Animals

0 pages, 1599 KiB

Open AccessArticle

Amoxicillin Resistance: An In Vivo Study on the Effects of an Approved Formulation on Antibiotic Resistance in Broiler Chickens

by Ádám Kerek, Ábel Szabó and Ákos Jerzsele

Animals 2025, 15(13), 1944; https://doi.org/10.3390/ani15131944 - 1 Jul 2025

Abstract

Background: Antimicrobial resistance (AMR) is a growing global concern in poultry production, where antibiotic use can disrupt gut microbiota and enrich antimicrobial resistance genes (ARGs). Objectives: This study aimed to assess the in vivo effects of a veterinary-approved amoxicillin formulation on gut microbiome [...] Read more.

Background: Antimicrobial resistance (AMR) is a growing global concern in poultry production, where antibiotic use can disrupt gut microbiota and enrich antimicrobial resistance genes (ARGs). Objectives: This study aimed to assess the in vivo effects of a veterinary-approved amoxicillin formulation on gut microbiome composition and ARG profiles in broiler chickens. Methods: A total of 120 Ross-308 broiler chickens were randomly allocated into 12 experimental groups (n = 10 per group), with three replicates per treatment. Birds received either full-dose (1×), a subtherapeutic quarter-dose (¼×) of amoxicillin, a placebo (starch), or no treatment. Cloacal swabs were collected on days 0, 14, and 28 for shotgun metagenomic sequencing. One-way ANOVA was used to evaluate treatment effects on body weight, with significant differences observed from day 14 onward (p < 0.0001). Results: The ¼× dose caused a more pronounced microbiome shift than the 1× dose, with a marked reduction in Pseudomonadota and increase in Bacillota and Bacteroidota. ARG abundance declined in the ¼× group (from 1386 to 1012). While TEM-type ESBL genes were ubiquitous, CTX-M-1 emerged only after ¼× treatment. Worryingly, 20 types of vancomycin resistance genes were detected across all samples. Plasmid-borne ARGs and mobile genetic elements decreased in the ¼× group. Conclusions: Even subtherapeutic antibiotic exposure significantly reshapes the gut microbiota composition and ARG landscape, highlighting the need for refined risk assessments and microbiome-conscious antimicrobial policies in poultry farming. Full article

(This article belongs to the Section Poultry)

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28 pages, 795 KiB

Open AccessReview

Efficacy of Feeding Grape By-Products on Performance, Nutrient Digestibility, Gut Morphology, Gut Microbial Community, Oxidative Stress and Immune Response in Fast-Growing Broilers

by Robert Ringseis, Klaus Eder and Denise K. Gessner

Animals 2025, 15(13), 1943; https://doi.org/10.3390/ani15131943 - 1 Jul 2025

Abstract

By-products from winemaking, such as grape pomace, grape seeds, grape skins, or extracts made from them, represent a cost-effective and sustainable bioresource. These by-products are a source of polyphenolic compounds, plant fibers and—in the case of seeds—essential fatty acids with various health-promoting effects [...] Read more.

By-products from winemaking, such as grape pomace, grape seeds, grape skins, or extracts made from them, represent a cost-effective and sustainable bioresource. These by-products are a source of polyphenolic compounds, plant fibers and—in the case of seeds—essential fatty acids with various health-promoting effects for livestock. Numerous studies involving fast-growing broiler breeds—which often suffer from metabolic inflammation and oxidative stress due to disproportionate breast muscle growth leading to issues like cardiorespiratory insufficiency—indicate that supplementing feed with grape by-products improves performance, particularly weight gain and feed efficiency. This literature review demonstrates that the performance-enhancing effects of grape by-products in fast-growing broiler breeds can be attributed to various mechanisms such as improved nutrient digestibility, a positive influence on intestinal morphology and integrity, the favorable modulation of the microbial community in the gut, the inhibition of oxidative stress or the enhancement of the antioxidant defense system, and the stimulation of the immune response. Full article

(This article belongs to the Special Issue Plant Extracts as Feed Additives in Animal Nutrition and Health)

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16 pages, 5477 KiB

Open AccessArticle

Structural Analysis of the AlkB Family in Poultry

by Yuling Niu, Kan Li, Xuerong You, Yutao Wu, Xue Du, Ayong Zhao and Zhijun Wang

Animals 2025, 15(13), 1942; https://doi.org/10.3390/ani15131942 - 1 Jul 2025

Abstract

The objective of this study was to identify the AlkB family genes in poultry using bioinformatics, and to explore their molecular characteristics, evolutionary relationships, and expression patterns to clarify their potential functions in poultry. (1) Methods: The study utilized the NCBI database to [...] Read more.

