Volatile Fatty Acid Profile Research Articles

Sequential dark fermentation and microbial electrolysis cells for hydrogen production: Volatile fatty acids influence and energy considerations

Hydrogen production from food waste by coupling dark fermentation (DF) and microbial electrolysis cells (MEC) was studied. Metabolic patterns in DF, their effects on MECs efficiency, and the energy output of the coupling were investigated. Mesophilic temperature and acidic pH 5.5 resulted in 72 ± 20 mL H2/g CODin and a butyrate-enriched profile (C2/C4, 0.5–0.6) contrasting with an acetate-enriched profile (C2/C4, 1.8–1.9) and 36 ± 10 mL H2/g CODin at pH 7. Assessment in series of the DF effluents in MECs resulted in a higher hydrogen yield (566–733 mL H2/g CODin) and volatile fatty acids (VFAs) removal (84–95%) obtained from pH 7 effluents compared to pH 5.5 effluents (173–186 mL H2/g CODin and 29–59%). Finally, the output energy was lower in DF at pH 7, however, these effluents retrieved the highest energy in the MEC, showing the importance of process pH and VFAs profile to balance the coupling.

Chemical composition of different plant part from Lactuca serriola L.- focus on volatile compounds and fatty acid profile.

The family Asteraceae comprises many species that have medicinal importance in terms of their chemical components. Some species of the genus Lactuca have been used in folk medicine for a long time ago. One of them is L.serriola L., a wild plant that is a weed in agriculture. To date, few studies have been published on its chemical profile. In this research, we investigated the volatile compounds andfatty acids of L.serriola roots, leaves, and seeds. To this end, a microsteam distillation-solid phase microextraction technique (MSD-SPME) followed by a gaschromatography-mass spectrometry analysis was performed. Aldehydes and terpenoids were predominantly present in the leaves with phenylacetaldehyde as the major compound (up to 18%) while2-ethyl hexanol (up to 36.9%) was the most abundant substance in the roots. Among the fatty acids, nonadecanoic acid (38.3%) was the main one detected in the leaves, while linoleic acid (57.7%) was predominant in the seeds. Some ofthe detected constituents have already demonstrated importance in medicinal and industrial areas. As a result, this species could be further investigated for its biological features and be considered as a source of ingredients beneficial in different fields, including pharmaceuticals.

Nutritional and quality evaluation of hyperbaric stored fresh cheeses

Cow's and goat's fresh cheese (FC), two highly perishable dairy products, were stored under hyperbaric storage at room temperature (HS/RT, 50–100 MPa) and compared with refrigeration (RF, 4 °C), for 60 days.Under HS/RT (≥75 MPa), FCs presented a more stable volatile organic and fatty acid profiles, and reduced lipid oxidation rate, particularly for cow's FC, resembling more to FC prior storage, contrarily to refrigerated cheeses. No changes were observed for total protein, but free amino acids increased over time after 60 days at 75/RT of 13- and 16-fold, and at 100/RT of 14- and 8-fold, respectively in cow's and goat's FC, which may have contributed to increased protein digestibility (5.2%) observed for goat's FC after 60 days at 100/RT.In general, the results indicate the overall increased preservation performance achieved by HS/RT for cow's and goat's FC when compared with RF, slowing down FC matrix degradation, possibly leading to considerable shelf-life extension.

Replacing Concentrate with Yeast- or EM-Fermented Cassava Peel (YFCP or EMFCP): Effects on the Feed Intake, Feed Digestibility, Rumen Fermentation, and Growth Performance of Goats.

