Search Results (245)

Broiler meat is an important source of protein with a balanced essential amino acid profile; however, the environmental stress associated with a high stocking density can reduce its nutritional value. Adaptogen supplementation represents a promising strategy to mitigate this negative impact. This study aimed to evaluate the amino acid composition of the breast and thigh muscles of Smena-9 broiler chickens under a high stocking density and dietary supplementation with an adaptogens complex (dihydroquercetin + vitamins E and C). The experiment was conducted on 120 broilers allocated to four groups: recommended stocking density (negative control), high stocking density (positive control), high stocking density with adaptogens from day 21, and high stocking density with adaptogens from day 1 of the experiment. The stocking density changed as the bird grew. On day 21, the bird stocking density in the S(-)CON group was 38 heads per 1 m², in the other groups it was increased by 10% and amounted to 42 heads per 1 m². Each week, the stocking density changed and amounted to 32 and 35 heads per 1 m² in 28–35 days, 21 and 23 heads per 1 m² in 35–42 days, and 17 and 19 heads per 1 m² in 43 days and until the end of fattening, respectively. The amino acid profile was determined by ion-exchange chromatography with post-column derivatization using ninhydrin. Age was the primary factor influencing the amino acid composition, followed by muscle type and stocking density. Sex-related effects were less pronounced and were observed at 24 days of age. Breast meat exhibited higher amino acid content than thigh meat (82.4–89.9 vs. 65,8–77.8 g/100 g dry matter for total amino acids, respectively). Under a high stocking density, the most notable changes were observed in the thigh muscle at early ages. By day 52, the birds receiving the adaptogen complex from day 1 showed an increase in the sum of essential amino acids in the breast meat (+2.4%, p < 0.05), with the most pronounced improvements observed for methionine (+5.9%, p < 0.001) and lysine (+3.9%, p < 0.05) compared with the recommended-density control group (S(-)CON). Additionally, early adaptogen administration preserved the levels of flavor-related amino acids between days 34 and 52, whereas a decline was observed in other groups, indicating maintained sensory quality with age. Thus, the early administration of the adaptogen complex appears to mitigate for high stocking density negative effects and contributes to preserving the nutritional value of broiler meat, although the underlying mechanisms remain hypothetical and require further. Full article

Drought is one of the major abiotic stresses limiting soybean production, and its detrimental effects are jointly influenced by stress intensity, duration, and cultivation conditions. To investigate the morphological and physiological regulatory mechanisms by which mepiquat chloride (DPC) alleviates drought stress at the soybean seedling stage, this study used the drought-tolerant soybean cultivar Heinong 44 (H-44) and the drought-sensitive cultivar Heinong 65 (H-65) as experimental materials. Osmotic stress was simulated with 10% PEG-6000 at the V2 stage, and the effects of foliar application of different DPC concentrations (125–500 mg/L) on soybean morphology, biomass allocation, antioxidant systems, and osmotic adjustment capacity were systematically analyzed. The results showed that drought stress significantly inhibited the growth of both soybean cultivars and induced severe oxidative damage. Appropriate DPC concentrations moderately restricted shoot growth to reduce transpiration area while promoting root growth to enhance water acquisition capacity. The optimal DPC concentrations for alleviating drought stress were 200 mg/L for H-44 and 275 mg/L for H-65. Allometric growth analysis indicated that drought disrupted the original root–shoot growth pattern, whereas appropriate DPC concentrations significantly promoted dry matter accumulation in drought-stressed plants and improved root–shoot growth coordination. However, an excessive concentration of DPC (500 mg/L) caused an abnormal deviation in the growth trajectory. In addition, appropriate DPC concentrations synergistically enhanced the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in leaves and roots under drought conditions; promoted the accumulation of proline (Pro), soluble sugars (Ss), and soluble proteins (Sp); effectively reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂); and protected cell membrane stability. In conclusion, DPC synergistically enhances drought resistance in soybean by reshaping the root–shoot allometric growth configuration and systematically activating physiological defense networks, providing a theoretical basis for chemically regulated cultivation of soybean under stress conditions. Full article