The objective of this study was to identify the AlkB family genes in poultry using bioinformatics, and to explore their molecular characteristics, evolutionary relationships, and expression patterns to clarify their potential functions in poultry. (1) Methods: The study utilized the NCBI database to obtain chicken genome data, and screened and validated AlkB family members (ALKBH1-5, ALKBH8, and FTO) by hmmsearch and TBtools. MEGA 11.0 was used for phylogenetic analysis, PHYRE2 and I-TASSER predicted protein structures, and the String database was used to construct an interoperability network. Finally, the tissue expression profiles were analyzed by using The Human Protein Atlas online database and qRT-PCR. (2) Results: Phylogenetic analysis revealed distinct avian and mammalian clusters, with chicken AlkB proteins exhibiting low sequence homology but conserved 3D structures compared to mammals. Chromosomal synteny and conserved domains highlighted evolutionary divergence, with ALKBH4 lacking typical AlkB structural motifs. Protein interaction networks linked ALKBH1/2/3/5/8/FTO, underscoring functional coordination in poultry adaptation. Tissue-specific expression showed high AlkB levels in brain tissues, while ALKBH5 dominated in muscle. During differentiation, ALKBH3, ALKBH5, and FTO expression significantly increased during myoblast differentiation. (3) Conclusions: This study identified seven AlkB family genes in poultry, revealing their phylogenetic classification into two subfamilies, conserved structural domains, chromosomal synteny, and tissue-specific expression patterns. Full article

(This article belongs to the Special Issue Genetic Diversity and Conservation of Local Poultry Breeds)

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17 pages, 1873 KiB

Open AccessFeature PaperArticle

Intracytoplasmic Sperm Injection Using 20-Year-Old Cryopreserved Sperm Results in Normal, Viable, and Reproductive Offspring in Xenopus laevis: A Major Pioneering Achievement for Amphibian Conservation

by Louise Péricard, Sébastien Le Mével, Olivier Marquis, Yann Locatelli and Laurent Coen

Animals 2025, 15(13), 1941; https://doi.org/10.3390/ani15131941 - 1 Jul 2025

Abstract

The significant decline in amphibians worldwide is demanding the development of reliable techniques to save species and their genetic diversity. Considerable efforts are currently in progress to develop assisted reproductive technologies (ARTs), focusing mainly on sperm cryopreservation and in vitro fertilization (IVF). In [...] Read more.

The significant decline in amphibians worldwide is demanding the development of reliable techniques to save species and their genetic diversity. Considerable efforts are currently in progress to develop assisted reproductive technologies (ARTs), focusing mainly on sperm cryopreservation and in vitro fertilization (IVF). In Xenopus, a simple and efficient transgenesis method based on the intracytoplasmic injection (ICSI) of cryoconserved sperm was developed several decades ago, allowing for quick generation of large numbers of transgenic animals, for biological research. Such a methodology could be critical for the recovery of species and their genetic diversity, contributing to amphibian conservation. However, this approach raised the question of whether the sperm preservation method used with ICSI is compatible with long-term storage. To address this question, animals were generated by ICSI using a twenty-year-old cryopreserved sperm preparation. Their development, behavior, and reproduction ability were compared with those of animals obtained using a recently frozen sperm preparation and those of animals obtained via IVF using fresh semen. Although lower than with IVF, we showed that fertilization rates using ICSI after 20 years of cryopreservation are similar to those of a recent preparation, with viable offspring leading to normal F2 generation. This pioneering achievement is proof of concept for long-term sperm cryopreservation using simple and readily available technologies for the conservation of endangered amphibians. Full article

(This article belongs to the Section Animal Reproduction)

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15 pages, 2127 KiB

Open AccessArticle

High Prevalence of Lesions of Systemic Hypertension in Bile-Extracted Asiatic Black Bears (Ursus thibetanus) and Associated Renal Disease

by Monica K. H. Bando, O. Lynne Nelson, Kyle Taylor, Rance Sellon, Clark Kogan, Jill Robinson, Emily Drayton, Claudia Hartley, David Donaldson, Chris Linney and Hannah Stephenson

Animals 2025, 15(13), 1940; https://doi.org/10.3390/ani15131940 - 1 Jul 2025

Abstract

Approximately 17,000 bears undergo bile extraction in facilities across Asia for traditional medicines despite the availability of proven alternatives. Bears are confined to cages and bile harvested from the gallbladder via needle aspiration, implanted catheters, or transabdominal fistulas. Bile-extracted bears develop numerous detrimental [...] Read more.

Approximately 17,000 bears undergo bile extraction in facilities across Asia for traditional medicines despite the availability of proven alternatives. Bears are confined to cages and bile harvested from the gallbladder via needle aspiration, implanted catheters, or transabdominal fistulas. Bile-extracted bears develop numerous detrimental conditions, including abnormal repetitive behaviors, emaciation, dental disease, cholecystitis, hernias, abscesses, and neoplasia. A high prevalence of aortic dilation, commonly seen with systemic hypertension, was reported in bile-extracted bears, and aortic aneurysm rupture/dissection was the third leading cause of death in a population of 600 formerly bile-extracted bears. A high incidence of renal disease, a common cause of systemic hypertension in other species, was also identified in this population. We hypothesized that renal disease was positively correlated with lesions of systemic hypertension in bile-extracted bears. Archived medical records, imaging, and samples from 180 formerly bile-extracted bears were analyzed. Hypertensive retinopathy, left ventricular hypertrophy, and aortic dilation were used as validated correlates of systemic hypertension. The majority (76.1%) of bears exhibited at least one systemic hypertension lesion, and 62.8% had two or more lesions. Left ventricular hypertrophy was most common, followed by aortic dilation/aneurysm. Lesions of systemic hypertension were positively correlated to renal disease parameters of serum creatinine and renal histopathology. Understanding the etiology of systemic hypertension in this population is critical due to consequent comorbidities and increasing numbers of bile-extracted bears finding their way to sanctuary. Full article

