Search Results (15)

Goji berries (Lycium barbarum), rich in antioxidant and immunomodulatory compounds, have shown potential benefits for male reproductive health. This study aimed to evaluate the impact of dietary Goji berry (GB) supplementation on immune-related and antioxidant gene expression in the male reproductive tract of rabbits. Eighteen 7-month-old New Zealand White rabbit bucks were randomly assigned to two groups: a control group (n = 9) receiving a standard diet, and a Goji group (n = 9) receiving the same diet supplemented with 1% GB. After 60 days of nutritional adaptation and then 60 days of treatment, tissues from the testes, epididymis, seminal vesicles, prostate, and bulbourethral glands were collected and analyzed using quantitative real-time PCR. Gene expression analysis focused on immune markers (TLR4, IL-1β, IL-10, and TNFα) and antioxidant enzymes (SOD1, CAT, and GPX). Significant modulation was observed only in the epididymis, where TLR4 and GPX were significantly downregulated in the Goji group (p = 0.0274 and p = 0.007, respectively), while IL-1β and TNFα showed a downward trend. No significant differences were found in the other tissues. These results suggest that Goji berry supplementation exerts tissue-specific effects, particularly in the epididymis, by modulating inflammation and oxidative stress. This supports its potential use as a natural nutraceutical strategy to enhance male fertility in rabbits. Full article

Lipopolysaccharide (LPS)-induced inflammation impairs sperm function; however, its impact on ejaculated rabbit sperm remains unexplored. This dose-response study aims to determine the LPS concentration that negatively affects sperm motility in vitro, while also providing the first identification of TLR4 localization on rabbit spermatozoa. Additionally, it evaluates malondialdehyde (MDA) levels in seminal plasma as an indicator of oxidative stress. Sperm motility was analyzed using computer-assisted sperm analysis (CASA) after incubation with increasing LPS concentrations (0, 50, 100, 200, 400, 600, and 800 µg/mL) at multiple time points (0, 1, 2, and 4 h). LPS doses ≥ 400 µg/mL significantly reduced progressive and non-progressive motility, as well as curvilinear velocity (all p < 0.001), while increasing the proportion of static spermatozoa (p < 0.05). Receiver operating characteristic (ROC) analysis identified 300 µg/mL as the threshold dose for motility decline. Immunofluorescence revealed TLR4 localization in the midpiece of sperm tails, with weak labeling in control samples and a marked increase after 4 h of incubation with 400 μg/mL LPS. MDA levels were assessed using the thiobarbituric acid reactive substances (TBARS) assay with a colorimetric kit, showing no significant effect of LPS treatment. No correlation was found between MDA and other semen parameters. ccThese findings identify TLR4 on rabbit sperm for the first time and establish a threshold LPS dose for future in vitro studies. Full article

In a closed population with a limited population size, mating of related animals is unavoidable. In this study, the genealogy data of a synthetic maternal rabbit breed called Pannon Ka were used to calculate different inbreeding coefficients. The evaluated animals were born between 1995 and 2020, and the pedigree consisted of 5819 animals that originated from 4205 rabbit does and from 1314 rabbit bucks. The pedigree was further extended with 16,013 dummy progeny records in order to calculate litter inbreeding coefficients. Besides the conventional Wright inbreeding coefficients, the so-called ancestral and new inbreeding coefficients were also calculated using the gene dropping method. By the end of the evaluated period, the litter inbreeding increased to almost 11 and 60% for Wright and Ballou inbreeding, while the Kalinowski and the Kalinowski new inbreeding coefficients were 9.25 and 16.67%, respectively. Correlation coefficients were calculated for the does and for the litters. Finally, the effects of pedigree length and completeness were also taken into account using the complete generation equivalents in a partial correlation analysis. Based on the results, it could be seen that the different ancestral inbreeding coefficients had high correlation. Similarly, the conventional Wright inbreeding coefficients showed strong correlation with the new inbreeding coefficients. On the contrary, the correlation between ancestral and new inbreeding coefficients was low. Taking the complete generation equivalent into account did not give unambiguous results. It could be concluded that the different inbreeding coefficients are based on different concepts, and they are clearly different population parameters. Full article

The aim of the present study was to evaluate the characteristics of carcasses, monitor their pH evolution during the first 24 h post-mortem, and determine the time required for the establishment and resolution of rigor mortis in different categories of Botucatu rabbits. Live weight at slaughter, carcass weight, and yield were higher in 12-month-old animals compared to 3-month-old rabbits, regardless of sex. There was an effect of muscle type, age, and sex on the kinetics of muscle acidification, with the Biceps femoris showing a significantly higher pH than the Longissimus lumborum from 4 h post-mortem onward. The establishment of rigor mortis occurred at 5 h post-mortem in young rabbits and bucks and at 6 h post-mortem in does, along with pH stabilization, while the resolution of rigor occurred at 18 h post-mortem for all types of carcasses evaluated. In conclusion, Botucatu rabbit carcasses should be chilled continuously at 4 °C for a minimum of 18 h to ensure efficient rigor mortis progression and muscle-to-meat transformation throughout the carcass. Full article

