Search Results (99)

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

Metabolomics is increasingly applied in veterinary molecular biology to investigate physiological adaptations in animals. In this study, rabbit does were used as a model to explore plasma metabolomic changes associated with key reproductive stages, specifically parturition and weaning. Using an untargeted metabolomics approach, 48 plasma samples were analyzed to characterize metabolic differences between these physiological states: parturition (n = 24) and weaning (n = 24). The experiment was conducted between February and November 2019. Distinct metabolomic profiles were observed between stages, with variations detected in metabolites associated with lipid metabolism, energy homeostasis, and cellular metabolic pathways. Distinct changes included higher plasma levels of Betaine and alpha-CEHC at parturition, while weaning was characterized by elevated levels of 4-Pyridoxic acid, Proline betaine, Allysine, modified phospholipids, and other nitrogenous and lipophilic metabolites, reflecting stage-specific metabolic adaptations. These results contribute to the understanding of metabolic regulation during reproduction and lactation in mammals and highlight the usefulness of the rabbit as an experimental model in veterinary molecular and physiological research. 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

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

Valorisation of rabbit biodiversity plays a significant role in enhancing production by preserving genetic diversity, which is crucial for maintaining adaptability and resilience in rabbit populations, thereby supporting sustainable development and conservation efforts. With this in mind, the present research aimed at comparing live performance, carcass traits, meat quality and muscle fibre characteristics of different rabbit genotypes. Forty-five weaned rabbits (15 commercial hybrids—C; 15 Burgundy Fawn crosses—BF; 15 Vienna Blue crosses—VB) were farmed until slaughter (n = 15 replicated cages/rabbit genotype). The slaughter age was scheduled when all genotypes reached the same live weight (approx. 2800 g). After slaughtering and carcass dissection, the hind legs and longissimus lumborum muscles were excised and subjected to different evaluations. Hind legs were exploited for physicochemical analyses, while longissimus lumborum muscles were used for physical evaluations and for fibre typing, morphometric traits and enzymatic activity. As a direct response to the experimental design, results highlighted that the three genotypes exhibited different slaughter ages. Commercial hybrids displayed the fastest growth cycle, but they showed an efficiency comparable to that of VB crosses (p > 0.05). Genotypes displayed some differences in carcass characteristics, namely perirenal fat (p < 0.01) and hind leg weight (p < 0.05). The physical characteristics of meat were overall similar in the three genotypes, except for biceps femoris L*, which showed the highest value in the BF group. Meat chemical composition differed depending on the genotype, with BF rabbits having the highest ether extract (p < 0.05) content. The three genotypes displayed an overall similar fatty acid profile with some minor differences: VB rabbits had the highest C18:2 n-6 proportion (p < 0.01) and thus n-6/n-3 (p < 0.05). Cholesterol content was the highest in C rabbits (p < 0.05). Overall, the present research highlighted that BF and VB genotypes provided interesting potentialities which would be further valorised in rural farming conditions, given their higher resilience and adaptability than commercial hybrids. Full article

The aim of this study was to investigate the effect of phyto-additive mixture supplementation on semen quality and on some reproductive parameters after artificial insemination in rabbits. The trial run 120 days on 20 adult New Zealand white rabbit bucks that were allocated into two different groups, first was control (CON; n = 10) fed with commercial pelleted-feed and second was considered experimental group (EXP; n = 10) which received in feed a natural feed additive mixture (0.1% of dried Chlorella vulgaris powder and 0.1% of dried Laurus nobilis leaves powder). Consequently, the quality assessment of semen by the Computer Assisted Semen Analyzer (CASA) system, samples were instrumentally inseminated on rabbit does for two consecutive reproductive cycles, and productive and reproductive indexes were evaluated. Results demonstrate that while spermatozoa concentration and ejaculate volume did not differ significantly among experimental groups or between reproduction cycles, spermatozoa motility parameters were significantly enhanced in rabbits receiving the phyto-additive mixture, as evidenced by increased total motility (87.83% vs. 70.63%) and progressive motility (75.68% vs. 50.10%) compared with the control group (p < 0.01). No differences were observed in prolificacy traits during the first reproductive cycle, whereas in the second cycle the phyto-additive treatment increased the number of kits born alive per litter (12.29 vs. 10.19; p < 0.05) and improved kit growth performance at birth (79.17 vs. 66.75 g), at weaning (1085.28 vs. 963.15 g), and in average daily gain (28.75 vs. 25.61 g/day). The study provides evidence of alternative practises based on feeding programme to enhance reproductive traits in rabbit production. The goal is to provide farmers with examples of good farming practise (such as precision farming), focused on sustainability and efficiency, and a certain transfer of knowledge. Full article