Abiotic stresses, such as drought, salinity, and aluminum toxicity (Al³⁺), affect the growth and initial establishment of wheat plants, limiting crop yield in restrictive growing environments. Therefore, the early selection of tolerant genotypes adapted to multiple production environments is essential to optimize wheat production. A laboratory experiment was conducted to identify and recommend wheat cultivars that simultaneously combine adaptability and stability for initial morphological responses when subjected to stressful environmental conditions. Plants from 12 wheat cultivars were grown under non-stressful (control) and stressful conditions (drought, salinity and Al³⁺ stress), using a 4 × 12 factorial arrangement with four replicates. On the 28th day, the emergence rate, length, dry matter and vigor of the plants were measured. Abiotic stresses limit the initial growth and vigor of wheat plants, with drought causing the greatest limitation for plant growth and biomass accumulation, while salinity had the greatest impact on plant vigor indices. Aluminum toxicity limits root development and biomass allocation. Principal component analysis explained 67.76% of the total variability and distinguished the plant growing environments. The multi-trait index proved effective in cultivar selection, highlighting the cv. ORS Feroz due to its proximity to the ideotype and adaptability to multiple abiotic stresses. Full article

This study investigated the effects of dietary sodium butyrate supplementation on blood gas profiles, biochemical parameters, and untargeted plasma metabolomics in tumbler pigeons. Eighty tumbler pigeons of similar age, body weight, and training intensity were randomly allocated into four groups: a control group without sodium butyrate supplementation (CON) and three sodium butyrate-supplemented groups receiving 6 mg/d (T1), 12 mg/d (T2), and 18 mg/d (T3), respectively. All birds were maintained under identical husbandry conditions and fed the same basal diet throughout a 40-day experimental period consisting of a 10-day acclimation phase and a 30-day feeding trial. Results showed that dietary sodium butyrate supplementation significantly improved dry matter digestibility, with T2 and T3 exhibiting higher values than CON (p < 0.05), while metabolizable energy utilization was significantly increased in T3 compared with CON (p < 0.05). Sodium butyrate supplementation also significantly altered several blood gas parameters associated with acid–base balance and gas exchange. In addition, antioxidant enzyme activities were enhanced, with SOD, CAT, GSH-Px, and T-AOC activities significantly increased in supplemented groups compared with CON (p < 0.01). Furthermore, sodium butyrate supplementation significantly modulated inflammatory responses, increasing IL-10 concentrations (p < 0.01) while decreasing IL-6 and IL-8 levels (p < 0.01). Untargeted metabolomic analysis revealed significant alterations in pathways related to lipid metabolism, amino acid metabolism, and inflammatory regulation. In conclusion, dietary sodium butyrate supplementation influenced nutrient utilization, blood physiological parameters, antioxidant capacity, inflammatory status, and plasma metabolic profiles in tumbler pigeons. Among the tested supplementation levels, 18 mg/d sodium butyrate was associated with the most favorable overall physiological responses. These findings provide a basis for future investigations into the physiological and metabolic effects of sodium butyrate supplementation in competitive pigeons. Full article

This study systematically compared the effects of dietary supplementation with glutamine (Gln) and its precursors, including glutamic acid (GA) and α-ketoglutarate (AKG), on growth performance, serum antioxidant and immune parameters, and multi-region gastrointestinal microbiota in suckling lambs. Forty healthy suckling Hu lambs with similar body weight (7.37 ± 1.18 kg) and age (7 ± 0.8 d) were selected and randomly allocated into four groups (n = 10 per group): a control group (CON, without additive), and three treatment groups (GA, AKG, and Gln), each receiving 2 g per animal per day of the corresponding additive. The experimental period lasted for 42 d. All three additives showed a tendency to increase the final body weight (p = 0.056) and significantly increased the average daily gain (ADG) of lambs (p < 0.05). GA supplementation increased the dry matter intake throughout the entire trial (p < 0.05), whereas the addition of AKG and Gln increased the dry matter intake only during the later period (d 21–42) (p < 0.05). The feed-to-gain ratios did not differ among all groups (p > 0.05). Compared with the CON group, all three treatment groups showed elevated serum activities of catalase, glutathione peroxidase, and total antioxidant capacity, as well as increased IgA and IgG contents (p < 0.05). In addition, malondialdehyde concentration was decreased in all three treatment groups (p < 0.05). Moreover, GA supplementation reduced the ruminal alpha diversity while increasing the abundance of butyrate-producing bacteria (Ruminococcaceae UCG-014) (p < 0.05). All three interventions consistently decreased the abundance of the intestinal pathogen Escherichia-Shigella in the ileum (p < 0.05). Correlation analyses showed that ruminal Treponema 2 abundance was negatively correlated with ADG, whereas jejunal Methylobacterium and ileal [Eubacterium] coprostanoligenes group were positively correlated with final body weight or ADG. In conclusion, glutamine and its precursors play an important role in modulating gastrointestinal bacterial diversity and composition, enhancing antioxidant and immune functions, and improving the growth performance of suckling lambs. Full article

