Search Results (2,466)

Anaerobic digestion (AD) plays an important role in the circular bioeconomy by converting organic waste into renewable methane and nutrient-rich fertilizer. However, consistent, high-quality biomethane production is hindered by four main factors: hydrolysis limitations, fluctuating feedstock quality, microbial instability, and the high cost/energy demand of purification. This review explores three key areas that improve biomethane production: (i) process intensification (pretreatments and advanced reactors), (ii) microbial regulation through additives, and (iii) biogas upgrading for pipeline use. Anaerobic digestion can be greatly improved by combining thermal or hybrid pretreatments, staged digestion, high-solids technology, and electrochemical systems. These methods speed up hydrolysis and help the system handle higher amounts of organic material more effectively. However, actual performance benefits depend on specific substrate characteristics, heat integration, and control complexity. Optimizing the C:N ratio, buffering capacity, and trace-element supplementation, while simultaneously diluting toxic inhibitors, makes co-digestion an effective and adaptable approach to enhancing anaerobic digestion processes. Additives like carbon, iron nanoparticles, enzymes, and buffers can optimize digestion, but their performance is highly dependent on dosage and substrate. Additionally, they lack validation in long-term, industrial-scale applications. Conventional physicochemical techniques continue to be standard for generating high-quality biomethane, but biological methanation and microalgal systems are playing a growing role in integrating Power-to-Gas technology and using CO₂ efficiently. Critical research needs to focus on four areas: (1) standardized reporting metrics, (2) AI-enabled monitoring and control, (3) coupled techno-economic and life-cycle analysis (TEA-LCA), and (4) long-term pilot or full-scale validation. Overall, comprehensive optimization of the entire flow is more effective than improving isolated parts. Full article

Corn, paddy, wheat, sorghum, and cassava serve as the primary energy sources in both human and animal diets. This study aimed to evaluate their nutrient release patterns in a simulated gastrointestinal environment and to assess the in vitro biological activity of the metabolites produced during digestion. The results showed that wheat exhibited the highest dry matter degradation in the stomach–jejunum–ileum digestion stage, while wheat and paddy showed the highest crude protein degradation compared with the other starch sources. In addition, wheat had a higher total free sugar concentration than paddy, sorghum, and cassava. Among the individual free sugars, such as D-sorbitol and D-(+)-trehalose, were found to have the highest concentrations in wheat, whereas cassava had the highest D(−)-fructose concentration. Several differential metabolites, including valeric acid, caproic acid, octanoic acid, and azelaic acid were highly released in paddy, whereas glucaric acid, threonic acid, phenylacetic acid, and shikimic acid were highly released in cassava, and 4-hydroxycinnamic acid was highly released in paddy and sorghum. Four unique metabolites were identified during the digestion process of five starch sources. Particularly, isocitric acid and trans-cinnamic acid were released only from cassava; caffeic acid was released only from sorghum and corn; and pimelic acid was released only from paddy and wheat. Furthermore, cassava was distinct from the other starch sources, displaying a higher abundance of differential metabolites within the glucagon signaling pathways as mapped in KEGG pathway analysis. In summary, compared with other starch sources, wheat provides more dry matter, protein, and sugars for the body. Cassava is unlikely to offer any advantage in glycemic regulation, while paddy and cassava possess stronger biological activity in terms of differential metabolites. Full article

This research explored how dietary supplementation of calcium nitrate influences methane emissions, nitrogen excretion, ruminal fermentation parameters, and microbiota in Liuyang black goats. A total of twelve male goats from this breed were divided into two groups: one serving as a control group (CON), while the other received a treatment of 3% calcium nitrate (CAL). The research was conducted over a period of 40 days and comprised two separate trial phases. A 10-day adaptation period and a 5-day sampling period (days 11–15) for each stage. Results showed that incorporating calcium nitrate significantly reduced the emissions of methane (CH₄) (p < 0.05) and carbon dioxide (CO₂) (p < 0.05). Moreover, the use of calcium nitrate modified the trends in ruminal fermentation, resulting in an increase in pH (p < 0.05). Moreover, the ratio of acetate to propionate (A:P) was notably reduced in the CAL group (p < 0.05), indicating a shift toward enhanced production of propionate. At the microbial level, an increased presence of Bacteroidota and Prevotella was observed in the CAL group (p < 0.05). In contrast, the CON group exhibited elevated levels of Firmicutes and Methanobrevibacter (p < 0.05). This finding suggests that calcium nitrate plays a significant role in reducing methane emissions and also affects the fermentation processes in the rumen along with the microbiota of Liuyang black goats. Further research is needed to examine the long-term implications of calcium nitrate supplementation on the health and productivity of these goats. Full article