(This article belongs to the Special Issue Wildlife Clinical Pathology: A One Health Key to Ecosystem Assessment)

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21 pages, 3288 KiB

Open AccessArticle

Narasin Supplementation Enhances Growth Performance in Grazing Cattle

by Daniel M. Polizel, Rodrigo S. Marques, Arnaldo C. Limede, Fernando A. A. Cidrini, José Renato S. Gonçalves, Pedro H. V. Carvalho and Alexandre V. Pires

Animals 2025, 15(13), 1939; https://doi.org/10.3390/ani15131939 - 1 Jul 2025

Abstract

Three experiments were conducted to evaluate the effects of narasin inclusion on the growth performance of grazing beef cattle under similar forage availability and quality. All three experiments were arranged in a randomized complete block design according to the initial BW. Exp 1: [...] Read more.

Three experiments were conducted to evaluate the effects of narasin inclusion on the growth performance of grazing beef cattle under similar forage availability and quality. All three experiments were arranged in a randomized complete block design according to the initial BW. Exp 1: 200 Nellore calves (initial BW = 177 ± 15 kg) were randomly allocated in three treatments for 84 d during the rainy season: (1) CONT: mineral supplement; (2) 1400 N: 1400 mg of narasin/kg of supplement; and (3) 2100 N: 2100 mg of narasin/kg of supplement. Narasin inclusion increased (p ≤ 0.01) ADG by 0.077 kg/d and final BW by 6.7 kg, with no differences (p ≥ 0.50) between narasin doses. Exp 2: 240 Nellore calves (initial BW = 195 ± 19 kg) were allocated to CONT or N1400 for 112 d during the rainy season. Narasin inclusion increased (p ≤ 0.01) ADG by 0.082 kg/d and final BW by 9.1 kg. Exp 3: 150 Nellore yearlings (initial BW = 332 ± 22 kg) were allocated for 112 d during the dry season: (1) PROT: protein supplement and (2) PROT250: inclusion of 250 mg of narasin/kg of supplement. Narasin inclusion increased (p ≤ 0.04) ADG by 0.048 kg and final BW by 5.3 kg. For all experiments, narasin inclusion did not impact (p ≥ 0.25) supplement intake. Hence, inclusion of narasin in mineral and protein supplements consistently enhances growth performance of grazing beef cattle across different seasons and production stages, without impacting supplement intake, providing an effective nutritional strategy to enhance productivity on tropical pastures. Full article

(This article belongs to the Special Issue Novel Techniques for Efficient and Sustainable Cattle Production: Precision Farming, Feed Ingredients and Efficiency and Rumen Health)

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20 pages, 12581 KiB

Open AccessArticle

Metabolomics and Transcriptomics Reveal Age-Dependent Development of Meat Quality Traits in Jingyuan Chicken

by Jiahuan Hu, Wei Zhao, Jinyan Zhao, Jinli Tian, Lijuan Yang, Hua Wang, Siyu Chen, Ruimin Ma, Yaling Gu, Dawei Wei and Juan Zhang

Animals 2025, 15(13), 1938; https://doi.org/10.3390/ani15131938 - 1 Jul 2025

Abstract

In this study, we investigated the dynamic changes in muscle lipid content (MLC) deposition in the breast muscle of Jingyuan chickens at different stages (42, 126, and 180 days old) using metabolomics. The pH_45min, a*, and L* were significantly increased in the [...] Read more.

In this study, we investigated the dynamic changes in muscle lipid content (MLC) deposition in the breast muscle of Jingyuan chickens at different stages (42, 126, and 180 days old) using metabolomics. The pH_45min, a*, and L* were significantly increased in the breast muscle of 126-day-old chickens, and MLC and b* were significantly increased in the breast muscle of 180-day-old chickens. A total of 4643 differentially expressed metabolites (DEMs) were identified, of which 10 decreased and 29 increased with age. Key pathways associated with meat quality traits included oxidative phosphorylation, β-alanine metabolism, and glycerophospholipid metabolism. Combined transcriptomic and phenotypic correlation analyses revealed significant positive correlations of MLC, pH_45min, a*, and L* with LysoPC 20:4, CD3E, TARP, IL7R, ENSGALG00010025331, and RASSF5. In the 42- and 180-day-old chickens, MLC, pH_45min, a*, and L* were significantly and positively correlated with L-Anserine, Dihydroxyacetone phosphate, ENSGALG00010006904, and HSPB7. MLC, pH_45min, a*, and L* were significantly and positively correlated with beta-Nicotinamide adenine dinucleotide in the 126- and 180-day-old chickens. This study deepens our understanding of the differences in MLC deposition at different stages of Jingyuan chickens and its relationship with meat quality traits. Full article

