Animals

17 pages, 440 KB

Open AccessArticle

Reproductive Success and Diet of the Swainson’s Hawk (Buteo swainsoni) in the Grasslands of Janos, Chihuahua, Mexico

by Nereyda N. Cruz Maldonado, Cayetano J. Villareal Lozoya, Javier Cruz Nieto, Alina Olalla Kerstupp, Gabriel Ruiz Aymá, Antonio Guzmán Velasco and José I. González Rojas

Animals 2026, 16(1), 131; https://doi.org/10.3390/ani16010131 - 2 Jan 2026

Abstract

Understanding the breeding ecology and trophic dynamics of the Swainson’s Hawk (Buteo swainsoni) is essential for conserving grassland raptor populations in northern Mexico. We evaluated reproductive success, nest-site characteristics, and diet of the species in the grasslands of Janos, Chihuahua, during [...] Read more.

Understanding the breeding ecology and trophic dynamics of the Swainson’s Hawk (Buteo swainsoni) is essential for conserving grassland raptor populations in northern Mexico. We evaluated reproductive success, nest-site characteristics, and diet of the species in the grasslands of Janos, Chihuahua, during the 2006 breeding season. Eighteen nests were monitored to estimate daily survival rates (DSRs) using the Mayfield method. Overall nest success was 44.4%. DSR declined significantly from incubation (0.99 ± 0.00079) to the nestling stage (0.98 ± 0.00087; z = 8.5, p < 0.001), resulting in cumulative survival of 79.9% and 56.2%, respectively. Successful nests tended to occur farther from towns, although this trend was not statistically significant. Most nests were built in mesquite trees at intermediate elevations and in areas with low human disturbance. Diet analyses of 56 pellets and 91 prey remains revealed a predominance of vertebrates (63.17%), mainly mammals and reptiles, with vertebrate frequency significantly exceeding that of invertebrates (χ² = 23.19, p < 0.001). These results highlight the species’ reliance on vertebrate prey and the vulnerability of the nestling stage, underscoring the importance of long-term monitoring in semi-arid grasslands. Full article

(This article belongs to the Section Birds)

29 pages, 1276 KB

Open AccessReview

Phosphorus Metabolism and Function in Ruminants: Current Knowledge

by Beata Abramowicz, Ewa Tomaszewska, Oliwia Brzezińska, Karolina Kłos, Miroslav Urosevic and Łukasz Kurek

Animals 2026, 16(1), 130; https://doi.org/10.3390/ani16010130 - 2 Jan 2026

Abstract

Phosphorus (P) is a key macromineral essential for numerous physiological processes, including energy metabolism, skeletal mineralization, and cellular signaling. In dairy cattle, its homeostasis is tightly regulated by parathyroid hormone, calcitriol, and fibroblast growth factor 23 (FGF23). Phosphorus deficiency is common during the [...] Read more.

Phosphorus (P) is a key macromineral essential for numerous physiological processes, including energy metabolism, skeletal mineralization, and cellular signaling. In dairy cattle, its homeostasis is tightly regulated by parathyroid hormone, calcitriol, and fibroblast growth factor 23 (FGF23). Phosphorus deficiency is common during the transition period and is associated with reduced milk yield, anemia, muscle weakness, and immunosuppression in severe or prolonged cases. This review summarizes the current understanding of phosphorus metabolism in ruminants, emphasizing differences from monogastric species, hormonal regulation, and the clinical manifestations of deficiency. Particular attention is given to postpartum hypophosphatemia, its relationship with acute-phase proteins, and the pathogenesis of postpartum hemoglobinuria and recumbency. The review also discusses diagnostic methods for assessing phosphorus status, recent findings on FGF23 physiology in cattle, and including demonstrated effects of phosphorus imbalance on periparturient immune suppression and increased environmental phosphorus losses through manure. Maintaining optimal phosphorus nutrition is crucial for bovine health, productivity, and reduction in environmental phosphorus losses. Full article

(This article belongs to the Section Cattle)

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13 pages, 2221 KB

Open AccessTechnical Note

Simulating Dairy Herd Structure and Cash Flow: Design and Application of a Web-Based Decision-Support Tool

by Victor E. Cabrera

Animals 2026, 16(1), 129; https://doi.org/10.3390/ani16010129 - 2 Jan 2026

Abstract

Dairy herd decisions about replacement, herd size, reproduction, and capital investments have long-lasting consequences for herd structure and farm cash flow. Yet most planning tools emphasize static budgets rather than the dynamic evolution of animal numbers and cash availability. The Dairy Herd Structure [...] Read more.