Goji berry (GB) shows beneficial effects on human health, although its effects on the male rabbit have been little investigated. This study examines the impact of GB dietary supplementation on the semen traits, antioxidant capacity of seminal plasma, and histological features of the reproductive tract of rabbit buck. Eighteen rabbits were distributed into two dietary groups: one receiving a commercial feed (Control), and the other a feed supplemented with 1% of GB (Goji). After a nutritional adaptation period of 60 days, the animals were subjected to semen collection every 15 days. The semen traits, libido, antioxidant, and inflammatory parameters were collected and analyzed. The rabbits were sacrificed after 60 days, and tissues of the genital tract were analyzed. Compared to the Control group, the Goji group showed higher spermatozoa concentration, motility, and vitality (p < 0.05), as well as fewer abnormal spermatozoa and a higher libido (p < 0.1). Histological features such as functional activity and hyperplasia were improved by GB and correlated with some semen traits (p < 0.05). Conversely, antioxidant and anti-inflammatory parameters were unaffected by the diet. These findings suggest that GB acts on the tissues of the reproductive tract positively influencing semen quality, although further studies are needed to understand the effect on oxidative stress. Full article

Many dietary factors can affect sperm traits. We compared the effect of diets rich in pro-oxidant (flaxseed oil) and pro-atherogenic (coconut oil) substances without added antioxidants on semen traits, using the rabbit as an animal model. Thirty rabbit bucks (8 months old) were fed three diets for 150 days: CNT (control) a standard diet; HA (high-atherogenic) standard diet + 3% coconut oil, and HO (high-oxidizing) standard diet + 3% flaxseed oil. Semen samples were collected weekly for the evaluation of qualitative traits (kinetics, viability) and the oxidative damage (MDA and cytokines). Blood was collected at the start (T0) and end (T8) of the experimental period for the assessment of the oxidative damage (MDA and isoprostanoids), lipid profile, and testosterone. A worsening of sperm kinetics and viability was recorded in the HA group. Lipid oxidation in seminal plasma, as well as isoprostanoids in blood (F₃-IsoPs and F₄-NeuroPs), increased in both the HO and HA groups. A high level of TNF-α, a marker of inflammatory status, was recorded in the seminal plasma of the HA group. The resulting outcomes were mainly attributable to the different fatty acid profiles (SFA vs. PUFA) of the diets, which modulated an inflammatory/oxidative response. Full article

The effectiveness of rabbit-sperm cryopreservation is still below average compared to other domestic species. After the sperm cryopreservation process, post-thawing parameters like motility and membrane integrity are significantly compromised. The use of new extender constituents is an approach that can be used to improve the effectiveness of cryopreservation. Accordingly, we used honey (1.25, 2.5, 5, and 10%), coenzyme Q10 (100 and 200 μM), and β-carotene/α-tocopherol (500 μM/620 μM and 250 μM/310 μM) as candidate components for rabbit-sperm extenders during cryopreservation. Ejaculates from commercial adult rabbit bucks (n = 5) were cryopreserved using conventional freezing. Several post-thawing sperm parameters were assessed, including total motility, membrane integrity, viability, nuclear membrane integrity, acrosome reaction, and mitochondrial membrane potential and activation. Additionally, we performed hormonal analyses of the seminal plasma. Moreover, we analyzed the post-thawing levels of a molecular marker of sperm quality, proAKAP4, which was used in rabbits for the first time. Our findings showed that the 2.5% honey supplementation increased the post-thawing sperm motility (13.75 ± 3.75%) compared to the greater concentrations employed. However, the post-thawing motility was negatively affected by the coenzyme Q10 (0%, in both groups) but was not affected by the β-carotene/α-tocopherol supplementation (22 ± 18.15%, and 11.67 ± 10.17%). In conclusion, the cryopreservation protocols of this study did not help to maintain the sperm parameters after thawing. Further studies are required to identify novel protocols to mitigate the damage caused to rabbit sperm during cryopreservation. Full article

