Veterinary Sciences最新文献

Dietary fiber (DF) is a fundamental component of animal nutrition and has been widely studied for its nutritional and physiological functions in animals. While existing studies mainly focus on the independent effects of DF on gut microbiota or bile acids (BAs), the mechanisms underlying their interactions remain poorly understood. DF interacts closely with gut microbiota, promoting the production of beneficial metabolites such as short-chain fatty acids, which subsequently influence BA metabolism through microbial deconjugation and dehydroxylation processes, generating free and secondary BA essential for host health. Together, the gut microbiota and BA play key roles in mediating the effects of DF on intestinal and systemic physiology via the gut-liver axis. Although DF contributes to energy supply, nutrient digestion, and regulation of gut microbiota and BA metabolism, its physiological effects vary depending on fiber source, type, chemical composition, inclusion level, and animal species. Ruminant and non-ruminant animals differ in their capacity to utilize DF, with extensive fermentation occurring in the rumen of ruminants, whereas fermentation in non-ruminants mainly occurs in the hindgut and is more limited. Consequently, inappropriate DF supplementation may impair gastrointestinal function and overall physiological status. This review summarizes the diverse effects of different DF types in animals and critically examines the complex and bidirectional interactions among DF, gut microbiota, and BA metabolism, highlighting knowledge gaps that require further investigation to optimize DF application in animal nutrition.

Reproductive efficiency in female cattle is significantly influenced by micronutrient status, particularly the availability and balance of essential trace minerals. Selenium, copper, zinc, cobalt, and iron serve as critical components of enzymatic systems, antioxidant defense networks, hormone synthesis, and cellular metabolism, collectively sustaining reproductive health. This review integrates current research evidence on the physiological functions and molecular mechanisms through which these five trace minerals regulate reproductive performance in female cattle, with a specific focus on iron-an often overlooked element-highlighting the novelty of this synthesis. Both deficiency and excess of these minerals impair key reproductive outcomes such as estrous cyclicity, conception rate, and embryonic survival. Furthermore, complex interactions among minerals influence their bioavailability and physiological responses. Advances in mineral supplementation strategies, particularly the application of organic minerals and precision feeding technologies, offer promising solutions to improve reproductive performance. Elucidating these interrelationships provides a theoretical foundation for optimizing trace mineral nutrition, thereby enhancing female cattle fertility, reducing metabolic disorders and promoting the sustainable development of beef and dairy industries.

Pigeon circovirus (PiCV) is an important pathogen that infects pigeons, which can induce multiple disorders such as immunosuppression and respiratory symptoms, posing a serious threat to the pigeon industry. In this study, we combined the RAA and CRISPR/Cas12a assay to establish a highly sensitive and accurate detection method for PiCV. This detection method amplifies the target nucleic acids through RAA; and the resultant dsDNA is specifically recognized by crRNA, the trans-cleavage activity of Cas12a is activated, which further cleaves the fluorescent reporter group to generate a fluorescent signal that can be visually observed under blue light. The method established in this study exhibited high sensitivity, with a minimum detection limit of 6.08 copies/µL. It showed no cross-reactivity with non-PiCV samples, demonstrating high specificity. When 40 clinical samples were tested by this method and quantitative polymerase chain reaction (qPCR) respectively, the coincidence rate was 92.5%, and the method developed herein achieved a higher positive detection rate. In conclusion, we successfully developed a rapid, on-site operable, one-step visual detection method for PiCV, which holds promising application prospects.

Giardiasis, caused by Giardia duodenalis, is a common gastrointestinal infection. This study aimed to evaluate the effects of Hedera helix leaf extract (HLE) and HLE-loaded chitosan nanoparticles (HLE-CsNPs) against Giardia duodenalis isolates from individuals with gastrointestinal issues, using an experimental rat model. Stool samples from 147 participants were analyzed for Giardia duodenalis, with positive samples further characterized by nested PCR-RFLP, revealing a 4.8% prevalence, all belonging to assemblage B. Ten groups of male albino rats were used to evaluate the antigiardial activity of various treatments. This included five non-infected groups [one untreated and four treated with HLE, HLE-CsNPs, CsNPs, and metronidazole (MTZ)] and five infected groups [one untreated and four similarly treated]. Treatment efficacy was assessed using parasite counts, intestinal histopathology, CD117 immunohistochemistry, and markers of liver and kidney function. HLE-CsNPs markedly reduced Giardia cysts by 88.8%, approaching the 99.2% reduction achieved by MTZ, while also improving intestinal architecture and reducing inflammation. Importantly, HLE and HLE-CsNPs provided superior protection for the liver and kidneys compared to MTZ. In conclusion, HLE-CsNPs exhibited significant antigiardial activity and organ protection in rats, suggesting a potential alternative treatment for Giardia duodenalis isolated from individuals with gastrointestinal issues.