Dairy herd decisions about replacement, herd size, reproduction, and capital investments have long-lasting consequences for herd structure and farm cash flow. Yet most planning tools emphasize static budgets rather than the dynamic evolution of animal numbers and cash availability. The Dairy Herd Structure Simulation and Cash Flow tool is a web-based decision-support system, available through the Dairy Management Decision Support Tools website, designed to simulate these dynamics under alternative management strategies. The model operates in monthly time steps using a Markov–chain framework in which transition probabilities among animal states are driven by user-specified parameters such as culling, reproduction, and heifer management. Calves, heifers, and cows are tracked by age and lactation group, and starting conditions can be entered as herd-level summaries or via individual-animal spreadsheets. Economic components include milk income, variable costs, cull-cow income, heifer purchases or sales, miscellaneous costs, and loan amortization. For each scenario, the tool projects monthly cash flow and income over variable cost per cow, together with graphical summaries of herd structure. An example application compares a baseline steady-state herd with a heifer-driven herd growth scenario, illustrating how replacement strategies influence herd composition and net cash flow, supporting more informed dairy herd planning and risk management. Full article

(This article belongs to the Section Animal System and Management)

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19 pages, 355 KB

Open AccessReview

Feline Infectious Peritonitis: A Challenging Diagnostic and Therapeutic Labyrinth

by Violetta Iris Vasinioti, Maria Stella Lucente, Cristiana Catella, Canio Buonavoglia, Nicola Decaro, Annamaria Pratelli and Paolo Capozza

Animals 2026, 16(1), 128; https://doi.org/10.3390/ani16010128 - 2 Jan 2026

Abstract

Feline coronaviruses (FCoVs) are ubiquitous pathogens, exhibiting high prevalence across feline populations worldwide. Although the virulent mutated biotype feline infectious peritonitis virus (FIPV) is observed in only a small percentage of cats, it causes a systemic and often fatal disease. Diagnosis of feline [...] Read more.

Feline coronaviruses (FCoVs) are ubiquitous pathogens, exhibiting high prevalence across feline populations worldwide. Although the virulent mutated biotype feline infectious peritonitis virus (FIPV) is observed in only a small percentage of cats, it causes a systemic and often fatal disease. Diagnosis of feline infectious peritonitis (FIP) is challenging due to its non-specific clinical signs and the difficulty in differentiating between the two biotypes, feline enteric coronavirus (FECV) and FPIV. Currently, veterinarians rely on a combination of diagnostic methods, integrating laboratory tests, anamnesis and clinical signs to improve the diagnostic accuracy of FIP. Once considered untreatable, FIP now benefits from recent pharmacological advances that suggest promising therapeutic options, including antiviral drugs and immunomodulatory therapies. Despite these developments, the lack of an effective vaccine and definitive curative treatment highlights the need for continued research. This review provides a comprehensive analysis of the current literature on diagnostic and treatment approaches for FIP. The aim is to improve understanding of the available options and strategies for FIP to mitigate its severe consequences. Full article

(This article belongs to the Special Issue Prevention and Control for Animal Transmissible Diseases)

13 pages, 2151 KB

Open AccessFeature PaperArticle

Infrared Thermal Imaging as a Predictor of Lumbar Paravertebral Block Effectiveness in Cattle

by Jaime Viscasillas, Elsa Rave, Ariel Cañón-Pérez, María De Los Reyes Marti-Scharfhausen, Eva Zoe Hernández-Magaña, Agustín Martínez, José Ignacio Redondo and Angel García-Muñoz

Animals 2026, 16(1), 127; https://doi.org/10.3390/ani16010127 - 2 Jan 2026

Abstract

In the daily clinical practice of cattle, the use of locoregional anaesthesia is needed to provide analgesia during standing surgical procedures. It is important to ensure the success of the blockade before starting the surgery. One of the most used techniques is the [...] Read more.

In the daily clinical practice of cattle, the use of locoregional anaesthesia is needed to provide analgesia during standing surgical procedures. It is important to ensure the success of the blockade before starting the surgery. One of the most used techniques is the paravertebral lumbar block. In this pilot study we evaluated the efficacy of thermography in assessing this block. For this matter, 12 cows from our university research and teaching farm, with similar characteristics, were included and in which an ultrasound-guided technique of lumbar paravertebral block (T₁₃/L₁) or (L₁/L₂) with lidocaine was performed. Thermal photographs were taken with a FLIR^® One camera at 0, 15, 30 and 45 min and at the same time a test to evaluate the response to a painful stimulus was performed in each dermatome (T₁₃, L₁, L₂ and L₃). The data was collected in predesigned cards and placed in the Excel programme for further statistical analysis with the R programme. The analysis determined a correlation between the increase in skin temperature of the dermatomes that had been blocked and the increase in skin temperature and the negative response to the painful stimulus test. Although the pilot study has some limitations, this allows us to assess the use of thermography as an efficient method for assessing the success of lumbar paravertebral blockade in cattle. Full article

(This article belongs to the Special Issue Anaesthesia and Pain Management in Large Animals—Second Edition)

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18 pages, 3833 KB

Open AccessArticle

Early-Life Galacto-Oligosaccharide Supplementation Induces Persistent Immunoglobulin and Metabolic Alterations in Holstein Dairy Calves by Shaping Gut Microbiota

by Qi Huang, Meinan Chang and Peng Sun

Animals 2026, 16(1), 126; https://doi.org/10.3390/ani16010126 - 1 Jan 2026

Abstract

Early-life development of immune functions is crucial for calf health, growth, and future productivity. Galacto-oligosaccharides (GOSs) have been reported to facilitate ruminal microbial establishment and improve growth in Holstein dairy calves, but their prolonged influence on immunoglobulin levels, hindgut microbiota, and metabolic regulation [...] Read more.