This study evaluated the effects of forage-free diets with reduced starch levels on the productive performance, metabolism, ruminal fermentation, nutrient digestibility, and meat quality of feedlot beef cattle. Two experiments were conducted. In Experiment 1, forty uncastrated Nellore steers were distributed into 20 pens in a completely randomized design, receiving diets with increasing inclusion levels of ground corn in the total diet: C400 (400 g kg⁻¹), C200 (200 g kg⁻¹), C100 (100 g kg⁻¹), and C50 (50 g kg⁻¹), formulated without forage and based on fibrous co-products. Increasing ground corn inclusion promoted linear improvements in final body weight and average daily gain, while dry matter intake and feed efficiency showed quadratic responses. Meat quality parameters were not affected by dietary treatments. In Experiment 2, eight crossbred steers were assigned to a double 4 × 4 Latin square design and fed the same experimental diets. Higher corn inclusion increased starch and fat intake, whereas dry matter, organic matter, and protein intake showed quadratic responses. Apparent total-tract digestibility of dry matter, organic matter, and starch also followed a quadratic pattern. Ruminal fermentation parameters were affected by dietary treatments, with greater ammoniacal nitrogen concentrations at higher corn levels and quadratic responses for propionate, butyrate, and methane production. Nitrogen metabolism indicated increased urinary nitrogen and uric acid excretion with increasing dietary corn inclusion. These results demonstrate that forage-free diets based on citrus pulp and soybean hulls with different levels of ground corn can be effectively used in finishing beef cattle, improving performance without impairing meat quality while modulating ruminal fermentation and nutrient utilization. Full article

This study demonstrates a hierarchical spectral modelling approach for predicting pasture nutrition metrics using TabPFN (Tabular Prior-Data Fitted Network), a transformer-based machine learning architecture. In the face of climate variability, aligning stocking rates with pasture resources is crucial for sustainable livestock grazing, requiring accurate assessments of both pasture biomass and nutrient composition. Our research, conducted across diverse growth stages at five tropical and subtropical savanna rangeland properties in Queensland, Australia, with native and introduced C4 grasses, employed a hierarchical sampling and modelling strategy that scales from laboratory spectroscopy to Sentinel-2 satellite predictions via uncrewed aerial vehicle (UAV) hyperspectral imaging. Spectral data were collected from leaf (laboratory spectroscopy) through field (point measurements), UAV hyperspectral imaging, and Sentinel-2 satellite imagery. Traditional laboratory wet chemistry methods determined plant leaf and stem nutrient content, from which crude protein (CP = total nitrogen (TN) × 6.25) and dry matter digestibility (DMD = 88.9–0.779 × acid detergent fibre (ADF)) were derived. TabPFN models were trained at each spatial scale, achieving validation ${\mathrm{R}}^2$ of 0.76 for crude protein at the leaf scale, 0.95 at the UAV scale, and 0.92 at the Sentinel-2 satellite scale. For dry matter digestibility, validation ${\mathrm{R}}^2$ was 0.88 at the UAV scale and 0.73 at the Sentinel-2 scale. A pasture classification masking approach using a deep neural network with 98.6% accuracy (7 classes) was implemented to focus predictions on productive pasture areas, excluding bare soil and woody vegetation. The Sentinel-2 models were trained on 462 samples from 19 site–date combinations across 11 field sites. The TabPFN architecture provided notable advantages over traditional neural networks: no hyperparameter tuning required, faster training, and superior generalisation from limited training samples. These results demonstrate the potential for accurate and efficient prediction and mapping of pasture quality across large areas (100 s–1000 s ${\mathrm{k}\mathrm{m}}^2$) using freely available satellite imagery and open-source machine learning frameworks. Full article