(This article belongs to the Section Poultry)

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15 pages, 1101 KiB

Open AccessArticle

Influence of Oregano Essential Oil on the Rumen Microbiome of Organically Reared Alpine Goats: Implications for Methanobacteria Abundance

by Dimitrios Kyrtsoudis, Maria V. Alvanou, Dimitrios Loukovitis, Dimitrios Gourdouvelis, Vasileios A. Bampidis, Dimitrios Chatziplis and Ioannis K. Mitsopoulos

Animals 2025, 15(13), 1937; https://doi.org/10.3390/ani15131937 - 1 Jul 2025

Abstract

The present study aimed to evaluate the effects of dietary supplementation with organic oregano (Origanum vulgare) essential oil (OEO) on the rumen microbial population, with a focus on methanogenic archaea, in lactating dairy goats. A total of nine age-matched goats (mean [...] Read more.

The present study aimed to evaluate the effects of dietary supplementation with organic oregano (Origanum vulgare) essential oil (OEO) on the rumen microbial population, with a focus on methanogenic archaea, in lactating dairy goats. A total of nine age-matched goats (mean body weight 49 ± 1.8 kg) were assigned to three experimental groups (n = 3 per group) in a completely randomized design. All animals were fed a basal diet consisting of a corn-based concentrate and a forage mix composed of alfalfa hay, wheat straw and corn silage. Group 1 was the control group while Groups 2 and 3 received an OEO supplement at dosages of 1 mL/day and 2 mL/day per animal, respectively, incorporated into the concentrate feed. Rumen fluid samples were collected on days 15, 30 and 45 of the feeding trial and their microbial profile was assessed using NGS analysis. The results demonstrated a reduction in the relative abundance of methanobacteria in both OEO-supplemented groups compared to the control group. Statistical analysis revealed significant differences between feeding groups and days of sampling. These findings suggest that OEO has the potential to modulate the rumen microbiome by reducing methane-producing archaeal populations. In conclusion, dietary supplementation with OEO may serve as a natural strategy to mitigate enteric methane emissions in Alpine dairy goats. Full article

(This article belongs to the Collection Feeding Strategies to Improve Sustainability and Welfare in Animal Production)

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17 pages, 1013 KiB

Open AccessArticle

Visual Discrimination Task in Guppies Using a Simultaneous Matching-to-Sample Procedure

by Gabriela Gjinaj, Marco Dadda and Maria Elena Miletto Petrazzini

Animals 2025, 15(13), 1936; https://doi.org/10.3390/ani15131936 - 1 Jul 2025

Abstract

Cognitive abilities in fish have been widely demonstrated using experimental protocols commonly adopted with mammals and birds. Only a few studies have tested fish in the simultaneous match-to-sample task (sMTS), and mixed evidence regarding their capacity to solve the task has been reported. [...] Read more.

Cognitive abilities in fish have been widely demonstrated using experimental protocols commonly adopted with mammals and birds. Only a few studies have tested fish in the simultaneous match-to-sample task (sMTS), and mixed evidence regarding their capacity to solve the task has been reported. Here we investigated whether guppies (Poecilia reticulata) could discriminate stimuli based on their sameness in the sMTS where fish presented with a sample stimulus had to choose which of two simultaneously presented comparison stimuli matched it. We also assessed how performance was influenced by the training set size and stimulus type. Three experiments were conducted using three different sets of stimuli: two colors (red and green), two geometric shapes (circle vs. triangle); and multiple shapes. Performance was analyzed using binomial tests, t-tests, and generalized linear mixed models. The results showed that guppies learned to select the rewarding stimulus in a relatively limited number of trials and were successful in all experiments. Although no effect of the training set size was observed, guppies were more accurate when multiple stimuli were used. These findings support previous evidence suggesting that multiple training stimuli may improve generalization abilities and set the basis for future studies that adopt a delayed version of the task. Full article

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3 pages, 139 KiB

Open AccessEditorial

Ruminant Welfare Assessment

by Marek Gaworski

Animals 2025, 15(13), 1935; https://doi.org/10.3390/ani15131935 - 1 Jul 2025

Abstract

Animal welfare studies are among the key areas of research contributing to the development of knowledge in the life sciences [...] Full article

(This article belongs to the Special Issue Ruminant Welfare Assessment)

36 pages, 4575 KiB

Open AccessCommentary

Regulatory Integrity and Welfare in Horse Sport: A Constructively Critical Perspective

by Mette Uldahl and David J. Mellor

Animals 2025, 15(13), 1934; https://doi.org/10.3390/ani15131934 - 30 Jun 2025

Abstract

This commentary evaluates contemporary equestrian sport governance through the lens of equine welfare science. Drawing on evidence from the FEI Sport Forum 2025 debates, the IFHA Racing Integrity Handbook, media coverage of horse sport, recent scientific presentations, regulatory texts, and published research, we [...] Read more.