Early-life development of immune functions is crucial for calf health, growth, and future productivity. Galacto-oligosaccharides (GOSs) have been reported to facilitate ruminal microbial establishment and improve growth in Holstein dairy calves, but their prolonged influence on immunoglobulin levels, hindgut microbiota, and metabolic regulation remains insufficiently understood. This study evaluated the effects of early-life GOS supplementation on immune-related indicators, intestinal microbial ecology, and metabolic profiles in Holstein calves. Twenty-four newborn Holstein female dairy calves were randomly assigned to a control group (CON, n = 12) or a GOS group (GOS, n = 12; 10 g/day from birth to day 28). After supplementation ceased on day 28, calves previously receiving GOS were referred to as the GOSS group (n = 6). Immunoglobulin levels, gut microbiota, and fecal and serum metabolomes were evaluated during supplementation and six weeks after withdrawal. GOS supplementation significantly increased serum IgA and IgG levels during the treatment, with IgG levels remaining elevated for six weeks after discontinued supplementation. Although overall microbial diversity was not markedly altered, GOS selectively enriched bacterial taxa and function pathways linked to amino acid synthesis, unsaturated fatty acid production, and coenzyme-related metabolism. On day 70, GOSS group displayed distinct fecal and serum metabolomic profiles, with altered metabolites primarily associated with vitamin B6, folate, cobalamin metabolism, branched-chain amino acid biosynthesis, and purine and arginine pathways. These results demonstrate that early-life GOS supplementation promotes sustained immune and metabolic alterations following supplementation cessation, potentially mediated by modulation of gut microbial functions. These findings suggest that early dietary GOS supplementation may support physiological maturation in calves and could be useful as a nutritional strategy in calf-rearing systems. Full article

(This article belongs to the Section Animal Nutrition)

15 pages, 698 KB

Open AccessArticle

Optimization of the Embryo Transfer Technique in the Korean Native Cattle: Effects of Key Influencing Factors

by Seungki Jung, Heejae Yang, Yeonsub Jung, Minki Lee, Hyeonseok Sul, Yeon-Gil Jung, Joohyeong Lee and Sang-Hwan Hyun

Animals 2026, 16(1), 125; https://doi.org/10.3390/ani16010125 - 1 Jan 2026

Abstract

The success rate of embryo transfer (ET) is influenced by various factors, including embryo quality, environmental conditions, and recipient cows. This study examines the impact of ET on embryo success rates using embryos produced using the ovum pickup method, with fresh and frozen [...] Read more.

The success rate of embryo transfer (ET) is influenced by various factors, including embryo quality, environmental conditions, and recipient cows. This study examines the impact of ET on embryo success rates using embryos produced using the ovum pickup method, with fresh and frozen embryos generated on day 7 after in vitro fertilization and subsequently implanted into recipient cows. The factors that contributed to the success rate of ET were investigated, with a focus on embryo type, parity, and farm management. Furthermore, metabolic profile tests were conducted to determine the factors underlying the observed differences in pregnancy rates across the farms. The analysis revealed that pregnancy rates did not significantly differ according to embryo type or parity. However, significant differences (p < 0.05) were observed in the glucose, cholesterol, non-esterified fatty acid, total protein, globulin, albumin/globulin, and aspartate aminotransferase levels of the recipients. Furthermore, a comparison of farms with high and low pregnancy rates revealed significant differences in the glucose, cholesterol, total protein, albumin, globulin, and albumin/globulin levels (p < 0.05). Differences between farms were associated with the feed management strategy, which highlights the significance of optimal recipient cow management. Full article

(This article belongs to the Section Animal Reproduction)

13 pages, 1235 KB

Open AccessReview

Theoretical Discussion of Applicability and a Practical Example of Using Statistical Second-Generation Techniques to Analyze Causal Relationships in Animal Experiments

by Becker Katrin

Animals 2026, 16(1), 124; https://doi.org/10.3390/ani16010124 - 1 Jan 2026

Abstract

In animal experiments, causal relationships in physiological or disease processes are investigated by using interventions. Applying second-generation statistical methods could be used to identify important links in life processes. This article as a first step describes how second-generation statistical methods that are often [...] Read more.

In animal experiments, causal relationships in physiological or disease processes are investigated by using interventions. Applying second-generation statistical methods could be used to identify important links in life processes. This article as a first step describes how second-generation statistical methods that are often used in social sciences are currently applied in veterinary medicine, including a single-animal experimental study, or an ecotoxicity study in fish. It explains how second-generation statistical methods allow flexible modeling to simultaneously calculate causal relationships between constructs in several layers. It continues with a discussion on how theoretical concepts from this statistical approach could be transferred to experimental or medical data. As an applied example, an investigation on a data set analyzed with a second-generation method is presented, showing how this allows us to calculate relationships between variables within a complex theoretical model. Limitations of the use of second-generation statistical methods as strict requirements on the data sets are overcome by technical developments; however, causality cannot be established by statistically testing hypothesized causal structures. Using second-generation statistical methods in the future might promote obtaining more data from one animal and thereby potentially even reducing animals in line with the 3R principle. Full article