The escalating global threat of antimicrobial resistance (AMR) has intensified efforts to identify safe, effective, and sustainable alternatives to in-feed antibiotics in livestock production. The bovine gastrointestinal microbiome plays a central role in host immunity, nutrient utilization, and disease resilience, positioning microbiome-modulating interventions as promising candidates for antimicrobial stewardship. Despite growing experimental interest, a systematic synthesis of the available evidence in cattle is lacking. This systematic review aimed to evaluate the efficacy of microbiome-modulating interventions, including probiotics, prebiotics, postbiotics, phytogenic feed additives, essential oils, organic acids, and native rumen microbial supplements, as strategies to reduce antimicrobial use in cattle, and to characterize their effects on gut microbial diversity, fermentation characteristics, and host health and performance outcomes. A systematic search of Scopus, Web of Science, and EBSCOhost (including Academic Search Ultimate, MEDLINE with full text, and CAB Abstracts with Full text) was conducted in accordance with PRISMA guidelines. Studies were eligible if they used cattle (dairy cattle, beef cattle, calves, or mixed production systems), employed a microbiome-modulating intervention, and reported at least one microbiological or host outcome. Seventeen peer-reviewed studies published between 2010 and 2025 were included after full-text screening. Risk of bias was assessed using an adapted SYRCLE tool, which identified moderate overall study quality; the majority of included studies were randomized controlled trials or controlled experiments, though reporting of allocation concealment and blinding was inconsistent across studies. Across the 17 included studies, five broad categories of interventions were evaluated: probiotics (n = 5 studies), prebiotics (n = 2), postbiotics and organic acids (n = 4), phytogenic additives and essential oils (n = 4), and native rumen microbial supplements (n = 2). Animals spanned neonatal dairy calves, weaned Holstein calves, dairy heifers, lactating dairy cows, and Bos indicus feedlot beef cattle. Probiotics and organic acids most consistently improved growth performance: benzoic acid supplementation increased average daily gain by 8.4% (p < 0.05) and fructo-oligosaccharide prebiotics elevated body weight at weaning by 6.7% (p < 0.01). Native rumen microbial supplements improved energy-corrected milk yield by up to 3.1% without increasing dry matter intake. Polyphenols and bile acids demonstrated the strongest immunological and disease-preventive effects, reducing calf mortality by approximately 40% and disease severity by approximately 35%, respectively. Microbiome analyses revealed intervention-dependent increases in microbial diversity and shifts toward taxa associated with improved fermentation efficiency, including enrichment of propionate-producing Prevotellaceae, butyrate-associated Ruminococcus, and hindgut Bifidobacterium. Rumen fermentation outcomes included reductions in the acetate:propionate ratio and ammonia-N concentrations and improvements in fiber digestibility of 3.6–4.4 percentage units in dairy cows. Phytogenic additives preserved microbial diversity without inducing broad-spectrum suppression, functioning primarily as microbiome stabilizers rather than direct antimicrobial replacements. This systematic review provides evidence that gut microbiome modulation may enhance growth performance, improve fermentation efficiency, and reduce disease susceptibility in cattle, thereby supporting antimicrobial use reduction across dairy, beef, and mixed production systems. Effect magnitudes varied substantially across intervention categories and production contexts, and study quality was moderate, underscoring the need for larger, pre-registered trials with standardized outcome reporting and direct antibiotic comparator arms. Probiotics, prebiotics, and bile acid metabolites showed the greatest potential as components of integrated antimicrobial stewardship strategies in cattle production. Full article