This commentary evaluates contemporary equestrian sport governance through the lens of equine welfare science. Drawing on evidence from the FEI Sport Forum 2025 debates, the IFHA Racing Integrity Handbook, media coverage of horse sport, recent scientific presentations, regulatory texts, and published research, we identify systemic shortcomings in how horse welfare is assessed, prioritised, and protected. Key issues include reliance on performance as a proxy for welfare, inadequate “fit-to-compete” protocols, neglect of horses’ mental states, coercive tack and equipment practices (e.g., double bridles, tight nosebands, ear hoods), pharmacological and surgical interventions that mask pain, euphemistic regulatory language (e.g., whip “encouragement”), and inconsistent implementation of welfare rules. Through a series of case studies, from dressage and show jumping forums to racing integrity handbooks, we illustrate euphemistic language, defensive group dynamics, dismissive rhetoric towards evidence-based criticism, and a troubling “stable blindness” that sidelines the horse’s perspective. We conclude that meaningful reform requires (1) embedding validated behavioural and physical welfare indicators into all competition and pre-competition protocols, (2) transparent, evidence-inclusive rule-making under a precautionary principle, (3) genuine engagement with independent equine welfare experts, and (4) establishment of empowered, impartial oversight bodies to ensure that stated codes of conduct translate into consistent, enforceable practice. Only by catering to the horse’s subjective experiences and applying modern ethological and bioethical standards can equestrian sport retain its social licence and ensure integrity in all areas of competition management. Full article

(This article belongs to the Section Equids)

20 pages, 1706 KiB

Open AccessCommentary

Applying Transdisciplinary Thinking to Pastoral Livelihoods and Environments

by Keith Woodford, Xiaomeng Lucock and Derrick Moot

Animals 2025, 15(13), 1933; https://doi.org/10.3390/ani15131933 - 30 Jun 2025

Abstract

Transdisciplinary thinking lies at one end of a continuum within system thinking, with discipline-based approaches at the other end. Interdisciplinarity and multidisciplinarity are intermediate domains within this continuum. Transdisciplinary thinking is unique in always starting with problem-structuring related to contexts, in which people, [...] Read more.

Transdisciplinary thinking lies at one end of a continuum within system thinking, with discipline-based approaches at the other end. Interdisciplinarity and multidisciplinarity are intermediate domains within this continuum. Transdisciplinary thinking is unique in always starting with problem-structuring related to contexts, in which people, typically with multiple and competing objectives, interact with a biophysical world. As such, transdisciplinary thinking is particularly relevant to pastoral systems where livelihoods and environmental issues intersect, and where multiple stakeholders are the norm. Integration, both within transdisciplinary thinking and consequent action, is particularly challenging. This is because there is no quantitative methodology that can capture the complex essence of transdisciplinary issues that encompass both human and biophysical disciplines. Nevertheless, a transdisciplinary approach provides a framework for civilised debate and communication within a broad framework of policy generation. We illustrate these issues with two highly contrasting studies, these being pastoralism at the country level in New Zealand and at the county level in Qinghai on the Qinghai-Tibet Plateau in Western China. Both case studies are characterised by complex property rights within a dynamic resource-constrained environment, in which environmental issues have planetary implications that extend well beyond the bounds of the pastoral system itself. Full article

(This article belongs to the Special Issue Pastoralism and Animal Management within Agroecosystems and Society)

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25 pages, 8724 KiB

Open AccessArticle

Transcriptomic Analysis of Trachinotus ovatus Under Flow Velocity Stress

by Jing Zhang, Xixi Liu, Jiayue Dai, Sufang Niu, Xuefeng Wang and Baogui Tang

Animals 2025, 15(13), 1932; https://doi.org/10.3390/ani15131932 - 30 Jun 2025

Abstract

Trachinotus ovatus is a euryhaline, warm-water pelagic fish species with strong adaptability, rapid growth, and a high survival rate, making it one of the most important marine aquaculture species in China. In recent years, extensive experience has been accumulated in the cage farming [...] Read more.