(This article belongs to the Special Issue Research Animal Welfare: Current Practices and Future Directions)

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19 pages, 4816 KB

Open AccessArticle

Milk-Derived Extracellular Vesicles Inhibit Staphylococcus aureus Growth and Biofilm Formation

by Peng Liu, Zhaoyuan Wang, Ziqiang Gao, Juan Liu, Yutong Zhang, Yangyang Song, Xiaolin Li, Huaxue Song, Xingli He, Fanzhi Kong, Changyuan Wang and Binglei Shen

Animals 2026, 16(1), 123; https://doi.org/10.3390/ani16010123 - 1 Jan 2026

Abstract

Staphylococcus aureus is a key pathogen in bovine mastitis, and antibiotic therapy is challenged by resistance and residue concerns. Milk-derived extracellular vesicles emerge as promising natural antimicrobials. This study aimed to evaluate the antimicrobial activity and explore potential associated mechanisms of milk-derived extracellular [...] Read more.

Staphylococcus aureus is a key pathogen in bovine mastitis, and antibiotic therapy is challenged by resistance and residue concerns. Milk-derived extracellular vesicles emerge as promising natural antimicrobials. This study aimed to evaluate the antimicrobial activity and explore potential associated mechanisms of milk-derived extracellular vesicles against S. aureus. Milk-derived EV-enriched fractions (mEVs) from healthy (HmEVs) and mastitic (MmEVs) bovine milk suppressed S. aureus growth in vitro and were associated with oxidative imbalance, with MmEVs showing stronger inhibition. In addition, MmEVs significantly reduced biofilm biomass, extracellular matrix production, and the expression of key biofilm-associated genes (sarA, icaB, fnbA, clfB, cidA). Small RNA sequencing revealed distinct miRNA profiles between HmEVs and MmEVs; in particular, MmEVs were enriched in miRNAs predicted to target the S. aureus biofilm-associated gene clfB. Although we did not directly demonstrate uptake of mEV-derived miRNAs by bacteria or their regulation of bacterial gene expression in this study, our small RNA sequencing data together with subsequent bioinformatic predictions suggest that vesicular miRNAs should be regarded as candidate contributors, rather than demonstrated mediators, of the observed antibacterial and antibiofilm effects. Taken together, these findings indicate the potential of mEVs as residue-free adjuncts for controlling bovine mastitis, while recognizing that the present conclusions are mainly derived from in vitro experiments with S. aureus and bioinformatic analyses. Therefore, functional validation of candidate miRNAs, in vivo studies, and evaluation of activity against other mastitis-associated pathogens are still required to clarify the underlying mechanisms, therapeutic potential, and spectrum of activity of mEVs. Full article

(This article belongs to the Section Cattle)

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12 pages, 559 KB

Open AccessArticle

Third-Generation Cephalosporin-Resistant Enterobacterales and Methicillin-Resistant Staphylococcus aureus (MRSA) in Pigs in Rwanda

by Emmanuel Irimaso, Valens Hagenimana, Emmanuel Nzabamwita, Michael Blümlinger, Otto W. Fischer, Lukas Schwarz, Michael P. Szostak, Olga Makarova, Adriana Cabal Rosel, Werner Ruppitsch, Elke Müller, Andrea T. Feßler, Sascha D. Braun, Stefan Schwarz, Stefan Monecke, Ralf Ehricht, Suzana Tkalcic, Christophe Ntakirutimana, Joachim Spergser, Doris Verhovsek and Igor Loncaric Show full author list Hide full author list

Animals 2026, 16(1), 122; https://doi.org/10.3390/ani16010122 - 31 Dec 2025

Abstract

This pilot study investigated the presence of methicillin-resistant Staphylococcus aureus (MRSA) and third-generation cephalosporin-resistant (3GC-R) Enterobacterales in conventionally kept domestic pigs and their environment across four districts in Rwanda. A total of 114 swabs (nasal, rectal, manure, dust) from 29 farms were collected [...] Read more.

This pilot study investigated the presence of methicillin-resistant Staphylococcus aureus (MRSA) and third-generation cephalosporin-resistant (3GC-R) Enterobacterales in conventionally kept domestic pigs and their environment across four districts in Rwanda. A total of 114 swabs (nasal, rectal, manure, dust) from 29 farms were collected and processed to isolate resistant bacteria. Thirty-two 3GC-R Enterobacterales were detected. Escherichia coli predominantly harboring bla_CTX-M group 1 β-lactamase genes, alongside Klebsiella pneumoniae isolates, all displaying extended-spectrum β-lactamase (ESBL) phenotypes. Four MRSA isolates, all belonging to clonal complex 398 and SCCmec type IV, the typical livestock MRSA, were recovered from nasal and environmental samples. Multidrug resistance was frequently observed. The co-occurrence of β-lactamase genes, non-β-lactam resistance genes, and virulence factors such as fimH and loci associated with extraintestinal pathogenic and enteropathogenic E. coli. The detection of both MRSA and 3GC-R Enterobacterales in the present study indicates pigs and their farm environments as reservoirs of WHO priority pathogens in Rwanda, highlighting a potential public health risk in the context of extensive human–animal–environment interaction. These findings emphasize the urgent need for integrated One Health surveillance and comprehensive AMR control strategies addressing both animal and environmental reservoirs to support Rwanda’s National Action Plan on Antimicrobial Resistance. Full article

