Journal of Advanced Veterinary and Animal Research最新文献

Objective: Embryo vitrification facilitates multiple ovulation and embryo transfer (MOET) application in the sheep industry through the storage and transfer of genetically superior embryos. This study assessed the survival rate of vitrified embryos following direct transfer under field conditions.

Materials and methods: Thirty-five donors and 46 recipient ewes were synchronized for estrus using two injections of Cloprostenol. Superovulation was induced with 25 mg porcine follicle-stimulating hormone per donor twice daily for 4 days. Recipients were treated with 250 IU of pregnant mare serum gonadotrophin during the second injection of cloprostenol to ensure ovulation. Estrus donors were mated with rams. Embryos were collected on day 6 post-mating using a modified inguinal laparotomy and graded. Grade 1 embryos were vitrified in a medium containing tissue culture medium 199, 10% ethylene glycol, 10% dimethyl sulfoxide, and 0.5M sucrose and stored in liquid nitrogen. Following thawing, embryos were directly transferred to recipients through an open-pulled straw following an inguinal laparotomy. Sixteen recipients were treated with 20 µg Gonadorelin immediately after embryo transfer.

Results: Onset and duration of estrus in donor and recipient ewes were 30.2 ± 0.8, 27.9 ± 0.6, and 33.7 ± 0.4, 27.50 ± 0.42 h, respectively. Corpora lutea number and recovered embryos/donor were 8.47 ± 0.68 and 6.93 ± 0.57, respectively. 85.7% of donors responded to superovulation treatment, and the embryo recovery rate was 82.5%. Grade 1 embryos per donor (5.5 ± 0.8) were significantly higher (p < 0.05) than all other grades. Pregnancy rates in recipients treated with Gonadotrophin-releasing hormone (GnRH) and without GnRH treatment were 62.5% and 56.6%, respectively. The respective lambing rates were 80% and 76.5%.

Conclusion: These findings indicate the potential on-farm application of direct transfer of vitrified embryos in facilitating a MOET program for genetic improvement of sheep in Bangladesh.

Objective: This work aimed to develop Montanide-based inactivated duck plague (DP) vaccines from field isolates in Bangladesh and to evaluate the safety, potency, and efficacy.

Materials and methods: Suspected DP samples such as liver, spleen, trachea, and so on (N = 211) were collected from Netrokona, Mymensingh, and Kishoreganj districts. Duck plague virus (DPV) was identified through PCR and characterized by partial sequencing. Following pathogenicity tests in ducklings, the vaccine candidate virus was propagated in embryonated duck eggs and inactivated with 0.2% formalin to formulate 45% Montanide ISA 78 VG and ISA 71 VG-based vaccines. Formulated vaccines were administered following safety tests to G1 and G2, whereas G3 received 1X phosphate buffer saline. Blood samples were collected, and antibody titers were measured using an ELISA kit for up to 6 months. A challenge study was conducted to determine the potency of vaccines.

Results: The prevalence rate was 65.40% (138/211) of DPV-suspected samples, where Netrokona, Mymensingh, and Kishoreganj were 67.81% (59/87), 64.61% (42/65), and 62.71% (37/59), respectively. The pathogenicity test revealed significant morbidity and mortality in ducklings. Two formulated vaccines comply with the safety criteria in ducklings. In the challenge study, both vaccinated groups (G-1, G-2) achieved 88.89% protection against the virulent DP virus, whereas the control group exhibited 93.33% mortality. The antibody titer measured by ELISA peaked at 21 days and remained till 180 days post-vaccination, which showed a 0.1% (p < 0.001) level of significance.

Conclusion: After 6 months of vaccination, the Montanide ISA 78 VG-based vaccine showed slightly higher immunogenicity than ISA 71, though both were demonstrated to be safe against the DP virus.

Objective: This experiment explored the plausible effects of Ganoderma lucidum polysaccharides (GLP) to reduce the deterioration effects of heat stress (HS) in growing rabbits by studying blood physiology, growth, immunity, inflammation, and organ structure.

