Search Results (201)

Sugary phloem exudates are produced by many plant species and play key roles in carbon storage, defense, and ecological interactions. Among eucalypts, one such exudate, manna, is an important carbohydrate source for birds, mammals, and insects. Despite its ecological relevance, little is known about the composition and intra-specific variability of manna. Here, we investigated patterns of manna production in Eucalyptus viminalis, a widespread foundation tree species in southeastern Australia. We developed a repeatable ex situ method to extract and analyze manna, allowing us to characterize its sugar composition and examine variation within and between trees. Across years, manna contained six sugars, with sucrose and raffinose dominant. We found substantial variation in both the quality (sucrose/raffinose ratio) and quantity (mg) of manna produced. Both declined with increasing tree size (DBH), while quality increased with branch circumference. Seasonal and annual variation in manna was also evident, with quality increasing under drier conditions (positive correlation with aridity). Our findings demonstrate substantial intra-specific variation in phloem exudates (manna), shaped by temporal and tree-level factors. These patterns offer a foundation for future research into the ecological and physiological drivers of exudate variation and resource availability in foundation species like E. viminalis. Full article

Background: Reliable and non-invasive methods for assessing welfare in poultry are essential for improving evidence-based welfare monitoring and advancing management practices in commercial production systems. The iris-to-pupil (IP) ratio, previously validated by our group in primates and cattle, reflects autonomic nervous system balance and may serve as a physiological indicator of stress in laying hens. This study evaluated the utility of the IP ratio under field conditions across diverse commercial layer housing systems. Materials and Methods: In total, 296 laying hens (Lohmann Brown, n = 269; White Leghorn, n = 27) were studied across four locations in Canada housed under different systems: Guelph (indoor; pen), Spring Island (outdoor and scratch; organic), Ottawa (outdoor, indoor and scratch; free-range), and Toronto (outdoor and hobby; free-range). High-resolution photographs of the eye were taken under ambient lighting. Light intensity was measured using the light meter app. The IP ratio was calculated using NIH ImageJ software (Version 1.54p). Statistical analysis included one-way ANOVA and linear regression using GraphPad Prism (Version 5). Results: Birds housed outdoors had the highest IP ratios, followed by those in scratch systems, while indoor and pen-housed birds had the lowest IP ratios (p < 0.001). Subgroup analyses of birds in Ottawa and Spring Island farms confirmed significantly higher IP ratios in outdoor environments compared to indoor and scratch systems (p < 0.001). The IP ratio correlated weakly with ambient light intensity (r² = 0.25) and age (r² = 0.05), indicating minimal influence of these variables. Although White Leghorn hens showed lower IP ratios than Lohmann Browns, this difference was confounded by housing type; all White Leghorns were housed in pens. Thus, housing system but not breed was the primary driver of IP variation. Conclusions: The IP ratio is a robust, non-invasive physiological marker of welfare assessment in laying hens, sensitive to housing environment but minimally influenced by light or age. Its potential for integration with digital imaging technologies supports its use in scalable welfare assessment protocols. Full article

Mercury (Hg) pollution is a widespread ecological threat with sublethal effects on wildlife. Birds, due to their ecological diversity and sensitivity, serve as effective models for evaluating the behavioural impacts of Hg exposure. This review applies Tinbergen’s four questions: causation, ontogeny, function, and evolution, as an integrative framework. Mechanistically, Hg disrupts neuroendocrine pathways, gene expression, immune function, and hormone regulation, leading to behavioural changes such as reduced foraging, altered parental care, and impaired predator avoidance. Early-life exposure affects neural development, learning, and social behaviour into adulthood. Functionally, these changes reduce fitness by compromising reproduction and survival. Phylogenetic comparisons show interspecific variability, with piscivorous and insectivorous birds exhibiting high Hg burdens and sensitivity, linked to ecological roles and exposure. Behavioural responses often precede physiological or demographic effects, highlighting their value as early indicators. Both field and laboratory studies show that even low Hg concentrations can alter behaviour, though outcomes vary by species, life stage, and exposure route. Integrating behavioural endpoints into ecotoxicological risk assessments is essential to improve conservation strategies and understanding of sublethal pollutant effects on wildlife. Full article

