Animals

18 pages, 909 KB

Open AccessArticle

Differential Regulation of Ruminal Microbial Community Structure and Functional Pathways in Sheep Supplemented with Linseed Oil or Sunflower Oil

by Lu Shao, Jiaxun Dong, Ziang Wang, Peidi Zhao, Xiangpeng Yue and Wanhong Li

Animals 2026, 16(11), 1581; https://doi.org/10.3390/ani16111581 (registering DOI) - 22 May 2026

Abstract

This study evaluated the effects of dietary PUFA supplementation on growth performance, serum biochemical indices, rumen morphology, ruminal fermentation, and rumen microbial communities in Hu sheep. Thirty healthy male Hu sheep (80 days old; 18.70 ± 0.72 kg) were randomly assigned to three [...] Read more.

This study evaluated the effects of dietary PUFA supplementation on growth performance, serum biochemical indices, rumen morphology, ruminal fermentation, and rumen microbial communities in Hu sheep. Thirty healthy male Hu sheep (80 days old; 18.70 ± 0.72 kg) were randomly assigned to three groups (n = 10/group) and fed a basal diet supplemented with 4% rumen-bypass palmitic acid fat powder (POS), 4% linseed oil (LO; rich in ω-3 PUFA), or 4% sunflower oil (SO; rich in ω-6 PUFA). PUFA supplementation did not affect average daily gain or rumen tissue morphology (p > 0.05), but it significantly reduced serum creatinine, uric acid, and high-density lipoprotein concentrations (p < 0.05). Orthogonal comparative analysis showed that supplementing with PUFA significantly reduced acetate and propionate, while increasing isobutyrate, butyrate, isovalerate, and TVFAs (p < 0.05). The levels of propionate, butyrate and TVFAs in the SO group were higher than those in the LO group (p < 0.05), and the ratio of acetate to propionate was lower (p < 0.05). Supplementing with PUFA reshaped the rumen microbiota, increasing the relative abundances of Bacteroidota, Firmicutes, Euryarchaeota, Cyanobacteria, and Actinobacteriota, while decreasing Proteobacteria and Desulfobacterota (p < 0.05). At the genus level, Prevotella and Rikenellaceae_RC9_gut_group were enriched in both groups with added PUFA, while Prevotellace-UCG-001 was specifically enriched in the LO group; in contrast, Prevotella_7, Succinivibriaceae_UCG-001, Prevotella_9, and Dialist all showed a decrease (p < 0.05). The alpha diversity increased, while the beta diversity showed significant differences between the group with added PUFA and the control group. Functionally, LO enriches carbohydrate and energy metabolism, while SO enriches nucleotide metabolism. In summary, linseed oil and sunflower oil improved serum indices and ruminal fermentation without impairing growth, but through distinct microbial and functional pathways. Full article

(This article belongs to the Section Small Ruminants)

17 pages, 3571 KB

Open AccessArticle

The Role of Thioredoxin in Mitigating Ammonia-Induced Oxidative Stress in Nile Tilapia (Oreochromis niloticus)

by Yu Yu, Yanghui Chen, Yingying Chang, Junliang Luo, Haoze Li, Jinyuan Feng, Minghui Zhu, Bei Wang, Yu Huang and Jichang Jian

Animals 2026, 16(11), 1580; https://doi.org/10.3390/ani16111580 (registering DOI) - 22 May 2026

Abstract

Thioredoxin (TRX) is an important redox-related protein, which plays a key role in maintaining redox balance in cells. However, the role of TRX in ammonia exposure of Oreochromis niloticus is still unknown. In this study, we successfully cloned the TRX gene (OnTRX) of [...] Read more.

