Search Results (364)

This study aimed to characterize the reproductive performance of the local Algerian population (LAP) compared with the New Zealand White (NZW) rabbits, by evaluating sexual behavior, semen characteristics, and their modulation by environmental factors, namely photoperiod and temperature-humidity index (THI). Mature bucks (n = 14/breed) were monitored from January to April, with two successive ejaculates collected weekly. Sexual behavior, macroscopic and microscopic semen parameters, and testosterone concentrations were assessed. The effects of breed, ejaculate order, environmental factors, and their interactions were analyzed using Generalized Linear Mixed models. LAP and NZW bucks exhibited similar sexual behavior and blood testosterone levels (p > 0.05). Collection failures and ejaculate rejection causes were mainly clustered within specific individuals rather than being breed-dependent. However, LAP bucks showed higher sperm concentration (p = 0.01), viability (p = 0.02), and membrane integrity (p = 0.04) than NZW bucks, whereas most motility and quantitative semen traits remained comparable between breeds. Increasing photoperiod significantly improved reproductive performance (p < 0.05). Conversely, within the investigated range, THI mainly affected semen collection efficiency through increased urine contamination (p < 0.001), with limited effects on intrinsic sperm quality. Significant breed × environment interactions for sperm concentration (p = 0.03) suggested differential responsiveness between breeds, with LAP bucks showing a stronger positive response to increasing photoperiod and less pronounced variation under THI fluctuations. Overall, LAP bucks exhibited a more favorable seminal profile under the conditions of the present study, supporting the valorization of this local genetic resource for artificial insemination programs under Algerian conditions. Further studies are required to confirm these patterns under summer heat-stress conditions and evaluate their impact on fertility outcomes. Full article

This study evaluated the effects of adding zinc oxide nanoparticles (ZnNP), L-arginine (L-Arg), or a combination of both to the diets of growing rabbits to mitigate the physiological and productive consequences of heat stress. Two hundred and eighty 35-day-old New Zealand White rabbits were randomly assigned to four experimental treatments, with 70 rabbits per treatment and seven replicates (10 rabbits/replicate). The control group (Ctr) received the base diet without additives, while the diets of the other groups were fortified with arginine (L-Arg; 3 g/kg), zinc oxide nanoparticles (ZnNP; 40 mg/kg), or a combination of both (Arg-Zn). The results showed that the combined Arg-Zn significantly improved weight gain rate, feed conversion rate, carcass weight, and nutrient digestibility compared to the control group (p < 0.05). At the physiological level, we observed increased serum levels of total antioxidant capacity (T-AOC), glutathione peroxidase (GPx), superoxide dismutase (SOD), immunoglobulin G (IgG), immunoglobulin A (IgA), and triiodothyronine (T3), along with decreased levels of malondialdehyde (MDA), alanine aminotransferase (ALT), and aspartate aminotransferase (AST, p < 0.05) in Arg-Zn-fed rabbits. However, adding the Arg-Zn mixture contributed to a reduction in pathogenic bacteria counts and increased the volatile fatty acid (VFA) levels. At the molecular level, the gene expression of the inflammatory cytokines IL-6 and tumor necrosis factor alpha (TNF-α) decreased; however, the gene expression of claudins-1 (CLDN-1), cationic amino acid transporter-1 (CAT-1), mucin-2 (MUC-2), sodium-glucose co-transporter-1 (SGLT-1), and interferon gamma (IFNγ) increased (p < 0.05) in Arg-Zn-fed rabbits. These results suggest that dietary supplementation with ZnNP and L-Arg may serve as an effective nutritional strategy for improving growth performance, antioxidant status, immune function, and intestinal integrity in rabbits exposed to high ambient temperatures. Full article

