Background and Aim: Chitosan-based DNA nanoparticles have emerged as a promising next-generation platform for veterinary vaccines, addressing several limitations of conventional attenuated, inactivated, and recombinant formulations. Chitosan is a biodegradable, biocompatible, and low toxicity polymer with mucoadhesive properties that enhance cellular uptake and protect nucleic acids from enzymatic degradation. These characteristics make it an attractive candidate for delivering plasmid DNA encoding viral antigens across diverse animal species. Recent advances demonstrate that chitosan–DNA nanoparticles can induce robust humoral and cellular immune responses, stimulate mucosal immunity, and achieve high levels of protection in terrestrial livestock, poultry, fish, and crustaceans. A wide range of viral pathogens has been targeted using this approach, including Foot-and-Mouth disease virus, Newcastle disease virus, infectious bronchitis virus, spring viremia of carp virus, white spot syndrome virus, and infectious pancreatic necrosis virus. Depending on the species and formulation strategy, nanoparticles have been successfully administered intranasally, intramuscularly, intraperitoneally, or orally, highlighting their versatility for mass vaccination in both terrestrial and aquatic systems. Reported protection rates range from 60% to 100% in mammalian and avian models, while oral nanoparticle vaccines in shrimp and fish have demonstrated sustained immune activation and survival benefits. The ability to incorporate genetic adjuvants, such as cytosine-phosphate-guanine motifs, cytokines, or complement fragments, further enhances the immunogenicity of these platforms. Despite these promising results, several challenges remain. Most studies use small laboratory animals or controlled experimental settings, and data from large-scale field trials in cattle, pigs, and equines remain scarce. The stability of nanoparticle formulations during long-term storage, the scalability of manufacturing processes, and the standardization of dosing regimens require further investigation. Overall, chitosan–DNA nanoparticles represent a safe, flexible, and rapidly adaptable vaccine carrier system with significant potential to transform veterinary immunization. Their capacity to elicit mucosal and systemic immunity, enable needle-free delivery, and support DIVA-compatible vaccine design positions them as a valuable tool for controlling emerging and re-emerging viral diseases in the context of One Health.
Betaine has been proposed as a low-cost source of methyl groups in poultry feed, replacing methionine and choline. The present study aimed to investigate the effect of betaine on growth performance, methionine metabolism, and methyl transfer in broilers aged 1 to 21 days fed a low-methionine diet. A total of 960 one-day-old male broilers were randomly divided into four groups: positive control (0.62% methionine in the diet), negative control (0.37% methionine in the diet), and two treatment groups (0.37% methionine in the diet plus either 1500 or 3000 mg betaine/kg diet). Chicks fed the 1500 mg betaine/kg diet had the highest feed-to-gain ratio (P < 0.05), but no significant difference in final body weight, average daily gain, average daily feed intake, or mortality. Serum S-adenosyl-L-methionine and total homocysteine were higher at 1500 mg betaine/kg diet; whereas serum S-adenosylhomocysteine exhibited the opposite trend. Except for DNA methyltransferase 1, key enzymes and metabolites involved in the hepatic single-carbon pathway showed the highest levels at 1500 mg betaine/kg diet and declined thereafter. Furthermore, betaine promoted dose-dependent mRNA and protein expression of enzymes involved in the hepatic single-carbon metabolic cycle and methyl transferase pathways in chicks fed methionine-deficient diets. In conclusion, while the addition of betaine did not significantly improve the growth performance of chicks aged 1–21 days, inclusion of 1500 mg betaine/kg diet effectively stabilized methionine metabolism and methyl transfer in methionine-deficient diets.
Infectious bursal disease virus (IBDV) causes infectious bursal disease in poultry and poses a major challenge to the poultry industry globally. This study aimed to measure seroprevalences and so detect exposure to IBDV in backyard poultry in the selected zone of Horro Guduru Wollega. A cross-sectional study was conducted from January 2021 to November 2022. Blood samples were collected for serum extraction from 384 backyard chickens in the Horro and Horro Bulluq districts. IBDV antibody detection was conducted using an indirect ELISA serological diagnostic test. Questionnaires assessed poultry owners’ knowledge and health/hygiene management practices regarding the disease. The over all seroprevalence of IBDV was 14.84%. Significant variations in seroprevalence were seen based on district, bird age, bird sex, and flock size. Limited owner experience (just 1-3 years), disposing of carcasses in pits, and poor hygiene on the backyard premises were associated with higher IBDV seroprevalence. In conclusion, IBDV seroprevalence was linked to chicken management practices. Recommendations include improving poultry management among owners to control IBDV. The study indicates backyard poultry in the region have considerable IBDV exposure, and control should focus on improving management practices identified as high-risk, such as pit disposal of carcasses and poor hygiene.