Meat rabbits are ideal meat-producing animals. However, weaning-induced intestinal inflammation often leads to growth delays, and severe cases impair breeding efficiency. Alfalfa polysaccharides (APSs) have antioxidant and anti-inflammatory properties, making them potential natural alternatives to antibiotics. To date, relatively limited research has been conducted on APS in meat rabbits. This research investigated the effects of APS on growth performance, intestinal inflammation, and meat quality in rabbits. Eighty healthy rabbits were randomized into four treatment groups, each group consisting of five replicates, with four rabbits per replicate. The four experimental groups were the control group (CON, basal diet), 400 mg/kg APS group (basal diet + 400 mg/kg APS), 800 mg/kg APS group (basal diet + 800 mg/kg APS), and 1200 mg/kg APS group (basal diet + 1200 mg/kg APS). The results indicated that adding 800 mg/kg APS to the diet significantly increased ADG (p < 0.001) and reduced F/G (p = 0.008). With increasing APS supplementation levels, slaughter weight (p = 0.035), eviscerated weight (p = 0.020), semi-eviscerated weight (p = 0.015), and semi-eviscerated yield percentage (p = 0.035) were all significantly increased. Additionally, dripping loss in muscle was significantly reduced in the 800 mg/kg APS group (p = 0.006). In addition, the villus height of the small intestine and the expression of tight junctions were significantly increased by 800 mg/kg APS supplementation, which reduced intestinal permeability and lowered levels of intestinal inflammatory mediators by inhibiting the PPARγ/NF-κB pathway. Additionally, a diet with APS significantly increased the abundance of Flavonifractor, a butyrate-producing bacterium in the cecum. Cell assays further demonstrated that butyrate could inhibit the release of inflammatory cytokines from RAW264.7 via the PPARγ/NF-κB pathway. In conclusion, APS improved growth performance by reshaping the gut microbiota and increasing the level of butyrate in the cecum, further inhibiting intestinal inflammation through the PPARγ/NF-κB signaling pathway. Full article

Pomegranate peel, a rich agro-industrial by-product, contains abundant phenolic compounds with strong antioxidant and antimicrobial properties. However, the low stability and bioavailability of these compounds limit their efficacy in animal nutrition. This study investigated the effects of pomegranate peel phenolic extract (PE), either in raw form (PE300) or nano-encapsulated using gum–gelatin nano-capsules (NPE300), on health and growth parameters in newly weaned rabbits. Fifty-four male rabbits (40 days old) were assigned to three treatment groups: PE0 (control), PE300 (300 mg PE/L drinking water), and NPE300 (300 mg nano-encapsulated PE/L drinking water). Over six weeks, growth performance, hematological and immunological profiles, antioxidant status, microbial populations, and carcass traits were evaluated. NPE300 treatment demonstrated superior antimicrobial activity in vitro, with larger inhibition zones against all tested pathogens compared to PE300. In vivo, NPE300 significantly improved body weight gain (945.8 g) and feed efficiency, while also enhancing immune function, evidenced by higher white and red blood cell counts, phagocytic activity, and increased plasma IgG and IgM levels. Antioxidant markers showed that NPE300 significantly reduced malondialdehyde levels and tended to improve total antioxidant capacity. Furthermore, intestinal Clostridia counts were reduced, and beneficial microflora significantly increased in the NPE300 group. Carcass weight with edible parts, fur weight, kidney weight, and cecum length were also elevated under NPE300 treatment. In conclusion, nanoencapsulation of PE using gum–gelatin carriers enhanced its bio-efficacy, supporting better redox balance, immunity, gut health, and growth performance in rabbits. These findings support the application of nano-encapsulated PE as a promising natural growth promoter in rabbit production. Full article