Background: Hexavalent chromium (Cr(VI)) is a widespread environmental toxic heavy metal with strong oxidative properties; however, its immunotoxicity and metabolic mechanisms in rabbit spleen remain largely unclear. Methods: In this study, New Zealand rabbits were exposed to 0, 12.5, 25, and 50 mg/L Cr(VI) (as potassium dichromate, K₂Cr₂O₇) via drinking water for four weeks to investigate splenic damage and the underlying molecular pathways. Spleen pathological injury was evaluated by hematoxylin and eosin (H&E) staining, and the distribution of T cells, B cells, and macrophages was assessed by immunohistochemistry. Antioxidant enzyme activities and antioxidant substance levels were determined using ELISA, and the relative mRNA expression of immune factor genes, antioxidant-related genes, and ferroptosis-related genes was quantified by quantitative real-time PCR (qRT-PCR). In addition, the distribution of iron in splenic tissue was detected by enhanced Prussian blue staining. Results: Our results demonstrate that high-dose Cr(VI) significantly inhibited body weight gain, induced lymphocyte atrophy, vacuolization, and widening of intercellular spaces in the splenic white pulp. Furthermore, Cr(VI) reduced T and B lymphocyte populations, promoted macrophage infiltration and inflammatory cytokine gene expression in a concentration-dependent manner, impaired total antioxidant capacity, and led to a decrease in glutathione (GSH) levels in the spleen. Additionally, Cr(VI) exposure increased iron accumulation, activated the ACSL4–NOX lipid peroxidation cascade, and downregulated GPX4 expression, ultimately triggering ferroptosis. Conclusions: These findings reveal that Cr(VI) causes splenic immune injury by disrupting oxidative homeostasis and inducing ferroptosis, providing novel insights for evaluating immunotoxicity and identifying metabolic targets under Cr(VI) pollution. Full article

As the direct biosynthetic precursor of creatine, guanidinoacetic acid (GAA) exerts a pivotal regulatory role in energy homeostasis and protein metabolism. Rabbit meat has garnered increasing global recognition as a healthy food source, characterized by its outstanding high-protein and low-fat nutritional profile. Accordingly, the optimization of rabbit meat quality has attracted growing attention from both consumers and animal production practitioners. In the present study, we evaluated the impacts of dietary GAA supplementation on meat quality traits, in vivo antioxidant capacity, muscle fiber characteristics, and fatty acid metabolism in New Zealand white rabbits. A total of 960 male New Zealand white rabbits were assigned to two age groups: 40-day-old group and 60-day-old group (40 ± 2 days, 1.19 ± 0.09 kg; 60 ± 2 days, 1.82 ± 0.15 kg). Within each age group, rabbits were randomly allocated to a control diet or a diet supplemented with 100 mg/kg GAA (CON-40, GAA-40, CON-60, GAA-60). After a 45-day feeding period, two-way ANOVA revealed that GAA supplementation significantly reduced shear force (p < 0.01, diet main effect) and muscle fiber density (p < 0.01, diet main effect), with an age-dependent effect on shear force (age × diet interaction, p < 0.05). Moreover, GAA enhanced systemic antioxidant capacity, as indicated by increased serum superoxide dismutase (SOD) activity (p < 0.01) and total antioxidant capacity (T-AOC) (p < 0.05), while no significant effect on malondialdehyde (MDA) was detected under the current experimental conditions. GAA also regulated the expression of lipid metabolism-related genes (FAS, HSL, ACC) in intramuscular and perirenal fat, indicating its regulatory effect on fatty acid metabolism. In conclusion, dietary GAA supplementation improves rabbit meat tenderness and antioxidant capacity, with no negative effects on growth performance. These findings confirm that GAA has the potential to serve as a nutritional strategy to improve rabbit meat quality, supporting the development of rabbit meat as a functional food for human consumption. Full article