Nigella sativa meal (NSM) is a by-product of the oil extraction process with potential use as a functional feed ingredient in ruminant nutrition due to its rich bioactive compounds and nutrient content. Therefore, this replicated (n = 6) completely randomized design (CRD) study aimed to firstly characterize NSM for its the bioactive compounds by chromatography–mass spectrometry (GC–MS) and liquid chromatography–MS (LC–MS). The effects of its dietary inclusion at 0%, 5%, 7.5%, and 10% NSM on in vitro rumen fermentation, gas production, CH₄ production, and rumen degradability were analyzed. Rumen fluid was collected orally from five sheep (body weight 20 ± 2 kg/head) and incubated with basal diets supplemented with pre-determined levels of NSM. The identified bioactive compounds identified included palmitic acid, oleic acid, linoleic acid, phenolic, flavonoid, thymoquinone, and saponin. The results showed that the dietary NSM supplementation in the diet significantly increased (p < 0.05) gas production at 18 and 48 h, NH₃–N concentration, IVDMD (In vitro dry matter degradability), and IVOMD (In vitro organic matter degradability). However, there was no significant effect (p > 0.05) on gas production at 12 and 24 h, and CH₄ production, pH, acetate, propionate, iso-butyrate, butyrate, iso-valerate, valerate, the acetate-to-propionate ratio (A:P), or total VFA concentration. Rumen fermentation was optimally modulated up to 10% without adverse effects on digestibility or CH₄ production. In this context, NSM acted as a functional feed ingredient in vitro. Therefore, in vivo analyses are required to confirm the efficacy under practical feeding conditions. Full article

Liquid infant formula has garnered increasing attention due to its mild thermal processing and superior retention of bioactive nutrients. Within such matrices, the lipid source is a critical determinant of protein digestion behavior, yet its influence on peptide bioavailability and intestinal homeostasis remains undefined. Given that efficient peptide absorption is vital for the systemic delivery of bioactivity in infants, understanding the lipid–protein synergy is essential for formula optimization. Moreover, excessive oxidative stress is closely associated with impaired intestinal health and developmental disorders in infants, making the regulation of oxidative stress crucial for maintaining intestinal function. The present study evaluated the effects of three distinct lipid sources—soybean oil (SM), bovine milk fat (BM), and goat milk fat (GM)—on the physicochemical stability, proteolytic digestion, peptide release, intestinal absorption, and oxidative stress modulation of goat-milk-based infant formula. An integrated approach combining physicochemical characterization, in vitro simulated infant digestion, and a Caco-2 intestinal epithelial cell model was employed. we demonstrate that all three lipids (3% w/w) formed stable emulsions with uniform spherical structures and mean particle diameters of 117–300 nm, as visualized by laser confocal microscopy. Following in vitro simulation of infant gastrointestinal digestion, the SM group exhibited the most extensive protein hydrolysis, yielding the highest total peptide content (4.28 ± 0.10 mg/mL) and generated the highest number of peptides identified by LC-MS/MS (474 types). Bioinformatic analysis predicted that peptides from all groups possess potential antihypertensive, hypoglycemic, and immunomodulatory activities. The Caco-2 monolayer cell model demonstrated that although the GM group produced fewer identified peptide species than the SM group (365 types), it achieved significantly higher intestinal peptide absorption rate (55.34 ± 1.05%). Furthermore, the GM digests provided superior protection against H₂O₂-induced oxidative stress in Caco-2 cells, markedly reducing reactive oxygen species levels and suppressing the expression of pro-inflammatory cytokines TNF-α and IL-6. Collectively, these findings reveal that while soybean oil promotes more extensive proteolysis, the use of homologous goat milk lipid enhances peptide bioaccessibility and confers potential cytoprotective effects on intestinal epithelial cells, underscoring its potential as a preferred lipid source in infant formula formulations. Full article