The goal of this study was to improve the nutritional value of cassava peel by using yeast (Saccharomyces cerevisiae) or effective microorganisms (EM), then use it as a replacement for concentrate, and examine the effects on the feed intake, feed digestibility, rumen fermentation, and growth performance of goats. The experimental design was a randomized complete block design (RCBD), and the dietary treatments were (1) concentrate, (2) replacement of the concentrate by yeast-fermented cassava peel (YFCP) at 50% and (3) replacement of the concentrate by EM-fermented cassava peel (EMFCP) at 50%. Twelve goats were given concentrate based on their treatments at a rate of 1.5% of their body weight. Rice straw was used as roughage and fed freely. It was found that the crude protein (CP) content of the cassava peel from 2.1% to 13.7-13.8% after 14 days of fermentation. Moreover, there were no significant differences between the treatments in terms of the feed intake, feed digestibility, ruminal pH, blood urea nitrogen concentration, volatile fatty acid profile, overall average daily gain, and feed efficiency. However, the cost of the feed per gain decreased when the YFCP or EMFCP was used instead of the concentrate. Based on the results of this experiment, it was possible to conclude that yeast or EM might be utilized as microorganisms to increase the nutritional value of cassava peel. Moreover, YFCP or EMFCP can replace concentrate by up to 50% without an impact on the feed intake, feed digestibility, rumen fermentation characteristics, and the growth performance; whereas, it can reduce the feed cost per gain up to 32%.

Phytogenic blend in the diet of growing Holstein steers: Effects on performance, digestibility, rumen volatile fatty acid profile, and immune and antioxidant responses

The present study determined whether adding the phytogenic blend to the diet of growing steers would improve weight gain, the apparent digestibility of nutrients, volatile fatty acid profiles, and alter immune and antioxidant responses. The experiment included 24 Holstein calves, with an average weight of 149.6 ± 5 kg maintained in a semi-confinement system. The animals were divided into two groups (treated and control). In the concentrate of the treated group, the test product was a phytogenic blend composed of micro-encapsulated cinnamon and oregano essential oils, free turmeric extract, and tannic acid. The animals in the treated group showed more significant weight gain than the control on day 30; there was a trend toward more significant weight gain from 1 to 60 days (P = 0.07). Butyric acid concentrations were higher in the rumen, and there was an interaction between treatment and day (day 30) in the treated group. The ruminal acetic and propionic acid concentrations were higher in animals in the treated group on day 30. The intake of the phytogenic blend increased the apparent digestibility coefficient of neutral detergent fiber but did not affect the apparent digestibility coefficient of dry matter, crude protein, or mineral matter. There were significantly fewer lymphocytes in the treated group on day 30. There was a treatment effect and interaction between treatment and day for cholesterol levels, with lower levels in the treated group than in the control group. Serum glucose concentrations were lower in animals in the treated group. There was an effect of the treatment on the concentration of total proteins and globulins, with the highest levels of these proteins in the animals in the treated group. Protein electrophoresis revealed that IgA and ceruloplasmin levels showed a treatment effect and interaction, with higher levels in the treated group (P < 0.05). Heavy chain immunoglobulin levels were lower in steers in the treated group at day 90. Thiobarbituric acid reactive substance levels were lower in the treated group, indicating less lipid peroxidation (P < 0.05). We found that the levels of reactive oxygen species were lower in the treatment group at day 30, and glutathione S-transferase activity and protein thiol levels were higher in this group. These findings suggest that adding the phytogenic blend to the animals' diet was critical in the initial phase, as it modulates volatile fatty acids, stimulates immunological biomarkers, and has antioxidant activity.

Enhancing Biobased Volatile Fatty Acids Production from Olive Mill Solid Waste by Optimization of pH and Substrate to Inoculum Ratio

The pH and substrate-to-inoculum ratio (S/I) are important parameters in the anaerobic fermentation of agroindustrial residues, and therefore the optimization of these two parameters is needed for a stable, efficient, and sustainable reactor operation. In this work, the parameters pH (5–9) and S/I (0.5–3 gVS gVS−1) were optimized to produce biobased volatile fatty acids (VFAs) from hydrothermally pretreated olive mill solid waste (HPOMSW). The response variables evaluated in the Doehlert design were total VFAs concentration (tVFAs) (mg L−1) and amounts (%) of isobutyric, butyric, isovaleric, and valeric acids on the VFAs profile. The pH was the variable that most influenced the mixed culture fermentation of HPOMSW, proving to be a key parameter in the process. Microbial community analyses of conditions 1 (S/I = 3 gVS gVS−1 and pH = 7) and 4 (S/I = 1.13 gVS gVS−1 and pH = 5) showed that Proteobacteria and Firmicutes accounted for more than 87% of the total microorganisms identified for both conditions. In addition, the second-order model best fitted the experimental data for the VFAs production at the desirable condition (S/I = 3 gVS gVS−1 and pH = 8).