(This article belongs to the Special Issue Antimicrobial Resistance and Innovative Strategies in Veterinary Medicine)

21 pages, 2288 KB

Open AccessArticle

Declining Abundance and Variable Condition of Fur Seal (Arctocephalus forsteri) Pups on the West Coast of New Zealand’s South Island

by Alasdair A. Hall, Don Neale, Jim Roberts, B. Louise Chilvers and Jody Suzanne Weir

Animals 2026, 16(1), 121; https://doi.org/10.3390/ani16010121 - 31 Dec 2025

Abstract

New Zealand fur seals (Arctocephalus forsteri) were severely exploited by historical hunting. However, recently assessed colonies in New Zealand are mostly thought to be growing or stable. The exceptions are three colonies (Wekakura Point, Cape Foulwind and Taumaka Island) on the [...] Read more.

New Zealand fur seals (Arctocephalus forsteri) were severely exploited by historical hunting. However, recently assessed colonies in New Zealand are mostly thought to be growing or stable. The exceptions are three colonies (Wekakura Point, Cape Foulwind and Taumaka Island) on the West Coast of the South Island (‘WCSI’), previously documented as in decline. We used mark-recapture and morphometric data to update understandings of pup abundance and condition at these colonies. Pup abundance has continued to decline. In 2025, 186 (95% CI = 178–194) pups were estimated at Wekakura Point, 131 (95% CI = 122–140) at Cape Foulwind and 566 (95% CI = 555–577) at Taumaka Island, representing declines of 83%, 71% and 61% from the respective maxima in the 1990s. Rates of decline have slowed at Wekakura Point and Cape Foulwind since 2016 but have increased at Taumaka Island. Pup condition demonstrated substantial interannual variation. Cape Foulwind pups had the greatest average mass and body condition index score, followed by Wekakura Point and then Taumaka Island. There have been consistencies between years of particularly low pup abundance and condition across the colonies, suggesting common stressors; however, there are likely also some localised factors. Emerging diseases and marine environmental change are evaluated as potential drivers. Full article

(This article belongs to the Section Ecology and Conservation)

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28 pages, 11280 KB

Open AccessArticle

Ontogenetic Changes in the Digestive Capacities of the Naozhou Stock of Large Yellow Croaker (Larimichthys crocea)

by Yue Liu, Shu-Pei Huang, Eric Amenyogbe, Ye Yang, Hao-Jie Wang, Zhong-Liang Wang and Jian-Sheng Huang

Animals 2026, 16(1), 120; https://doi.org/10.3390/ani16010120 - 31 Dec 2025

Abstract

This study examined the digestive and metabolic responses of Naozhou (NZ) stock large yellow croaker (Larimichthys crocea) larvae and juveniles under five developmental feeding stages (DAH3, DAH7, DAH12, DAH19, DAH49) to clarify mechanisms of early nutritional adaptation. Digestive enzyme assays, transcriptome [...] Read more.

This study examined the digestive and metabolic responses of Naozhou (NZ) stock large yellow croaker (Larimichthys crocea) larvae and juveniles under five developmental feeding stages (DAH3, DAH7, DAH12, DAH19, DAH49) to clarify mechanisms of early nutritional adaptation. Digestive enzyme assays, transcriptome sequencing, and metabolomics were integrated to compare physiological changes across diets. Protease activity increased sharply from DAH7–19 with the introduction of rotifers, Artemia, and copepods, while amylase and lipase activities rose at DAH19–49, reflecting enhanced carbohydrate and lipid utilization during transition to formulated feeds. Transcriptomic analysis showed that differentially expressed genes were enriched in pathways involving protein digestion, lipid and energy metabolism, and cell cycle regulation. The metabolomic analysis further highlighted dynamic changes in amino acid, lipid, carbohydrate, and vitamin metabolism, consistent with transcriptomic findings. The integrated analysis suggests that the coordinated modulation of digestive enzyme activities, gene expression, and metabolite profiles enabled a smooth transition from yolk dependency to live prey feeding and a subsequent use of artificial diets. These findings provide new insights into the early nutritional development of NZ large yellow croaker and provide a scientific basis for the improvement of artificial aquaculture seed production. Full article

(This article belongs to the Section Animal Nutrition)

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14 pages, 3847 KB

Open AccessArticle

Mutated Hif-1αa Proteins with Increased Stability Under Normoxic Conditions Enhance Hypoxia Tolerance of Otomorphs by Promoting Glycolysis and Lactate Shuttle

by Xianzong Wang, Junli Yan, Huili Zhai, Jiali Guo, Xueyi Wang, Qing Liu and Shaozhen Liu

Animals 2026, 16(1), 119; https://doi.org/10.3390/ani16010119 - 31 Dec 2025

Abstract

Fishes are frequently exposed to hypoxic stress, yet their tolerance to hypoxia varies significantly among species. The association between this variation and alterations in the hypoxia-inducible factor (HIF) pathway remains unclear. We discovered that otomorphs generally retain two Hif-1α paralogs (Hif-1αa and Hif-1αb), [...] Read more.