Food-grade emulsion gels are increasingly being used to create food products with innovative properties and functional attributes. However, the rapid expansion of research in this area has outpaced the establishment of standardized methodologies, leading to challenges in reproducibility and cross-study comparability. This review addresses this critical gap by providing a comprehensive set of methodological guidelines for the reliable preparation, characterization, and evaluation of food-grade emulsion gels intended for gastrointestinal-targeted nutrient delivery. Initially, systematic approaches for emulsion gel preparation are reviewed, focusing on formulation parameters and processing conditions that dictate the structure and function of these products. A multi-scale framework for physicochemical characterization of emulsion gels is then presented, encompassing structural, rheological, mechanical, thermal, and fluid-holding properties. Guidelines for testing the performance of emulsion gels under simulated food matrix and storage conditions are then given, including methods to monitor bioactive degradation. Furthermore, best practices for evaluating the gastrointestinal behavior of emulsion gels using standardized in vitro digestion models, and subsequent biological evaluation using cell-based assays, animal models, and human trials are discussed. This review concludes that standardized fabrication, characterization, digestion, and reporting protocols are critical for improving reproducibility and comparability across studies and for advancing food-grade emulsion gels toward reliable functional food applications. Full article

The rumen simulation technique (RUSITEC^®) is a known model for research in rumen microbiology and fermentation. However, our research group observed inconsistencies in gas production across trials. This study investigated the effects of different gas outlet locations on digestibility, ruminal fermentation, gas production, and microbial protein synthesis. Fifteen fermenters tested three different gas outlet locations within the RUSITEC^® equipment: (1) gas outlet directly on the effluent vessel for output liquid (EV); (2) gas outlet directly on fermenter cap (F); and (3) gas outlet on both effluent vessel and fermenter cap (EVF). Data were analyzed using a completely randomized design in SAS (v. 9.4) with the MIXED procedure, and significance was set at p < 0.10. Results showed that altering the gas outlet location did not affect nutrient digestibility (p > 0.10), microbial protein synthesis (p > 0.10), and volatile fatty acid (VFA) production when expressed on a molar basis (p > 0.10). However, total gas production (p = 0.108) was higher in the EVF group and ammonia nitrogen produced in the fermenter was higher in group F (p = 0.081). Furthermore, methane (CH₄) production was underestimated when the gas outlet location was in just one of the locations when compared to the EVF group (p = 0.006). VFA proportion was also affected, with lower acetate (p = 0.005) and higher butyrate (p = 0.014) for group EV. These results indicate that the location of the gas outlet is an important methodological factor affecting fermentation measurements in the RUSITEC system, with outlets positioned in both the effluent and fermenter vessels enhancing gas recovery. Full article

Dietary phytogenic additives and microalgae are increasingly investigated as natural alternatives to antibiotic growth promoters in rabbit production due to their potential effects on gut health and nutrient utilisation. This study evaluated the nutraceutical potential of Chlorella vulgaris and Laurus nobilis as plant-based additives for growing New Zealand White rabbits. A 45-day feeding trial was conducted using control and experimental diets enriched with 0.1% Chlorella and 0.1% Laurus. Productive performance, nutrient digestibility, blood biochemistry and faecal composition were monitored, and polyphenolic compounds were analysed in feed, blood, faeces and caecal microbiota using HPLC-DAD. Final body weight (3097 vs. 2909 g) and feed intake (142.7 vs. 145.0 g day⁻¹) did not differ significantly between treatments. However, crude protein digestibility was significantly lower in the supplemented group than in the control group (54.39–47.79% vs. 63.73–62.33%; p < 0.05). Faecal chemical composition differed significantly between groups, particularly for dry matter, which was higher in the supplemented group across sampling times. Polyphenols detected across biological matrices confirmed the bioavailability of selected phytochemicals, with ferulic acid showing the highest stability. Correlation analysis indicated shared metabolic or absorptive pathways among several compounds. Overall, low-dose supplementation with C. vulgaris and L. nobilis appears safe and may support improved digestive physiology and nutrient utilisation without compromising rabbit health. Further research with larger sample sizes and detailed microbiome profiling is needed to clarify metabolic interactions and long-term effects of these nutraceutical strategies. Full article