Tropical tree foliage supplementation in ruminants improves rumen fermentation and the bacterial profile and decreases methane production

The main of this study was to evaluate the effect of supplementation of tropical tree foliage in ruminant diets on the in vitro fermentation, bacterial population, volatile fatty acids (VFAs), and enteric CH4 production. Seven experimental diets were evaluated: a control treatment of Pennisetum purpureum (T7) and six treatments of P. purpureum supplemented (30%) with the foliage of Neomillspaughia emargiata (T1), Tabernaemontana amygdalifolia (T2), Caesalpinia gaumeri (T3), Piscidia piscipula (T4), Leucaena leucocephala (T5), and Havardia albicans (T6). The T2, T7, and T5 treatments had the highest (p < 0.05) digestibility of dry matter. Overall, supplementation increased (p < 0.05) the concentrations of propionic and butyric acid and decreased acetic acid. Methanogenic bacteria decreased (p < 0.05) in T1, T2, T5, and T6. Ruminococcus albus decreased in T1, T2, T3, and T5 and Selenomonas ruminiantum increased in T3. Fibrobacter succinogenes increased, except in T5. Methane production decreased (p < 0.05) in T1, T4, T5, and T6. The supplementation with Leucaena leucocephala, Tabernaemontana amygdalifolia, Neomillspaughia emargiata, Piscidia piscipula, Havardia albicans, and Caesalpinia gaumeri is a potential alternative nutritional strategy for ruminants that results in positive changes in VFAs profile, a decrease on CH4 production and methanogenic bacteria, and changes on fibrolytic and non-fibrolytic bacteria composition. HIGHLIGHTS Tropical tree foliage supplementation increased propionic and butyric acid and decreased acetic acid concentrations. Fibrolytic, non-fibrolytic, and Methanogenic bacteria were selectively modulated with the supplementation of tropical tree foliage. The enteric methane (CH4) production decreased with the supplementation of tree foliage. The supplementation of Tabernaemontana amygdalifolia and Leucaena leucocephala had the highest digestibility and is a potential alternative nutritional strategy for ruminants.

Effects of a novel direct-fed microbial on growth performance, carcass characteristics, nutrient digestibility, and ruminal morphology of beef feedlot steers.

The effects of a novel direct-fed microbial (DFM) on feedlot performance, carcass characteristics, digestibility, ruminal morphology, and volatile fatty acid (VFA) profile of finishing steers were evaluated. Single-source Angus-crossbred yearling steers (n = 144; initial body weight (BW) = 371 ± 19kg) were used in a randomized complete block design. Steers were blocked by initial BW and randomly assigned to treatments (12 pens/treatment; 4 steers/pen). Treatments included (A) CONTROL (no DFM, tylosin, or monensin, (B) MONTY (monensin sodium [330mg/animal-daily] and tylosin phosphate [90mg/animal-daily]), and (C) MONPRO (monensin sodium [same as previous] and Lactobacillus salivarius L28 [1 × 106 CFU/animal-daily]). Treatments were included in a steam-flaked corn-based finisher diet offered once daily using a clean-bunk management for ~149d. The digestibility assessment was performed from days 70 to 74. Ruminal fluid and rumen tissue samples were collected at the slaughter for VFA profile and papillae morphology analyses, respectively. Data were analyzed using the GLIMMIX procedure of SAS with pen serving as the experimental unit, treatment as fixed effect, and BW block as random effect. Steers offered MONPRO had on average 5.3% less (P < 0.01) dry matter intake (9.56kg/d) compared with either CONTROL (10.16kg/d) or MONTY (9.96kg/d). The carcass-adjusted final BW (613kg; P = 0.23), overall average daily gain (1.64kg/d; P = 0.23), and gain-efficiency (0.165; P = 0.61) were not affected by treatments. Steers offered CONTROL had greater (P < 0.01) marbling score and tended (P = 0.06) to have less carcasses grading Select and tended (P = 0.10) to have more carcasses grading Upper-Choice, while other carcass characteristics and liver-abscesses were not affected (P ≥ 0.23) by treatments. The digestibility of nutrients (P ≥ 0.13) and the ruminal VFA profile (P ≥ 0.12) were not affected by treatments. Steers offered MONPRO tended (P = 0.09) to have 16% greater average papillae number compared to other treatments. Yearlings offered finishing diets containing L. salivarius L28 plus monensin did not affect growth performance, digestibility, or ruminal VFA, but reduced feed intake. Carcass quality was negatively affected by treatments, while animals consuming L. salivarius L28 and monensin tended to improve ruminal morphology. Current findings in ruminal morphology and feed intake may warrant further assessment of diets containing L. salivarius L28 on beef cattle food safety aspects.

