Animals最新文献

This study comprehensively explored the epidemiology, virulence, antibiotic resistance, and genomic features of ovine-derived Mannheimia haemolytica across three provinces in Northwest China (Gansu, Ningxia, and Shaanxi). Lung tissue samples were collected postmortem from sheep with respiratory disease (nine per province), cultured under sterile conditions, and screened by morphological, Gram staining, PCR, and NGS methods. Nine M. haemolytica strains were successfully isolated (isolation rate 33.33%) and identified as serotypes A1, A2, and A6, with Shaanxi exhibiting a significantly higher isolation rate of 66.67%. Genomic analysis revealed that each isolate each harbored over 100 virulence genes and displayed notable genetic diversity. In murine assays, intraperitoneal inoculation in mice caused severe breathing problems and death within 24 h; necropsy revealed lung congestion, splenic necrosis foci, and hepatic congestion. Antibiotic susceptibility testing showed sensitivity to ciprofloxacin, azithromycin, gentamicin, and levofloxacin, while resistance was observed for tiamulin and enrofloxacin. These findings indicate a high prevalence and strong pathogenicity of ovine M. haemolytica in Shaanxi, underscore the presence of key resistance traits, and provide a genomic and pathogenic reference to guide region-specific surveillance, therapeutic decisions, and vaccine-oriented control in small ruminant herds. Importantly, these results highlight the need for region-specific monitoring and judicious antibiotic use, which are essential to forestall the spread of resistant strains and to ensure sustainable disease management strategies.

Background: Equine Infectious Anemia (EIA) is a notifiable disease caused by Equine Infectious Anemia Virus (EIAV), with major sanitary and economic importance for equids worldwide. There is limited and outdated information on the circulation of EIAV in many European countries. In the present study, we aimed to assess virus exposure in different equid species in Western Europe.

Methods: Between 2011 and 2023, a cross-sectional study was conducted to investigate the seroprevalence of EIAV in 1676 equids (1444 horses, 106 donkeys and 126 mules/hinnies) from four European regions: Andalusia (Southern Spain; n = 808), Catalonia (Northeastern Spain; n = 437), Southeastern United Kingdom (UK; n = 209), and Ireland (n = 222).

Results: None of the analyzed equines tested positive for antibodies against EIAV (0%; 95 %CI: 0.0-0.18), indicating limited virus exposure of the equid populations from these European regions.

Conclusions: This finding is consistent with the low EIAV circulation previously reported in Western Europe and the few official EIA outbreaks recorded in the region during the last decade. To the best of the author's knowledge, this serosurvey represents the first investigation assessing EIAV exposure in equids from Ireland and the UK. Our results not only provide novel epidemiological evidence for the four European regions assessed but also reinforce the effectiveness of surveillance strategies and control measures implemented by European countries, in accordance with national and international regulations, to successfully limit EIAV circulation.

Kittens are born with some maternally derived antibodies (MDA) that, together with maternal gut microbiota, bring some form of early defense against pathogens. However, this protection declines and the rapid changes and challenges the kitten typically encounters can adversely affect their health. Nutrition can modulate the immune system and gut microbiota, offering a boost to protection following weaning. This controlled, randomized, double-blinded study tests a dietary supplement containing nucleotides, oligosaccharides, vitamin E and β-carotene in 50 domestic short-haired kittens. Control kittens were fed standard, dry kitten diet whilst test kittens received the same diet with supplement for 52 weeks. Kittens received routine vaccinations and blood samples were collected throughout the study for standard hematology, serum antibodies and cytokine expression. Rectal fecal samples were analyzed for gut microbiota via 16S rRNA gene sequencing. Supplemented kittens showed significantly improved antibody response to Chlamydia vaccine at various timepoints versus controls, with no consistent effects of supplementation on responses to other vaccines. Several cytokines were significantly influenced by the supplement, which also significantly altered gut microbiota diversity. In conclusion, a dietary supplement was shown to promote immune response and gut microbiota changes in kittens and may help to support a healthy transition into adulthood.

The development of males and females of the cephalopod Amphioctopus fangsiao is asynchronous. The male produces sperm after maturity for storage in a spermatophore prior to mating. After mating, the sperm enter the female spermatheca for storage until ovulation occurs, a period that lasts for 8 months. This is a biologically uncommon phenomenon because sperm cells generally fail to maintain their ability to fertilize for a long time after being ejaculated. However, the molecular mechanisms of this phenomenon are still not clear. Sperm cells are stored in the male spermatophore and the female spermatheca, each of which provides a suitable environment. To determine the molecular basis of the sperm storage mechanisms in A. fangsiao, protein profiles from spermathecal fluid and seminal plasma were characterized separately using mass spectrometry-based proteomics. The antioxidant enzymes superoxide dismutase (SOD), glutathione S-transferase (GST), and Thioredoxin (Trx), and the glycolytic enzymes lactate dehydrogenase (LDH), hexokinase (HK), pyruvate dehydrogenase kinase (PDK), and ATP synthase were significantly enriched in the spermathecal fluid. Catalase (CAT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), triosephosphate isomerase (TIM), phosphoglycerate kinase (PGK), and Chitinase were significantly enriched in the seminal plasma. The antimicrobial proteins transforming growth factor beta regulator 1 (TBRG1) and interleukin enhancer binding factor 2 (ILF2) and the extracellular matrix-related proteins transforming growth factor beta induced protein (TGFBIp) and thrombospondin type-1 domain-containing protein 4 (THSD4) were also significantly expressed in the spermathecal fluid. These proteins may be crucial for successful long-term sperm storage. We measured the activities of four antioxidant enzymes based on the proteomic results, supporting the antioxidant mechanism during the sperm storage process. This study enhances our understanding of the sperm storage ability of A. fangsiao.