This study aimed to assess the effect of concentrate supplementation frequency on the nutrient intake, performance, carcass characteristics, and tissue composition of sheep for meat raised on Panicum maximum cv. Massai pasture. A group of 36 sheep of the Santa Inês breed (18 males and 18 females) with a mean initial weight of 17.0 ± 1.5 kg and mean age of 90 ± 10 days were assigned to three treatments: supplementation every 24 h, every 48 h, and every 72 h. The formulation comprised ground maize kernels (70%), soybean meal (25%), mineral mix (2.5%), urea (1.8%), table salt (0.5%), and ammonium sulfate (0.2%). The females reached a higher final weight than the males (p < 0.05). Dry matter intake did not differ among the treatment groups (p > 0.05), but the sheep supplemented every 72 h showed greater pasture and neutral detergent fiber (NDF) intake, while those supplemented every 24 h and 48 h consumed more concentrate and had higher total weight gain (7.19 and 7.10 × 5.68 kg) (p < 0.05). The same behavior was found for carcass and meat cut weights and for leg and carcass compacity indexes, but carcass and cut yields were not impacted by supplementation strategy. Supplementation on alternate days, i.e., every 48 h, maintains the performance and productive efficiency levels in sheep kept on Massai grass pasture compared to those supplemented daily, but providing intermittent supplementation with intervals above 48 h is not recommended as a nutritional strategy. Full article

Yeast culture (YC), a complex functional feed additive containing fermentation metabolites, has demonstrated potential in dairy production systems. However, its mechanistic effects on rumen function and host metabolism in lactating dairy cattle warrant further investigation. This study evaluated the impacts of YC supplementation on production performance, systemic antioxidant status, and rumen function in late-lactation Holstein cows. Fourteen multiparous Holstein cows (body weight 655 ± 28 kg; days in milk 270.4 ± 1.6 d) were randomly allocated into two groups, a control group (CON, basal diet) and a YC-supplemented group (YC, basal diet + 50 g/d YC), in a 28-day feeding trial. YC supplementation significantly increased dry matter intake (p < 0.01), nutrient digestibility (p < 0.01 for DM, CP, EE, NDF, and ADF), and milk yield (p < 0.05) compared to CON. Systemic antioxidant capacity was enhanced, as evidenced by elevated serum superoxide dismutase activity (p < 0.01) and total antioxidant capacity (p < 0.05). Rumen fermentation was improved with higher concentrations of total volatile fatty acids (p < 0.01) and microbial protein (p < 0.01) and reduced ammonia nitrogen levels (p < 0.01). Macrogenomic analysis revealed a YC-mediated restructuring of the rumen microbiota, characterized by an increased relative abundance of Firmicutes and decreased Bacteroidota. Untargeted metabolomic profiling identified significant alterations in rumen metabolite profiles, with differential metabolites enriched in pyrimidine metabolism and vitamin digestion and absorption pathways. These results indicate that YC supplementation improves production performance in late-lactation dairy cows through multi-faceted mechanisms involving rumen microbial community modulation and metabolic pathway activation, ultimately enhancing nutrient utilization and metabolic efficiency. Full article

Solid-state fermentation (SSF) is a long-established biotechnological approach gaining renewed interest for its ability to enhance nutrient availability and improve the functional properties of agro-industrial by-products. This strategy is particularly relevant for early post-weaning piglets, which are highly susceptible to weaning stress due to an immature digestive system and a gut microbiota not yet adapted to solid feed. In this study, the fermentation parameters of flaxseed cake were optimized using a Plackett–Burman experimental design. Protease activity was selected as the response variable due to its relevance for improving protein degradation and potential digestibility in fermented feed ingredients. Accordingly, based on the statistical analysis, the conditions selected for the in vivo trial were 1% molasses, 0.5% yeast extract, 0.05% CaCl₂, 0.5% NaCl, 7.5% inoculum (4.12 × 10⁹ CFU/mL), 60% moisture, and 72 h fermentation. Fermentation time was identified as the main factor positively influencing protease production, while higher CaCl₂ concentrations and inoculum levels negatively affected enzyme activity. Optimization increased protease activity, microbial viability and free amino acid content. In addition, SSF reorganizes the carbohydrate profile by reducing structural fiber fractions, with neutral detergent fiber and acid detergent fiber decreasing by 27% and 29%, respectively, while simultaneously increasing soluble carbohydrates by 14.67%. Phytic acid content being also reduced by 23.81%. A pilot nutritional trial on post-weaned piglets (35 days old) showed that including 8% fermented flaxseed cakes (FFSC group) improved body weight, average daily gain, feed conversion ratio, and diarrhea score, without affecting average daily feed intake, compared with 8% unfermented flaxseed cakes (FSC group). These performance improvements were accompanied by changes in fermentation metabolites and gut microbial composition. Lower isovalerate concentrations suggested reduced proteolysis, while higher propionate levels may contribute to increased blood glucose availability in the FFSC group. These changes coincided with a shift in microbial composition, characterized by a reduced abundance of methanogenic archaea and increased abundances of taxa such as Lactobacillus, Enterococcus, and members of the Lachnospiraceae and Eubacteriaceae families. Full article

