Research in veterinary science最新文献

Feline Leukemia Virus is a retrovirus causing fatal disease in domestic cats. While FeLV has been controlled in many countries, it remains a major concern in Latin American countries. This study conducted an epidemiological survey of FeLV in 182 Chilean domestic cats using PCR to detect provirus infection. The results were analysed using Multivariate Logistic Regression to examine risk factors associated with FeLV detection. The FeLV prevalence was 54.95 %, and statistically significant associations (p < 0.05) were found for two protective factors and one risk factor. Cats from Concepcion city (95 %CI 0.08–0.56 %) and cats sampled in 2022 (95 %CI 0.1–0.06 %) had lower odds ratios for provirus positivity, whereas non-vaccinated cats (95 %CI 2.3–15.8 %) had an increased odds ratio. No other factors were statistically significant. The high FeLV prevalence is similar to other Latin American countries and the geographical differences highlighted in this study likely correspond to the socioeconomic status of the owners. This study highlights the need for improved FeLV control measures such as promoting FeLV vaccination, implementing health screening prior to adoption of new cats, and educating owners about FeLV to control its circulation.

Bitter melon (Momordica charantia) has several biological properties including anthelmintic activity. Presented in vivo study evaluated the anthelmintic activity of the hydroalcoholic extract of M. charantia Presented in vivo study (HEMC) and its effect on animal performance, carcass characteristics and lamb meat quality in animals infected by Haemonchus contortus. The HEMC demonstrated effectiveness against the parasite. Lambs treated with HEMC showed a significant reduction in egg count per gram of faeces and in the number of parasites in the abomasum. However, nutrient intake decreased with increasing doses of HEMC, leading to reductions in final live weight and carcass weight. No significant effects were observed on meat quality. Therefore, it is concluded that HEMC presents anthelmintic action, but it also impairs animal performance, highlighting the need to assess the benefits and impacts of HEMC use for H. contortus control.

Human dirofilariasis is an emerging vector-borne zoonotic parasitic disease in India. Humans are accidental hosts. Symptomatic dirofilariasis, although uncommon is typically manifested in humans as pulmonary, ocular, or subcutaneous nodules. The present research reports the prevalence of the species, Dirofilaria sp. hongkongensis among the dog population in the Kani tribal settlements within the Agasthyamala Biosphere Reserve located at the southernmost end of the Western Ghats, Kerala. To study the prevalence, we conducted a random blood survey among the dog population in these tribal settlements in Thiruvananthapuram. Whole blood was collected from stray and domesticated animals. Genomic DNA was extracted and the microfilariae in the blood were characterized using the slide smear and COI-based marker specific to nematodes. After processing the data from the Sanger sequencer using BLAST, the sequences were submitted to GenBank. Over 25 % of dogs were found positive for Dirofilaria sp. hongkongensis, which is genetically identical to the strain causing human dirofilariasis as is shown by the phylogenetic analysis. The study reveals that the Kani tribes, who reside in deep forests, are particularly vulnerable to this strain of Dirofilaria sp. hongkongensis. Human case reports of this specific strain have been recorded in Kerala over the past decade. The effective elimination is ultimately impacted by a lack of knowledge regarding the mosquito vectors. Dirofilariasis in dogs and humans is on the rise, which demands both active disease surveillance and proper treatment.

Cryopreservation of porcine spermatozoa is detrimental due to their high sensitivity to cold shock, leading to changes akin to capacitation, known as cryocapacitation. These changes, including the acrosomal reaction, hypermotility induction, and protein phosphorylation, might be influenced by the presence of progesterone in seminal plasma and egg yolk, used in most freezing extenders. We tested the effect of various progesterone concentrations added to the freezing extenders (1, 10, and 100 μg/mL). At 100 μg/mL, progesterone decreased the proportion of straightness and tended to reduce viability and the proportion of progressive motility (p < 0.1). At 10 μg/mL, it increased reacted acrosomes in dead sperm (p < 0.05), protein phosphorylation rate (p < 0.05), and tended (p < 0.1) to enhance linear movement compared to the control. To counteract the capacitating effect of progesterone, we examined the effect of antiprogesterone mifepristone (RU 486) at concentrations of 5, 10, 20, 50, 100, and 200 μM, and co-incubated 10 μM of RU 486 with 10 μg/mL of progesterone. RU 486 maintained capacitation levels and motility parameters similar to the control, although high concentrations (100 μM) tended (p = 0.152) to increase protein phosphorylation. Co-incubation reduced the acrosome reaction in dead sperm, and RU 486 appeared to prevent hypermotility stabilizing motility and viability parameters compared to samples with progesterone alone. Protein phosphorylation increased and RU 486 could not restore capacitation to control levels due to its competitive antagonism for progesterone receptors, having less affinity than progesterone, which displaces RU 486 at high concentrations, allowing normal sperm capacitation.