Trachinotus ovatus is a euryhaline, warm-water pelagic fish species with strong adaptability, rapid growth, and a high survival rate, making it one of the most important marine aquaculture species in China. In recent years, extensive experience has been accumulated in the cage farming of T. ovatus, but whether it can adapt to deep-sea environments and grow normally remains a current research focus. This study used RNA-Seq sequencing technology to analyze the gene expression changes in the liver of T. ovatus under three conditions: rest (0 cm/s), medium flow velocity (54 cm/s), and high flow velocity (90 cm/s). Through differential expression analysis, Short Time-series Expression Miner (STEM) analysis and protein–protein interaction (PPI) network analysis, a total of 5107 differentially expressed genes (DEGs), three significantly expressed gene profiles (profile6, profile1, and profile5), and 15 hub genes were identified. The results showed that changes in flow speed significantly impacted key biological processes such as energy metabolism, protein homeostasis, and endoplasmic reticulum (ER) stress response. Under moderate and high flow conditions, glycolysis-related genes were upregulated to meet the energy demands of swimming, while the downregulation of the PPARγ-RXRG complex and its downstream genes in the lipid metabolism pathway suggested a limitation in its fatty acid β-oxidation capacity. At the same time, protein synthesis was enhanced, and the unfolded protein response (UPR) was activated to help cope with ER stress. Furthermore, when the flow speed reached 90 cm/s, the expression of UPR- related genes and the anti-apoptotic factor JNK significantly decreased, suggesting that the stress response was nearing its limit and could potentially trigger cell apoptosis. These findings provide new insights into the molecular adaptation mechanisms of T. ovatus to flow speed stress and offer theoretical support for its rational farming in deep-sea cages, suggesting that the water flow speed in farming should not exceed 90 cm/s. Full article

(This article belongs to the Section Aquatic Animals)

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17 pages, 1791 KiB

Open AccessArticle

Interaction Between Ruminal Acetate Infusion and Diet Fermentability on Milk Fat Production in Dairy Cows

by Natalie L. Urrutia, Camila Muñoz, Emilio M. Ungerfeld, Claudia Cisterna and Kevin J. Harvatine

Animals 2025, 15(13), 1931; https://doi.org/10.3390/ani15131931 - 30 Jun 2025

Abstract

Acetate is naturally produced in the rumen through feed degradation and fermentation. It serves as a primary energy source for ruminants and as a key substrate for de novo fatty acid synthesis in the mammary gland. The interaction of exogenous acetate with different [...] Read more.

Acetate is naturally produced in the rumen through feed degradation and fermentation. It serves as a primary energy source for ruminants and as a key substrate for de novo fatty acid synthesis in the mammary gland. The interaction of exogenous acetate with different animal and dietary factors is an area of growing interest, as it may have significant implications for milk fat synthesis. This study aimed to assess the effect of two diet fermentability levels on the short-term response of lactation to acetate supplementation in dairy cows. Eight ruminally cannulated multiparous European Holstein cows were randomly assigned to treatments in a crossover design that tested the effect of diet fermentability, acetate supply, and their interaction. Using corn silage as the only forage source and a constant forage-to-concentrate ratio, high-fermentability (HF) and low-fermentability (LF) diets were formulated. Acetate supply was investigated by infusing ruminally 10 moles of sodium acetate/d (ACE) or an equimolar infusion of control (CON). Therefore, the treatments were as follows: LF + CON; LF + ACE; HF + CON; and HF + ACE. No interactions between acetate and diet fermentability were found on performance variables. Acetate infusion decreased dry matter intake (DMI), milk yield, and milk protein yield and content but did not affect milk fat yield; however, it increased milk fat concentration, and this response tended to be more pronounced in the HF diet. Acetate infusions increased plasma β-hydroxybutyrate in the HF diet, but not in the LF diet, and increased plasma non-esterified fatty acid, which was likely a lipolysis response to reduced DMI and decreased energy balance. This study demonstrates that acetate availability can be a constraint on mammary lipogenesis, even with adequate dietary fiber. Full article

(This article belongs to the Section Animal Nutrition)

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18 pages, 1194 KiB

Open AccessArticle

In Ovo Feeding of Arginine, Leucine, and Methionine in Broiler Breeders’ Eggs During Summer: Effects on Hatchability and Chick Oxidation, Inflammation, and Apoptosis

by Huan Ge, Zhenwu Huang, Jinghai Feng and Minhong Zhang

Animals 2025, 15(13), 1930; https://doi.org/10.3390/ani15131930 - 30 Jun 2025

Abstract

Summer high temperatures (27–38 °C, more than 7 days) readily induce heat stress in late-laying broiler breeders, which impedes offspring growth and development. This study aimed to provide a scientific basis for improving the offspring development of late-laying broiler breeders during summer. Six [...] Read more.

Summer high temperatures (27–38 °C, more than 7 days) readily induce heat stress in late-laying broiler breeders, which impedes offspring growth and development. This study aimed to provide a scientific basis for improving the offspring development of late-laying broiler breeders during summer. Six hundred fertilized eggs from 50-week-old LiFeng broiler breeders were divided into five treatment groups (non-injected, NaCl-injected, 6 mg/egg L-arginine-injected, 3.5 mg/egg L-methionine-injected, 8.4 mg/egg L-leucine-injected), with six replicates per group and 20 eggs per replicate. Embryos were incubated for 21 days and chicks raised for 21 days post-hatch. Methionine injection significantly enhanced hatchability (+5.8%), increased daily chick weight gain (+8.8%), reduced serum urea nitrogen (−53.13%), decreased inflammatory cytokine levels, elevated antioxidant enzyme activities, lowered malondialdehyde content (−47.99%), and suppressed expression of inflammatory and apoptotic pathway genes. The comprehensive effect of methionine was the best among the three amino acids when injected into chicken embryos. Methionine promoted protein synthesis, enhanced antioxidant and anti-inflammatory capacities, and consequently improved chick growth performance. Full article