Immunoglobulin Y (IgY), the major antibody class in birds, has gained increasing attention in recent years as a versatile and ethically sustainable alternative to mammalian immunoglobulins. IgY has demonstrated strong potential in diagnostics, prophylaxis, and therapy across a wide range of fields, including infectious diseases, allergy management, oral health, and food safety. Its applications in animal health—particularly in poultry, livestock, and companion animals—further underscore its relevance within the One Health framework. This review provides a comprehensive synthesis of IgY technology, starting with its physiological role in maternal immunity and the structural characteristics that distinguish it from mammalian immunoglobulin G (IgG). This review outlines current strategies for IgY production and purification. It also provides an overview of its biomedical and veterinary applications, including its use in diagnostics, prevention, and treatment—such as for SARS-CoV-2—primarily based on studies published in the past five years. The final section addresses the current limitations of IgY technology, such as variability in protocols, stability challenges, and the need for safety assessment, while highlighting the importance of harmonized guidelines to support broader implementation. With growing scientific interest, expanding clinical research, and increasing availability of commercial products, IgY is well positioned to become a valuable immunobiological tool for both human and veterinary applications. Full article

Soundscape is the sonic environment that a living being, like a human or animal, experiences in a certain setting. It affects how a space functions and how the being perceives its quality. Consequently, the soundscape is crucial in ecosystems globally. In recent decades, researchers have explored soundscapes using various methodologies across different disciplines. This study aims to provide a brief overview of the soundscape research history, pinpoint key authors, institutions, and collaboration networks, and identify trends and main themes through a bibliometric analysis. A search in the Scopus database on 26 February 2025 found 5825 articles, reviews, and conference papers on soundscape published from 1985 to 2024. The analysis indicated a significant increase in soundscape publications, rising from 1 in 1985 to 19 in 2002, and reaching 586 in 2024. J. Kang was the most prolific author with 265 publications, while University College London emerged as the most productive institution. Co-citation analysis revealed three research groups: one focused on urban soundscapes, another on aquatic soundscapes, and a third on soundscapes in landscape ecology. The keyword co-occurrence analysis identified three themes: “soundscape(s), acoustic environment, and urban planning”, “noise, animal(s), bioacoustics, biodiversity, passive acoustic monitoring, fish, and bird(s)”, and “human(s), sound, perception, and physiology”. Full article

Controlling low ambient temperatures and ammonia levels is critical for effective environmental management in poultry houses during winter, as both represent persistent stressors affecting bird health and productivity. However, evidence regarding their combined long-term effects on the physiological responses of laying hens remains limited. In this study, 576 eighteen-week-old Hy-Line Brown hens were randomly assigned to six treatments (8 replicates with 12 birds per replicate each treatment) and housed in environmentally controlled chambers for 20 weeks: T1 (8 °C, ≤5 ppm ammonia), T2 (8 °C, 20 ppm ammonia), T3 (8 °C, 45 ppm ammonia), T4 (20 °C, ≤5 ppm ammonia; control), T5 (20 °C, 20 ppm ammonia), and T6 (20 °C, 45 ppm ammonia). Plasma samples were collected at 22, 26, 30, 34, and 38 weeks to evaluate physiological stress biomarkers (corticosterone, CORT; total antioxidant capacity, T-AOC), immunoglobulins (IgG, IgM, and IgA), and reproductive hormones (luteinizing hormone, LH; follicle-stimulating hormone, FSH; estradiol, E2). At 38 weeks, hypothalamus, pituitary, and spleen tissues were collected to assess the relative mRNA expression of gonadotropin-releasing hormone (GnRH), FSH, tumor necrosis factor-α (TNF-α), and interleukins (IL-1β, IL-6, and IL-10). Results showed that both cold and ammonia stress reduced antioxidant capacity, disrupted immune homeostasis, and altered reproductive hormone profiles. Cold exposure induced acute immunoendocrine alterations with partial physiological adaptation over time, whereas ammonia exerted progressive and cumulative damage, including elevated immunoglobulins (IgG and IgM) and downregulation of GnRH and FSH expression. Combined exposure significantly upregulated TNF-α and IL-1β expression, suggesting a synergistic inflammatory response. These results highlight complex, parameter-specific interactions between cold and ammonia stressors, emphasizing the need for targeted environmental strategies. Stage-specific interventions—thermal regulation in early laying and ammonia control in later phases—are recommended to safeguard hen health and optimize productivity under winter conditions. Full article