EU regulations on organic rabbit farming are relatively recent, and scientific evidence on key technical aspects remains limited. Outdoor systems may improve health and welfare by allowing natural behaviours, but their effectiveness depends on management practices, environmental conditions, and breed. The objective of this study was to explore breed-related differences in rabbit behaviour under outdoor rearing conditions. A total of 15 Leprino di Viterbo (LV) and 15 New Zealand White (NZW) rabbits were weaned at 29 days of age and reared under outdoor conditions until 84 days of age, during October and November. All animals had ad libitum access to a commercial pelleted diet and pasture, and the intake of both was measured weekly. Animal behaviour was monitored by video recording, and eight one-minute sample intervals per day were analysed using focal sampling and continuous recording methods. Grass intake and estimated digestible energy (DE) were assessed on a weekly basis. Data were analysed using Generalized Estimating Equations to evaluate the effects of time, time of day, and breed. Behavioural patterns varied depending on genetic strain and time of day. Notably, LV rabbits exhibited a higher frequency of grazing and active behaviours compared to NZW rabbits, whereas NZW rabbits showed a higher frequency of resting behaviours and social contact. Breed-related differences in other behaviors and in grass intake patterns were not statistically robust. In conclusion, LV rabbits appear to be better adapted to outdoor conditions, exhibiting a greater pasture utilization, but further studies are recommended to confirm these findings and to evaluate their robustness across different seasonal and environmental conditions. Full article

The effects of chlorogenic acid (CGA) on intestinal histomorphology, barrier integrity, antioxidant parameters, and gut microbiota in heat-stressed rabbits were assessed in this study. One hundred and twenty weaned New Zealand rabbits were assigned to three groups: control (CON) at 25 ± 1 °C, heat stress (HS) at 35 ± 1 °C, and HS with CGA supplementation (HS + CGA) at 35 ± 1 °C. Rabbits in the CON and HS groups were fed a basic diet, while those in the HS + CGA group receive the basic diet added with 800 mg/kg CGA. HS induced intestinal oxidative stress, impaired intestinal morphology and barrier function, and altered the gut microbiota. CGA supplementation mitigated HS-induced increases in serum diamine oxidase and D-lactate levels, and intestinal malondialdehyde content (p < 0.05), and countered HS-induced reductions in intestinal superoxide dismutase activity, villus height/crypt depth ratio, and claudin-1 and ZO-1 mRNA expressions (p < 0.05). In addition, HS decreased the abundances of Akkermansia and uncultured_bacterium_g__Akkermansia and increased the Firmicutes/Bacteroidota ratio and uncultured_bacterium_g__unclassified_o_Clostridia_UCG-014 abundance as well as the abundance of bacterial functions related to animal_parasites_or_symbionts and human_pathogens_all. HS-induced gut microbiota dysbiosis was significantly restored by CGA supplementation. The findings indicated that dietary 800 mg/kg CGA supplementation effectively safeguarded intestinal health in rabbits under high temperatures. Full article