(This article belongs to the Section Animal Nutrition)

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11 pages, 222 KiB

Open AccessArticle

Effects of Rumen-Protected Taurine Supplementation on Ruminal Fermentation, Hematological Profiles, Liver Function, and Immune Responses in Yaks

by Shoupei Zhao, Lianghao Lu, Yuanyuan Chen, Huaming Yang, Bao Zhang, Mingyu Cao, Wenju Chao, Wanchao Xue, Xiaorong Fan, Jianxin Xiao, Rui Hu, Quanhui Peng, Lizhi Wang, Zhisheng Wang and Bai Xue

Animals 2025, 15(13), 1929; https://doi.org/10.3390/ani15131929 - 30 Jun 2025

Abstract

The present study evaluated the effects of dietary rumen-protected taurine (RPT) supplementation on ruminal fermentation, hematological parameters, liver function, stress-related hormones, and immune responses in yaks. Eighteen yaks were randomly allocated to three groups: a control group receiving no RPT (CON), a low-dose [...] Read more.

The present study evaluated the effects of dietary rumen-protected taurine (RPT) supplementation on ruminal fermentation, hematological parameters, liver function, stress-related hormones, and immune responses in yaks. Eighteen yaks were randomly allocated to three groups: a control group receiving no RPT (CON), a low-dose group receiving 20 g/day (RPT20), and a high-dose group receiving 40 g/day (RPT40). Supplementation with RPT did not significantly affect ruminal pH, microbial protein concentration, ammonia nitrogen, total volatile fatty acids, or the individual volatile fatty acid profiles (p > 0.05). A decreasing trend in red blood cell count was observed (p = 0.050), while no significant changes were detected in white blood cell or platelet indices (p > 0.05). Liver function markers, including albumin, alanine transaminase, aspartate transaminase, and total protein, remained unchanged, although a trend toward altered alkaline phosphatase activity was noted (p = 0.074). No significant effects were observed on acute-phase proteins (serum amyloid A, C-reactive protein) or stress-related hormones (epinephrine, adrenocorticotropic hormone, cortisol) (p > 0.05). Importantly, serum immunoglobulin A and immunoglobulin G levels were significantly increased in response to RPT supplementation (p = 0.029 and p = 0.043, respectively), suggesting enhanced humoral immunity. These findings indicate that RPT may improve immune function in yaks without negatively affecting rumen fermentation or liver health. Full article

(This article belongs to the Special Issue Advances in Nutritional Manipulation of Rumen Fermentation: Second Edition)

22 pages, 2035 KiB

Open AccessArticle

Bioaccumulation, Ecotoxicity, and Microbial Responses in Hoplobatrachus rugulosus Tadpoles Following Co-Exposure to Imidacloprid and Microplastics

by Xinyu Hu, Sipu Zhu, Yiru Chen, Linxia Zhang, Huadong Tan, Chunyuan Wu, Xiaoying Zhang, Xiao Deng and Yi Li

Animals 2025, 15(13), 1928; https://doi.org/10.3390/ani15131928 - 30 Jun 2025

Abstract

Agricultural organic pollutants have been identified as a key factor contributing to amphibian population decline, particularly during early developmental stages when tadpoles are frequently exposed to neonicotinoids (NEOs) and microplastics (MPs). In this study, Hoplobatrachus rugulosus tadpoles were exposed to imidacloprid (IMI: 0.045, [...] Read more.

Agricultural organic pollutants have been identified as a key factor contributing to amphibian population decline, particularly during early developmental stages when tadpoles are frequently exposed to neonicotinoids (NEOs) and microplastics (MPs). In this study, Hoplobatrachus rugulosus tadpoles were exposed to imidacloprid (IMI: 0.045, 0.45, and 4.5 mg L⁻¹) and polyethylene-derived MPs (10 mg L⁻¹) from agricultural mulch films, both individually and in combination. We systematically evaluated acute toxicity, bioaccumulation, developmental and oxidative stress responses, and changes in the skin and gut microbiota. The results showed that the 96 h median lethal concentration (LC₅₀) of IMI was 44.8 mg L⁻¹ in the IMI-only group and was 40.5 mg L⁻¹ in the IMI + MPs group, indicating the negligible impact of MPs on acute toxicity. However, in the highest co-exposure group (IMI4.5 + MPs), tadpole body length and weight decreased by 14.7% and 22.6%, respectively, alongside marked changes in oxidative stress, whereby catalase (CAT) and superoxide dismutase (SOD) activities were suppressed, while malondialdehyde (MDA) levels increased by 35%, indicating elevated lipid peroxidation. Furthermore, the micronucleus frequency in erythrocytes was significantly elevated, suggesting genotoxic effects. Microbial community analysis revealed significant shifts in the relative abundance of gut and skin microbiota under IMI + MPs exposure, with a notable enrichment of Proteobacteria, Fusarium, Actinomycetota, and Bacteroidota, indicating the disruption of host–microbiome interactions. This study proposes a comprehensive multi-tiered assessment framework encompassing environmental exposure, bioaccumulation, toxicological endpoints, oxidative stress biomarkers, and microbiome shifts. Our findings provide new mechanistic insights and quantitative evidence on the compound threats posed by IMI and MPs to amphibians in aquatic environments. Full article