Optimizing the interaction between planting density and nitrogen (N) application rate is critical for simultaneously improving grain yield and nitrogen use efficiency (NUE) in winter wheat (Triticum aestivum L.). However, the underlying regulatory mechanism remains poorly understood in the fluvo-aquic soil region of the southern Huang–Huai–Hai Plain. This study aimed to elucidate the physiological mechanism by which planting density and nitrogen application interactively regulate source–sink coordination to achieve synergistic high grain yield and high NUE, and to screen the optimal local cultivation combination for winter wheat in southeastern Henan. A two-year consecutive field experiment was conducted from 2018 to 2020 in Shangshui, Henan, using a split-plot design. Three planting densities (D1: 225 × 10⁴ plants ha⁻¹; D2: 375 × 10⁴ plants ha⁻¹; D3: 525 × 10⁴ plants ha⁻¹) and five N rates (N0: 0; N1: 180; N2: 240; N3: 300; N4: 360 kg N ha⁻¹) were established. Results demonstrated that planting density, N rate, and their interaction significantly regulated grain yield, NUE, and dry matter and N allocation, with consistent trends across both years. Increasing density enhanced total biomass and N accumulation, but dry matter and N partitioning to grains declined when density exceeded 375 × 10⁴ plants ha⁻¹. Grain yield exhibited a quadratic response to N rate; the optimal N rate for maximum yield decreased from 296.33 kg ha⁻¹ at low density (D1) to 237.50–245.38 kg ha⁻¹ at medium and high densities. The combination of 240 kg N ha⁻¹ and 375 × 10⁴ plants ha⁻¹ (D2N2) produced the highest average grain yield (8875.35 kg ha⁻¹), with simultaneous improvements in spike number and kernels per spike as well as superior dry matter and N partitioning to grains. This combination also maintained high nitrogen recovery efficiency (NRE) and nitrogen agronomic efficiency (NAE). Correlation analysis revealed that grain yield and NUE were significantly positively correlated with dry matter accumulation, N accumulation, and their partitioning proportions to grains. Overall, D2N2 achieved simultaneous high yield and high NUE by coordinately optimizing dry matter and N partitioning to grains. We therefore recommend reducing N fertilizer to approximately 240 kg ha⁻¹ combined with a moderate planting density of 375 × 10⁴ plants ha⁻¹ as the preferred strategy for sustainable and intensive winter wheat production in the fluvo-aquic soil region of southeastern Henan and adjacent areas. Full article

Summer maize (Zea mays L.) production on the North China Plain is highly dependent on variable seasonal rainfall, which increases the likelihood that inappropriate water and nitrogen allocation will cause yield fluctuations and ecological and environmental risks. Previous studies have mainly relied on single-site field comparisons or basic statistical evaluation methods, limiting the understanding of the dynamic response mechanisms of drought stress coupled with nitrogen application during the jointing and grain-filling stages. Based on field experiments conducted in 2024–2025, the DSSAT model was used to simulate aboveground dry matter accumulation (CWAM), grain yield, leaf area index (LAI), dry matter evapotranspiration productivity (DMPEM), and dry matter nitrogen productivity (DPNAM) of summer maize under different water–nitrogen treatments at different growth stages. Then, historical meteorological data for Henan Province from 2003 to 2023 were imported. The years were classified into three hydrological year types: wet years, normal years, and dry years. Subsequently, Principal Component Analysis (PCA), the TOPSIS method, and the Rank-Sum Ratio (RSR) method were employed to construct a multidimensional evaluation system for assessing water and nitrogen management strategies under different hydrological year types. The results showed that the nitrogen application rate had a significant regulatory effect on yield, DPNAM, and DMPEM. All three initially increased and then decreased as the nitrogen application rate rose, with the optimal performance observed under the normal nitrogen (N2) treatment. Under drought conditions during the same growth stage, the increase in the maximum yield under the N2 treatment was approximately 8.1% and 50% higher than that under the high-nitrogen (N1) and low-nitrogen (N3) treatments, respectively. Compared with drought during the grain-filling stage, drought during the jointing stage had a smaller negative effect on CWAM and LAI. A comprehensive evaluation with long-term meteorological data reflects that drought during the jointing stage combined with normal nitrogen (Q2) is the optimal water–nitrogen management strategy for wet years (with an RSR value of 0.994). The treatments of drought during the jointing stage combined with high nitrogen (Q1) and drought during the grain-filling stage combined with normal nitrogen (H2) reveal greater adaptability and favorable universality across different hydrological year types. The model’s reliability under various water–nitrogen coupling conditions was validated by integrating field experiments, DSSAT model simulations, and a multidimensional evaluation system. This study lays a scientific theoretical foundation for achieving high and stable yields in summer maize under different water–nitrogen coupling conditions and across various hydrological year scenarios. Full article

