl3, CeCl3 or PrCl3 at 204 mg/kg DM to the basal ration, respectively, which were allocated in a 4 × 4 Latin square design. Each experimental period lasted 15 d, consisting of 12 d for pre-treatment and three subsequent days for sampling. Results showed that all tested levels of REE tended to increase neutral detergent fibre digestibility (p = 0.064) and tended to decrease rumen CH4 production (p = 0.056). Supplementing LaCl3 and CeCl3 decreased total N excretion and urinary N excretion, increased N retention (p < 0.05), tended to increase total urinary purine derivatives (PD) (p = 0.053) and microbial N flow (p = 0.095), whereas supplementing PrCl3 did not affect N retention, urinary PD and microbial N flow. No differences were found in the effects of nutrient digestibility, CH4 production and plasma biochemical parameters among LaCl3, CeCl3 and PrCl3. Further trials using graded levels of LaCl3, CeCl3 and PrCl3 in a wide range are needed to obtain more pronounced results for comparing effects of La, Ce and Pr on rumen fermentation and nutrient digestion in beef cattle.

Effects of rare earth element lanthanum on rumen methane and volatile fatty acid production and microbial flora in vitro

The objectives of the trial were to study the effects of rare earth element (REE) lanthanum (La) on the in vitro rumen methane (CH4 ) and volatile fatty acid (VFA) production and the microbial flora of feeds. Four feed mixtures with different levels of neutral detergent fibre (NDF), that is 20.0% (I), 31.0% (II), 41.9% (III) and 52.7% (IV), were formulated as substrates. Five levels of LaCl3 , that is 0, 0.4, 0.6, 0.8 and 1.0 mmol/kg dry matter (DM), were added to the feed mixtures, respectively, as experimental treatments in a two-factor 5 × 4 randomized design. The in vitro incubation lasted for 24 h. The results showed that supplementing LaCl3 increased the total gas (p < 0.001) production and tended to increase the total VFA production (p = 0.072) and decreased the CH4 production (p = 0.001) and the ratios of acetate/propionate (p = 0.019) and CH4 /total VFA (p < 0.001). Interactions between LaCl3 and NDF were significant in total gas production (p = 0.030) and tended to be significant in CH4 production (p = 0.071). Supplementing LaCl3 at the level of 0.8 mmol/g DM decreased the relative abundance of methanogens and protozoa in the total bacterial 16S rDNA analysed using the real-time PCR (p < 0.0001), increased F. succinogenes (p = 0.0003) and decreased R. flavefaciens (p < 0.0001) whereas did not affect R. albus and anaerobic fungi (p > 0.05). It was concluded that LaCl3 decreased the CH4 production without negatively affecting feed digestion through manipulating rumen microbial flora when feed mixtures with different levels of NDF were used as substrates.

Effects of Cordyceps militaris on the growth of rumen microorganisms and in vitro rumen fermentation with respect to methane emissions

This experiment was designed to investigate the effects of different concentrations (0.00, 0.10, 0.15, 0.20, 0.25, and 0.30 g/L) of dried Cordyceps militaris mushroom on in vitro anaerobic ruminal microbe fermentation and methane production using soluble starch as a substrate. Ruminal fluids were collected from Korean native cattle, mixed with phosphate buffer (1:2), and incubated anaerobically at 38 °C for 3, 6, 9, 12, 24, 36, 48, and 72 h. The addition of C. militaris significantly increased total volatile fatty acid and total gas production. The molar proportion of acetate was decreased and that of propionate was increased, with a corresponding decrease in the acetate:propionate ratio. As the concentration of C. militaris increased from 0.10 to 0.30 g/L, methane and hydrogen production decreased. The decrease in methane accumulation relative to the control was 14.1, 22.0, 24.9, 39.7, and 40.9% for the 0.10, 0.15, 0.20, 0.25, and 0.30 g/L treatments, respectively. Ammonia-N concentration and numbers of live protozoa decreased linearly with increasing concentrations of C. militaris. The pH of the medium significantly decreased at the highest level of C. militaris compared with the control. In conclusion, C. militaris stimulated mixed ruminal microorganism fermentation and inhibited methane production in vitro. Therefore, C. militaris could be developed as a novel compound for antimethanogenesis.

Meta-analysis on Methane Mitigating Properties of Saponin-rich Sources in the Rumen: Influence of Addition Levels and Plant Sources

Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (p<0.05). There was a decrease in acetate proportion (linear pattern; p<0.001) and an increase in propionate proportion (linear pattern; p<0.001) with increasing levels of saponin. Log protozoal count decreased (p<0.05) at higher saponin levels. Comparing between different saponin-rich sources, all saponin sources, i.e. quillaja, tea and yucca saponins produced less methane per unit of total gas than that of control (p<0.05). Although numerically the order of effectiveness of saponin-rich sources in mitigating methane was yucca>tea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent.