Materials and methods: Growing male rabbits (n = 160) were divided into 4 groups and fed a basal diet containing 0 (GLP0), 100 (GLP100), 250 (GLP250), and 400 (GLP400) mg of GLP/kg diet under tropical environmental conditions for 8 weeks. Growth, blood indices, redox state, immune markers, and histology of the liver and kidney were assessed.

Results: The addition of GLP (100-400 mg/kg diet) significantly improved the growth indices and reduced the value of the feed conversion ratio (FCR) compared to the GLP0 group (p < 0.05). The liver enzymes, cytochrome C and caspase-3, were significantly decreased by GLP supplementation, while it significantly improved IgG and IgM compared to the control group (p < 0.05). Adding 250 or 400 mg of GLP significantly improved antioxidant enzymes and reduced oxidative stress markers compared to other groups (p < 0.001). Supplementing diets with GLP up to 400 mg/kg diet had lower pro-inflammatory cytokines and greater IL-10 compared to stressed rabbits in the GLP0 group (p < 0.001). The renal and lung tissues were supported by the supplementation of GLP to the stressed rabbit diets.

Conclusion: Overall, adding GLP to the diet can be recommended as an effective intervention to alleviate the adverse influences of HS. It enhances growth indices, maintains organ histology, boosts immunity, and reduces pro-inflammatory cytokines and apoptotic biomarkers.

Objective: This study examines the neuroprotective and anticonvulsant effects of quercetin on pentylenetetrazol (PTZ)-induced convulsive seizures in chicks.

Materials and methods: Sixty Ross broiler chicks were randomly assigned to six groups: a negative control, a positive control treated with PTZ at 80 mg/kg, a diazepam-treated group (5 mg/kg), and three quercetin-treated groups receiving 50, 100, and 200 mg/kg orally for six consecutive days, respectively. Two hours after the final dose, PTZ was administered to groups 3-6 to induce seizures. The onset of convulsions and mortality rates were recorded over a period of 3 h. Brain tissue was collected to determine biochemical parameters, malondialdehyde (MDA), total antioxidant capacity (TAO-C), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF- α).

Results: The delay in the onset of convulsions and survival improvement were found in quercetin pretreatment, in a dose-dependent manner. The highly significant survival was found at 200 mg/kg (p < 0.001), and moderately at 50 and 100 mg/kg (p < 0.05). MDA (p < 0.05) and TNF- α (p < 0.01) levels were significantly decreased at all doses. TAO-C levels were significantly elevated, while IL-1β levels declined at 200 mg/kg (p < 0.05).

Conclusion: Quercetin pretreatment at 200 mg/kg showed antioxidant and anti-inflammatory potential against PTZ-induced convulsive seizure as a preventive therapy for epilepsy management.

Objective: To compare the structural and functional variations in the Photorhabdus insect-related B (pirB) genes of selected bacterial species such as Photorhabdus luminescens, Xenorhabdus doucetiae, and Vibrio parahaemolyticus.

Materials and methods: The study implemented phylogenetic analysis, three-dimensional (3D) structural modelling, and functional motif analysis of the pirB gene of three bacterial genera. Inferred evolutionary relationships as well as functional and structural differences were drawn based on the generated topology of the Neighbor-Joining (NJ) Tree and genetic analysis of protein sequences, domain structures, and functional motifs.

Results: Phylogenetic analysis and NJ tree topology revealed close evolutionary affinity of Photorhabdus spp. and Xenorhabdus spp. This is possibly due to their known shared ecological niche as insect pathogens and nematode symbionts. In contrast, the known shrimp pathogen, V. parahaemolyticus remarkably showed significant divergence and clustered out from the clade of Photorhabdus and Xenorhabdus. This can be attributed to the adaptive changes in a marine environment, since V. parahaemolyticus is a known marine bacterium. The constructed 3D protein structures of pirB exhibited conserved transmembrane helices essential for membrane interaction. Species-specific adaptation was also evident in the generated pirB 3D model of V. parahaemolyticus. A unique structural element that confers resistance to environmental stresses was also observed. Analysis of functional motifs depicted evolutionary conservation in membrane interaction domains. Species-specific variations that may reflect adaptations to different host environments and pathogenic strategies were also predominant.