Fasciola infection, which is widely distributed and has a major impact on livestock production, is emerging as a significant zoonotic parasitic disease affecting both human and animal health worldwide. The main control strategy currently relies on a limited number of anthelmintic drugs, especially benzimidazoles such as albendazole and triclabendazole. The aim of this study was to evaluate the efficacy of albendazole and triclabendazole in a sheep flock in northwestern Spain naturally infected with F. hepatica and to test fenbendazole and oxfendazole as alternative formulations. For this purpose, a faecal egg count reduction test (FECRT) was conducted applying various statistical methods based on the guidelines used for gastrointestinal nematodes. This study represents the first application of the new classification framework for F. hepatica, emphasizing the urgent need for standardized resistance detection protocols for this parasite and underlining the growing challenge of anthelmintic resistance in the treatment of fasciolosis.

The close physiological relationship between the left atrium (LA) and left ventricle (LV) suggests that an index assessing both the cardiac chambers simultaneously could provide useful information about disease severity. Consequently, investigators have proposed the atrioventricular coupling index (LACi) and demonstrated its utility in predicting the likelihood of atrial fibrillation, heart failure, and other cardiovascular events in humans. No studies have been reported in veterinary medicine. Therefore, we measured the LACi in healthy dogs and dogs affected by myxomatous mitral valve disease (MMVD). Two hundred and thirty-three dogs (105 healthy dogs and 128 dogs with MMVD) were retrospectively included in the study. The LACi (LA volume/LV volume × 100) at LV end-diastole (LACi-ED) and LV end-systole (LACi-ES) of each dog was measured using a monoplane Simpson's Method of Discs from the left apical four-chamber view. In healthy dogs, LACi-ED and LACi-ES showed no relationship with bodyweight, heart rate and age (R² < 0.03, for all variables). In MMVD dogs, LACi-ED and LACi-ES differed between ACVIM stages (p < 0.001 and p < 0.02, for all stages). The LACi-ED and LACi-ES had similar accuracy in identifying MMVD dogs with congestive heart failure (area under the curve of 0.920 and 0.906, respectively). Our data suggest that the LACi can be useful in assessing left atrioventricular function in dogs with MMVD but the diagnostic accuracy in identifying dogs with congestive heart failure was not superior to the left atrial-to-aortic ratio. Prospective studies are needed to evaluate the predictive value of this new echocardiographic index in dogs affected by MMVD.

An outbreak of mastitis caused by Staphylococcus aureus occurred in a commercial dairy goat herd during kidding season, resulting in fatal gangrenous mastitis in approximately 30% of the herd. S. aureus was recovered from milk, mammary tissue, and other organs in does subjected to necropsy. The S. aureus milk culture-positive rate among does in the hospital pen was 58.3%, while whole-herd milk cultures of clinically normal mature does identified S. aureus in 15.0% with an additional 15.0% positive for coagulase-negative Staphylococcus (CNS), yielding a total culture-positive rate of 30.0%. The prevalence of CNS in subclinical animals was consistent with previous reports from U.S. dairy goats; in contrast, S. aureus isolation rates substantially exceeded previously reported prevalences. Poor milking hygiene and milking machine dysfunction were identified as major factors contributing to the spread of the S. aureus from goat to goat. California Mastitis Test (CMT) scores were significantly higher in culture-positive does compared with culture-negative animals (p < 0.05), demonstrating the value of CMT as a practical on-farm tool for early treatment decision making. Interventions focused on addressing milking hygiene and milking machine maintenance, as well as segregation and vaccination of replacement females. S. aureus dropped to undetectable in the next two kidding seasons, whereas the CNS culture rates remained unchanged, suggesting other factors may be contributing to CNS infection. This case highlights the role of subclinical intramammary infection and milking practice factors in transmission and control of contagious mastitis pathogens like S. aureus.

Background: Microplastics (MPs) and nanoplastics (NPs) are now common in land and water ecosystems. Their spread is an increasing issue from a One Health perspective. These particles end up in soils, water, air, and farm inputs. This poses direct risks to animal health and indirect risks to people who eat animal-derived food. There are also risks from plastic additives and pesticides migrating with these particles in animal-based food. Scope and Approach: This review summarizes how MPs and NPs move in agroecosystems and livestock production. It covers their main sources, such as agricultural plastics, sludge-amended soils, plastic-lined storage, and environmental fallout. It explains how farm animals are exposed, including through feed, water, soil contact, and inhalation. Evidence is condensed for occurrence in manure, tissues, and animal products. The review also highlights key analysis challenges, especially those limiting the assessment of nanoplastic exposure.