Accumulation of Volatile Fatty Acids from Hydrothermally Treated Strawberry Extrudate through Anaerobic Fermentation at Different pH Values

The accumulation of volatile fatty acids (VFAs) through the anaerobic fermentation of organic waste, such as strawberry extrudate, is proposed for this work. A hydrothermal treatment was carried out, and it was proposed to break the complex matrix of the strawberry extrudate to favour the hydrolysis stage of the anaerobic digestion process. The production of volatile fatty acids from treated and untreated strawberry was evaluated by adjusting the pH to 5 and 9. After the hydrothermal treatment of the strawberry extrudate, an increase in the solubilisation of organic matter, such as sugars and phenols, was observed. In the production of VFAs by means of anaerobic digestion of the pretreated strawberry extrudate, a significant increase in the accumulation of volatile fatty acids was demonstrated at a pH of 9 with respect to the untreated strawberry extrudate. In addition, the operational pH also had a strong effect on the individual VFA profile. A stream enriched in acetic acid was obtained at a pH of 9 (around 65% of the VFAs), whereas the operation at a pH of 5 resulted in a more complex composition with a high percentage of propionic acid (29% of the VFAs).

Evaluating Ruminal and Small Intestinal Morphology and Microbiota Composition of Calves Fed a Macleaya cordata Extract Preparation.

The objective was to determine the impact of feeding MCE on ruminal and intestinal morphology and microbiota composition of calves. A total of 10 male and 10 female crossbred (dairy × beef) calves (6 d of age) were assigned randomly to control (CTL; n = 10) or MCE-supplemented (TRT; n = 10) groups. The MCE was fed in the milk replacer and top-dressed on the calf starter during pre-weaning (6 to 49 d) and post-weaning (50 to 95 d) periods, respectively. Calves were slaughtered at 95 d to collect rumen and intestinal samples to determine volatile fatty acid (VFA) profile, mucosal morphology, and microbiota composition. The effects of MCE were analyzed by accounting for the sex and breed effects. Feeding MCE increased rumen papillae length (p = 0.010) and intestinal villus height: crypt depth (p < 0.030) compared to CTL but did not affect rumen VFA profile. The TRT had a negligible impact on microbial community composition in both the rumen and the jejunum. In conclusion, feeding MCE from birth through weaning can improve ruminal and small intestinal mucosa development of calves despite the negligible microbiota composition changes observed post-weaning.

Interactions between Entodinium caudatum and an amino acid-fermenting bacterial consortium: fermentation characteristics and protozoal population in vitro.

Ruminal protozoa, especially entodiniomorphs, engulf other members of the rumen microbiome in large numbers; and they release oligopeptides and amino acids, which can be fermented to ammonia and volatile fatty acids (VFAs) by amino acid-fermenting bacteria (AAFB). Studies using defaunated (protozoa-free) sheep have demonstrated that ruminal protozoa considerably increase intraruminal nitrogen recycling but decrease nitrogen utilization efficiency in ruminants. However, direct interactions between ruminal protozoa and AAFB have not been demonstrated because of their inability to establish axenic cultures of any ruminal protozoan. Thus, this study was performed to evaluate the interaction between Entodinium caudatum, which is the most predominant rumen ciliate species, and an AAFB consortium in terms of feed degradation and ammonia production along with the microbial population shift of select bacterial species (Prevotella ruminicola, Clostridium aminophilum, and Peptostreptococcus anaerobius). From an Ent. caudatum culture that had been maintained by daily feeding and transfers every 3 or 4 days, the bacteria and methanogens loosely associated with Ent. caudatum cells were removed by filtration and washing. An AAFB consortium was established by repeated transfers and enrichment with casamino acids as the sole substrate. The cultures of Ent. caudatum alone (Ec) and AAFB alone (AAFB) and the co-culture of Ent. caudatum and AAFB (Ec + AAFB) were set up in three replicates and incubated at 39°C for 72 h. The digestibility of dry matter (DM) and fiber (NDF), VFA profiles, ammonia concentrations, pH, and microscopic counts of Ent. caudatum were compared among the three cultures. The co-culture of AAFB and Ent. caudatum enhanced DM degradation, VFA production, and Ent. caudatum cell counts; conversely, it decreased acetate: propionate ratio although the total bacterial abundance was similar between Ec and the Ec + AAFB co-culture after 24 h incubation. The ammonia production and relative abundance of C. aminophilum and P. anaerobius did not differ between AAFB alone and the Ec + AAFB co-culture. Our results indicate that Ent. caudatum and AAFB could have a mutualistic interaction that benefited each other, but their interactions were complex and might not increase ammoniagenesis. Further research should examine how such interactions affect the population dynamics of AAFB.