This study evaluated the effect of dietary supplementation with biochar and Tribulus terrestris (TT) on oxidative stress and metabolic parameters in New Zealand White rabbits. A total of 80 weaned rabbits (35 days of age) were assigned to four groups (20 each): a control group (C) and three experimental groups supplemented with 0.25% biochar (E1), 0.25% biochar and 0.1% Tribulus terrestris (E2), or 0.1% Tribulus terrestris (E3). The feeding experiment lasted 78 days following a 7-day adaptation period. Hematological, biochemical, and redox parameters, including malondialdehyde (MDA), glutathione (GSH), total reducing capacity (FRAP), immunoglobulin G (IgG), and testosterone levels, were assessed and analyzed using one-way analysis of variance (ANOVA). Rabbits from group E1 exhibited the highest FRAP values (8.16 µmol/L; p < 0.05), whereas MDA concentrations were significantly elevated in groups E1 and C (2.02 and 1.83 µmol/L; p < 0.05), indicating increased lipid peroxidation. Groups E2 and E3 showed lower MDA levels (1.38 and 1.59 µmol/L; p < 0.05) and higher IgG concentrations (44.72 and 37.82 ng/mL; p < 0.05) compared to the control, suggesting improved antioxidant defense and immune status. GSH levels were significantly higher in groups E1 and E2 (6.34 and 6.79 µmol/L; p < 0.05). No adverse changes were observed in basic hematological and biochemical parameters. The results indicate that dietary supplementation with biochar and T. terrestris is safe and can beneficially modulate redox balance and immune response in rabbits, confirming their potential as natural feed additives in sustainable rabbit production. Full article

This study aimed to evaluate the individual and combined effects of dandelion extract and akebia extract on growth, inflammation, and gut microbiota in weaned rabbits. Using a two-factor randomized design, 120 rabbits (1.219 kg ± 0.077 kg, 35 days of age) were divided into four groups (10 replicates/group). Growth metrics (feed intake, fecal score, weight gain) and biological samples (blood, liver, jejunal/ileal mucosa, digesta) were analyzed over 28 days. Key results indicated that combined dandelion and akebia supplementation significantly increased daily weight gain during the first week (p < 0.05). Dandelion alone reduced liver Immunoglobulin G (IgG) and jejunal interleukin 6 (IL-6) (p < 0.05). Akebia supplementation decreased serum immunoglobulin A (IgA)/IL-6, liver interleukin 1β (IL-1β)/IL-6/IgG, and jejunal IL-1β/IL-6/IgG/IgA (p < 0.05). Gene expression revealed dandelion downregulated liver interferon-γ (IFN-γ)/interleukin 10 (IL-10) and jejunal IL-1β/interleukin 10 (TNF-α) (p < 0.05), while akebia suppressed hepatic C-C Motif Chemokine Ligand 3 (CCL3)/C-X-C Motif Chemokine Ligand 10 (CXCL10)/IFN-γ/IL-1β and mucosal IL-1β/IFN-γ (p < 0.05). A significant interaction effect (p < 0.05) between dandelion and akebia reduced ileal IL-6/IL-10/TNF-α and jejunal CXCL10/IL-10 mRNA expression. Akebia also increased cecal microbial diversity and the abundance of Oxalibacilli and Sutterella while reducing Firmicutes abundance (p < 0.05). In conclusion, both extracts modulated immunity and attenuated inflammatory responses through modulation of immunoglobulins, cytokines, and chemokines. Their combination demonstrated synergistic anti-inflammatory effects, alongside beneficial shifts in gut microbiota composition. Full article