Thioredoxin (TRX) is an important redox-related protein, which plays a key role in maintaining redox balance in cells. However, the role of TRX in ammonia exposure of Oreochromis niloticus is still unknown. In this study, we successfully cloned the TRX gene (OnTRX) of O. niloticus and performed systematic bioinformatics analysis. The results of multi-sequence alignment and phylogenetic tree analysis showed that OnTRX is highly conserved in vertebrates, but exhibits low sequence similarity with TRX homologs from arthropods (crustaceans). The tissue distribution of OnTRX and its transcriptional response to ammonia challenge were determined by qRT-PCR, and we further investigated the relationship between OnTRX and the response of the Nile tilapia epithelial cell line (TSE-04) to NH₄Cl treatment. The results showed that OnTRX exhibited tissue-specific expression, with a relatively high expression level in gill tissue. Ammonia exposure could significantly induce the expression of OnTRX in the gill, head kidney, intestine, skin, liver, and spleen of tilapia. In TSE-04 cells, OnTRX overexpression was associated with reduced NH₄Cl-induced morphological damage, a lower proportion of apoptotic cells, and altered transcript levels of several stress-related genes. Collectively, these findings indicate that OnTRX is likely involved in the regulatory response of Nile tilapia to ammonia-induced stress, while the underlying molecular mechanisms thereof remain to be further elucidated. Full article

(This article belongs to the Special Issue Environmental Pollutant Effects on the Physiological and Immune Functions of Aquatic Animals: Second Edition)

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19 pages, 2948 KB

Open AccessArticle

Integrated Multi-Omics Analysis Reveals the Role of the Gut Microbiota–Metabolite–Endocrine Axis in Post-Weaning Estrus Recovery in Tibetan Pigs

by Jian Zhang, Dong Yang, Mengjia Han, Mengqi Duan, Hongliang Zhang and Peng Shang

Animals 2026, 16(11), 1579; https://doi.org/10.3390/ani16111579 (registering DOI) - 22 May 2026

Abstract

The weaning-to-estrus interval (WEI) is an important indicator of sow reproductive performance, yet the mechanisms underlying post-weaning anestrus in Tibetan sows remain unclear. In this study, multiparous Tibetan sows were classified into an estrus group (FQ) and an anestrus group (WQ) based on [...] Read more.

The weaning-to-estrus interval (WEI) is an important indicator of sow reproductive performance, yet the mechanisms underlying post-weaning anestrus in Tibetan sows remain unclear. In this study, multiparous Tibetan sows were classified into an estrus group (FQ) and an anestrus group (WQ) based on estrus status after weaning. Serum reproductive hormones, hematological parameters, gut microbiota (16S rRNA sequencing), and fecal metabolites (untargeted metabolomics) were analyzed. Compared with the FQ group, the WQ group showed significantly lower estradiol (E₂) and higher progesterone (P) levels (p < 0.01), along with a decreased proportion of neutrophils and an increased proportion of lymphocytes (p < 0.05). No significant differences in alpha diversity were observed, whereas PLS-DA revealed differences in microbial community structures between groups. LEfSe analysis indicated that Methanobrevibacter and Acinetobacter were enriched in the FQ group, whereas Muribaculaceae and Prevotella were enriched in the WQ group. Differential metabolites were mainly involved in amino acid and lipid metabolism and enriched in pathways related to steroid hormone biosynthesis, oocyte maturation, and tryptophan metabolism. These findings suggest that post-weaning anestrus may be associated with endocrine imbalances, immune changes, and gut microbiota–metabolite interactions. They may provide a basis for future studies in Tibetan pig breeding and genetic improvement. Full article

(This article belongs to the Special Issue Advances in Pig Reproductive Physiology)

21 pages, 8127 KB

Open AccessArticle

Heat Stress Induces Metabolic and Physiological Imbalance in Laying Hens, Accompanied by Hepatic Transcriptomic, Cecal Microbial, and Metabolomic Alterations

by Zi Mei, Haobo Zhou, Hao Du, Kunyuan Liu, Chaoyang Gao, Zheya Sheng and Yanzhang Gong

Animals 2026, 16(11), 1578; https://doi.org/10.3390/ani16111578 - 22 May 2026

Abstract

Heat stress is a major constraint to productivity and physiological homeostasis in laying hens. This study investigated integrated responses to acute heat stress using a multi-omics approach, including performance traits, serum biochemical parameters, histology, hepatic transcriptomics, cecal metagenomics, and metabolomics. Acute heat stress [...] Read more.