The hypoxic, cold, and high-ultraviolet radiation environments at high altitude pose severe challenges to mammalian immune and metabolic systems. However, little is known about how captive forest musk deer adapt to high-altitude environments and their seasonal variations. This study analyzed peripheral blood transcriptomes of 33 captive forest musk deer (Moschus berezovskii) at high altitude (~3900 m) and low altitude (~1450 m) during autumn-winter and spring-summer seasons. Results revealed comprehensive immune suppression in the high-altitude group during autumn-winter (downregulation of complement system CFB/C2/C3, interferon pathway genes including FLT3, with only natural killer (NK) cell PRKCQ upregulated), coupled with energy-conserving metabolic reprogramming (altered carbohydrate metabolism, inhibited lipid synthesis, fat mobilization, suppressed protein degradation). During spring-summer, neutrophil antimicrobial responses (SLPI/NCF1/ELANE) and humoral immunity (B cell differentiation genes PAX5/RUNX1; class-switch enzyme AICDA) partially recovered while cellular immunity (IL15/B2M) remained suppressed, accompanied by enhanced anabolic metabolism and adipocyte differentiation. Notably, NK cell-mediated cytotoxicity showed selective enhancement despite comprehensive immune suppression, representing an energy-efficient innate defense strategy. This study provides the first characterization of seasonal immune dynamics in a high-altitude cervid species. These findings reveal persistent immune constraints in high-altitude populations and provide theoretical foundations for disease prevention and health management in captive forest musk deer at high altitudes.

Objectives: The aim of this experiment was to explore how the addition of Schizochytrium powder to the feeding ration affected the production performance, egg quality, and antioxidant function of chickens. Schizochytrium powder is a unicellular spherical marine microalga that can be cultivated through heterotrophic fermentation, with characteristics including rapid cell growth, stable composition, and ease of large-scale production.

Experimental design: Three hundred and twenty 33-week-old chickens with similar egg production rates and body weights were selected and randomly divided into four groups, with five replicates each and 16 hens in each replicate. The control group (Group I) was fed a corn-soybean meal basal diet, while the test groups were supplemented with 0.5% (Group II), 1.0% (Group III), and 2.0% (Group IV) Schizochytrium powder on top of this basal diet, respectively. The pretest period was 1 week, and the main test period was 8 weeks. The results revealed the following: (1) Compared with Group I, the average daily feed intake (ADFI) and laying rate (LR) were significantly lower (p < 0.05) in Group IV, and there was no significant difference (p > 0.05) in the ADFI and LR between Groups II and III. (2) Compared with Group I, the eggshell strength (ES) and docosahexaenoic acid (DHA) content of Groups II, III, and IV were significantly higher (p < 0.05). (3) Compared with Group I, serum triglyceride (TG) content was significantly decreased (p < 0.05), and serum low-density lipoprotein (LDL) content was significantly increased (p < 0.05) in Groups II, III, and IV. Serum total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and peroxidase (PO) activities were significantly higher (p < 0.05) and serum malondialdehyde (MDA) content was significantly lower (p < 0.05) in Groups II, III, and IV compared to Group I. In conclusion, adding Schizochytrium powder to the feeding ration could affect chickens' production performance, increase egg DHA content, and improve the antioxidant capacity of the organism. Based on the results of this study, we recommend a ratio of 1.0% Schizochytrium powder addition.

Studies on agricultural crop damage inflicted by wild boar (Sus scrofa) were conducted in hunting districts located in Lower Silesia, south-western Poland. The statistical analysis of damaged agricultural crops was based on documentation obtained via survey from hunting associations managing 81 hunting districts. For each hunting district (mean area 43.1 km²), this documentation detailed the area of damaged crops (maize, various cereals, root crops, rapeseed, grasslands, and other crops), the date of the damage, and the value of compensation paid to farmers. During three consecutive hunting seasons (2013/14-2015/16) the area of damaged farmlands was amounted to 2098.2 hectares. Maize constitutes 43.9% of the total damage area, while for various cereal crops and grasslands, the figures were 29.5% and 13.2%, respectively. The mean damage compensation per hectare amounted to €421.0, the highest being for root crops (€942.8/ha) and the lowest for grasslands (€214.8/ha). A positive correlation was shown between the wild boar harvest rate and the percentage of farmland area damaged by these animals. Between the 2015/16 and 2022/23 hunting seasons, a decline in the density of harvested wild boar from 1.99 to 1.05 individuals reduced the area of damage from 0.335 ha/km² to 0.164 ha/km² of farmland. Population density control has been suggested as the most effective method of protecting agricultural crops against wild boar.