Effect of increasing levels of seven tree species extracts added to a high concentrate diet on in vitro rumen gas output

This study was conducted to investigate the effects of increasing levels of extracts of Byrsonima crassifolia, Celtis pallida, Enterolobium cyclocarpum, Fraxinus excelsior, Ficus trigonata, Phoradendrom brevifolium and Prunus domestica on in vitro gas production (GP) and ruminal fermentation of a high concentrate diet. Plant extracts were prepared at 1 g dry matter (DM)/8 mL of solvent mixture (methanol : ethanol : water, 1:1:8) and added at levels of 0, 0.6, 1.2 and 1.8 mL/g DM of a high concentrate diet. In vitro GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48 and 72 h of incubation. Increasing addition of extracts linearly increased (P < 0.001), the GP24 , GP48 and GP72 (mL/g DM), and linearly decreased (P < 0.001), the discrete GP lag time. Moreover, increasing extract doses linearly increased (P < 0.001) the asymptotic GP and decreased (P < 0.001) the rate of GP. GP6 was not impacted by treatments and GP12 increased linearly (P = 0.01) with increasing addition of extracts. Rumen pH declined linearly (P < 0.05) with increasing doses of extracts added. As no interactions (P > 0.05) occurred between the extracts and doses, it could be conclude that all extracts positively modified rumen fermentation at doses of 1.2 to 1.8 mL extract/g diet DM.

Influence of Albizia lebbeck Saponin and Its Fractions on In Vitro Gas Production Kinetics, Rumen Methanogenesis, and Rumen Fermentation Characteristics

The present study was undertaken to investigate the effect of crude seed powder (CSP) and gross saponins extract (GSE) of seeds of Albizia lebbeck on antimicrobial activity by taking two Gram-positive (Staphylococcus aureus and Bacillus cereus), two Gram-negative (Escherichia coli and Salmonella Typhi) bacteria, and two fungi species (Aspergillus niger and Candida butyric) were taken at 25, 50, 100, 250, and 500 µg levels using agar well diffusion method. Zone of inhibition was increased with increasing of concentration of CSP and saponins which indicates that Gram-negative bacteria (E. coli), Gram-positive bacteria (B. cereus), and A. niger were significantly susceptible to inhibition. Another experiment was conducted to study the effect of GSE and saponins fraction A and B of A. lebbeck supplementation at 6% on DM basis on methane production and other rumen fermentation parameters using in vitro gas production test, by taking three different type diets, that is, high fiber diet (D1, 60R : 40C), medium fiber diet (D2, 50R : 50C), and low fiber diet (D3, 40R : 60C). Significant (P ≤ 0.05) increase was seen in IVDMD, methane production; however ammonia nitrogen concentration decreased as compared to control. The methane production was reduced in a range between 12 and 49% by saponin supplemented diets except in case of GSE in D2. Sap A showed the highest methane reduction per 200 mg of truly digested substrate (TDS) than other treatment groups. Results in relation with quantification of methanogens and protozoa by qPCR indicated the decreasing trend with saponins of A. lebbek in comparison with control except total methanogen quantified using mcr-A based primer.

Nutrient content, in vitro ruminal fermentation characteristics and methane reduction potential of tropical tannin-containing leaves

BACKGROUND

Plant tannins as rumen modifiers are better than chemicals or antibiotic-based modifiers since these compounds are natural products which are environmentally friendly and therefore have a better acceptance with regard to feed safety issues. Tropical plants containing phenols such as tannins were found to suppress or eliminate protozoa from the rumen and reduce methane and ammonia production. The screening of these plants is an important step in the identification of new compounds and feed additives which might contribute to mitigate rumen methanogenesis. The present study was carried out to determine the efficacy of tannins from tropical tree leaves for their methane reduction properties.

RESULTS

Activity of tannins, as represented by the increase in gas volume with the addition of polyethylene glycol (PEG)-6000 as a tannin binder (tannin bioassay) was highest in Ficus bengalensis (555%), followed by Azardirachta indica (78.5%). PEG addition did not alter (P > 0.05) methane percentage in Ficus racemosa, Glyricidia maculata, Leucena leucocephala, Morus alba and Semaroba glauca, confirming that tannins in these samples did not affect methanogenesis. The increase (P < 0.05) in protozoa population with PEG was maximal in Ficus religiosa (50), followed by Moringa oleifera (31.2), Azardirachta indica (29.9) and Semaroba glauca (27.5). There was no change (P > 0.05) in the protozoa population in Autocarpus integrifolia, Ficus bengalensis, Jatropha curcus, Morus alba and Sesbania grandiflora, demonstrating that methane reduction observed in these samples per se was not due to defaunation effect of the tannin. The increase in total volatile fatty acid concentration in samples with PEG ranged from 0.6% to > 70%. The highest increase (%) in NH(3)-N was recorded in Azardirachta indica (67.4), followed by Ficus mysoriensis (35.7) and Semaroba glauca (32.6) leaves, reflecting strong protein binding properties of tannin.