Olivia Brabant, Yuliya V. Karpievitch, Yuliya V. Karpievitch
et al.
Respiratory disease in cattle is a significant global concern, yet current diagnostic methods are limited, and there is a lack of crush-side tests for detecting active disease. To address this gap, we propose utilizing electrical impedance tomography (EIT), a non-invasive imaging technique that provides real-time visualization of lung ventilation dynamics. The study included adult cattle from farms in Western Australia. The cattle were restrained in a crush. A standardized respiratory scoring system, which combined visual, auscultation, and clinical scores, was conducted by two non-conferring clinicians for each animal. The scores were blinded and averaged. During assessment, an EIT electrode belt was placed around the thorax. EIT recordings of ten suitable breaths were taken for analysis before the cattle were released back to the herd. Based on the combined examination scoring, the cattle were categorized as having healthy or diseased lungs. To allow visual interpretation of each breath and enable the creation of the quartile ventilation ratio (VQR), Flow/Tidal Impedance Variation curves (F/TIV) were generated for each breath. The analysis focused on two EIT variables: The novel VQR over time during inhalation and exhalation and global expiratory impedance (TIVEXP) adjusted by breath length. A mixed effects model was used to compare these variables between healthy and diseased cattle. Ten adult cattle of mixed ages were used in the current analysis. Five cattle were scored as healthy and five as diseased. There was a significant difference in the examination scores between the healthy and diseased group (P = 0.03). A significant difference in VQR during inhalation (P = 0.03) was observed between the healthy and diseased groups. No difference was seen in VQR over time during exhalation (P = 0.3). The TIVEXP was not different between groups (P = 0.36). In this study, EIT was able to detect differences in inhalation mechanics when comparing healthy and diseased cattle as defined via clinical examination, highlighting the clinical utility of EIT.
Prolactin is essential for mammary gland development and lactation. Progesterone also induces ductal branching and alveolar formation via initial secretory differentiation within the mammary gland. Herein, we aimed to evaluate the role of progesterone as a prolactin substitute for the production of cell-cultured milk components in MAC-T cells. Cells were treated with various hormones such as prolactin (PRL), progesterone (P4), 17β-estradiol (E2), cortisol (COR), and insulin (INS) for 5 d. MAC-T cells cultured in a P4 differentiation media (2500 ng/mL of P4, 25 ng/mL of E2, 25 ng/mL of COR, and 25 ng/mL of INS) showed similar levels of E74-like factor 5 (Elf5) and milk component synthesis (<i>α</i>-casein, <i>β</i>-casein, <i>α</i>-lactalbumin, β-lactoglobulin, and triglycerides) compared to those cultured in a PRL differentiation media (5000 ng/mL of PRL, 500 ng/mL of CORT, and 50 ng/mL of INS). The levels of <i>α</i>-casein and triglycerides in the optimal P4 differentiation media were present at comparable levels to those in the PRL differentiation media. Our results demonstrated that P4 induces the activation of Elf5 and the synthesis of milk components in MAC-T cells, similar to PRL. Therefore, P4 may be used as an effective substitute of PRL for cell-cultured milk production in in vitro frameworks.
Oguzhan Kahraman, Fatma Inal, Huzur Derya Arık
et al.