Enzymes have the potential to enhance nutrient utilisation and provide economic and environmental benefits in reduced protein (RP) diets; however, responses to different inclusion levels of phytase and carbohydrase enzymes remain inconsistent. Therefore, the present study aimed to evaluate the effects of phytase, xylanase, and β-glucanase inclusion levels in RP diets on nutrient digestibility and performance in laying hens. A total of 8 dietary treatments were allocated to 13 replicate cages of two hens per cage per treatment (n = 208) from 35 to 57 weeks of age. Experimental diets comprised two protein levels (standard protein (SP) at 16.5% crude protein versus RP at 14.5% crude protein), two phytase levels (600 and 1200 FTU/kg), and two XB levels (xylanase, β-glucanase 100 g/ton and 150 g/ton) were examined via a 2 × 2 × 2 factorial design. Between 35 and 57 weeks of age, no significant interactions were observed in laying performance parameters. However, RP diets significantly decreased egg weight across all periods, 35–47 weeks (p = 0.049), 48–57 weeks (p = 0.045), and overall, from 35 to 57 weeks (p = 0.044). Reduced protein diets also decreased egg mass from 35 to 47 weeks (p = 0.035). High Xylanase and β-glucanase (XB) inclusion (150 g/ton) lowered hen day egg production during 48–57 weeks (p = 0.015). At 47 weeks, RP diets reduced yolk weight (p = 0.021) and increased egg shape index (p = 0.048). Additionally, XB at 150 g/ton with 600 FTU/kg PhyG improved shell breaking strength (p = 0.046) but reduced it at 1200 FTU/kg. At 57 weeks, RP diets decreased albumen weight (p = 0.016), albumen proportion (p = 0.006) and increased yolk proportion (p = 0.005). Xylanase and β-glucanase inclusion at 150 g/ton reduced shell breaking strength (p = 0.036), and XB reduced yolk colour score (p = 0.038) only in SP diets. Also, RP diets reduced excreta moisture (p = 0.015) and improved dry matter digestibility (p = 0.020). Notably, feeding RP diets increased apparent metabolisable energy digestibility (p = 0.003), decreased protein excretion (p < 0.001) and increased apparent protein digestibility (p = 0.013). It is therefore concluded that decreasing RP diets to appropriate levels may benefit the environment without affecting the feed efficiency of laying hens. Full article