Fishes are frequently exposed to hypoxic stress, yet their tolerance to hypoxia varies significantly among species. The association between this variation and alterations in the hypoxia-inducible factor (HIF) pathway remains unclear. We discovered that otomorphs generally retain two Hif-1α paralogs (Hif-1αa and Hif-1αb), resulting from the teleost-specific genome duplication (TGD), whereas most euteleosts possess only a single Hif-1αa copy. In otomorphs, key mutations disrupt one conserved Leu-X-X-Leu-Ala-Pro (LXXLAP) motif in the oxygen-dependent degradation (ODD) domain of the Hif-1αa proteins. Molecular dynamics simulations revealed that these mutations impede the recognition of the critical proline residue by prolyl hydroxylase domain protein 2 (PHD2), suggesting enhanced normoxic stability of Hif-1αa. We also investigated the expression profiles of hif-1α and downstream genes in four fish species (two otomorphs and two euteleosts). In otomorphs, the hif-1αa genes were highly expressed specifically in the heart; concomitantly, two critical downstream genes, ldha and mct4, exhibited relatively high expression levels in vital tissues such as the heart, brain, and muscle. This coordinated expression pattern promotes a heightened glycolytic capacity and facilitates lactate shuttling in these tissues, thereby ensuring energy supply during hypoxic stress. Our integrated computational analyses indicate that otomorphs achieve enhanced hypoxia tolerance through the subfunctionalization of Hif-1α paralogs. Full article

(This article belongs to the Section Aquatic Animals)

16 pages, 3099 KB

Open AccessArticle

Hermetia illucens Larvae Meal Enhances Colonic Antimicrobial Peptide Expression by Promoting Histone Acetylation in Weaned Piglets Challenged with ETEC in Pig Housing

by Qingsong Tang, Guixing Wu, Wentuo Xu, Jingxi Liu, Huiliang Liu, Bin Zhong, Qiwen Wu, Xuefeng Yang, Li Wang, Zongyong Jiang and Hongbo Yi

Animals 2026, 16(1), 118; https://doi.org/10.3390/ani16010118 - 31 Dec 2025

Abstract

The objective of this study was to investigate the effects of replacing fishmeal with H. illucens larval meal on the colonic immune homeostasis in weaned piglets in enterotoxigenic Escherichia coli (ETEC)-challenged pig housing. Seventy-two weaned piglets, aged 28 days, were randomly divided into [...] Read more.

The objective of this study was to investigate the effects of replacing fishmeal with H. illucens larval meal on the colonic immune homeostasis in weaned piglets in enterotoxigenic Escherichia coli (ETEC)-challenged pig housing. Seventy-two weaned piglets, aged 28 days, were randomly divided into three groups for dietary treatment: the basal diet (negative control, NC), the positive control diet (PC) supplemented with 1445 mg zinc/kg zinc oxide in the basal diet, and the H. illucens larval meal complete replacement of fishmeal in the basal diet (HILM), for 28 days in ETEC-challenged pig housing. The results showed that the relative transcript abundances of ZO-1, pBD2, PR39, and PG1–5 were increased (p < 0.05) in pigs fed the HILM diet compared with those fed the NC diet. In addition, the HILM diet reduced (p < 0.05) the serum contents of IL-8 and increased (p < 0.05) the serum contents of IL-10 and IgG compared with the NC diet. In terms of the molecular mechanisms by which immune homeostasis is improved, the p-NF-κB/ NF-κB ratio and TLR2 protein expression in the colon were decreased (p < 0.05) in pigs fed the HILM diet compared with those fed the NC diet. Compared with the NC diet, the HILM diet reduced (p < 0.05) the protein expression of HDAC3 and HDAC7 in the colon of pigs. The SIRT1, acH3K9, and pH3S10 protein expressions in the colon were the greatest (p < 0.05) in pigs fed the HILM diet compared with the NC diet. HILM diets improved the colonic immune homeostasis in weaned piglets by enhancing the antimicrobial peptide expression, thereby mitigating ETEC challenges in pig housing. Mechanistically, HILM diets promote antimicrobial peptide expression through increased histone acetylation (acH3K9 and pH3S10). Full article

(This article belongs to the Special Issue Dietary Components in Animal Nutrition: Favoring Sustainability, Welfare and Safety)

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17 pages, 2788 KB

Open AccessArticle

Genome-Wide Association Study Identifies Candidate Genes for Body Size Traits in Wanyue Black Pigs

by Haibo Ye, Wei Li, Fang Tian, Qianqian Wang, Zhonghua Ma, Jinyu Guan, Yueyun Ding, Xianrui Zheng, Zongjun Yin and Xiaodong Zhang

Animals 2026, 16(1), 117; https://doi.org/10.3390/ani16010117 - 31 Dec 2025

Abstract

This study aimed to elucidate the genetic basis of body-size-related traits in Wanyue Black pigs, including body length, chest circumference, forearm circumference, and hip circumference. Phenotypic data were collected from 139 four-month-old female pigs, and genotyping was performed using a 50K SNP array. [...] Read more.