Conclusion: The study provided valuable insights into the structure, function, and evolution of the pirB gene of three examined bacterial genera. This can be linked to evolutionary and selective pressures that led to the current pathogenicity of the pirB gene, with potential applications in public health, pharmaceuticals, agriculture, and fisheries.

Objective: Morphometric measurement is essential in the determination of breeding program zones that need to be improved.

Materials and methods: This research aims to compare the precision of morphometric measurement to linear models, such as regression analysis and machine learning methods, such as Random Forest (RF), to improve the precision of live weight estimation in animal breeding programs. A total of 228 rabbits were used in the current study, and they comprised the following breeds:39 Satin, 40 Rex, 40 New Zealand White, 29 Hyla, 40 Hycole, and 40 Reza were utilized for the study. Each rabbit was measured on body weight, head (width and length), chest circumference, body length, and hip width. Stepwise regression and linear regression analyses were conducted using the lm function in R version 4.4.1. For the RF algorithm, the caret and randomForest packages were utilized to build and evaluate the model.

Results: In this study, linear regression [R-squared value of 0.82 and an Root Mean Squared error (RMSE) of 300.16] outperformed RF (R-squared value of 0.8 and an RMSE of 326.37) in predicting rabbit body weight based on morphometric measurements. The results showed that chest circumference and body length were the most influential predictors, with the largest coefficients and highest significance levels, and the IncNodePurity illustration showed head length (IncNodePurity: 19388974) emerged as an important factor in predicting body weight.

Conclusion: The Linear regression model showed superior results compared to the RF model in predicting rabbit body weight based on morphometric measurements.

Objective: There is a particular lack of studies on the immune response of camels to cold stress conditions. The present study aimed, therefore, at the ex vivo investigation of the effect of a sudden decline in ambient temperature on some phenotypic and functional immunological parameters in camels.

Materials and methods: Using flow cytometry and antibody staining, leukocyte composition, distribution of lymphocyte subsets, and the expression of some cell activation markers were analyzed in camels under normal temperatures and a few days following a sudden environmental temperature decrease. In addition, phagocytosis activity and capacity of neutrophils and monocytes incubated ex vivo with Zymosan A Bioparticles or Staphylococcus aureus were comparatively investigated before and after cold exposure of the camels.

Results: Exposure of the camels to low ambient temperatures resulted in a significant increase in the total white blood cell count and the absolute counts of neutrophils and lymphocytes. On the other hand, the decrease in monocyte counts after cold exposure resulted in a decreased lymphocyte-to-monocyte ratio. In addition, ex vivo analysis of phagocytosis and activation marker expression revealed reduced phagocytosis activity and capacity, as well as the downregulation of the activation markers CD44 and lymphocyte function-associated antigen 1 on leukocytes from the camels after cold exposure.

Conclusion: The current study identified a significant impact of exposure to low ambient temperatures on the distribution of leukocyte subpopulations in camel blood. In addition, ex vivo analysis of phagocytosis revealed the impaired innate antimicrobial function of phagocytes in camels under cold stress. The underlying mechanisms for the observed effects of cold stress on the camel's immune system and their clinical significance for camel health remain to be elucidated in further studies.

Objective: The study assessed the anthelmintic activity of Artemisia absinthium ethanolic extract for controlling gastrointestinal nematodes in goats, both in vitro using infective larvae and in vivo in naturally infected goats under free-grazing conditions in the region of Ayacucho, Peru.

Materials and methods: For the in vitro assay, a larval motility inhibition test was performed on Trichostrongylus spp. infective larvae from goats using three different dilutions: 150, 175, and 200 mg/ml of the plant extract. In vivo efficacy was evaluated through the fecal egg count reduction test (FECRT), which was applied to 15 naturally infected Creole goats in one community. Animals were randomly assigned to 3 experimental groups and treated orally with 600 mg/kg of the plant extract. Fecal samples were collected directly from the rectum on days 0 (pre-treatment) and 7 and 15 post-treatment for egg count analysis.