This study aimed to determine the effects of kefir addition on dry matter (DM), organic matter (OM) and protein apparent digestibility, faecal characteristics, haematology, and biochemistry parameters of healthy dogs. Twenty-one adult Golden Retriever dogs were divided into three groups: Control (CON, no kefir), KF1 (2 × 106 CFU/g kefir), and KF2 (4 × 106 CFU/g kefir). The dogs were fed for a 30-day administration period. Blood was taken from all dogs on the initial (day 0) and last day (day 30). Stool consistency of the dogs were scored according to 1–5 system (1 = diarrhea-like, 5 = formed and too dry) on the last five days before taking fresh faecal samples to determine digestibility, short-chain fatty acids (SCFA), ammonia, pH and DM levels. The highest DM, OM and protein digestibility levels were determined in KF2 (p < 0.05). Kefir addition improved the faecal scores of KF1 and KF2 (p < 0.05). Faecal pH was lower in KF2 than CON (p < 0.001). The lowest faecal ammonia levels were found in KF1 and KF2 (p < 0.001). Increased faecal acetic and total SCFA levels were detected in the kefir groups, and KF2 had the highest propionic acid level (p < 0.05). The lowest cholesterol level was determined in KF2, and the lowest triglyceride levels were determined in KF1 and KF2 on the 30th day (p < 0.05). A significant decrease in cholesterol, triglyceride, and creatinine was detected to the KF2 dog’s first and last day (p < 0.05). Blood MCHC was affected by kefir in KF2 (p < 0.05). These results indicated that 2–4 gr of kefir had positive effects on nutrient digestibility, colon fermentation, stool consistency, and the blood parameters of dogs.Highlights Kefir is a traditional dairy product with multiple probiotic characteristics that boosts the immunity and overall gastrointestinal health of animals. In a study involving 21 dogs, dietary supplementation of kefir improved protein digestibility of food and reduced serum cholesterol and triglyceride levels. Kefir reduced faecal ammonia and increased SCFAs. Kefir could be further developed as a functional dietary food supplement to improve the quality of life of dogs.
Marc Orts‐Porcar, Alejandro Ororbia, Caroline Fina
et al.
Abstract Background Oesophageal pneumatosis (OP) is defined as the presence of gas within the oesophageal wall. The description of this condition in veterinary medicine is currently lacking. The pathogenesis of alimentary tract pneumatosis remains unclear. Current literature describes that access of gas into the oesophageal wall may occur by one or a combination of the following mechanisms: mucosal disruption, increased intra or extra‐luminal pressure or dissection of gas from an extra‐oesophageal source. Objectives The aim of this multi‐centric case series was to describe the computed tomography (CT) findings of OP in dogs. Methods Three adult dogs were included. One dog presented with gastrointestinal signs and general malaise while the other two presented with spontaneous facial and cervical subcutaneous emphysema. Results CT revealed different degrees of intramural gas along the oesophageal wall in all cases. The first dog was diagnosed with emphysematous gastritis based on the presence of gastric pneumatosis paired with compatible clinicopathological and endoscopic findings. This dog was successfully treated with antibiotics. The remaining two dogs were diagnosed with spontaneous pneumomediastinum and required no surgical or medical treatment. Conclusions In all cases with OP, there was concurrent gastric pneumatosis. Gas extensively and circumferentially distributed with a banded shape along the oesophageal wall was present in patients with presumed mural gas dissection because of pneumomediastinum. Conversely, a focal and mild amount of mural gas with a tubular shape was identified in the distal segment of the oesophagus in the patient with emphysematous gastritis.
ABSTRACT: Feed evaluation models (FEM) are a core part in dairy cow feeding. As these models are developed using different biological and mathematical approaches mainly tested in a research context, their abilities to predict production in commercial farms need to be validated, even more so when they are used outside the context of their development. Four FEM—National Research Council, 2001 (NRC_2001); Cornell Net Carbohydrate and Protein System, 2015 (CNCPS); NorFor, 2011; and INRA, 2018 (INRA_2018)—were evaluated on their abilities to predict daily milk protein yield (MPY) of 541 cows from 23 dairy herds in the province of Québec, Canada. The effects of cow and diet characteristics were tested on the residuals of MPY. Sensitivity and uncertainty analyses were then performed to evaluate the influence of the uncertainty of the main characteristics of cows and feed ingredients measured on the farm and used in the 4 FEM on the predictions of metabolizable protein (MP) supply and MPY. The 4 models had acceptable predictions of MPY, with concordance correlation coefficients (CCC) ranging from 0.75 to 0.82 and total bias ranging from 12.8% to 19.3% of the observed mean. The Scandinavian model NorFor had the best predictions with a CCC of 0.82, whereas the 3 other models had similar CCC at 0.75 to 0.76. The INRA_2018 and NRC_2001 models presented strong central tendency biases. Removing herd effect put the 4 FEM at the same level of performance, with 11.9 to 12.4% error. Analyzing model behavior within a herd seems to partly negate the effect of using predicted dry matter intake (DMI) in the comparison of models. Diet energy density, days in milk, and MPY estimated breeding value were related to the residual in the 4 models, and Lys and Met (as percent of MP) only in NRC_2001 and NorFor. This suggests that inclusion of these factors in these models would improve MPY predictions. From the sensitivity analysis, for the 4 FEM, DMI and factors affecting its prediction had the greatest influence on the predictions of MP supply and MPY. Of the feed ingredients, forage composition had the greatest effect on these predictions, including a strong effect of legume proportion with NorFor. Diet acid detergent fiber concentration had a very strong effect on MP supply and MPY predictions only in INRA_2018, because of its effect on organic matter digestibility estimation. The range of predictions of MP supply and MPY when combining all these potential uncertainties varied depending on the models. The INRA_2018 model presented the lowest standard deviation (SD) and NorFor the highest SD for the predictions of both MP supply and MPY. Overall, despite the fact that FEM were developed in a research context, their use in a commercial context yields acceptable predictions, with NorFor yielding the best predictions overall, although within-herd responses varied similarly for the 4 tested models.