Cow-calf systems represent a significant research area in animal husbandry, with differences depending on the final product (meat or milk). This study aimed to apply text mining and topic analysis on literature describing cow-calf systems in European, American, and Brazilian beef and dairy sectors between 1998 and 2023. Additionally, cow-calf contact (CCC) literature data was manually extracted. Our findings revealed the presence of 11 research areas among literature on cow-calf systems, with different priorities identified in the beef and dairy sectors. Beef industry mainly focused on animal proficiency and nutrition, while dairy on animal welfare and CCC, which showed a growing trend as emerging research topic, mostly in the EU. Current debates around calf welfare and EU's planned animal welfare legislation revision appeared to be driving the increasing interest in this topic. Studies in the beef sector were mainly localized in Brazil, showing that research in different contexts and species is important for CCC implementation. Manual data extraction showed considerable variation in the retained CCC documents regarding sample size, type of contact, methods and CCC duration. Learning about the varied CCC approaches used in beef and dairy farms in different locations, concentrating on their strengths and weaknesses, will help to develop novel solutions to global challenges. Adopting validated and robust indicators would help scientists and policymakers to monitor the system's quality. To improve CCC feasibility, match consumer demands, and move towards One Welfare and One Health, future research should focus on a variety of situations to overcome the current shortcomings.

The effectiveness of a visceral leishmaniasis (VL) control strategy based on the application of 4 % deltamethrin impregnated collars (DIC) exclusively in seropositive dogs was assessed between 2018 and 2019, through a prospective study. The effectiveness of DIC-collaring was evaluated by comparing the incidence rate of anti-leishmanial antibodies among dogs from two endemic districts in Brazil. In one of the areas, the conventional control measure which is based on the non-compulsory euthanasia of LV seropositive dogs, was practiced by the official healthy service as a regular procedure, whereas strategic collaring, conceived in this study, was carried out in the other. Results of serological tests applied to serum samples collected from all domiciled dogs were evaluated in three consecutive times, spaced by around 200 days. Incidence rates of VL seroreactivity were compared between districts in the same period of time as well as within the same district, in consecutive periods. Based on the results, the risk of infection in the population under conventional control measure was up to four times higher than the risk of infection where DIC-collaring was used. The strategic use of collar proposed here emerged as a promising measure for VL control in dogs from endemic areas. Strategic collaring does not rely on the euthanasia of infected animals, an extremely controversial procedure, and instead of being used in all dogs, as collaring is normally recommended; only seropositive dogs are intervened. Strategic use of DIC has the potential to drastically reduce costs, if compared to mass collaring canine population.

Although diphtheria is a vaccine-preventable disease, numerous cases are still reported around the world, as well as outbreaks in countries, including European ones. Species of the Corynebacterium diphtheriae complex are potentially toxigenic and, therefore, must be considered given the possible consequences, such as the circulation of clones and transmission of antimicrobial resistance and virulence genes. Recently, Corynebacterium rouxii was characterized and included among the valid species of the complex. Therefore, two cases of C. rouxii infection arising from infections in domestic animals are presented here. We provide molecular characterization, phylogenetic analyses, genome sequencing, and CRISPR-Cas analyses to contribute to a better understanding of the molecular bases, pathogenesis, and epidemiological monitoring of this species, which is still little studied. We confirmed its taxonomic position with genome sequencing and in silico analysis and identified the ST-918 for both strains. The clinical isolates were sensitive resistance to benzylpenicillin and rifampin. Antimicrobial resistance genes, including tetB, rpoB2, and rbpA genes, were predicted. The bla and ampC genes were not found. Several virulence factors were also detected, including adhesion, iron uptake systems, gene regulation (dtxR), and post-translational modification (MdbA). Finally, one prophage and the Type I-E CRISPR-Cas system were identified.

