Veterinary World最新文献

Background and aim: Foot-and-mouth disease (FMD) is a highly contagious transboundary livestock disease that poses serious economic and food security threats. In Indonesia, recurrent outbreaks since 2022 have highlighted the urgent need for localized vaccines to ensure sustainable control. Inactivation is a critical step in the development of inactivated FMD vaccines. While formaldehyde (FA) and binary ethylenimine (BEI) have been used individually or in combination for virus inactivation, their efficacy against new outbreak strains requires reevaluation. This study aimed to determine the optimal FA-BEI concentration and incubation time for inactivating the FMD virus (FMDV) Gresik sample no.12 (GR12) strain, isolated during the third outbreak in Gresik, East Java.

Materials and methods: FMDV serotype O GR12 was propagated in baby hamster kidney (BHK-21) cells, with titers determined by tissue culture infectious dose (TCID₅₀). Four FA-BEI formulations were evaluated: F1 (0.04% FA + 2 mM BEI), F2 (0.1% FA + 1 mM BEI), F3 (0.1% FA + 2 mM BEI), and F4 (0.2% FA + 1 mM BEI). Inactivation was conducted at 37°C with sampling at 24, 48, and 72 h. Validation was performed through three sequential blind passages on BHK-21 monolayers, and cytopathic effects (CPEs) were scored and statistically analyzed.

Results: FMDV GR12 propagated successfully in BHK-21 cells with titers of approximately 1.9 × 10⁸ TCID₅₀/mL. All FA-BEI combinations reduced CPE formation at 48 and 72 h; however, only F4 (0.2% FA + 1 mM BEI) achieved complete inactivation, showing no CPE across all passages after 72 h. Increasing BEI concentration alone did not significantly enhance inactivation. Statistical analysis confirmed that F4 was significantly more effective (p < 0.05) than other formulations.

Conclusion: The combination of 0.2% FA and 1 mM BEI at 37°C for 72 h effectively inactivated FMDV GR12, establishing a baseline protocol for strain-specific inactivation in Indonesia. This study underscores the necessity of tailoring inactivation strategies to emerging FMDV strains and provides a practical foundation for localized vaccine production. Limitations include reliance solely on CPE validation; future studies should assess antigenic integrity and immunogenicity of inactivated viral proteins to ensure vaccine efficacy.

Background and aim: Cow's milk allergy (CMA) is one of the most common food allergies, particularly in infants and young children, caused mainly by β-lactoglobulin (β-LG) and caseins. Conventional methods to reduce milk allergenicity, including heat and pressure treatments, often compromise nutritional quality or lack industrial feasibility. Safe, natural approaches to allergen reduction are essential for both food safety and One Health perspectives, as CMA contributes to nutritional deficiencies and impacts global health. This study aimed to isolate and characterize proteolytic lactic acid bacteria (LAB) from Chinese dairy products and fermented foods, evaluate their ability to degrade major cow's milk allergens, and assess their probiotic and safety profiles for application in hypoallergenic dairy products.

Materials and methods: Seventy-six LAB isolates were obtained from dairy and fermented foods and screened for proteolytic activity using skim milk agar and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The most active isolates were identified by phenotypic characterization and 16S ribosomal RNA sequencing. Probiotic potential was evaluated through in vitro gastrointestinal tolerance, bile salt hydrolase (BSH) activity, antimicrobial activity, and antibiotic susceptibility. Safety was assessed through hemolytic activity and screening for virulence-associated genes.

Results: Seventy isolates exhibited proteolytic activity, of which 7 (S30, S44, S46, S52, S63, S67, and S76) showed strong hydrolysis of β-LG and β-casein. These were identified as Streptococcus thermophilus, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus rhamnosus, and Lactobacillus paracasei. Notably, L. rhamnosus S46 achieved complete degradation of β-LG while maintaining high survival (>83%) under simulated gastrointestinal conditions, with BSH activity and broad antimicrobial effects. Most isolates lacked virulence genes and hemolytic activity, except L. paracasei S67.