This study aimed to elucidate the genetic basis of body-size-related traits in Wanyue Black pigs, including body length, chest circumference, forearm circumference, and hip circumference. Phenotypic data were collected from 139 four-month-old female pigs, and genotyping was performed using a 50K SNP array. After stringent quality control and genotype imputation, approximately 4,697,453 high-quality autosomal variants were retained for subsequent genome-wide association study (GWAS), transcriptome-wide association study (TWAS), and phenome-wide association study (PheWAS). The GWAS identified four genome-wide significant loci, including rs343276492 and rs321308815. TWAS results revealed that the expression level of PTH2R was significantly associated with pituitary-related traits. In addition, selection signal analysis identified multiple genomic regions related to growth, development, and environmental adaptability, which were significantly enriched in pathways such as circadian rhythm regulation and the MAPK signaling pathway. These pathways play critical roles in growth regulation and adaptive evolution in Wanyue Black pigs. Collectively, this study provides valuable candidate genes and potential molecular markers for the genetic improvement and breeding of Wanyue Black pigs. Full article

(This article belongs to the Section Animal Genetics and Genomics)

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16 pages, 6885 KB

Open AccessArticle

Distinct Rumen Microbial Features and Host Metabolic Responses in Three Cervid Species

by Yuhang Zhu, Yunfei Chai, Sibo Chen, Wenxi Qian, Huazhe Si and Zhipeng Li

Animals 2026, 16(1), 116; https://doi.org/10.3390/ani16010116 - 31 Dec 2025

Abstract

Rumen microbiota is pivotal for nutrient metabolism and physiological adaptation in ruminants. This study investigated the rumen microbial community, fermentation parameters, and serum biochemistry of three Cervid species—Sika deer (Cervus nippon), Reindeer (Rangifer tarandus), and Milu deer (Elaphurus [...] Read more.

Rumen microbiota is pivotal for nutrient metabolism and physiological adaptation in ruminants. This study investigated the rumen microbial community, fermentation parameters, and serum biochemistry of three Cervid species—Sika deer (Cervus nippon), Reindeer (Rangifer tarandus), and Milu deer (Elaphurus davidianus) (n = 5/group)—fed an identical diet. Using 16S rRNA sequencing and biochemical analyses, we found that while Bacteroidota, Firmicutes, and Proteobacteria were dominant phyla across species. Sika deer and Milu deer exhibited significantly higher microbial diversity and abundance of carbohydrate-digesting genera (e.g., Butyrivibrio, Saccharofermentans), and pathways of carbohydrate digestion and absorption, starch and sucrose metabolism compared to Reindeer. Conversely, Reindeer showed increased abundances of Lachnospiraceae ND3007 and butyrate metabolism pathway, and significantly elevated rumen volatile fatty acid concentrations, particularly acetate and butyrate. Serum profiling revealed that Milu deer had significantly higher lipid levels (CHO, TG, LDL-C) but lower total protein and AST levels compared to other species. Notably, WGCNA linked these blood lipid traits to host genes enriched in PI3K-Akt, MAPK, and bile secretion pathways. These findings demonstrate distinct species-specific rumen fermentation patterns and host metabolic adaptations, suggesting a coordinated regulation between the rumen microbiome and host genetics in Cervid. Full article

(This article belongs to the Special Issue Optimizing Rumen Functions for Digestive Efficiency)

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27 pages, 1780 KB

Open AccessArticle

Effect of Wet Aging on the Meat Quality of Two Cuts (Longissimus thoracis et lumborum and Quadriceps femoris) from Italian Local Goat Breeds Compared to the Saanen Cosmopolitan Breed

by Marica Egidio, Marika Di Paolo, Federica Capano, Sophia Alesio, Carmen Cabato, Roberta Matera, Matteo Santinello, Lucia Sepe and Raffaele Marrone

Animals 2026, 16(1), 115; https://doi.org/10.3390/ani16010115 - 31 Dec 2025

Abstract

Goat meat represents a valuable source of high-quality protein and healthy lipids, although its consumption remains limited in Europe. This study aimed to evaluate the qualitative–quantitative changes in the nutritional, rheological, and sensorial characteristics of meat (Quadriceps femoris and Longissimus thoracis et [...] Read more.

Goat meat represents a valuable source of high-quality protein and healthy lipids, although its consumption remains limited in Europe. This study aimed to evaluate the qualitative–quantitative changes in the nutritional, rheological, and sensorial characteristics of meat (Quadriceps femoris and Longissimus thoracis et lumborum muscles) from three different autochthonous goat breeds (Garganica, Derivata di Siria, and Capra di Potenza) and a cosmopolitan, genetically selected one (Saanen), reared in Basilicata (Italy), during a 7-day wet aging process. Forty kids (10 per breed) were slaughtered at 50 ± 3 days, and meat samples were vacuum-aged at 4 ± 1 °C and analyzed at 0, 3, and 7 days. Data showed that genotype was the main factor influencing meat quality, while wet aging mainly improved rheological parameters, particularly in LTL muscles. Notably, Capra di Potenza exhibited the most favorable fatty acid profile, with lower atherogenic (average values of 0.80 in LTL and 0.92 in QF) and thrombogenic (average values of 1.49 in LTL and 1.59 in QF) indices, whereas Derivata di Siria showed the greatest oxidative stability (average values of 0.060 in LTL and 0.036 in QF). Overall, local breeds of kids’ groups produced more tender and aromatic meat than Saanen. These findings highlight the potential of native goat breeds for premium meat production and suggest an effective post-mortem aging technique to enhance their quality, promoting the diffusion of niche products as well as biodiversity preservation. Full article