Live yeast supplementation altered the bacterial community's composition and function in rumen and hindgut and alleviated the detrimental effects of heat stress on dairy cows.

The objective of this study was to investigate the effects of live yeast (LY, Saccharomyces cerevisiae) on the lactation performance, bacterial community, and functions in the rumen and hindgut of dairy cows under heat stress. Thirty-three multiparous (parity 3.9 ± 0.8) Holstein dairy cows (189.1 ± 6.6 d in milk at the beginning of the experiment) were randomly assigned to three groups (11 cows per treatment). Cows in the three groups were fed a diet without yeast (CON), with 10 g yeast/d/head (LY-10), and with 20 g yeast/d/head (LY-20). The yeast product contained 2.0 × 1010 CFU/g. Supplementing LY decreased the rectal temperature and respiratory rate of cows, and increased dry matter intake, milk yield, milk fat yield, milk protein yield, and milk lactose yield (P < 0.001), yet decreased milk urea nitrogen concentration (P = 0.035). Interaction effects of treatment × week were observed for rectal temperature (P < 0.05), respiratory rate (P < 0.05), milk yield (P = 0.015), milk urea nitrogen (P = 0.001), milk protein yield (P = 0.008), and milk lactose yield (P = 0.030). In rumen, LY increased the concentrations of acetate, isobutyrate, isovaterate, valerate, total volatile fatty acids (VFAs), and NH3-N (P < 0.05). Miseq sequencing of the 16S rRNA genes showed that LY increased the relative abundance of Prevotella and Prevotellaceae UCG-003 at the genus level with a series of enriched pathways in the metabolism of carbohydrates and protein. In fecal samples, LY did not affect the profile of VFAs (P > 0.05). Clostridium sensu stricto 1 (P = 0.013) and Actinobacillus (P = 0.011) increased in the relative abundance by LY, whereas Bacteroides (P = 0.016) and Oscillospirales UCG-010 (P = 0.005) decreased with a series of enriched pathways in carbohydrate metabolism, secondary bile acid biosynthesis. In summary, LY supplementation altered the bacterial community's composition and function in rumen and hindgut, and simultaneously alleviated the detrimental effects of heat stress on dairy cows. These findings provide extended insight into the effects of LY in the rumen and hindgut of dairy cows exposed to heat stress.

Replacing soybean meal with sunflower meal in laying hens rations and its effects on cecal volatile fatty acids profile and intestinal microbial colonization

This experiment was performed to evaluate the effects of replacing different levels of soybean meal with sunflower meal (with and without enzyme) on cecal volatile fatty acid profile and intestinal microbial colonization in laying hens. In this experiment, 360 laying hens from the age of 47 to 57 weeks, in 9 treatments and five replications (8 hens in each replicate) were performed as a 3 × 3 factorial experiment in a completely randomized design for ten weeks. The results showed that the replacement of 30 and 60 percent sunflower meal and enzyme (100 and 200 gr/ton) has significantly improved the concentration of n-valeric acid on the cecum of laying hens (P&lt; 0.05). Simultaneously, increasing 30 percentage of sunflower meal or 100 of an enzyme enhanced isovaleric acid, n-butyric acid, isobutyric acid, propionic acid, and acetic acid (P&lt; 0.05). Reduction in intestinal log Ecoli was discovered for samples treated with 30 and 60 percent of sunflower (P&lt;0.05), but for log baglus that treated with 30 and 60 percent of sunflower showed higher (P&lt;0.05). The main effects of the enzyme had no significant impact on the cecal microbial population (P&gt;.0.05) while, the effect of meal source and enzyme additive interactions on the tested parameters was significant (P&lt;.0.05). Hence, sunflower meal could be used as an alternative protein source in laying hens ration to improve cecal VFA profile and reduce cecal Ecoli population. Substitution of sunflower meal in laying hens is recommended.