Conclusion: Proteolytic LAB strains, particularly L. rhamnosus S46 and L. plantarum S52, exhibited strong allergen-degrading activity, probiotic potential, and safety profiles, supporting their application in hypoallergenic dairy production. From a food safety and One Health perspective, these strains represent natural, functional alternatives for reducing milk allergenicity, improving consumer health, and supporting sustainable dairy innovation. However, in vivo validation and pilot-scale trials in real dairy systems are necessary to confirm industrial feasibility and consumer acceptance.

Background and aim: Mercury (hydrargyrum, Hg) exposure poses significant risks to human, animal, and environmental health due to its persistence and toxicity. Conventional chelating agents, though effective, are limited by adverse side effects and reduced efficacy in chronic exposure. Phosvitin (PSV), a highly phosphorylated protein from egg yolk with strong metal-binding capacity, offers potential as a natural detoxifying agent. This study aimed to evaluate, for the first time in vivo, the chelating efficacy of egg yolk-derived PSV against Hg toxicity in rats.

Materials and methods: PSV was isolated from Isa Brown hen egg yolks through ethanol precipitation and characterized for purity and antioxidant activity using Fourier Transform Infrared Spectroscopy, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis, Kjeldahl analysis, and the 2,2-diphenyl-1-picrylhydrazyl assay. Twenty-five male rats were exposed to Hg-contaminated fish feed (0.17 ppm for 14 days) and subsequently treated with commercial or isolated PSV at 10, 20, or 30 ppm for 4 weeks. Hematological indices, liver and kidney histopathology, and Hg accumulation in brain tissue were assessed. Data were analyzed using R software (v4.4.0), with p < 0.05 considered statistically significant.

Results: The isolated PSV exhibited moderate antioxidant activity, comparable to that of commercial standards, with a purity of 51.68%. Hg exposure significantly increased white blood cell (WBC) and basophil counts, indicating immune activation. PSV administration, particularly at 20 ppm, markedly reduced WBC and basophil levels, reflecting immunomodulatory activity. Histopathological analysis revealed reduced hepatic necrosis and milder liver damage in treated groups, with modest improvement in renal structure, though not statistically significant. Brain analysis showed decreased Hg accumulation in the 10 and 20 ppm PSV groups, while the 30 ppm group exhibited inconsistent effects.

Conclusion: Egg yolk-derived PSV, especially at 20 ppm, effectively mitigated Hg-induced hematological, hepatic, and neural toxicity, supporting its role as a safe natural chelator. These findings highlight its potential as a dietary intervention in Hg-exposed populations. Optimization of extraction methods, larger-scale studies, and long-term safety assessments are needed to advance its translational application in toxicology and public health.

Background and aim: Insect-derived proteins are gaining attention as sustainable pet food ingredients, but the use of cricket protein hydrolysate (CPH) in canine diets remains underexplored. This study evaluated the effects of CPH on diet palatability, physiological responses, and antioxidant potential for shelf-life extension in commercial dog food.

Materials and methods: Thirty-two healthy adult dogs were assigned to four diets containing 0%, 2%, 4%, or 6% CPH for a 30-day feeding trial. Palatability was assessed through a two-bowl preference test, while biochemical, hematological, and fecal parameters were measured pre- and post-trial. Antioxidant efficacy was evaluated by monitoring acid value (AV) and peroxide value (PV) during accelerated storage (55°C for 46 days, simulating 12 months). Nutritional adequacy was confirmed through proximate and amino acid analysis.

Results: The 2% CPH diet significantly improved palatability, with a 57% increase in intake compared to control (p < 0.05), whereas higher inclusions (4% and 6%) reduced acceptance due to bitterness from hydrophobic peptides. All health parameters remained within reference ranges, though the 6% CPH diet lowered serum glucose (87.0 vs. 112.0 mg/dL; p < 0.001) and increased blood urea nitrogen (11.0 mg/dL; p = 0.0023). Antioxidant activity increased with CPH level, with 6% CPH reducing PV by 33% after 46 days (p < 0.05). CPH lacked certain essential amino acids, notably tryptophan, requiring complementary protein supplementation.

Conclusion: CPH is a multifunctional ingredient that can enhance palatability and oxidative stability in dog diets at moderate inclusion (2%). High inclusion levels improve antioxidant capacity but may impair sensory acceptance and alter metabolic markers. Long-term safety, allergenicity, and flavor-masking strategies warrant further study.