Thermal manipulation (TM) during embryogenesis is a promising non-pharmacological strategy to enhance physiological resilience in broiler chickens. This study evaluated the impact of thermal conditioning of fertile eggs on growth performance, inflammatory responses, and molecular stress markers following a post-hatch lipopolysaccharide (LPS) challenge. Fertilized eggs (average weight 62 ± 3 g) were obtained from 35-week-old Indian River broiler breeder hens. A total of 720 eggs were randomly assigned to either the control group (n = 360) or the TM group (n = 360), with each group consisting of two replicates of 180 eggs. Control eggs were maintained under standard incubation conditions (37.8 °C, 56% RH), while TM eggs were subjected to elevated temperature (38.8 °C, 65% RH) for 18 h daily from embryonic day 10 to 18. On post-hatch day 15, control and TM groups were administered either saline or LPS via intraperitoneal (IP) injection. Body weight and temperature, internal organ weights, and splenic mRNA expression levels of inflammatory cytokines, toll-like receptors, transcription factors, and heat shock proteins were assessed. TM did not alter hatchability (p = 0.633), but significantly shortened hatch time (p < 0.05) and improved feed efficiency (p < 0.05). While LPS induced marked inflammatory responses in all birds, those subjected to TM exhibited attenuated proinflammatory cytokine expression, enhanced anti-inflammatory signaling, and differential regulation of stress-associated genes, including nuclear factor kappa B (NF-κB), heat shock protein 70 (HSP70), and heat shock factors (HSFs). These findings suggest that TM during incubation promotes a more regulated immune response and improved stress adaptation post-hatch. This approach offers a potential antibiotic-free intervention to enhance broiler health, performance, and resilience under immunological stress. Full article

Plant modeling uses mathematical and computational methods to simulate plant structures, physiological processes, and interactions with various environments. In precision agriculture, it enables the digital monitoring and prediction of crop growth, supporting better management and efficient resource use. Wheat, as a major global staple, is vital for food security. However, wheat stripe rust, a widespread and destructive disease, threatens yield stability. The paper proposes wheat cultivation suitability evaluation with stripe rust disease using an agriculture group consensus framework (WCSE-AGC) to tackle this issue. Assessing stripe rust severity in regions relies on wheat pathologists’ judgments based on multiple criteria, creating a multi-attribute, multi-decision-maker consensus problem. Limited regional coverage and inconsistent evaluations among wheat pathologists complicate consensus-reaching. To support wheat pathologist participation, this study employs artificial-intelligence-generated content (AIGC) techniques by using Claude 3.7 to simulate wheat pathologists’ scoring through role-playing and chain-of-thought prompting. WCSE-AGC comprises three main stages. First, a graph neural network (GNN) models trust propagation within wheat pathologists’ social networks, completing missing trust links and providing a solid foundation for weighting and clustering. This ensures reliable expert influence estimations. Second, integrating secretary bird optimization (SBO), K-means, and three-way clustering detects overlapping wheat pathologist subgroups, reducing opinion divergence and improving consensus inclusiveness and convergence. Third, a two-stage optimization balances group fairness and adjustment cost, enhancing consensus practicality and acceptance. The paper conducts experiments using publicly available real wheat stripe rust datasets from four different locations, Ethiopia, India, Turkey, and China, and validates the effectiveness and robustness of the framework through comparative and sensitivity analyses. Full article