When placing dental implants, xenografts are most commonly used clinically to compensate for the insufficient bone volume of patients. However, xenografts have limitations including low osteoinductive capacity and prolonged healing time. This study aimed to determine whether non-thermal plasma treatment could enhance the regenerative performance of bovine cancellous bone graft (SANTA-OSS^®) in a rabbit calvarial defect model. Twenty-four adult male New Zealand white rabbits received bilateral 8 mm critical-size calvarial defects. One defect was filled with untreated SANTA-OSS (control) and the contralateral defect with plasma-treated SANTA-OSS using the ACTILINK™ Reborn device. Animals were sacrificed at 2, 4, and 8 weeks (n = 8 per group) for histomorphometric analysis. The plasma-treated group showed significantly higher new bone area (14.12 ± 0.69%, 18.93 ± 0.68%, and 32.72 ± 0.61% at 2, 4, and 8 weeks) than the control at all time points (p < 0.05). In addition, the experimental group exhibited accelerated graft resorption, larger bone marrow area, greater blood vessel area, and more TRAP-positive osteoclasts compared with the control (p < 0.05). Within the limitations of this study, non-thermal plasma treatment significantly enhanced new bone formation and promoted favorable graft remodeling, while also accelerating graft resorption, increasing bone marrow area, and improving vascularization. These findings suggest that simple chairside plasma activation can improve the regenerative performance of xenografts. Full article

This study evaluated how abutment screw preload affects peri-implant bone under vertical dynamic loading using an in vivo rabbit tibia model. Eight Japanese white rabbits received two implants in each tibia. After 8 weeks of healing, implants were assigned to a control group without abutment connection or to abutment-connected groups tightened to 35 Ncm or 70 Ncm. The abutment groups were further divided into loading and non-loading subgroups. In the loading groups, vertical dynamic loading (50 N, 3 Hz, 1800 cycles) was applied twice weekly for 4 weeks. Peri-implant bone responses were assessed by micro-computed tomography, histology, and histomorphometry. Under loading conditions, the 35 Ncm group showed significantly higher bone volume, bone-to-implant contact, and bone area fraction than the 70 Ncm group (p < 0.05). Histologically, the 35 Ncm group exhibited more continuous cortical bone and new bone formation, whereas the 70 Ncm group more frequently showed cortical discontinuity and enlarged marrow spaces. Within the limitations of this animal study, abutment screw preload influenced peri-implant bone adaptation under repeated loading, and the manufacturer-recommended torque of 35 Ncm was associated with more favorable bone parameters than the 70 Ncm condition. Full article

This paper investigates the impact of atmospheric conditions on distance determination accuracy in the VDES R-Mode system, based on system development and long-term analytical work conducted within the ORMOBASS project. A dedicated VDES R-Mode transmitter and monitoring station were developed and deployed in Poland, in the Port of Gdynia and at the boatswain’s office in the port of Jastarnia, respectively. Both stations were synchronized in time and frequency using a fiber-optic link and White Rabbit technology, ensuring high-precision and stable operation during long-term measurements. Based on a one-year stationary measurement campaign, a comprehensive dataset combining ranging results and meteorological observations was collected and analyzed. Statistical evaluation demonstrated that atmospheric conditions—particularly rainfall intensity and water vapor density—have a measurable impact on ranging accuracy. These findings motivated the development of a mathematical model describing the relationship between atmospheric conditions and distance measurement errors. The proposed logarithmic regression-based approach was validated using real measurement data; the authors also demonstrated its ability to reduce error variability during changing weather conditions, indicating its potential for future implementation in VDES R-Mode receivers. Full article