Background and aim: Pregnancy induces significant anatomical and physiological changes, many of which are regulated by the autonomic nervous system (ANS). Heart rate variability (HRV) is a well-established non-invasive tool for assessing ANS activity. While changes in heart rate (HR) and HRV during the third-trimester of equine pregnancy are documented, there is limited understanding of cardiac autonomic adaptations during the early stages of gestation. This study aimed to compare HR and time-domain HRV parameters between healthy non-pregnant mares and those in the first and second trimesters of pregnancy.

Materials and methods: A total of 45 Thai native crossbred mares were enrolled and divided into three groups: Non-pregnant (n = 5), first-trimester pregnant (0-114 days; n = 18), and second-trimester pregnant (115-226 days; n = 22). All mares were clinically healthy and free from cardiac abnormalities. Electrocardiographic data were collected using a Holter electrocardiogram system over a 15 min period at rest, and HRV was analyzed using time-domain measures: Standard deviation of all NN intervals (SDNN), SDNN index, root mean square of successive differences, standard deviation of 5-min mean NN intervals, percentage of successive NN intervals >50 ms, and vasovagal tonus index (VVTI). Data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests.

Results: HR was significantly higher in first-trimester pregnant mares compared to non-pregnant mares (p < 0.05), and even higher in the second-trimester compared to the first (p < 0.05). However, there were no significant differences among the groups in any of the HRV parameters or VVTI.

Conclusion: The findings indicate that cardiovascular adaptation during early pregnancy in mares is characterized by a progressive increase in HR, likely reflecting increased cardiac output to support fetal development. However, the lack of significant changes in time-domain HRV parameters and VVTI suggests that ANS balance is maintained during the first and second trimesters. These results provide valuable reference values for equine reproductive monitoring and contribute to a better understanding of physiological changes in early gestation.

Background and aim: Accurate prediction of body weight (BW) in goats is vital for breeding, feeding, drug administration, and marketing decisions, particularly in resource-limited farming systems where weighing scales are often unavailable. Traditional regression models have been applied but are limited by multicollinearity and non-linearity in body measurement data. This study aimed to evaluate the predictive performance of two machine learning (ML) approaches - Classification and Regression Trees (CART) and Multivariate Adaptive Regression Splines (MARS) - for estimating BW in non-descript indigenous goats across birth, weaning, and yearling stages, compared with stepwise regression models.

Materials and methods: A total of 100 goats were assessed at three growth stages: Birth (24 h), weaning (4 months), and yearling (12 months). Linear body measurements, body length (BL), sternum height, heart girth (HG), rump height, and withers height, were recorded alongside BW. Correlation analyses, stepwise regression, CART, and MARS models were developed. Model performance was evaluated using the coefficient of determination (R²), Pearson's correlation coefficient (r), Akaike information criterion (AIC), and relative root mean square error (RMSE).

Results: BW showed strong positive correlations with HG and BL across all stages, while associations varied with other morphometric traits. Stepwise regression models exhibited lower predictive power, as indicated by reduced R^² values and higher RMSE and AIC scores. In contrast, ML approaches demonstrated superior accuracy. CART consistently outperformed MARS, with R² values of 0.87, 0.94, and 0.99 at birth, weaning, and yearling, respectively. CART also exhibited the highest r values (up to 0.99) and lowest RMSE across training and test datasets.

Conclusion: ML techniques, particularly CART, provide robust and reliable prediction of BW in non-descript indigenous goats, surpassing conventional regression methods. These approaches can guide practical herd management decisions, including optimized feed allocation, drug dosage, and breeding selection, especially in resource-limited settings. While the study underscores CART's effectiveness, further validation with larger datasets and additional morphometric traits is recommended to enhance generalizability.