Heat stress is a major constraint to productivity and physiological homeostasis in laying hens. This study investigated integrated responses to acute heat stress using a multi-omics approach, including performance traits, serum biochemical parameters, histology, hepatic transcriptomics, cecal metagenomics, and metabolomics. Acute heat stress impaired productive performance, as reflected by changes in egg production and reduced eggshell strength, and induced systemic physiological disturbances, including increased stress- and injury-related blood indicators and disrupted metabolic and electrolyte balance. Histological analysis confirmed liver and intestinal tissue damage. Hepatic transcriptomics revealed inflammatory activation and suppression of metabolic pathways, particularly those involved in lipid metabolism, energy production, and redox homeostasis. Cecal metagenomic and metabolomic analyses showed altered microbial composition and functional potential, along with disruptions in amino acid, lipid, and energy metabolism. Collectively, these findings suggest that acute heat stress is associated with coordinated inflammatory responses and metabolic reprogramming, together with liver and intestinal injury and gut microbiota–metabolite alterations. The study provides a framework for understanding early heat stress responses and highlights potential targets for nutritional and microbiota-based interventions in poultry production. Importantly, serum biochemical indicators such as D-lactic acid and aspartate aminotransferase may serve as potential early biomarkers for monitoring heat-stress-induced physiological disturbances. Full article

(This article belongs to the Special Issue The Effects of Heat Stress on the Physiology, Immunity, and Behavior of Livestock and Poultry)

14 pages, 12324 KB

Open AccessArticle

Exploring Growth Pattern and Candidate Genes for Chicken Spur

by Hong Yuan, Qianhui Liao, Zhuliang Yang, Zhen Zhang, Jianneng Li, Fuqiu Li, Yunsheng Wang, Biyan Zhou, Jintang Luo and Xiurong Yang

Animals 2026, 16(11), 1577; https://doi.org/10.3390/ani16111577 - 22 May 2026

Abstract

The chicken spur is a bony structure located on the tarsometatarsus and extending posteriorly. Because its length increases with age, it has become an important indicator of rearing duration and a trait of interest in high-quality chicken breeding. The developmental pattern of the [...] Read more.

The chicken spur is a bony structure located on the tarsometatarsus and extending posteriorly. Because its length increases with age, it has become an important indicator of rearing duration and a trait of interest in high-quality chicken breeding. The developmental pattern of the chicken spur and its underlying genetic mechanisms remain poorly understood. In this study, Nandan-Yao chickens were used to investigate spur growth and development. Phenotypic measurements and X-ray imaging were performed to characterize spur growth, and RNA sequencing was used to identify candidate genes associated with spur length. Candidate genes were further evaluated by tissue expression profiling and RNA interference. The results showed that spur length was not significantly associated with body weight, body size, or laying traits (p > 0.05). In roosters, sperm motility and ln(T/E2) were significantly higher in the long spur group than in the short spur group (p < 0.05). X-ray imaging and gene expression analysis indicated that the chicken spur is a bony structure that develops through an endochondral ossification pattern, with the ossification center appearing at approximately 15 weeks of age in Nandan-Yao chickens. TENM2 was identified as a key candidate gene associated with spur development, and functional analysis suggested that it may be involved in this process through the BMP signaling pathway. These findings provide a basis for understanding the developmental pattern and genetic mechanisms of chicken spur formation and support the potential breeding value of spur traits. Full article

(This article belongs to the Section Poultry)

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20 pages, 2557 KB

Open AccessArticle

The Invasive Blue Crab Callinectes sapidus from the Northern Adriatic Sea: Feeding Behaviour and Fecundity Data

by Antonio Casalini, Laura Gentile, Dario Lombardi, Riccardo Brusa, Pietro Emmanuele and Oliviero Mordenti

Animals 2026, 16(11), 1576; https://doi.org/10.3390/ani16111576 - 22 May 2026

Abstract

The population of the blue crab Callinectes sapidus is rapidly expanding in the Mediterranean Sea, where it is causing increasing ecological and economic impacts. However, biological information from recently colonised areas remains limited. This study combined controlled experiments and reproductive analyses to investigate [...] Read more.