Metabolic syndrome (MetS) drives cardiac remodeling and fibrosis, contributing to diastolic dysfunction and heart failure with preserved ejection fraction, but chamber-specific mechanisms remain poorly defined. New Zealand White rabbits were fed a high-fat/high-sucrose diet for 28 weeks to induce experimental MetS. Systemic phenotype, cardiac structure (echocardiography), myocardial fibrosis (Picrosirius red histology), myosin/collagen gene expression (qRT-PCR), and chamber-specific proteomics were assessed across left/right atria and ventricles. The model reproduced central obesity, glucose intolerance, dyslipidemia, and mild hypertension, with concentric left ventricular hypertrophy and selective ventricular fibrosis, as follows: increased collagen in left ventricle (LV) and right ventricle (RV), unchanged in atria. Ventricular α-myosin heavy-chain gene expression was upregulated, while collagen I and α-smooth muscle actin transcripts showed ventricular-specific downregulation. Proteomics revealed atrial metabolic and cytoskeletal adaptations with minimal extracellular matrix involvement; ventricles displayed early profibrotic cues (galectin-3 in LV), metabolic inefficiency (impaired glycolysis/ATP production in LV; lipid oxidation shift in RV), and diminished provisional matrix support. Conclusions: concentric LV hypertrophy and great vessel enlargement occurred without systolic/diastolic dysfunction; ventricular-selective fibrosis, α-myosin heavy-chain upregulation, type I collagen/α-smooth muscle actin downregulation, and chamber-specific proteomic changes showed atrial adaptation versus ventricular early profibrotic/metabolic inefficiency. Full article

This study aims to develop and systematically evaluate a new lipid-based formulation of blueberry anthocyanins, which can accelerate the healing effect of the cornea. The study first successfully screened and optimized the formulation and preparation process for blueberry anthocyanin liposomes. Characterization via transmission electron microscopy and dynamic light scattering revealed uniformly distributed, near-spherical liposomes with distinct phospholipid bilayers. Key physicochemical parameters—particle size, zeta potential, encapsulation efficiency, and drug loading capacity—all met formulation standards. In vivo pharmacodynamic experiments demonstrated that topical administration of blueberry anthocyanin liposomes significantly accelerated the repair process and effectively mitigated depressional damage to the corneal epithelium in a New Zealand white rabbit corneal injury model induced by 10.6 μm mid-infrared CO₂ laser. In summary, the blueberry anthocyanin liposomes successfully prepared in this study exhibit excellent performance, effectively enhancing drug exposure levels in vivo and promoting corneal repair. This provides reliable experimental evidence for the development of plant natural active ingredients in ophthalmic treatments. Full article

This study aimed to investigate the effects of supplementing with an essential oil blend and ascorbic acid on performance, semen characteristics, antioxidant status, gut microbiota, immunity, and gene expression in heat-stressed male rabbits. One hundred and forty male New Zealand White rabbits, aged 6 months, were randomly distributed into four dietary groups: the control group receiving basal feed (CON), the group receiving an essential oil blend (EOB, 200 mg/kg), the group receiving ascorbic acid (ASA, 1000 mg/kg), and the group receiving an essential oil blend and ascorbic acid (MAO). The experimental period lasted for eight weeks. The MAO mixture supported rabbits’ tolerance to heat stress by enhancing stress markers, as demonstrated by decreased glucose and HSP70 and increased triiodothyronine (T3). In addition, increased body weight, carcass weight, and nutrient digestibility, but reduced mortality rate, were observed in rabbits fed the MAO mixture. Additionally, semen density and volume, as well as sperm progressive motility and normality, were enhanced in rabbits fed the MAO mixture. Furthermore, MAO mixture supplementation decreases plasma cholesterol, triglycerides, AST, urea, and creatinine levels, while raising HDL and total protein levels. Adding MAO mixture contributed to an increase in plasma SOD and GPx levels, as well as seminal fluid TAC and GSH levels. Additionally, the incorporation of MAO increases IgA, IgG, and IL-10 levels while decreasing IL-6 and TNF-α levels. Adding the MAO mixture reduced C. perfringens and E. coli, as well as increased the expression of the MUC-2, CAT-1, and CLDN-1 genes. Combining an essential oil blend and ascorbic acid may contribute to improvements in performance, semen quality, immune response, antioxidant capacity, and gut health in heat-stressed male rabbits. Full article