(This article belongs to the Section Ecology and Conservation)

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29 pages, 1231 KiB

Open AccessReview

Markers of Gut Health in Small Animals: Focus on Fatty Acids and Amino Acids as Indicators of Intestinal Functionality and Microbiome Activity

by Ana I. Rey, Cristina Higueras, Patricia Olmeda, Angel Sainz, Beatriz G. Gálvez and Mar Larrosa

Animals 2025, 15(13), 1927; https://doi.org/10.3390/ani15131927 - 30 Jun 2025

Abstract

Chronic inflammatory enteropathies (CIEs) in companion animals represent a group of idiopathic, immune-mediated gastrointestinal disorders in which the intestinal epithelium can be altered, affecting intestinal functionality, nutrient absorption, and microbiota composition. This review presents an overview of markers that could be used for [...] Read more.

Chronic inflammatory enteropathies (CIEs) in companion animals represent a group of idiopathic, immune-mediated gastrointestinal disorders in which the intestinal epithelium can be altered, affecting intestinal functionality, nutrient absorption, and microbiota composition. This review presents an overview of markers that could be used for the assessment of intestinal health, focusing extensively on functional biomarkers, with particular attention to fatty acids (including short-chain fatty acids, SCFAs) and amino acids. Studies have consistently shown reduced concentrations of SCFAs in companion animals with CIEs compared to healthy groups. These alterations occur with varying intensity depending on the type of enteropathy. Alterations in saturated, monounsaturated, and long-chain polyunsaturated fatty acids have also been reported in blood and feces, particularly in omega-3 and omega-6 derivatives, as well as in the elongase and desaturase indices responsible for endogenous synthesis. In addition, amino acids serve as precursors to key metabolites involved in mucosal immunity, oxidative stress regulation, and microbial homeostasis. In CIEs, alterations in systemic and fecal amino acid profiles have been observed, reflecting both host metabolic adaptation and microbial dysbiosis. Integrating fatty acid and amino acid profiles can help distinguish different types of enteropathies, providing additional discriminatory power for determining response to dietary treatment. Future research should aim to elucidate the causal relationships between metabolic alterations and disease pathogenesis, which could lead to novel dietary interventions targeting metabolic interactions between the microbiota and the host. Full article

(This article belongs to the Special Issue Companion Animal Nutrition and Gut Health)

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17 pages, 3275 KiB

Open AccessArticle

Dietary Choline Supplementation Modulates Growth Performance and Protein Metabolism by Promoting Glucose and Lipid Catabolism in Chinese Perch (Siniperca chuatsi)

by Wanjia Zhu, Yi Yi, Liwei Liu, Zhiwei Zou, Jianming Chen and Jianmei Su

Animals 2025, 15(13), 1926; https://doi.org/10.3390/ani15131926 - 30 Jun 2025

Abstract

An 8-week trial was conducted to investigate the effects of choline on the growth of Chinese perch (85.57 ± 0.54 g) with dietary choline supplementation at 0 (P0), 400 (P1), 800 (P2), 1600 (P3), 3200 (P4), and 6400 mg/kg (P5). Protein efficiency ratio [...] Read more.

An 8-week trial was conducted to investigate the effects of choline on the growth of Chinese perch (85.57 ± 0.54 g) with dietary choline supplementation at 0 (P0), 400 (P1), 800 (P2), 1600 (P3), 3200 (P4), and 6400 mg/kg (P5). Protein efficiency ratio and protein retention value (PRV) were higher in the P1–P4 groups than in the P0 group (p < 0.05). Compared to the P0 group, weight gain rate and specific growth rate (SGR) increased in the P2 and P3 groups (p < 0.05). The orexigenic gene agrp expression level rose in the P2–P4 groups (p < 0.05). The expression level of the lipolysis-related gene hsl or pparα was elevated in the P2 and P4 groups (p < 0.05). Proteolysis-related gene (ampd, mafbx, and murf1) expressions decreased in the P1–P4 groups, while tor and gk gene expressions increased in the P2 and P3 groups (p < 0.05). Broken-line analysis indicated that the optimal choline supplementation level for Chinese perch is 788.38 mg/kg based on SGR and 851.04 mg/kg based on PRV. The results demonstrate that moderate dietary choline supplementation enhances growth performance by promoting glucose and lipid catabolism and inhibiting protein catabolism in Chinese perch. Full article

(This article belongs to the Special Issue Advances in Functional Diets and Culture Conditions in Fish: Applications in Aquaculture)

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