The population of the blue crab Callinectes sapidus is rapidly expanding in the Mediterranean Sea, where it is causing increasing ecological and economic impacts. However, biological information from recently colonised areas remains limited. This study combined controlled experiments and reproductive analyses to investigate the key biological traits of C. sapidus in the northern Adriatic Sea. Feeding trials were conducted under controlled conditions to assess prey consumption and feeding behaviours using Manila clams (Ruditapes philippinarum) and Mediterranean mussels (Mytilus galloprovincialis), offered as monospecific and mixed diets. The results showed that, while the number of prey items consumed did not differ markedly between species, mussels provided a significantly higher edible biomass, indicating greater energetic profitability. Handling and consumption times were comparable between prey types, suggesting compensatory differences between opening and feeding phases. Food intake was strongly influenced by temperature, with peak consumption observed between 25 and 28 °C and reduced feeding at both lower and higher temperatures. Reproductive analysis of ovigerous females revealed high fecundity, with a mean of 1.63 ± 0.53 million eggs per individual and a positive relationship between fecundity and body size. Overall, the results confirm that C. sapidus combines trophic flexibility with high reproductive output—traits that support its invasive success. These findings improve the understanding of the blue crab’s ecological role in the northern Adriatic, providing useful insights for assessing its impact on shellfish aquaculture and developing management strategies. Full article

(This article belongs to the Special Issue The Invasive Blue Crab: Implications for Fisheries, Aquaculture and One Health Perspective)

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22 pages, 9718 KB

Open AccessArticle

Effects of Dietary Glycerol Monolaurate on Growth Performance, Bile Acid Metabolism, and Intestinal Health in Asian Swamp Eel (Monopterus albus)

by Haiyan Liu, Hang Yang, Xiaogang Guo, Menghui Lin, Minjie Zhao, Wenzong Zhou and Haiying Cai

Animals 2026, 16(11), 1575; https://doi.org/10.3390/ani16111575 - 22 May 2026

Abstract

This study investigated the dose-dependent effects of dietary glycerol monolaurate (GML) supplementation on the growth performance, bile acid metabolism, and intestinal health of Asian swamp eel (Monopterus albus). A total of 225 healthy eels with an initial body weight of 25.0 [...] Read more.

This study investigated the dose-dependent effects of dietary glycerol monolaurate (GML) supplementation on the growth performance, bile acid metabolism, and intestinal health of Asian swamp eel (Monopterus albus). A total of 225 healthy eels with an initial body weight of 25.0 ± 2.0 g were randomly divided into three groups and fed a basal diet (control), 0.5 g/kg GML, or 1.0 g/kg GML for 60 days, respectively. The results showed that dietary GML supplementation increased the weight gain rate by 8.75% and decreased the feed conversion ratio by 8.16% in the GML1 group compared with the control. Dietary GML significantly reduced the contents of TP and ALB (p < 0.05). Meanwhile, the MDA content in the GML0.5 and GML1 groups decreased significantly by 24.80% and 38.15%, respectively. The contents of total bile acids and secondary bile acids were significantly elevated in the GML1 group (p < 0.05). In addition, GML supplementation optimized the intestinal microbial community and significantly reduced the relative abundance of potentially harmful bacteria such as Nocardia and Stenotrophomonas (p < 0.05). In conclusion, under the conditions of this study, dietary GML could effectively the improve growth performance, bile acid metabolism, antioxidant capacity, and intestinal health of M. albus. Among the tested concentrations, 1.0 g/kg GML showed the optimal beneficial effects. Full article

(This article belongs to the Section Aquatic Animals)

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16 pages, 1852 KB

Open AccessArticle

Resveratrol Alleviates Corticosterone-Induced Hepatic Lipid Metabolism Disorder and Oxidative Stress by Regulating the Nrf2 and AMPK/Sirt1 Signaling Pathways in AA Broilers

by Chendi Fu, Jiawei Ma, Xiaoxuan Zong, Jin Sun and Xingjun Feng

Animals 2026, 16(11), 1574; https://doi.org/10.3390/ani16111574 - 22 May 2026

Abstract

Excessive glucocorticoids induced by stress trigger hepatic lipid metabolism disorder and oxidative stress in poultry, impairing growth performance and welfare. At the same time, resveratrol (RSV) has antioxidant and lipid-regulating properties, but the protective mechanisms in corticosterone (CORT)-challenged broilers remain unclear. This study [...] Read more.