Reproductive performance in rabbits is highly sensitive to seasonal environmental variation and management practices, while the proportion of variance attributable to additive genetics for litter-level traits is typically low. The objective of this study was to evaluate the effects of year and season on litter size at birth (BR), litter size at weaning (WR), and weaning rate (WT), and to estimate the heritability of these traits in a commercial rabbit farm. A total of 770 kindling events recorded between 2015 and 2021 were analyzed. The mixed model for BR included the fixed effects of year and season, and the random effects of sire and residual error. The model for WR included the same structure, with BR added as a covariate. Least-squares means for fixed effects were used for pairwise comparisons using Tukey’s test. Year and season effects were significant for BR (p < 0.005), and the year effect was also significant for WR (p < 0.021). Litter size at birth ranged from 7.80 (dry season) to 9.21 (year 2020), with higher means observed during the semi-dry (8.52) and humid (8.56) seasons compared to the dry season (7.80). Litter size at weaning varied between 4.65 and 5.81 kits depending on the year. Weaning rate showed interannual variation (56.1–68.2%), but seasonal differences did not reach statistical significance (p < 0.075). Heritability estimates from the sire variance component were low: 0.01 for BR, 0.04 for WR, and 0.05 for WT. These results indicate that phenotypic variation in prolificacy in this population was predominantly driven by interannual and seasonal environmental factors, as well as perinatal management practices, while the additive genetic contribution was marginal. Full article

Clostridium piliforme (Cp) is a pleomorphic spore-forming obligate intracellular bacterium and the causative agent of Tyzzer’s disease. The condition affects multiple species, including rabbits, in which the disease is sporadic in recently weaned animals. This report details a case of disease caused by Cp observed exclusively in breeding rabbits of a commercial farm. The clinical manifestations were a higher mortality rate in does and late-gestation abortions. We performed necropsy and further microbiological, parasitological and histopathological analyses. Anatomopathological lesions were suggestive of Tyzzer’s disease and the presence of Cp was confirmed by PCR. Parasitological analysis tested negative and standard bacteriological examination of intestines revealed a high load of Escherichia coli and Clostridium perfringens, which were considered secondary pathogens. Chlamydophila sp. and Toxoplasma gondii infections were excluded by PCR as causative agents of abortions. Moreover, in the months following the diagnosed outbreak, episodes of subcutaneous edema occurred in multiple does and young breeders born after the resolution of the epidemic. The constant reduction in the use of antimicrobials in recent years could make some neglected diseases emerge again. Therefore, it is crucial to suspect such uncommon pathologies in commercial rabbitries to properly manage them on farms. Full article

This study investigated the effects of individual and combined supplementation of eucalyptus essential oil (EEO) and soy isoflavones (SI) on the growth performance, intestinal health and meat quality of weaned meat rabbits. A total of 120 Ira female rabbits were stratified by body weight (BW) and randomly allocated into four treatment groups. The rabbits were fed for 35 days using (a) basal diet (Control), (b) basal diet + 150 mg/kg EEO, (c) basal diet + 25 mg/kg SI, or (d) basal diet + 150 mg/kg EEO + 25 mg/kg SI. The results showed that supplementing EEO and SI in the diet had a synergistic effect on production performance by increasing BW and average daily gain and reducing the feed intake/gain ratio. The EEO + SI group exhibited the most pronounced improvement in growth performance. Compared with the Control group, individual or combined supplementation significantly increased both semi-clean slaughter and total eviscerated slaughter rates, and showed a synergistic effect when supplemented together. The antioxidant capacity of the rabbits was enhanced, with the EEO + SI group showing the largest improvement. Serum biochemical analysis revealed that the combined treatment improved hepatic and cardiovascular functions. Additionally, we observed that the combined addition of EEO and SI has a synergistic effect on increasing the height of intestinal villi and the villus height/crypt depth ratio. Moreover, EEO and SI synergistically improved meat quality by elevating pH value, water-holding capacity, tenderness, and fat proportion. Notably, supplementation of EEO and SI in the diet regulated the composition of the intestinal microbiota, demonstrating increased relative abundance of beneficial Bacteroides and Lachnospiraceae_NK4A136_group. In conclusion, the combination of EEO and SI outperformed individual supplements in promoting growth and intestinal barrier function, potentially through enhancing antioxidant activity, attenuating oxidative stress, protecting the hepatic/cardiovascular systems, and improving intestinal morphology and microbial composition, thereby collectively enhancing growth performance, slaughter traits, and meat quality. Full article