CONCLUSION

The results of our study established that in vitro methanogenesis was not essentially related to the density of protozoa population. Tropical tree leaves containing tannins such as Autocarpus integrifolia, Jatropha curcus and Sesbania grandiflora have the potential to suppress methanogenesis. Therefore tannins contained in these plants could be of interest in the development of new additives in ruminant nutrition.

Bioactivity of phytochemicals in some lesser-known plants and their effects and potential applications in livestock and aquaculture production systems

Livestock and aquaculture production is under political and social pressure, especially in the European Union (EU), to decrease pollution and environmental damage arising due to animal agriculture. The EU has banned the use of antibiotics and other chemicals, which have been shown to be effective in promoting growth and reducing environment pollutants because of the risk caused to humans by chemical residues in food and by antibiotic resistance being passed on to human pathogens. As a result of this, scientists have intensified efforts in exploiting plants, plant extracts or natural plant compounds as potential natural alternatives for enhancing the livestock productivity. This paper discusses work on the effects of various phytochemicals and plant secondary metabolites in ruminant and fish species. The focus is on (i) plants such as Ananas comosus (pine apple), Momordica charantia (bitter gourd) and Azadirachta indica (neem) containing anthelmintic compounds and for their use for controlling internal parasites; (ii) plants containing polyphenols and their applications for protecting proteins from degradation in the rumen, increasing efficiency of microbial protein synthesis in rumen and decreasing methane emission; for using as antioxidants, antibacterial and antihelmintic agents; and for changing meat colour and for increasing n-3 fatty acids and conjugated linoleic acid in meat; (iii) saponin-rich plants such as quillaja, yucca and Sapindus saponaria for increasing the efficiency of rumen fermentation, decreasing methane emission and enhancing growth; for producing desired nutritional attributes such as lowering of cholesterol in monogastric animals; for increasing growth of fish (common carp and Nile tilapia) and for changing male to female ratio in tilapia; and for use as molluscicidal agents; (iv) Moringa oleifera leaves as a source of plant growth factor(s), antioxidants, beta-carotene, vitamin C, and various glucosinolates and their degraded products for possible use as antibacterial, antioxidant, anticarcinogenic and antipest agents; (v) Jatropha curcas toxic variety with high levels of various phytochemicals such as trypsin inhibitor, lectin, phytate and phorbol esters in seeds limiting the use of seed meal in fish and livestock diets; and the use of phorbol esters as bio-pesticidal agent; and (vi) lesser-known legumes such as Entada phaseoloides seeds containing high levels of trypsin inhibitor and saponins, Sesbania aculeate seeds rich in non-starch polysaccharides and Mucuna pruriens var. utilis seeds rich in l-3,4-dihydroxyphenylalanine and their potential as fish feed; Cassia fistula seeds as a source of antioxidants; and the use of Canavalia ensiformis, C. gladiata and C. virosa seeds containing high levels of trypsin inhinitor, lectins and canavanine. The paper also presents some challenges and future areas of work in this field.

Phenolic Composition, Fermentation Profile, Protozoa Population and Methane Production from Sheanut (Butryospermum Parkii) Byproducts In vitro

Sheanut cake (SNC), expeller (SNE) and solvent extractions (SNSE) samples were evaluated to determine their suitability in animal feeding. The CP content was highest in SNSE (16.2%) followed by SNE (14.7%) and SNC (11.6%). However, metabolizable energy (ME, MJ/kg) was maximum in SNC (8.2) followed by SNE (7.9) and SNSE (7.0). The tannin phenol content was about 7.0 per cent and mostly in the form of hydrolyzable tannin (HT), whereas condensed tannin (CT) was less than one per cent. The in vitro gas production profiles indicated similar y max (maximum potential of gas production) among the 3 by-products. However, the rate of degradation (k) was maximum in SNC followed by SNE and SNSE. The t(1/2) (time taken for reaching half asymptote) was lowest in SNC (14.4 h) followed by SNE (18.7 h) and SNSE (21.9 h). The increment in the in vitro gas volume (ml/200 mg DM) with PEG (polyethylene glycol)-6000 (as a tannin binder) addition was 12.0 in SNC, 9.6 in SNE and 11.0 in SNSE, respectively. The highest ratio of CH4 (ml) reduction per ml of the total gas, an indicator of the potential of tannin, was recorded in SNE (0.482) followed by SNC (0.301) and SNSE (0.261). There was significant (p<0.05) reduction in entodinia population and total protozoa population. Differential protozoa counts revealed that Entodinia populations increased to a greater extent than Holotricha when PEG was added. This is the first report on the antimethanogenic property of sheanut byproducts. It could be concluded that all the three forms of SN byproducts are medium source of protein and energy for ruminants. There is a great potential for SN by-products to be incorporated in ruminant feeding not only as a source of energy and protein, but also to protect the protein from rumen degradation and suppress enteric methanogenesis.