Background and aim: Brucellosis remains a globally significant zoonotic disease with significant public health and economic implications. While domestic pigs are absent in Iraq due to religious restrictions, wild pigs (Sus scrofa) represent a potential reservoir for zoonotic pathogens, including Brucella suis. Despite this, no prior investigations have assessed the prevalence of swine brucellosis in Iraq. This study aimed to (i) determine the seroprevalence of brucellosis in wild pigs using enzyme-linked immunosorbent assay (ELISA), (ii) evaluate associated risk factors such as age, sex, and region, and (iii) confirm infection and characterize isolates through molecular detection and phylogenetic analysis.

Materials and methods: Between September 2022 and January 2024, venous blood samples (n = 42) from recently killed wild pigs in Wasit province were analyzed. Sera were screened using ELISA, while DNA was extracted and tested with conventional polymerase chain reaction (PCR) and quantitative real-time PCR (qPCR) targeting the 16S ribosomal RNA gene. Positive isolates were sequenced and compared to reference strains in GenBank using phylogenetic analysis. Statistical associations with risk factors were assessed using odds ratios and relative risk.

Results: ELISA detected anti-Brucella antibodies in 54.76% of samples, with mild (39.13%), moderate (34.78%), and severe (26.09%) infections. Molecular assays revealed B. suis DNA in 33.33% of samples by PCR and 45.24% by qPCR. Seropositivity was significantly higher in pigs aged 2-4 years (73.33%) compared with <2 years (38.1%) and >4 years (66.67%) (p < 0.05). Female pigs exhibited a higher prevalence (57.58%) than males (44.44%), and animals from Al-Numaniyah showed the highest rates (73.68%). Phylogenetic analysis revealed 98.87%-99.76% similarity with Indian B. suis strains (MF173089.1), characterized by minor nucleotide variations.

Conclusion: This study provides the first molecular evidence of B. suis in wild pigs in Iraq, underscoring their role as potential reservoirs for zoonotic transmission. The findings highlight the importance of integrating molecular diagnostics with serology for accurate surveillance. Strengthening One Health strategies, including wildlife monitoring, biosecurity, and public health education, is critical to preventing spillover to domestic animals and humans. Further large-scale investigations are warranted to better characterize the epidemiology of swine brucellosis in the region.

Background and aim: Leptospirosis is a globally neglected zoonosis caused by pathogenic spirochetes of the genus Leptospira. It affects a wide range of animals and poses serious public and veterinary health risks. Backyard cattle systems, common across Latin America, are particularly vulnerable due to poor biosecurity and close animal-human-wildlife interfaces. This study assessed the seroprevalence, spatial distribution, and risk factors associated with Leptospira infection in backyard cattle herds of central Chiapas, Mexico.

Materials and methods: A cross-sectional study was conducted from January to September 2022 across five municipalities. A total of 590 serum samples were collected and analyzed using the microscopic agglutination test with six serovars. The geographical coordinates of production units (PUs) were recorded using a Global Positioning System (GPS), and spatial analysis was conducted with ArcGIS 10.5. Risk factor associations were evaluated through Chi-square tests and multivariate logistic regression using RStudio and Statistical Package for the Social Sciences software.

Results: The overall seroprevalence of Leptospira was 27.72% (95% confidence interval [CI]: 23.97%-31.75%), with the Portland Vere serovar being predominant (22.89%). Cintalapa exhibited the highest municipal seroprevalence (61.75%; odds ratio [OR] = 6.2). Logistic regression identified significant risk factors for seropositivity, including artificial insemination (OR = 2.43), use of Jagüey reservoirs (OR = 0.47), and cattle aged 3 years (OR = 0.54) or 8 years (OR = 1.98). The American Swiss × Holstein crossbreed was significantly associated with increased seroprevalence (OR = 3.15). The presence of dogs within PUs was significantly associated with Portland Vere seropositivity (OR = 3.82), highlighting a possible role in disease transmission.

Conclusion: This study highlights a high burden of Leptospira interrogans serovar Canicola Portland Vere in backyard cattle of central Chiapas. Key risk factors include specific breeding methods, water sources, age, and breed. The integration of serological surveillance, spatial mapping, and statistical modeling proved effective in identifying epidemiological hotspots and informing future One Health-based prevention strategies. The findings emphasize the need for enhanced disease surveillance, targeted control programs, and public health interventions tailored to small-scale cattle systems in tropical regions.