Key findings: Field surveys show very different contamination levels in the environment. Agricultural soils range from 0.36 to 42,960 particles/kg. Livestock indicators, like contaminated feed and manure, range from 10² to 10⁵ particles/kg. In free-roaming systems, chicken feces have very high loads, showing trophic transfer in land food chains. A pilot study found plastic particles in pig and cow blood, suggesting some particles cross the gut into the blood. Experimental models link MPs/NPs to oxidative stress, inflammation, mitochondrial dysfunction, metabolic disturbance, and potential reproductive toxicity in livestock and poultry.

Conclusions and outlook: Animal-based foods provide a major source of human exposure. MPs and NPs have been observed in milk and poultry products, such as packaged meat and eggs (mean 11.67 ± 3.98 particles/egg). There is still a research gap on raw milk taken directly from the teat and on raw eggs that have not been handled or packaged. This gap makes it hard to identify real contamination sources and control strategies. The review stresses the need for harmonized detection methods (especially for NPs), monitoring from farm to fork, and practical ways to reduce plastic use on farms and minimize contamination during processing, feed handling, and packaging.

This study investigates the nutritional effects of a thyme meal and B. subtilis mixture on growth performance, immune function, antioxidant capacity, gene expression, and gut microbiota in heat-stressed rabbits. One hundred and twenty male New Zealand White rabbits were divided into four dietary treatments (five replicates/group). The rabbits in the first group were fed a basal diet, while the other three groups were fed a basal diet containing B. subtilis, thyme meal, and their mixture, respectively. The B. subtilis and thyme meal mixture increases the heat-stressed rabbits' body weight gain and carcass weight, and enhances nutrient digestibility and the feed conversion ratio. Supplementing the CBT mixture improved the lipid profile and liver and kidney function via decreasing plasma triglycerides, cholesterol, LDL, creatinine, urea, and AST levels, while increasing total protein and albumin levels. Furthermore, the CBT mixture enhanced the immune response and oxidative stability by increasing IgA and IgG levels, GPx enzyme activity, and SOD, while decreasing plasma MDA content. Adding the CBT mixture enhanced gut health by reducing pathogens and inflammation, as well as increasing volatile fatty acid levels and the expression of CAT-1, MUC-2, and SGLT-1 genes. The combination of a thyme meal and B. subtilis enhanced growth, immune function, antioxidant capacity, gut microbiota modification, and the expression of gut health nutrient absorption-related genes in heat-stressed rabbits.

Rabies is an acute, progressive, viral encephalitis. Warm-blooded vertebrates are susceptible. Major reservoirs reside in the Chiroptera and Carnivora. Among the latter, representatives include dogs, ferret badgers, foxes, jackals, mongooses, raccoons, and skunks. Within the Carnivora, pinnipeds represent a diverse group of >30 extant species. These marine mammals range from the Arctic to Antarctica, but there is no review about rabies in this group. Apparently, only a single 1980 case of rabies occurred from Svalbard in a ringed seal (Phoca hispida). However, in 2024, incidental cases appeared within South African Cape fur seals (Arctocephalus pusillus). Retrospective testing of archival material identified suspect cases dating back to 2022. Currently, more than 80 cases have been documented in seals. Moreover, a new 2025 focus appeared in Namibia and cases in Angola are predictable. Viral characterization supports spillover infection via rabid black-backed jackals (Lupulella mesomelas). A host shift appears likely, with ongoing seal intraspecific transmission. Given the unique nature of this epizootic, implications for the southern hemisphere abound. Unfortunately, comprehensive data are lacking on pinniped specimens examined outside of southern Africa. For example, although Antarctica is considered 'rabies-free', minimal international standards for support are unmet. No routine laboratory-based surveillance occurs. This enzootic rabies focus among seals in southern Africa presents unique challenges for the region and a rare opportunity for considering broader surveillance. Besides targeted parenteral vaccination of fur seals, local engagement involves vagrant species, including elephant (Mirounga leonina) and leopard seals (Hydrurga leptonyx). The void of regional pinniped surveillance, especially encompassing the Southern Ocean would require considerable proactive local resolution and much wider collaboration regarding future concerns to both public health and conservation biology.