Enhancing the recovery of volatile fatty acids from strawberry extrudate through anaerobic fermentation at different pH values

Strawberry extrudate (SE) is a by-product derived from the elaboration of strawberry-tasted products. Adequate management of this substrate would entail a new source of benefit for the berry sector, instead of a costly waste to be treated. The aim of this work is to assess the potential use of SE as a carbon soured for volatile fatty acids (VFA) production through anaerobic fermentation at controlled pH (5, and 9) and without pH control (operational pH around 7). Anaerobic digestion at pH 7 resulted in a negligible accumulation of VFA, being mainly degraded to methane. The operation at the other pHs resulted in a marked drop in methane production and, thus, the accumulation of VFA. At pH 9, around 50% of the fed COD tot (total chemical oxygen demand) was accumulated as VFA. Acetic acid represented 61% of these total VFA. The operation at pH 5 resulted in a lower VFA accumulation, i.e. 15% fed COD tot , although the VFA profile was more complex than at pH 9. Propionic and butyric acids represented 43% and 32%, respectively, of the total VFA accumulated at pH 5. • Operation at pH 5 and 9 effectively limited the methanogenesis activity. • pH 9 was the most effective pH to produce volatile fatty acids, mainly acetic acid. • Accumulation of propionic and butyric acids was favoured at pH 5. • pH 7 favoured the production of biogas instead of the accumulation of acids.

PSIX-5 Ruminal Papillae Morphology and Volatile Fatty Acid Profile of Beef Steers Consuming Finishing Diets with an Added Nutritional Packet in a Calf-fed System

Abstract The effects of a nutritional packet containing a direct-fed microbial combined with vitamins/electrolytes offered to beef steers in a calf-fed system on ruminal papillae morphology and volatile fatty acid (VFA) profile were evaluated. Angus crossbred steer-calves (n = 60; BW = 234 ± 4 kg) were assigned to a randomized complete block design (block = body weight; steer = experimental unit) and stratified into two treatments: a) control (no packet, finely-ground corn carrier only); and b) 30 g of DM/animal-daily of a nutritional packet [live-yeast (Saccharomyces cerevisiae; 8.7 Log CFU/g), Vitamin C (5.4 g/kg of Ascorbic acid), Vitamin B1 (13.33 g/kg of Thiamine hydrochloride), and electrolytes of NaCl (80 g/kg) and KCl (80 g/kg)]. Animals were individually offered [electronic feed-bunks (Smart-Feed/C-Lock Inc.)] a steam-flaked corn-based finishing diet ad libitum once daily for 233 d, while treatments were offered during the first and last 60 days on feed only. Upon harvest (federally inspected facility), individual samples of ruminal cranial sac epithelium and rumen content (quickly frozen) were collected. Preserved (70% alcohol at 5oC) ruminal tissue fragments were trimmed (1 cm2), in which papillae were counted, followed by a random removal of 12 individual papillae for further area measurement using electronic scanning (ImageJ). Data were analyzed using the GLIMMIX procedure of SAS. Steers offered to nutritional packet had a 30% increased (P = 0.02) average papillae area, which induced a tendency (P = 0.14) to improve ruminal absorptive surface area (89 vs. 93%), while not affecting ruminal papillae number (P = 0.39). Molar proportions of acetate, butyrate, and propionate were not affected (P ≥ 0.51) by treatments, while total VFA (mM) tended (P = 0.09) to increase by 8% for animals consuming the nutritional packet. The nutritional packet seemed to improve ruminal fermentation products while positively affecting ruminal papillae morphology.