Results: In vitro results showed the highest inhibition of larval motility (81.79%) and larvicidal efficacy (82.2%) at the highest extract concentration (200 mg/ml). However, the in vivo results indicated that A. absinthium, at the concentration used, did not exhibit any significant effect on the FECRT.

Conclusion: Although A. absinthium showed promising in vitro anthelmintic effects, the extract failed to demonstrate significant efficacy in vivo at the tested dose. Additionally, continuous monitoring of drugs in the region of study is strongly recommended based on the results obtained for albendazole.

Objectives: We investigated the effect of different incorporations of Acacia mearnsii forage (AM) in maize silage or A. mearnsii tannin extract (AME) in pellets on dairy rumen CH₄.

Materials and methods: Using a completely randomized design per experiment, 24 crossbred Holstein-Friesian and Jersey dairy cows per experiment were divided into groups (n = 6 cows per experiment). Dairy cows were fed pellets with 0% (0PEL), 0.75% (0.75PEL), 1.5% (1.5PEL), or 3.0% (3PEL) of AME (Experiment 1). Furthermore, dairy cows were fed 0% (0AM), 5% (5AM), 15% (15AM), or 25% (25AM) of AM in maize silage (Experiment 2). Data sampling period (21 days) of ruminal CH₄ and nitrogen (N₂), carbon dioxide (CO₂), and hydrogen (H₂) gases (% vol) was conducted after the adaptation period (14 days) for each experiment.

Results: Enteric CH₄ was not affected by AME inclusion, but AM inclusions affected CH_4, except for CH₄ (% vol per cow per day). The inclusions of 25AM decreased CH₄ per nutrient intake (kg/day), such as dry matter (DM), organic matter (OM), crude protein, acid detergent fiber (ADF), and neutral detergent fiber (NDF). In addition, there was a linear and quadratic AM inclusion effect on CH₄ per intake of nutrients, including DM, NDF, ADF, and OM.

Conclusion: Enteric CH₄ was not affected by AME but was decreased by AM in dairy cows.

Objectives: The objective of this study was to evaluate the effects of genotypes on semen quality and fertility of Murrah, Nili-Ravi, and Bangladeshi indigenous buffalo bulls.

Materials and methods: Fresh semen was collected from pure Murrah, Nili-Ravi, and indigenous buffalo bulls. Sperm concentration, motility, morphology, kinematics, and dose/ejaculation were assessed by a computer-assisted sperm analyzer. Fresh semen was cryopreserved, and post-thaw semen quality and fertility were evaluated. The hypoosmotic swelling test (HOST) was used to evaluate plasma membrane integrity.

Results: Indigenous bulls produce a lower volume of semen but exhibit higher total motility than Murrah and Nili-Ravi bulls. After cryopreservation, the post-thaw motility remains consistent, except for significant motility losses observed in Nili-Ravi bulls. Nili-Ravi bulls also showed a higher incidence of bent and coiled tails, while indigenous bulls exhibited significantly lower percentages of distal droplets than the others. Static sperm have significantly smaller head width, head elongation, and head area, and higher tail straightness than motile and progressively motile sperm. Fresh indigenous bull sperm have higher average path velocity, straight linear velocity, curvilinear velocity, and linearity than others. The Nili-Ravi bull has significantly lower HOST-positive sperm than others in fresh and post-thaw conditions. Genotypes did not exhibit any significant differences in dose/ejaculation and fertility rate.

Conclusion: Indigenous bulls exhibit superior semen quality in motility, plasma membrane integrity, and post-thaw viability compared to Murrah and Nili-Ravi bulls. Additionally, the higher progressive motility and improved kinematic properties observed in indigenous bulls may have contributed to their higher fertility rates. However, no significant differences in fertility outcomes were found among the genotypes, suggesting that all three genotypes performed similarly in terms of fertility through artificial insemination (AI), at least under on-station conditions. Further research needs to be carried out to evaluate AI efficiency and fertility rate under on-farm conditions.