Background: Dietary crude protein (CP) acts as a key nutritional factor that affects the growth performance and liver metabolism of fattening Hu sheep, with metabolizable energy (ME) representing a major confounding factor in CP-related responses. To isolate the specific effects of CP on liver metabolism and minimize energy–protein interactions, we standardized dietary ME at 9.4 MJ/kg dry matter. Methods: We then established three isoenergetic CP concentrations: 11.07%, 13.07%, and 15.11%. A total of ninety 4-month-old male Hu sheep (with an initial body weight of 27.09 ± 1.83 kg) were allocated at random to three dietary treatment groups, each containing 30 animals distributed across three replicate pens, and fed pelleted total mixed rations (PTMRs) for 75 days under pen conditions in southern Xinjiang. Exploratory combined transcriptomic and metabolomic profiling of liver tissue was conducted to characterize how graded CP levels modulate growth traits and hepatic metabolic pathways, thereby identifying the appropriate dietary CP level for efficient and sustainable fattening of Hu sheep in this region. Result: Results indicated that animals fed the 15.11% CP diet showed a significantly higher average daily gain (ADG) and cumulative weight gain compared with those fed 11.07% or 13.07% CP (p < 0.05). Exploratory multi-omics enrichment analysis demonstrated significant overrepresentation (p < 0.05) of differentially expressed genes and metabolites in key biological pathways—including bile secretion, AMP-activated protein kinase (AMPK) signaling, steroid biosynthesis, peroxisome proliferator-activated receptor (PPAR) signaling, and oxidative stress-related and oxidative phosphorylation. Correlation analyses characterized two hub genes—ATP6AP1 and LOC101119853—that were significantly and negatively correlated with ADG (p < 0.05), whereas two metabolites—calcidiol and ADP—displayed significant positive relationships with ADG (p < 0.05). Pathway-level comparisons further demonstrated that both the 13.07% vs. 15.11% CP and the 11.07% vs. 15.11% CP contrasts yielded significant enrichment in AMPK signaling and steroid biosynthesis. Notably, calcidiol and ADP both declined numerically in the 13.07% vs. 15.11% CP comparison, whereas only ADP reached statistical significance in the 11.07% vs. 15.11% CP contrast. Conclusions: Collectively, under an ME level of 9.4 MJ/kg, a dietary CP concentration of 15.11% contributes to favorable growth of 4-month-old fattening Hu sheep housed in pens in southern Xinjiang. This level is associated with improved growth performance and coordinated regulation of central hepatic regulatory networks—particularly those involved in energy homeostasis and steroidogenesis—thereby supporting metabolic stability without compromising animal health or production efficiency. These findings provide a preliminary molecular basis for precision protein nutrition in Hu sheep feeding systems and offer translational insights for optimizing ruminant nutrition under arid and semi-arid environmental constraints. All correlations indicate potential associations, not causal relationships. Full article

Nitrogen application rate (N rate) is a key factor affecting maize yield, but the physiological mechanisms by which it improves yield through the coordination of the source-sink relationship remain unclear. In this study, field experiments were conducted in the black soil region of Northeast China for three consecutive years (2022–2024). Five N rates were tested: 0 kg ha⁻¹ (N0), 90 kg ha⁻¹ (N90), 135 kg ha⁻¹ (N135), 180 kg ha⁻¹ (N180), and 225 kg ha⁻¹ (N225). The results showed that the N180 treatment achieved the highest yield across the three growing seasons, with yields 7.23–51.40% higher than those of the other treatments. This was mainly attributable to the synergistic improvement in grain number per ear and 100-grain weight. After anthesis, the N180 and N225 treatments significantly increased chlorophyll content (SPAD), PSII photochemical efficiency-related parameters (F_v/F_m, Φ_PSII, and qP), and the activities of carbon assimilation-related enzymes (RuBPCase and PEPCase) in the ear leaf, indicating improved photosynthesis-related physiological status. Meanwhile, N180 significantly promoted the translocation of stored dry matter from pre-anthesis vegetative organs to the grains, resulting in a 5.21–51.41% increase in the proportion of dry matter allocated to the grains at maturity compared with the other treatments. Logistic equation fitting showed that an increased grain-filling rate and an extended grain-filling period were the main reasons for the higher grain weight under N180. Although N225 maintained high post-anthesis dry matter accumulation, more assimilates were retained in vegetative organs, which limited further improvement in grain-filling and grain weight. These findings provide a theoretical basis and practical guidance for the rational application of nitrogen fertilizer in this region. Full article