Gluten-free (GF) products developed for individuals with celiac disease and gluten sensitivity often suffer from low protein and mineral content. Fish proteins offer a promising solution to address these deficiencies; however, the characteristic “fishy odor” and related technological challenges limit consumer acceptance. This study aimed to develop an innovative GF pasta with improved nutritional density and acceptable sensory quality by incorporating deodorized and lyophilized trout powder. GF pasta formulations were prepared using buckwheat flour, xanthan gum, and 5% or 10% odorless trout powder. Vinegar pretreatment was applied to reduce fish odor, while lyophilization was chosen to minimize nutrient losses. The samples were analyzed for nutritional composition, techno-functional properties, in vitro digestibility, and sensory attributes. Results showed that trout powder significantly increased protein and ash content compared to the control (p < 0.05). A slight darkening was observed in color analysis due to fish pigments and buckwheat phenolics, but overall visual stability remained high. In vitro digestibility revealed enhanced protein digestibility (p < 0.05) and a slight reduction in starch digestibility. Sensory evaluation demonstrated that odor scores (8) at 10% trout inclusion remained close to the control, reversing the commonly reported decline in acceptance with increasing fish content. These findings indicate that combining vinegar pretreatment with lyophilization enables the incorporation of fish proteins into GF pasta without sensory disadvantages, while simultaneously improving nutritional quality. Full article

Livestock production systems are considered some of the most environmentally degrading due to greenhouse gas (GHG) emissions and their contribution to poor air, soil and water quality, amongst other impacts. Advanced manure treatment technologies are required in response to intensification of dairy production worldwide, and the considerably greater volumes of manure generated that require collection and management. Similarly, in Australian dairy systems cows spend more time off pasture, with increased collection of larger manure volumes from a range of contained housing facilities. Adoption of advanced treatment is required to capture nutrients at risk of loss, and ideally to valorise manure to support uptake of these technologies. This review describes the generation of manure and the manure sources found in commercial Australian systems, including grazing-based and intensive dairy farms, supporting zero grazing. The review draws on manure data from pasture-based industries elsewhere and summarises their properties for comparison with Australian systems. Manure treatments that recover and retain nutrients, water and energy are reviewed. These include additives, mechanical/chemical/membrane separation, thermochemical and biological treatments which produce organic and inorganic soil amendments, clarified or potable water, gases (N₂, H₂), biofuels and energy. The review describes the technical and operational details of the technologies, and where there are opportunities for the Australian dairy industry. Treatment technologies need to be validated for Australian systems based on the collated data of local manure properties, as differences with international manure data have been observed. The relative costs, technological maturity, and the benefits and challenges associated with adoption are discussed. Many advanced technologies are ready for adoption, but others are experimental or at pilot stage and relative costs range from low to very high. However, to accurately assess feasibility of manure treatments, environmental, and production benefits should be balanced against capital and operating expenses and account for costs associated with current management. For large intensive farms, implementing advanced manure technologies may be required to ensure approval to operate/expand and to meet regulatory compliance. Future research for the Australian industry should investigate nutrient retention and further develop separation treatments incorporating chemical and mechanical technologies. Bioconversion of manure through insect composting as well as investigating co-digestion opportunities to enhance biogas production would support famers currently using these systems. Full article