In Vitro Fermentation and Degradation Characteristics of Rosemary Extract in Total Mixed Ration of Lactating Dairy Cows

Rosemary extract (RE) is characterized as an antioxidant, and it has the potential to reduce methane emission and change microbial fermentation. Hence, to the extent of the evaluation of RE in ruminant nutrition, the in vitro fermentation technique was used to investigate the effects of RE on the fermentation characteristics of a total mixed ration (TMR) fed to dairy cows. Different doses of RE were added to the TMR to obtain different concentrations of antioxidants, including 0 (CON), 0.05 (LRE), and 0.10 g/kg (HRE). A total of 500 mg ground TMR was incubated in buffer solution and rumen fluid for 48 h at 39 °C. Nutrient degradability, gas production parameters, gas composition, fermentation parameters, and microbial composition were analyzed. The results showed that nutrient degradability and total volatile fatty acid concentration were not affected by the treatments. Furthermore, total methane production and proportion were depressed in a dose-dependent way. The RE increased the propionate concentration and proportion linearly and decreased the acetate concentration and proportion linearly. Finally, microbial diversity analysis showed that the richness and evenness indexes were unchanged by different treatments, while Prevotella_1 was decreased and Prevotella_7 was increased with RE supplementation. In conclusion, RE is an effective inhibitor of methane emission of microbial fermentation and changed the profile of volatile fatty acids with no disadvantageous effects on diet utilization.

Comparative Elucidation of Aroma, Key Odorants, and Fatty Acid Profiles of Ivorian Shea Butter Prepared by Three Different Extraction Methods

In the present study, the volatile compounds, key odorants, and fatty acid profiles of Ivorian shea butter produced by cold press extraction (CPE), solvent extraction (SE) and traditional extraction (TE) methods were investigated for the first time. The aroma compounds of shea butter were extracted by the purge and trap method and analyzed by the gas chromatography–mass spectrometry and olfactometry (GC-MS/O) technique. Totals of 51, 49 and 46 aroma compounds were determined in samples from CPE, SE and TE, respectively. It was observed that the volatile compounds of studied material dominated after CPE, in which alcohols (11) were the most abundant chemical group, followed by aldehydes (10) and acids (7). The application of aroma extract dilution analysis (AEDA) resulted in 22, 20, and 16 key odorants in shea butter from CPE, SE and TE, respectively. 3-Hexanol with flavor dilution (FD) factors (2048 in CPS, 1024 in SE and 64 in TE) was found to be the most active aroma compound in all samples. In the fatty acid fraction obtained using the gas chromatography–flame ionization detector (GC-FID) method, 22, 24 and 19 fatty acids were detected in samples after CPE, SE and TE, respectively. The highest number of fatty acids was determined in shea butter using CPE (89.98%). Stearic and oleic acids were the most dominant fatty acids, and all samples of shea butter were rich sources of saturated fatty acids (SFAs). Moreover, the SE samples showed the highest values of DPPH (238.36 µM TEq/kg) and ABTS (534.96 µM TEq/kg), while the CPE samples had the highest total phenolic content (104.64 mg GAE/kg). Principal component analysis (PCA) clearly indicated that the extraction technique could quantitatively or qualitatively induce changes. Thus, this investigation demonstrated that extraction methods have a considerable impact on the quality and chemical composition of the presented material.

Calf rumen microbiome from birth to weaning and shared microbial properties to the maternal rumen microbiome.

Optimization of host performance in cattle may be achieved through programming of the rumen microbiome. Thus, understanding maternal influences on the development of the calf rumen microbiome is critical. We hypothesized that there exists a shared microbial profile between the cow and calf rumen microbiomes from birth through weaning. Specifically, our objective was to relate the calf's meconium and rumen fluid microbiomes in early life to that of the cow rumen fluid prior to parturition and at weaning. Rumen fluid was collected from multiparous Angus crossbred cows (n = 10) prior to parturition and at weaning. Immediately following the parturition, meconium and rumen fluid were collected from the calf. Rumen fluid was collected again from the calf on day 2, day 28, and at weaning. The rumen fluid microbial profile and subsequent volatile fatty acid (VFA) profile were characterized using 16S rRNA sequencing and gas liquid chromatography, respectively. Microbial data was analyzed using QIIME2 and the GLM procedure of SAS was used to analyze the VFA profile. Alpha diversity was similar in the early gut microbiome (meconium, rumen fluid at birth and day 2; q ≥ 0.12) and between the cow and calf at weaning (q ≥ 0.06). Microbial composition, determined by beta diversity, differed in the early rumen microbiome (rumen fluid at birth, day 2, and day 28; q ≤ 0.04), and VFA profiles complimented these results. There were similarities in composition between meconium, rumen fluid at birth, and rumen fluid from the cow at weaning (q ≥ 0.09). These data indicate successive development of the rumen microbiome and stabilization over time. Similarities between meconium and rumen fluid at birth potentially indicates in utero colonization of the calf gastrointestinal tract. Similarities in composition between the early calf rumen microbiome and the cow at weaning prompt an interesting comparison and area for future consideration in terms of identifying at what stage of gestation might colonization begin. Overall, this study provides insight into similarities between the cow and calf microbiomes and may be helpful in developing hypotheses for the pathway of colonization and programming potential in the early gut.