(This article belongs to the Special Issue Current Research in Sheep and Goats Reared for Meat)

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17 pages, 1666 KB

Open AccessArticle

Immune Response of Pigs Vaccinated Against Proliferative Enteropathy and Co-Infected with Lawsonia intracellularis and Brachyspira hyodysenteriae

by Sarah Chagas, Peyton Jensen, Eliana Paladino, Lívia Mendonça Pascoal, Stephan von Berg, Connie Gebhart and Fabio A. Vannucci

Animals 2026, 16(1), 114; https://doi.org/10.3390/ani16010114 - 31 Dec 2025

Abstract

Vaccination is a tool to control Lawsonia intracellularis (LI) in pigs. However, pigs may have co-infections that worsen clinical signs and lesions. The aim of this study was to characterize systemic and gut-mediated humoral and cell-mediated immune (CMI) responses in pigs vaccinated with [...] Read more.

Vaccination is a tool to control Lawsonia intracellularis (LI) in pigs. However, pigs may have co-infections that worsen clinical signs and lesions. The aim of this study was to characterize systemic and gut-mediated humoral and cell-mediated immune (CMI) responses in pigs vaccinated with a killed intramuscular LI vaccine and to analyze the impact of co-infection with Brachyspira hyodysenteriae (Bhyo) on the immune response. The study included eighty pigs and five study groups: V-CO (LI-vaccinated and co-infected with LI + Bhyo, n = 21), P-CO (placebo and co-infected with LI + Bhyo, n = 18), V-LI (LI-vaccinated and infected with LI, n = 21), P-LI (placebo and infected with LI, n = 12), and NC (negative control, placebo and non-challenged, n = 8). Parameters analyzed: fecal score and pathogen shedding), gross intestinal lesions, LI intestinal colonization (IHC), serum IgG, LI-specific IFN-γ production (ELISPOT), and immune cell subsets (flow cytometry) in blood, mesenteric lymph nodes, Peyer’s patches, and intestinal epithelium. LI vaccination significantly reduced LI fecal shedding, intestinal colonization, and macroscopic lesions—even under Bhyo co-infection. Vaccinated pigs had earlier and stronger serum IgG and IFN-γ responses. B cells seem to play an important role in the local immune response, and T regulatory cells apparently do not have a significant role in immunomodulation. This study contributes to a better understanding of LI immune response and can provide subtract for further research in the control of LI. Full article

(This article belongs to the Section Pigs)

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20 pages, 1397 KB

Open AccessFeature PaperArticle

Capybaras (Hydrochoerus hydrochaeris) in the City: Understanding Urban Coexistence, Management Strategies and the Animal Welfare Implications

by Katia M. Nunes Sayn, Maria José Hötzel and Selene S. C. Nogueira

Animals 2026, 16(1), 113; https://doi.org/10.3390/ani16010113 - 31 Dec 2025

Abstract

In Brazil, the presence of capybaras (Hydrochoerus hydrochaeris) in urban environments has raised concerns due to ecological, sanitary and coexistence challenges. This study investigates the growing presence of capybaras on Santa Catarina Island, Brazil, exploring their integration into urban areas. We [...] Read more.

In Brazil, the presence of capybaras (Hydrochoerus hydrochaeris) in urban environments has raised concerns due to ecological, sanitary and coexistence challenges. This study investigates the growing presence of capybaras on Santa Catarina Island, Brazil, exploring their integration into urban areas. We interviewed 1505 residents of the Island to understand capybara distribution, public perceptions and associated risks. Beliefs about management strategies were also assessed. The findings reveal that capybaras are present in all neighborhoods of Florianópolis, the sole city in the Island. Participants expressed positive views of capybaras, describing them as “beautiful” and “cute” and showing concerns for their well-being in urban environments. Despite these positive perceptions, participants demonstrated limited knowledge about capybara biology (88%) and potential problems, such as disease transmission (37%), traffic accidents (10%), pet conflicts (56%) and garden damage (42%). Most respondents agreed with the statements: “Capybaras are part of nature and should be left undisturbed, even in urban areas” (70%) and “It is important for people to see capybaras in the city, as long as their population is not causing problems” (82%). After risk awareness, more participants rated these issues as highly relevant: disease transmission (97%), destruction of urban gardens (77%), pet incidents (92%) and traffic accidents (98%). This led to greater acceptance of population control, though elimination remained unpopular. Sociodemographic factors influenced opinions. Addressing knowledge gaps can foster ethical, supported management strategies. This case places Florianópolis within a broader South American phenomenon of urban capybara conflicts, highlighting the global challenge of managing human–wildlife interactions in cities. Full article

(This article belongs to the Topic Conservation at the Crossroads: Forest Ecology, Wildlife Dynamics, and Emerging Challenges for Ecosystem Resilience)

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