Summary: While the effects of stocking density on broiler welfare and performance have been extensively and regularly studied as genetics and production models have evolved, feeder space recommendations has received less attention. Most feeder space data for broilers dates from the 1950’s and 1960’s, with relatively few assessments since, targeting market weights below 2.5 kg. This study examined live performance and yield in broilers reared to 56 d as influenced by provision of three feeder space allocations: 2.3 (nominal), 4.6, and 6.9 cm/bird. BW was significantly improved during the starter and grower phases as feeder space increased (P < 0.0001 and P = 0.0066, respectively); BW gain and feed consumption likewise improved in the starter phase (P < 0.0001 and P = 0.0002, respectively). Effects on live performance diminished in the finisher and withdrawal phases, however overall feed conversion ratio was significantly lower for 2.3 cm/bird when compared to 4.6 cm/bird (0.03 f:g, P = 0.0198). No significant differences were observed for carcass weight or yield, however abdominal fat weights and yield were reduced for 4.6 cm/bird as compared to 2.3 cm/bird (P = 0.012 and P = 0.016, respectively). The data herein illustrates that feeder space allowance affects broiler performance, particularly in early life. Expanded feeder space allowance during early life allows broilers to maximize productivity during this period, yet these effects appear to diminish in regards to BW and may be detrimental to overall feed conversion ratio. Further research is warranted to ascertain optimal expanded feeding space and duration during early life in commercial broilers.
Natapol Pumipuntu, Suphang Kulpeanprasit, Sirijan Santajit
et al.
Background: Staphylococcus aureus is one of the most important contagious bacteria causing subclinical bovine mastitis. This bacterial infection is commonly identified by determine the pathogen in bovine milk samples through conventional technique including coagulase test. However, this test has several disadvantages as low sensitivity, risk of biohazard, cost expensive, and limited preparation especially in local area.
Aim: Aim of this study was to compare and assess the screening method, Mannitol fermentation test (Mannitol salt agar [MSA]), and deoxyribonuclease (DNase) test, for S. aureus identification in milk samples.
Materials and Methods: A total of 224 subclinical bovine mastitis milk samples were collected from four provinces of Thailand and determined S. aureus using conventional method and also subjected to the screening test, MSA and DNase test. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) among both tests were analyzed and compared to the tube coagulase test (TCT), as reference method. Immunological test by latex agglutination and molecular assay by determined spa gene were also used to identify and differentiate S. aureus.
Results: A total of 130 staphylococci were isolated by selective media, Gram-stain, and catalase test. The number of S. aureus which identified using TCT, MSA and DNase test were 32, 102, and 74 isolates, respectively. All TCT results were correlated to results of latex agglutination and spa gene which were 32 S. aureus. MSA showed 100% sensitivity, 28.57% specificity, 31.37% PPV, and 100% NPV, whereas DNase showed 53.13% sensitivity, 41.84% specificity, 22.97% PPV, and 73.21% NPV. DNase test showed higher specificity value than MSA but the test presented 26.79% false negative results whereas no false-negative result from MSA when comparing to TCT.
Conclusion: MSA had a tendency to be a good preference for screening S. aureus because of its high sensitivity and NPV. The result from this study will improve a choice to use a screening test to diagnose S. aureus of veterinary field for prompt disease controlling and effective treatment.