To investigate the effects of planting density and chemical regulation measures, as well as their interactions, on the plant morphological characteristics, stem mechanical properties, leaf anatomical structure, dry matter accumulation and allocation, and yield and its components of grain maize in the Hexi Oasis irrigation area, a field experiment was conducted from 2024 to 2025. Planting density was set as the main factor, with five density levels: 82,500 plants·ha⁻¹ (M1), 97,500 plants·ha⁻¹ (M2), 112,500 plants·ha⁻¹ (M3), 127,500 plants·ha⁻¹ (M4) and 142,500 plants·ha⁻¹ (M5). Chemical regulation measures were set as the secondary factor, consisting of two treatments: spraying 30% aminoethyl hexanoate·ethephon at the 10-leaf stage (T1) and spraying an equal amount of water as the control (T2). The results revealed that, as planting density increases, the maize plant height, ear height and stem breakage rate rise continuously, whilst stem diameter, stem breaking resistance, rind puncture strength, leaf thickness and epidermal tissue thickness showed a downward trend. The leaf area index, ear length, kernel number per ear, kernel weight and yield all exhibited a trend of first increasing and then decreasing, reaching their peak at the M3 planting density. Compared with conventional planting patterns, spraying chemical regulators significantly reduced plant height by 10.66~13.99% and ear height by 16.12~19.57%, increased stem diameter by 2.12~13.79%, and enhanced stem breaking resistance by 7.71~23.11% and rind puncture strength by 5.17~12.65% at 30 days after silking. Additionally, it delayed leaf senescence, increased the leaf area index by 4.37~10.03% during the filling stage, and increased yield by 1.99~4.06%. The synergistic effect of moderately increasing planting density combined with chemical regulation can effectively coordinate the ‘population–individual’ contradiction in maize, reduce plant height and ear height and increase stem diameter and rind puncture strength, while maintaining a higher leaf area index after the silking stage and promoting dry matter translocation to grains, thereby achieving a synergy between lodging resistance and high yield. Among them, a planting density of 112,500 plants·ha⁻¹ combined with spraying chemical regulators yielded the highest maize yield and harvest index, reaching 20.28~20.48 t·ha⁻¹ and 0.52~0.53, respectively. Compared with other treatments, the increases ranged from 2.54~47.51% for yield and from 1.92~36.84% for the harvest index. Meanwhile, this treatment exhibited superior stem mechanical properties and a lower stem breakage rate. Taking into account factors such as lodging resistance, yield, dry matter accumulation and allocation, it has been determined that a planting density of 112,500 plants·ha⁻¹ combined with spraying 30% aminoethyl hexanoate·ethephon at the 10-leaf stage is an effective strategy for achieving both lodging resistance and high yield in grain maize in the Hexi Oasis irrigation area. Full article

Yaks (Bos grunniens) on the Qinghai–Tibetan Plateau face severe nutritional limitations during the dry season due to dependence on highly lignified, low-quality roughage. Identifying safe and effective rumen regulators capable of enhancing fiber utilization in this species is therefore of great practical importance. This study employed a two-pronged approach integrating in vitro mechanistic investigation and in vivo validation to evaluate the effects of the amphoteric surfactant cocamidopropyl betaine (CAPB) on rumen fermentation, the micro-spatial distribution of digestive enzymes, apparent total tract digestibility, and the macroscopic growth performance of yaks. In the in vitro fermentation trial (Experiment 1), a randomized block design was employed where a straw-based high-forage diet was used as the substrate and supplemented with 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% CAPB (based on substrate dry matter, DM) for a 48 h batch culture. The results showed that as the CAPB supplementation level increased, cumulative gas production, the degradation rates of DM and neutral detergent fiber (NDF), and the yields of total volatile fatty acids and microbial protein all exhibited significant quadratic responses (p < 0.05), peaking at the 0.5–1.0% supplementation levels. Concurrently, CAPB significantly promoted the transfer and release of carboxymethyl cellulase and xylanase into the free liquid phase (p < 0.01). In the in vivo validation trial (Experiment 2), 24 healthy growing male yaks (initial body weight 131.2 ± 8.4 kg) were allocated in a completely randomized design to four groups and fed a basal diet supplemented with 0, 0.5, 1.0, or 2.0% CAPB for 44 days. The results indicated that, while maintaining a stable DM intake, the addition of 0.5% CAPB significantly increased the average daily gain (ADG) of yaks (p < 0.05), improved the feed-to-gain ratio, and significantly enhanced the apparent total tract digestibility of NDF and ether extract (p < 0.05). However, when the supplementation dose exceeded the safety threshold (≥2.5% in vitro and ≥2.0% in vivo), both fermentation parameters and growth advantages declined. In conclusion, under the present experimental conditions, 0.5% CAPB improved roughage fermentation efficiency, putatively through an ‘enzyme elution’ mechanism, and was associated with macroscopic improvements in NDF and EE apparent digestibility and ADG in growing yaks. These findings identify 0.5% CAPB as a promising candidate rumen regulator for improving roughage utilization in growing yaks; broader generalization will require larger-scale and longer-duration trials. Full article