Amazonian parrots (Psittacidae) are essential to ecosystem balance. Already vulnerable to habitat fragmentation and weak environmental regulations, they are now increasingly threatened by heavy metal contamination. This review synthesizes evidence on the sources, transgenerational bioaccumulation, and physiological impacts of metals such as mercury (Hg), lead (Pb), cadmium (Cd), zinc (Zn), and arsenic (As) in these birds. Anthropogenic activities, including illegal gold mining, agricultural intensification, and urban expansion, release metals that biomagnify along food webs. Parrots, as long-lived, high-trophic consumers, accumulate metals in vital tissues, leading to severe neurotoxic effects, immunosuppression, reproductive failure, and reduced survival. Furthermore, maternal transfer of contaminants to eggs exacerbates genetic erosion and threatens population viability. While biomonitoring tools and habitat restoration have been proposed, current strategies are insufficient against the synergistic pressures of pollution and climate change. Addressing heavy metal exposure is critical to conserving Amazonian biodiversity and safe-guarding ecosystem services. Future efforts should prioritize multidisciplinary predictive models, bioremediation actions, and the strengthening of international environmental governance to ensure the survival of these sentinel species. Full article

Lead is among the most toxic heavy metals, posing significant risks to all living organisms. It is a pervasive and persistent contaminant in the environment. Ingested lead in birds and wildlife induces a range of sublethal effects that disrupt physiological functions and behavior, ultimately resulting in mortality at higher doses or with prolonged exposure. To investigate the relation of lead to accidents and injuries in wild birds, we analyzed lead concentration in 43 wild birds that were admitted as patients to the Wildlife Rehabilitation and Breeding Center (WRBC). The findings reveal a significant dependency between the detected levels of lead in the birds’ bone samples and the reported etiology of their injuries, with variances in the age groups of the patients received at the WRBC in Bulgaria. Full article

Mycotoxins are secondary fungal metabolites that frequently contaminate poultry feed, posing significant risks to animal health, productivity, and food safety. In broiler production, mycotoxins such as aflatoxins, trichothecenes, fumonisins, ochratoxin A, deoxynivalenol, and zearalenone have been shown to impair growth performance, damage key organs, and disrupt immune function. This review explores the multifaceted impact of mycotoxin exposure in broilers, with particular emphasis on immunosuppression, decreased vaccine efficacy, and increased vulnerability to infectious diseases, including coccidiosis, salmonellosis, E. coli, and viral infections like infectious bursal disease and infectious laryngotracheitis. Mycotoxin contamination in poultry feed can lead to direct economic losses through reduced feed conversion efficiency, increased mortality, and reproductive disorders, while also resulting in the transfer of toxic residues into meat and eggs, thereby threatening consumer health. The review further examines the synergistic interactions between mycotoxins and pathogens, the physiological and histopathological changes in exposed birds, and the implications for public health. Finally, it discusses current mitigation strategies, including mycotoxin binders, probiotics, and regulatory approaches to reduce exposure. An integrated management strategy combining feed hygiene, monitoring, and targeted nutritional interventions is essential to safeguard poultry health, enhance vaccine responses, and ensure the safety of poultry-derived food products. This review offers actionable insights for veterinarians, nutritionists, and policymakers, reinforcing the importance of mycotoxin mitigation strategies within a One Health framework. Full article

Birds exhibit naturally high blood glucose concentrations, a physiological trait that, unlike in mammals, does not lead to typical pathological consequences such as diabetes mellitus. This review explores the unique features of glucose metabolism in birds, with a particular focus on the anatomy and function of the avian pancreas, the roles of key hormones such as insulin and glucagon, as well as the distinctive mechanisms of glucose absorption and utilization. Evidence suggests a dominant role of glucagon over insulin, along with adaptations such as insulin resistance and antioxidant defenses, which may contribute to birds’ apparent resilience to hyperglycemia-related complications. Despite these adaptations, cases of diabetes mellitus have been reported, primarily as secondary to other pathologies, including pancreatitis, hemochromatosis, infections, and toxicities. Diagnosis remains challenging due to interspecies variability and the lack of standardized assays. Treatment, mainly via insulin therapy, has shown mixed outcomes, often limited by the underlying disease severity. This review highlights the need for species-specific diagnostic tools and a deeper investigation into the pathophysiology of glucose regulation in birds, aiming to improve clinical outcomes, develop standardized therapies, and ultimately broaden the perspectives of comparative endocrinology. Full article