Neospora caninum (N. caninum) is a protozoan parasite that poses a serious risk to livestock by infecting various domestic and wild animals. Loop-Mediated Isothermal Amplification (LAMP) offers a cost-effective, highly sensitive, and specific method for detecting protozoan parasites. This study aims to develop a precise, rapid, and visually assessable colorimetric LAMP method, improving on traditional techniques. We employed a rigorous screening process to identify the optimal primer set for this experiment. Subsequently, we fine-tuned the LAMP reaction at 65 °C for 40 min with 270 μmol/L neutral red. We then confirmed the specificity of primers for N. caninum through experimental validation. The LAMP method demonstrated a lower detection limit compared to traditional Polymerase Chain Reaction (PCR) techniques. While LAMP offers clear advantages, the prevalence of DNA detected in 89 sheep serum and 59 bovine serum samples using the nested PCR method was 3.37 % (3/89) and 1.69 % (1/59), respectively. In contrast, when the LAMP method was employed, the prevalence of detected DNA rose to 5.61 % (5/89) for sheep and 3.38 % (2 /59) for bovine. A comparison of two molecular assays using the intragroup correlation coefficient (ICC) resulted in a value of 0.999 (95 % CI: 0.993–0.996, p < 0.001), indicating the LAMP method is in the “better” range according to James Lee's categorization. The LAMP technique, optimized with specific primers of N. caninum and neutral red dye, not only exhibited higher sensitivity but also provided convenience over conventional PCR methods, highlighting its potential for on-site applications and cost-effective field detection.

With increasing demand for improved protein-rich food, diverse poultry birds like turkey are gaining popularity in India. However, with the rising concerns of antibiotic residues and drug resistance, safe alternatives like formic acid (FA) and thymol (TH) have attracted the attention of researchers as effective replacer of antibiotic growth promoters (AGP). This experiment investigated the effects of combinations of FA and TH on growth performance, immunity, gut microflora and jejunal microstructures in turkey. A total of 240 turkey poults were reared in 6 treatment groups for a period of 16 weeks with standard management and feeding: T1 (basal diet only); T2 (AGP); T3 ([email protected] ml + TH@240 mg/kg); T4 ([email protected] ml + TH@360 mg/kg); T5 ([email protected] ml + TH@240 mg/kg) and T6 ([email protected] ml + TH@360 mg/kg). The results revealed that T5 group had the highest final body weight and best FCR while the feed consumption across the groups was comparable. The immune status of the turkey improved (p ≤ 0.05) in treatment groups compared to control with T4 and T5 group showcasing the best CBH response, antibody titres and relative immune organ weight index. A significant improvement (p ≤ 0.05) in jejunal microstructures was observed at 16th week in T5 group over control and AGP fed group. There was significant (p ≤ 0.001) reduction in total plate and coliform counts, but a positive shift was seen in Lactobacillus population in T5 group as compared to control and AGP fed group. In conclusion, the concoction of formic acid (7.5 ml/kg) + thymol (240 mg/kg) in-feed supplement improved the performance, immune status and gut health in turkey as an efficient alternative to AGPs.

Despite the diagnostic capacity of ultrasonography (US) in cases of bovine enzootic hematuria (BEH), it has been underused in the medical clinic for ruminants. Studies comparing ultrasound findings in healthy animals (HA) with subclinical (SCH) and clinical (CH) BEH are scarce in the literature. As a result, the present work aims to describe the US findings of cattle at different stages of BEH evolution, evaluating the diagnostic capacity and precocity of the technique. The study was carried out on five rural properties in the municipalities of Rio Preto and Bom Jardim de Minas – MG, Brazil, using 46 dairy cattle, females over 18 months of age, evaluated and classified as G1/CH, G2/SCH and G3/HA, according to history, clinical examination and urinalysis, with subsequent ultrasound analysis of the bladder. The mean bladder wall thickness was 36.50 mm in G1/CH, 33.53 mm in G2/SCH and 37.93 mm in G3/HA. Irregular walls were observed in 53.33 % (8/15) of G1/CH, 27 0.78 % (5/18) of G2/SCH and 38.46 % (5/13) of G3/HA. Loss of the architecture of the urothelium layers was observed in 53.33 % (8/15) of G1/CH, 33.33 % (6/18) of G2/SCH and 38.46 % (5/13) of G3/HA. Multifocal and Grade I lesion were the most common. Ultrasonography allowed the identification of lesions in 38.46 % of animals that did not present hematuria and in 33.33 % of animals that presented occult blood and proved to be an efficient technique for detecting pre-clinical cases of BEH, allowing easy identification. and early onset of BEH cases.