Excessive glucocorticoids induced by stress trigger hepatic lipid metabolism disorder and oxidative stress in poultry, impairing growth performance and welfare. At the same time, resveratrol (RSV) has antioxidant and lipid-regulating properties, but the protective mechanisms in corticosterone (CORT)-challenged broilers remain unclear. This study investigated RSV’s effects on CORT-induced hepatic damage in AA broilers, with 240 one-day-old broilers randomized into three groups: control (basal diet), CORT (basal diet + 4 mg/kg BW CORT intraperitoneal injection), and RSV (400 mg/kg RSV-supplemented diet + CORT injection). Growth performance, hepatic redox status, serum biochemistry, liver histopathology, and gene/protein expression related to antioxidant/lipid metabolism were determined. The growth performance of AA broilers injected with CORT was significantly affected, showing reduced body weight gain (p < 0.05), increased abdominal fat content (p < 0.05), and hepatomegaly (p < 0.05). The addition of RSV in the diet significantly reduced abdominal fat accumulation and hepatomegaly (p < 0.05), improving the growth performance of broilers; Effects of RSV on liver function and lipid metabolism of CORT-treated AA broilers: After CORT injection, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activity and total bile acid (TBA) content significantly increased (p < 0.05). Hepatic total cholesterol (TC) and triglycerides (TG) increased after CORT injection (p < 0.05), causing severe liver damage. RSV supplementation could reverse the increases in serum ALP, ALT, and AST activity (p < 0.05) and reduce TBA content in stressed broilers (p < 0.05). TC and TG levels in the liver decreased under the alleviation of RSV (p < 0.05), and serum TG levels declined (p < 0.05). Microscopic and ultrastructural observations showed that after CORT injection, hepatic tissue cells were swollen, scattered fat vacuoles were present, pores were enlarged, and intracellular lipid droplets appeared. The RSV group significantly alleviated hepatocyte damage, reduced vacuolation, showed uniform chromatin, and decreased lipid droplets. RSV significantly mitigated the CORT-induced increase in SREBP-1 mRNA and protein expression and the decrease in PPARα protein expression; CORT caused a decline in the antioxidant function of AA broiler livers, with significant decreases in SOD and GSH-PX (p < 0.05), and the expression of Nrf2 and its downstream genes also showed a decreasing trend. Compared to the CORT group, the RSV group exhibited significant increases in liver CAT, SOD, and GSH-PX (p < 0.05), and Nrf2 protein expression was elevated (p < 0.05). In summary, resveratrol can alleviate the decline in growth performance, liver steatosis, and hepatic oxidative stress in AA broilers induced by CORT, downregulate lipogenic genes such as SREBP-1c, regulate liver lipid metabolism, and mitigate CORT-induced hepatic oxidative stress in broilers by upregulating the Nrf2 pathway. Full article

(This article belongs to the Special Issue Metabolic, Health, and Productivity Challenges in Poultry Production)

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13 pages, 267 KB

Open AccessArticle

Advantages of Increasing Histidine to Lysine Ratios on Growth Performance, Blood Parameters and Histidine-Containing Dipeptides for Weaning Piglets

by Diana Siebert, Katharina Schuh-von Graevenitz and Georg Dusel

Animals 2026, 16(11), 1573; https://doi.org/10.3390/ani16111573 - 22 May 2026

Abstract

A total of 192 weaned piglets (Topigs TN70), 26 days of age, with an initial body weight of 7.2 ± 0.5 kg, were used to determine the standardized ileal digestible (SID) histidine (His) to lysine (Lys) ratio required to maximize growth performance. Six [...] Read more.