Epilepsy is a common neurological disorder in cats, but its seizure types, etiologies, and clinical associations remain incompletely characterized compared to dogs. This retrospective study analyzed 118 feline epilepsy cases from two veterinary hospitals in Finland and Lithuania, aiming to evaluate the distribution of seizure types and their associations with demographic, clinical, neurological, diagnostic, and diagnostic test results. Seizures were classified as single generalized (SG), cluster seizures (CS), or status epilepticus (SE). SG and CS occurred with nearly equal frequency (44.9% and 45.8%, respectively), while SE was less common (9.3%). Median age at presentation was 72 months, and no significant differences were found in age, sex, reproductive status, or body weight between seizure types. Abnormal clinical findings (p = 0.009) and neurological abnormalities (p < 0.001) were significantly more frequent in cats with SE, indicating greater neurological compromise in severe seizure forms. MRI was performed in 74.6% of cases and revealed a significant difference in utilization among seizure types (p = 0.004), with lower imaging rates in SE, likely reflecting clinical instability at presentation. Etiology of seizure development was established in 89 cats: idiopathic epilepsy (IE) predominated (80.9%), followed by structural (15.7%) and metabolic/toxic (3.4%) causes. Seizure type and etiology were significantly associated (p = 0.006), with structural epilepsy most common in SE and idiopathic epilepsy prevailing in SG and CS. Among cats with known outcomes (n = 35), seizure control was achieved in 68.6%, while mortality and euthanasia were higher in SE. These findings provide new insight into feline epilepsy by linking seizure type to clinical and etiological profiles, emphasizing that severe presentations are more often associated with neurological abnormalities and structural causes, whereas demographic factors alone do not predict seizure severity.

Rescue operations involving baleen whales trapped in dammed environments are difficult to perform successfully, yet increasingly relevant under growing coastal development. We report on a two-day (9-10 February 2023) rescue of a juvenile humpback whale trapped upstream of the Rance Tidal Power Station (TPS) in Brittany, France, providing rare peer-review evidence on response strategies in highly engineered estuaries. A collaborative, non-invasive strategy was implemented by adjusting water levels and creating artificial tidal currents to prevent the whale from stranding and to guide the individual back to open water. Approximately 100 people were mobilized as part of the rescue operation. This paper describes a detailed spatiotemporal account of the whale's movements and a chronological record of the actions taken by the rescue team. After several attempts to guide it out, rescue efforts enabled its successful exit from the estuary on the second day of operations, and it was not subsequently reported stranded along the French coast. This case demonstrates the value of rapid multidisciplinary coordination between the French National Stranding Network (composed of marine scientists, veterinarians and local correspondents), local organizations, the local marine biology station, international marine mammal experts, national institutions, authorities and a tidal energy operator. Beyond documenting an unusual event, this paper provides operational lessons, highlighting (i) the adaptative management of a TPS as a guidance tool, (ii) the prioritization of animal welfare and responders' safety, (iii) the effective public and media management and (iv) the involvement of trained volunteers during the rescue, promoting environmentally responsible behavior. These insights are transferable to other cases to inform future baleen whales rescue protocols in anthropogenic environments.

Sheep are an economically important livestock species, and reproductive performance is a key trait affecting productivity. The Dorper × Hu hybrid sheep (DHS), widely bred in China, provides a valuable model for studying the genetic basis of prolificacy. This study aimed to investigate the genomic architecture and identify candidate genes associated with high litter size in DHS using whole-genome selective sweep analysis and genome-wide association study (GWAS). A total of 31 DHS individuals with complete reproductive records were sequenced and compared with publicly available genomic data from 20 Hu sheep (HUS) and 10 Dorper sheep (DPS). Population genetic structure and diversity were assessed using phylogenetic trees, principal component analysis (PCA), and ADMIXTURE analysis. To identify key genomic regions associated with litter size, we performed selective sweep analysis between the polytocous and monotocous subpopulations of DHS using multiple methods within a 50 kb sliding window framework, including FST, θπ ratio, XP-CLR, and XP-EHH; we also conducted GWAS. DHS exhibited a distinct genetic structure with admixed ancestry and elevated genetic diversity. Genetic diversity analysis showed that DHS retained moderate levels of heterozygosity and polymorphism, comparable to or exceeding those of its parental breeds. Comparative analysis between polytocous and monotocous DHS identified reproduction-associated genes, including MUC1, PLCB4, SIN3A, and ELAVL2, enriched in pathways such as ovarian steroidogenesis, insulin secretion, and circadian entrainment. Furthermore, genome-wide association study (GWAS) identified 140 significant loci (p < 10^-5) associated with reproductive traits. From these, 10 candidate SNPs were selected for validation through single-marker association analysis in 200 DHS individuals, among which two loci-g.88680390 C>A (SLC24A2/MLLT3) and g.18197516 T>C (ABCA1)-showed significant correlations with litter size. These findings enhance our understanding of the genetic basis of prolificacy in DHS and provide valuable molecular markers for genomic selection in sheep-breeding programs.