Wetland ecosystems have been a central focus of ecological research for an quite some time. Nevertheless, the degradation of wetland riparian zones has markedly accelerated due to anthropogenic activities, climate change, and habitat heterogeneity. The objective of this paper is to investigate the differences in functional traits of riparian plants under changing wetland environments on a karst plateau, as well as to elucidate the adaptive strategies of wetland plants across different habitats. This study examines the Caohai Wetland located on the Guizhou karst plateau, selecting the leaves of four dominant plant species (Phragmites australis, Onopordum acanthium, Galium odoratum, Paspalum distichum) in the Caohai Wetland lakeshore zone and analyzes the influence of soil factors on the variation of plant functional traits within the wetland riparian zone. The results reveal that: (1) significant differences exist in the functional traits of dominant plants in the riparian zones of karst plateau wetlands, with complex interrelationships among these traits; (2) the coefficients of variation for magnesium (Mg) and calcium (Ca) in the soil are notably high (79.53% and 67.21%, respectively), whereas soil oxidation-reduction potential (ORP) exhibits the lowest coefficient of variation (4.36%)—furthermore, the convergent variation in specific leaf area (SLA) and leaf dry matter content (LDMC) directly reflects the strong environmental filtering imposed by this habitat—and (3) redundancy analysis (RDA) indicates that leaf length (LL), specific leaf area (SLA), leaf area (LA), and plant carbon content (PCC) are particularly sensitive to environmental changes, while soil calcium (Ca), total nitrogen (TN), water-dispersible clay (WDR), soil organic matter (SOM), soil moisture content (SPMC), and total potassium (TK) constitute the principal soil factors influencing plant adaptive strategies in karst plateau wetlands. In conclusion, this study demonstrates that adaptation to karst wetland habitats is mediated through trade-offs in the allocation of photosynthetic products and the regulation of carbon (C), nitrogen (N), and phosphorus (P) nutrient balances under calcium-enriched and phosphorus-limited conditions, thereby reflecting the response characteristics of functional traits in karst plateau wetland plants to environmental changes. Full article

Under the combined pressures of climate change and irrigated cropland expansion, groundwater tables are declining rapidly across arid regions, thereby intensifying water limitation in riparian ecosystems. However, the mechanisms by which dominant riparian tree species coordinate multiple functional traits to maintain carbon–water balance remains poorly understood. This study investigated coordinated ecophysiological trait shifts of Populus euphratica Oliv. along a groundwater-depth gradient (2.19, 4.88, and 7.45 m) in the middle reaches of the Tarim River (China), hereafter referred to as shallow, middle, and deep groundwater depths, respectively. We quantified photosynthetic, hydraulic, stomatal, leaf anatomical and nutrient traits, and estimated long-term intrinsic water-use efficiency (WUE_i) from foliar δ¹³C. As the groundwater table declined, (1) photosynthetic capacity and photochemical performance decreased, whereas WUE_i increased markedly from 38.5 ± 2.9 to 54.2 ± 1.0 μmol mmol⁻¹, accompanied by the lowest transpiration rate at the deep groundwater depth (4.6 ± 0.5 mmol m⁻² s⁻¹); (2) stomatal and anatomical adjustments consistent with water-loss reduction were observed, including a significant decline in stomatal density from 93.5 ± 14.5 to 79.3 ± 17.4 pores mm⁻², and reduced stomatal size and stomatal area fraction (−20.3% and −32.7%, respectively); (3) the percentage loss of hydraulic conductivity increased, whereas sapwood-specific hydraulic conductivity declined, accompanied by greater sapwood investment relative to leaf area, with Huber value rising from 0.06 ± 0.02 to 0.11 ± 0.04 mm² cm⁻² at deep water depth; and (4) chlorophyll concentrations and leaf water content declined, whereas structural investment increased, as reflected by higher specific leaf mass and leaf dry matter content, and leaf nutrients were enriched, with total nitrogen and total phosphorus increasing by 67.1% and 42.0%, respectively. Trait-WUE_i relationships further indicated that WUE_i covaried most strongly with leaf anatomical and nutrient traits. These results demonstrate that increasing groundwater depth was associated with coordinated shifts in carbon assimilation, water-use regulation, hydraulic function, and nutrient allocation in P. euphratica. Such trait coordination may help explain how this species persists under chronic water limitation in arid riparian forests. Full article