Lactic acid bacteria (LAB) isolated from plant sources are gaining increasing attention due to their potential probiotic and postbiotic functionalities. In the present study, Limosilactobacillus fermentum isolated from Prunus padus (bird cherry) was evaluated for its physiological, functional, and technological attributes for application in fermented dairy products. The strain was isolated through anaerobic fermentation and identified using API 50 CHL and 16S rRNA sequencing. Its acid tolerance, antioxidant capacity, antibacterial effects, and hemolytic activity were assessed. The cell-free supernatant (CFS) was evaluated for thermal and pH stability. Fermentation trials were conducted using both mono- and co-culture combinations with the commercial yogurt starter strain YC-380. Physicochemical properties, viable cell counts, and viscosity were monitored throughout fermentation and refrigerated storage. The L. fermentum isolate exhibited strong acid resistance (48.28% viability at pH 2.0), non-hemolytic safety, and notable DPPH radical scavenging activity. Its CFS showed significant antibacterial activity against five Escherichia coli strains, which remained stable after heat treatment. Co-cultivation with YC-380 enhanced fermentation efficiency and improved yogurt viscosity (from 800 to 1200 CP) compared to YC-380 alone. During 24 days of cold storage, co-cultured samples maintained superior pH and microbial stability. Additionally, the moderate acidification profile and near-neutral pH of L. fermentum created favorable conditions for postbiotic compound production. These results indicate that L. fermentum derived from P. padus holds considerable promise as a functional adjunct culture in yogurt production. Its postbiotic potential, technological compatibility, and heat-stable bioactivity suggest valuable applications in the development of safe, stable, and health-promoting fermented dairy products. Full article

The objective of this study was to evaluate the inoculation of nutrient solutions with increasing levels of putrescine on the hatchability, physiology, and performance of broilers during the initial phase. The study is composed of four treatments with increasing doses of putrescine (0.015; 0.030; 0.060, and 0.090%) and a control group. At hatch, hatchability rate; ratio between egg weight and chick weight; ratio between yolk sac, liver, breast and intestine weight, and chick weight; glycogen concentration in the liver and breast; and morphometric characteristics of the jejunum and ileum were evaluated. After hatch, 400 birds were housed in metabolic cages according to the treatments received, and feed intake, body weight gain, and feed conversion ratio were assessed at specific time points. Hatchability, chick performance at hatch, and organ weight were not affected by the inoculation of increasing levels of putrescine. Intestinal villi at hatch were higher in groups supplemented with putrescine (p < 0.001). The amounts of hepatic glycogen per gram of tissue at hatch were higher in groups with the lowest levels of putrescine and decreased with increasing doses (p = 0.017). Growth performance from 1 to 21 days was not influenced by the inoculation of putrescine. Full article

The relentless drive to meet global demand for poultry products has pushed for rapid intensification in chicken farming, dramatically boosting efficiency and yield. Yet, these gains have exposed a host of complex welfare challenges that have prompted scientific scrutiny and ethical reflection. In this review, I critically evaluate recent innovations aimed at mitigating such concerns by drawing on advances in behavioral science and digital monitoring and insights into biological adaptations. Specifically, I focus on four interconnected themes: First, I spotlight the complexity of avian sensory perception—encompassing vision, auditory capabilities, olfaction, and tactile faculties—to underscore how lighting design, housing configurations, and enrichment strategies can better align with birds’ unique sensory worlds. Second, I explore novel tools for gauging emotional states and cognition, ranging from cognitive bias tests to developing protocols for identifying pain or distress based on facial cues. Third, I examine the transformative potential of computer vision, bioacoustics, and sensor-based technologies for the continuous, automated tracking of behavior and physiological indicators in commercial flocks. Fourth, I assess how data-driven management platforms, underpinned by precision livestock farming, can deploy real-time insights to optimize welfare on a broad scale. Recognizing that climate change and evolving production environments intensify these challenges, I also investigate how breeds resilient to extreme conditions might open new avenues for welfare-centered genetic and management approaches. While the adoption of cutting-edge techniques has shown promise, significant hurdles persist regarding validation, standardization, and commercial acceptance. I conclude that truly sustainable progress hinges on an interdisciplinary convergence of ethology, neuroscience, engineering, data analytics, and evolutionary biology—an integrative path that not only refines welfare assessment but also reimagines poultry production in ethically and scientifically robust ways. Full article