A total of 192 weaned piglets (Topigs TN70), 26 days of age, with an initial body weight of 7.2 ± 0.5 kg, were used to determine the standardized ileal digestible (SID) histidine (His) to lysine (Lys) ratio required to maximize growth performance. Six dietary treatments with graded SID His to Lys ratios ranging from 0.2 to 0.38 were generated with the supplementation of L-His to a grain-based basal diet deficient in His. At the end of the trial (day 41 post weaning), 72 male piglets were euthanized for the analysis of histidine-containing dipeptides, particularly carnosine, in the M. longissimus dorsi. In addition, blood samples were collected from 72 piglets to determine plasma urea-nitrogen and hematological parameters. Piglets fed low dietary His (SID His to Lys < 0.27) exhibited hemoglobin concentrations below the reference value, indicating anemia. Muscle carnosine content increased linearly with increasing dietary His and did not reach a plateau within the tested range. Based on growth performance responses, the SID His to Lys ratio required to achieve maximum growth performance in fast-growing piglets is 0.34. These findings emphasize the importance of supervising the SID His to Lys ratio, particularly in practical piglet feed formulations. Full article

(This article belongs to the Section Animal Nutrition)

5 pages, 184 KB

Open AccessEditorial

Physiological Responses of Fishes to Nutrition Management and Environmental Stresses

by László Ardó and Janka Nagyné Biró

Animals 2026, 16(11), 1572; https://doi.org/10.3390/ani16111572 - 22 May 2026

Abstract

The goal of this Special Issue was to collect the latest research results on the topics of (1) the physiological response of fish to various stressful situations and nutritional changes, (2) the replacement of fish meal and fish oil with sustainable, alternative protein [...] Read more.

The goal of this Special Issue was to collect the latest research results on the topics of (1) the physiological response of fish to various stressful situations and nutritional changes, (2) the replacement of fish meal and fish oil with sustainable, alternative protein and lipid sources in fish feeds, and (3) supplementing fish feeds with various additives in order to enhance the immune response and increase the stress and disease resistance of fish reared in intensive systems. These topics are very important for the development of a more effective and sustainable intensive aquaculture, as fish farming systems are becoming more intensive and industrialized, which results in a more stressful environment for farmed fish. Another important challenge is providing enough high-quality fish feed to fulfill the increasing demand of intensive aquaculture. There are 14 original research articles published in this Special Issue. The authors come from a wide array of countries, and they worked with a wide variety of freshwater and marine fish species, which are important for intensive aquaculture. These articles represent only a modest contribution to the overall literature of stress and nutritional physiology of farmed fish. However, each of these papers contain interesting new information regarding the solution of the two major problems of intensifying aquaculture: environmental stresses and nutrition management. Full article

(This article belongs to the Special Issue Physiological Responses of Fishes to Nutrition Management and Environmental Stresses)

14 pages, 448 KB

Open AccessArticle

Effects of Defatted Black Soldier Fly (Hermetia illucens) Meal on the Performance, Digestibility and Blood Parameters of Weaned Piglets

by Mara Parreiras, Victor Pinheiro, Olga Moreira, Maria Soares, Daniel Murta, Ana Novo Barros and Divanildo Outor-Monteiro

Animals 2026, 16(11), 1571; https://doi.org/10.3390/ani16111571 - 22 May 2026

Abstract

This study investigated the effects of different inclusion levels of defatted black soldier fly (Hermetia illucens: BSF) larval meal on growth performance, haematological and biochemical blood parameters, and nutrient digestibility in piglets. Forty-eight male piglets weaned at 28 days of age [...] Read more.

This study investigated the effects of different inclusion levels of defatted black soldier fly (Hermetia illucens: BSF) larval meal on growth performance, haematological and biochemical blood parameters, and nutrient digestibility in piglets. Forty-eight male piglets weaned at 28 days of age ((Landrace × Large White) × (Piétrain)) were randomly assigned to three experimental treatments. Each treatment included eight pens with two piglets per pen. Diets were formulated to be isoenergetic and isoproteic, containing defatted BSF meal as a partial replacement for fishmeal and soybean meal: Control (0% BSF), BSF3% (3% inclusion), and BSF6% (6% inclusion). Over the whole experimental period, dietary treatment did not significantly affect final body weight, average daily gain, average daily feed intake, or feed conversion ratio, although feed intake differed during the 7–28-day period. Red and white blood cell parameters were not influenced by diet. Apparent total tract digestibility of dry matter and organic matter increased at the 6% inclusion level, while crude protein and crude fat digestibility were not affected. These results indicate that defatted BSF meal can be used as a sustainable alternative protein source in piglet diets, maintaining growth performance and health status. Full article

(This article belongs to the Section Animal Nutrition)

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