Market failures are the main cause of poor acknowledgement of the true impact of functional sheep traits on the management and economic performance of farms, which results in their omission from the breeding goal or the estimation of non-representative economic weights in the breeding goal. Consequently, stated-preference non-market valuation techniques, which recently emerged to mitigate these problems, are necessary to estimate economic weights for functional traits. The purpose of this paper is to present an example of the use of a choice experiment (CE) in the estimation of economic weights for sheep traits for the design of breeding goals. Through a questionnaire survey the preferences of sheep farmers are recorded and their marginal willingness to pay (MWTP) for 10 production and functional traits is estimated. Data are analysed using random parameter logit models. The results reveal unobserved preference heterogeneity for fertility, adaptability to grazing and resistance to disease, thus highlighting that these traits are appreciated differently by farmers, because their needs are diverse. Positive MWTP is found for Greek breeds, high milk production and lambs with low fat deposition, for which there is high demand in Greek markets. On the other hand, MWTP for the cheese-making ability of milk is negative, stemming from the fact that sheep milk prices in Greece are not formulated according to milk composition. In addition, farmers seem to understand differences between udder shapes and attribute different values to various types. This application of the CE method indicates that communication channels among farmers and breeders should be established in order to enhance market performance and to provide orientation to the design of breeding programmes. Non-market valuation can be used complementarily to market valuation techniques, in order to provide accurate estimates for production and functional traits.
The term `sacrifice' is used by experimental biologists to describe methods for killing laboratory specimens. In Western societies, `sacrifice' usually connotes a process of `making sacred', a process Durkheim and his followers interpreted as a ritual transformation between `profane' and `sacred' realms. This paper examines whether `sacrifice' in the experimental context bears any relation to such traditional usage, or whether, as animal rights advocates argue, the term is no more than a euphemism for brutal and unnecessary slaughter. Drawing on ethnographic observations of laboratory practice, the paper argues that `sacrifice' means much more than simply killing a specimen, and that the violence done to the animal victim is part of a systematic `consecration' of its body to transform it into a bearer of transcendental significances. While scientists do not treat their practices as ceremonial rituals endowed with religious meaning, laboratory `sacrifice' is a part of a sequence of procedures through which the naturalistic animal body is transformed into an abstracted analytic object with generalized significance for members of the research community.
Background: The main goal of the present study was to set up an axenic cultivation of Acanthamoeba and assess the pathogenic ability of T4 genotypes from different clinical and environmental strains of Acanthamoeba using two physical assays.
Methods: Sixteen Acanthamoeba isolates including 10 environmental and 6 clinical strains were cul-tured axenically. Axenic cultivation was performed using Proteosepepton, yeast extract and glucose medium and TY-I-S33culture. Pathogenic survey was done using osmotolerance and thermotoler-ance assay. Briefly, differentosmolarity (0.5 M and 1 M) of non-nutrient agar plates were performed. One hundred fiftyμl of axenic culture were collected and were inoculated in 1% agar medium. For thermotolerance assay 150 μl of amoebas from axenic culture were divided into fresh culture me-diums. Cultures were incubated at 37oC and 42 oC. All plates were monitored for 24 h, 48 h and 72 h.
Results: Overall, 16 strains of Acanthamoeba isolates previously genotyped as T4 were cultivated axenically after several months. Thermotolerance and osmotolerance assay revealed that all of clinical strains, soil and animal feces strains were highly pathogenic isolates. Two dust and water strains did not grow at high temperature (42 oC) and osmolarity (1.5 M) and thus they were classified as weak pathogens.
Conclusion: Most of T4 genotypes are highly pathogenic organisms. This is an important finding since Acanthamoeba belonging to T4 type is the predominate genotype in environmental and clinical samples. The presence of highly pathogenic Acanthamoeba may pose a risk within susceptible people
The causative agents of respiratory diseases of turkeys represent, primarily in fattening farms, a substantial risk of economic and breeding problems. The purpose of this communication is to provide information on the prevalence of respiratory agents of turkeys and chickens in several fattening and production farms in Southern Moravia. This study was focused on pathogens causing bacterial diseases such as Ornithobacteriosis and Mycoplasmosis, as well as viral rhinotracheitis and laryngotracheitis of poultry. The laboratory diagnosis of these diseases has been performed in our institute since January 2008. We examined 249 samples of turkeys and chickens from a single rearing house and six fattening farms in Southern Moravia. The samples were examined using the PCR or RT-PCR method. The typing of isolates of Ornithobacterium rhinotracheale was done using the M13 fingerprinting method. We established the prevalence of pathogens such as Ornithobacterium rhinotracheale (ORT), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), avian metapneumovirus (aMPV) and laryngotracheitis virus (ILT) in selected farms.