Background and aim: Enhancing poultry reproductive performance is essential for improving productivity and addressing protein shortages in developing regions. Yoruba ecotype chickens (YECs) are resilient but limited in commercial potential due to small body size and low egg yield. This study assessed the fertilizing potential of YEC × Sussex (SS) crossbred cocks by integrating conventional reproductive morphometrics with seminal plasma metabolite profiling to identify potential biomarkers of sperm quality.

Materials and methods: Thirty 24-week-old YEC × SS cocks (2842.86 ± 137.33 g) were evaluated over 28 days. Semen was collected through abdominal massage, and semen volume, sperm concentration, and testosterone levels (enzyme-linked immunosorbent assay) were recorded. Testicular and epididymal morphometrics, densities, and sperm reserves were measured. Seminal plasma metabolites were analyzed using high-performance liquid chromatography-mass spectrometry. Pearson correlations and linear regression models were applied to predict testosterone concentration from semen and morphometric traits.

Results: The left testis was heavier (8.00 g) and larger in volume (12.77 mL) than the right (6.75 g; 1.35 mL). Spermatozoa reserves averaged 0.20 × 10⁹, with a strong positive correlation with testis volume (r = 0.998, p < 0.01) and a moderate negative correlation with daily sperm production (r = -0.585, p < 0.01). Testosterone concentration prediction from live weight, semen volume, and sperm concentration achieved high accuracy (R² = 0.829). Thirteen seminal plasma metabolites were identified, including ascorbic acid, quercetin, epicatechin, citric acid, and procyanidin B2 - compounds linked to antioxidant defense, energy metabolism, and sperm viability.

Conclusion: YEC × SS crossbred cocks exhibit favorable reproductive morphometrics, strong correlations between testis volume and sperm reserves, and a metabolite profile enriched in fertility-enhancing antioxidants. Predictive models using basic semen traits can reliably estimate testosterone levels, while identified metabolites have potential as biochemical markers for breeding selection. Integrating morphometric and metabolomic profiling can refine breeding strategies, improve artificial insemination outcomes, and enhance the genetic improvement of local poultry breeds.

Background and aim: Stallion sexual behavior during semen collection can be influenced by multiple factors, yet the role of sexual arousal intensity remains underexplored. Understanding how arousal modulates behavioral and physiological reproductive traits is essential for improving artificial insemination (AI) efficiency and semen quality. This study aimed to evaluate the effects of sexual arousal intensity, age, origin, and semen collection method on stallion sexual behavior and the quality of fresh and frozen semen.

Materials and methods: Thirteen Arabian stallions (7 Tunisian, 6 foreign parentage) aged 6-20 years (total ejaculates = 49) were assessed during semen collection using either a dummy or an estrous mare. Sexual arousal intensity was scored on a four-point scale (- to +++). Behavioral responses, mounting and erection parameters, and semen traits were recorded. Fresh semen was evaluated for volume, motility, concentration, and morphology; frozen semen was assessed for motility, viability, membrane integrity, and abnormalities. Data were analyzed using multifactorial analysis of variance with significance at p < 0.05.

Results: High arousal (+++) increased vocalizations, anogenital sniffing, and Flehmen responses (p < 0.05) but prolonged preparation time (p = 0.05). Low arousal (-/+) prolonged full erection duration (p < 0.01) and improved sperm motility in fresh and frozen semen (p < 0.01). Stallions of foreign origin exhibited higher fresh semen motility (p < 0.01) but required longer preparation and collection times (p < 0.05). The estrous mare method improved fresh semen motility and concentration (p < 0.05) but did not affect frozen semen traits. Younger stallions produced larger semen volumes, but had higher abnormal sperm counts in fresh samples, whereas older stallions showed more abnormalities post-freezing (p < 0.01).

Conclusion: Sexual arousal intensity significantly modulates both behavioral and semen quality parameters in stallions. Lower arousal is associated with prolonged erection and superior sperm motility, suggesting dissociation between behavioral excitement and physiological semen traits. Collection from an estrous mare can enhance fresh semen motility, though the dummy remains safer for handlers. These findings highlight the importance of tailoring semen collection protocols to individual stallion profiles to optimize AI outcomes.