Background: Long-acting drug delivery strategies could augment pediatric human immunodeficiency virus (HIV) treatment effectiveness by bypassing population-specific challenges such as adherence. We harnessed pharmacokinetic (PK) modeling to develop a biodegradable, subcutaneous (SQ), reservoir-style implant for HIV treatment in 2–5-year-old children. Methods: Plasma was collected from New Zealand White rabbits over 30 h after a single intravenous (IV) bolus of bictegravir (BIC, 0.75 mg/kg), islatravir (ISL, 5 mg/kg) and/or emtricitabine (FTC, 30 mg/kg) then over a year after subcutaneous insertion of two to three implants eluting these antiretrovirals. Plasma antiretrovirals were quantified by HPLC-MS/MS and population PK models were fit to the IV PK profile to derive a mean unit impulse response (UIR). UIR was used to numerically deconvolve SQ absorption rate from the implant PK profile. SQ dosing rates were translated to pediatric plasma concentrations using published clinical PK parameters. Results: BIC, FTC, and ISL PK profiles were best described by two-compartment models. Each implant achieved quantifiable plasma concentrations for >360 days. Median SQ absorption rates (μg/day) at 3, 6 and 12 months of implantation were 116, 98 and 71 for BIC; 116, 37 and 5 for ISL; and 236, 116 and 24 for FTC. These 6-month dosing rates translated to pediatric plasma concentrations of 24 ng/mL BIC, 0.14 ng/mL ISL, and 0.7 ng/mL FTC. Conclusions: Our novel long-acting delivery platform exhibited antiretroviral SQ dosing rates for ≥6 months that are anticipated to achieve plasma concentrations in children within an efficacious range warranting further development for pediatric HIV treatment. Full article

This study evaluated the effects of heat stress on productive performance, physiology, reproduction, and oxidative status in pregnant New Zealand White (NZW) rabbit does, as well as the potential synergistic effects of curcumin and vitamin D3 (Cur + VD₃) supplementation in alleviating these stress-induced impairments. Eighty multiparous does (12–18 months old) were assigned to a 2 × 2 factorial design involving two ambient temperatures (indoor vs. outdoor) and two supplementation levels (with or without Cur + VD₃). Outdoor does experienced severe heat stress (THI = 33.22) compared to indoor thermal comfort conditions (THI = 25.13). The supplement (Cur + VD₃) was administered orally at 1 mL/kg body weight. Heat stress significantly decreased body weight, milk yield, litter size, weight at weaning, and behavioral activity. Conversely, rectal temperature, respiration rate, and mortality increased. Supplementation with Cur + VD₃ showed improved body weight, reproductive parameters, milk yield, and behavior, while reducing mortality (0% vs. 5%) compared to treatment without these additives. Physiologically, Cur + VD₃ lowered rectal temperature and respiration rate. In conclusion, combined curcumin and vitamin D₃ supplementation is an effective nutritional strategy to improve heat stress tolerance and maintain productivity in pregnant rabbits exposed to high ambient temperatures. Full article

The focus of modern livestock production is increasingly shifting toward improving animal health, welfare, and product quality through the use of natural feed ingredients. Pumpkin (Cucurbita spp.) and its seeds are of interest because they contain biologically active compounds, including tocopherols and phenolic antioxidants. This study evaluated the effects of pumpkin seed cake (PSC) in rabbit diets on blood parameters, oxidative status, and trace element distribution in tissues. Sixty Popielno White rabbits were initially assigned to three dietary groups: control (0% PSC), 5% PSC, and 10% PSC. At 90 days of age, samples from 30 rabbits (10 per group) were collected and analysed. PSC supplementation significantly increased red blood cell count, haemoglobin, haematocrit, and platelet indices (p ≤ 0.05), indicating affected haematological status. It also reduced (p ≤ 0.05) urea, triglycerides, total cholesterol, and LDL cholesterol. Antioxidant status significantly improved, as indicated by higher superoxide dismutase activity and ferric-reducing antioxidant power, together with lower malondialdehyde levels (p ≤ 0.05). Mineral analysis showed lower manganese concentrations in muscle and kidney tissues; cadmium remained low, and lead was below the detection limit in muscle and liver samples. Overall, PSC may be considered a promising feed ingredient that supports haematological status, antioxidant protection, and metabolic balance under the conditions of the present study. Full article