Inclusion of the aerial part and condensed tannin extract from Cistus ladanifer L. in lamb diets – Effects on rumen microbial community and fatty acid profile

This study was carried out to test the hypothesis that the inclusion of condensed tannins (CT) from Cistus ladanifer aerial part or extract in a diet composed of dehydrated lucerne and supplemented with 60 g/kg of soybean oil can modulate the rumen microbiome and increase the production of healthy biohydrogenation intermediates (BI). Hence, thirty-six lambs were used to evaluate the effect of 3 levels of C. ladanifer CT (0 %, 1.25 % and 2.5 % of CT) and two ways of CT supply (C. ladanifer aerial parts and C. ladanifer CT extract) on rumen fatty acids and volatile fatty acids profile and ciliate protozoa and bacteria community composition. The experiment lasted 35 days, and rumen samples were collected immediately after slaughter. Ciliate protozoa were analyzed by microscopic counting, and high-throughput 16 S rRNA gene sequencing was used to analyse rumen bacterial composition. Condensed tannins diets did not affect ruminal fermentation. The inclusion of C. ladanifer aerial part or extract in lamb diets did not increase the t11–18:1 in the rumen content. On the other hand, the t11–18:1 proportion was lower in the rumen of lambs fed both C. ladanifer diets and the highest level of extract diet when compared with the lowest level of extract diet and the diets without CT inclusion. Regarding the rumen microbiome, the total of ciliates was not influenced by the CT level in diets but decreased with the inclusion of C. ladanifer aerial part in the diet. Entodinium genus was strongly and positively related with both total BI and t11–18:1 and it also was the ciliate genus most negatively related with rumen estimate biohydrogenation (BH) completeness. Independently of the diets, the bacterial community of rumen content was dominated by Firmicutes (49.8 %) and Bacteroidetes (30.8 %) phyla. The Lachnobacterium was the genus most closely related with t11–18:1 and negatively related with 18:0 and BH completeness, which suggests that the Lachnobacterium plays an important role on the BH when diets without CT inclusion and lower dose of C. ladanifer extract was fed to lambs, being responsible for t11–18:1 ruminal production. Cistus ladanifer aerial part and extract influenced the ruminal microbial composition, but at the conditions used, the increase in the ruminal production of healthy BI was not observed, highlighting the inconsistent BH response to dietary CT and underlining the need to develop efforts to increase knowledge about this CT source and its interactions with other feed factors and with the ruminal microbial community.

A redox-based strategy to enhance propionic and butyric acid production during anaerobic fermentation

This study investigated the selective production of volatile fatty acids (VFAs) during anaerobic mixed‐culture fermentation. The experiment used chicken manure (CM) as a potential substrate to produce high added‐value propionic acid and butyric acid under an alkaline environment. The conversion of CM into selective VFAs depends highly on operational conditions such as pH and redox balance. Therefore, the current experiment is designed to employ amino acid addition and develop a redox balance control method to control the final VFA profile. This study showed that 0.2–5.0 % valine and threonine addition successfully enhanced propionic acid and butyric acid production during alkaline fermentation and hence decreased the proportion of acetic acid from 83 % to approximately 47 %. The oxidation–reduction potential (ORP) and redox cofactor ratio (NADH/NAD+) were measured to support the selective VFA production mechanism. The results obtained in this study bring extra value to the valorization of CM within the circular economy concept for selective value-added VFA production.