Critical-sized bone defects represent a major clinical challenge, as defects of this magnitude do not heal spontaneously without regenerative intervention. This study aimed to evaluate the osteoinductive effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded β-tricalcium phosphate (β-TCP) scaffolds on bone regeneration and vascularization in a rabbit calvarial critical-sized defect model. Eighteen male New Zealand White rabbits were used, and four standardized circular defects (5 mm in diameter) were created in the calvaria of each animal. The defects were assigned to four groups: control (unfilled), β-TCP + 5 µg rhBMP-2, β-TCP + 10 µg rhBMP-2, and β-TCP + 20 µg rhBMP-2. Bone healing was evaluated at 2, 4, and 8 weeks using histological, histomorphometric, and cluster of differentiation 31 (CD31) immunohistochemical analyses. The results demonstrated that rhBMP-2–loaded β-TCP scaffolds significantly enhanced bone regeneration compared with the control group, with a progressive increase in bone formation observed with increasing rhBMP-2 doses. The β-TCP + 20 µg rhBMP-2 group exhibited the highest levels of new bone formation, more advanced bone maturation, improved collagen organization, and increased vascularization. However, no statistically significant differences were observed between the 10 µg and 20 µg groups at later time points (p > 0.05), suggesting a dose-dependent saturation (plateau) effect. In conclusion, rhBMP-2–loaded β-TCP scaffolds promote bone regeneration and angiogenesis in a dose-related manner up to a threshold, beyond which additional increases in dose do not result in proportional improvements. These findings emphasize that optimal rhBMP-2 dosing is critical to maximize regenerative outcomes while avoiding unnecessary dose escalation. Full article

Background/Objectives: Improving rabbit welfare through alternative housing systems requires a better understanding of how environmental conditions modulate physiological and immune responses at the molecular level. This study aimed to evaluate the influence of different rearing systems on the expression of genes associated with inflammation, immune regulation, and stress response in Termond White rabbits. Methods: After weaning (35 days of age), Termond White females (n = 16 per group) were allocated to five housing systems differing in space allowance and activity opportunities: hutches with outdoor runs, rabbit tractor cages with outdoor runs, single-floor indoor cages without bedding, indoor pens on deep litter, and modified indoor cages (two cages connected with a plastic pipe). At slaughter weight (2600–2900 g; 90–120 days), blood and spleen samples were collected. The relative expression of IL6, CXCR1, IL10, TGFB1, IL8, PTGS2, IL1B, and TNF was quantified by RT-qPCR using the 2^−ΔΔCt method, with ACTB and B2M as reference genes. Results: The housing system significantly affected the expression of most analysed genes in peripheral blood (IL6, CXCR1, IL1B, PTGS2, IL8, TNF, and IL10; p ≤ 0.05), whereas in the spleen significant differences were observed only for selected genes (IL1B, TNF, CXCR1, IL10, and TGFB1), with no effect detected for IL6, IL8, and PTGS2 (p > 0.05). In blood, system-dependent differences were observed for both pro-inflammatory and regulatory genes, with some housing conditions associated with higher expression of inflammatory markers. In the spleen, the response was more selective and gene-specific, suggesting tissue-dependent modulation of immune-related pathways. Conclusions: Rearing environment influences the expression of immune-related genes in Termond White rabbits; however, these effects appear to be tissue-dependent and vary among specific genes. The observed transcriptional changes suggest potential associations between housing conditions and immune responses, but further studies integrating behavioural, physiological, and protein-level data are required to confirm their relevance for animal welfare assessment. Full article