Egypt’s animal protein shortfall cannot be overcome by expanding the production of large animals alone, but rather by increasing the production of highly reproducing animals in the livestock unit. The goal of this study was to examine how adding pomegranate peel (PP), garlic powder (GP), or a mixture of the two to the diet of does affect their weight, the number of offspring, reproductive performance, hematological indices, and several antioxidants indicators as well as the liver and kidney functions. A total of 20 adult and mature female mixed rabbits at age 4.5–5 months and averaging 3.05 ± 0.63 kg body weight, were allocated into four experimental groups (n = 5). The first group was provided with the basal diet and was considered as control animals, while the second, third, and fourth groups were fed the basal diet supplemented with PP 3.0%, GP 3.0%, and a mixture of PP 1.5% + GP 1.5%, respectively. After 2 weeks of feeding the experimental diets, natural mating with untreated bucks was carried out. The kits were weighed immediately after parturition, and then every week. The study found that rabbits fed with 3% PP led to a 28.5% increase in the number of kits at birth compared to the control group. As an effect of supplementing PP 3%, GP 3%, and PP 1.5% + GP 1.5%, the birth weight increased by 9.2%, 7.2%, and 10.6%, respectively, as compared to the control. Hemoglobin increased significantly in all treatment groups as compared to the control at the age of kit weaning. Lymph cells increased significantly in the rabbits that were fed with GP (3%) than in other groups and even the control. The results showed that creatinine levels were significantly decreased in the PP (3%) and GP (3%) than in control rabbits. The level of triglycerides significantly declines in groups treated with PP (3%) than in other treatment groups and the control. The addition of PP 3% or GP 3% increased the progesterone hormone. The addition of PP 1.5% + GP 1.5% improved the immunoglobulin IgG. The results of superoxide dismutase, catalase, glutathione, and total antioxidant capacity showed a significant decline in groups treated with GP (3%) than other treated groups. In conclusion, pomegranate is a promising substance to include in a rabbit’s diet, followed by garlic to boost reproductive efficiency. Full article

Background: Rabbits are common companion animals in many European countries. Rabbit-assisted interventions in primary schools are suitable for decreasing the anxiety levels of children, which may increase the education efficiency of teachers. Methods: In our present study, the behavior of dwarf rabbits was tested in a children’s summer camp organized by the Family and Child Protection Service in Várpalota, Hungary, 2021. In two occasions, altogether 20 rabbits were evaluated, while 120 children were involved in the examinations. All the rabbits were the progeny of the same buck and three different does. Four of them had been previously socialized to humans during the sensitive period after birth. Results: The familiarity level of the rabbits with their owner was significantly lower after the interventions compared to the previously measured scores (p < 0.05). In the interventions, children also made behavior surveys with the rabbits in which they contacted the animals, touched them and held them. After three successive interventions, rabbits became significantly less tolerant compared to the first intervention (p < 0.05). In both cases, the rabbits who had been socialized obtained higher scores on the behavior tests compared to the non-handled conspecifics. However, by the third session, socialized rabbits showed a considerable decrease in cooperation. Conclusions: The stress tolerance of rabbits receiving handling exceeds that of those that were not handled previously. The familiarity level of the imprinted rabbits was higher in both cases: with the owner and children. When using rabbits in AAI, a maximum of two 20 min sessions is recommended for handled rabbits. Full article

Background: Nerve Growth Factor (NGF) plays an important role in the reproductive system through its receptor’s interaction (p75^NTR). This paper aims to analyze the impact of NGF p75^NTR in epididymal and ejaculated rabbit semen during in vitro sperm storage. Methods: Semen samples from 10 adult rabbit bucks were collected four times (n = 40) and analyzed. NGF was quantified in seminal plasma, and the basal expression of p75^NTR in sperm was established (time 0). Moreover, we evaluated p75^NTR, the apoptotic rates, and the main sperm parameters, at times 2–4 and 6 h with or without the administration of exogenous NGF. Results: Based on the level of p75^NTR, we defined the threshold value (25.6%), and sperm were divided into High (H) and Normal (N). During sperm storage, p75^NTR of H samples significantly modulated some relevant sperm parameters. Specifically, comparing H samples with N ones, we observed a reduction in motility and non-capacitated cell number, together with an increased percentage of dead and apoptotic cells. Notably, the N group showed a reduction in dead and apoptotic cells after NGF treatment. Conversely, the NGF administration on H sperm did not change either the percentage of dead cells or the apoptotic rate. Conclusion: The concentration of p75^NTR on ejaculated sperm modulates many semen outcomes (motility, apoptosis, viability) through NGF interaction affecting the senescence of sperm. Full article

Polyunsaturated fatty acid (PUFA) metabolism and tissue distribution is modulated by the oxidation of these molecules. This research aimed to investigate the implication of dietary n-3 PUFA supplementation (precursor and long-chain PUFA) on the PUFA profile and oxidative status of the liver, testis, and brain of adult rabbit bucks. Twenty New Zealand White rabbit bucks were divided into four experimental groups (n = 5 per group) and were fed different diets for 110 days: control (CNT), standard diet containing 50 mg/kg alpha-tocopheryl acetate (vitamin E); CNT+, standard diet + 200 mg/kg vitamin E; FLAX, standard diet + 10% flaxseed + 200 mg/kg vitamin E; or FISH, standard diet + 3.5% fish oil + 200 mg/kg vitamin E. Antioxidants (enzymatic and non-enzymatic), oxidative status (malondialdehyde and isoprostanoids), and n-3 and n-6 PUFAs of tissues were analysed. A chain mechanism of oxidant/antioxidant molecules, which largely depended on the particular PUFA composition, was delineated in the different organs. The liver showed an oxidant/antioxidant profile and lipid pathways widely modulated by PUFA and vitamin E administration; on the other hand, the testis’ oxidative profile rather than its lipid profile seemed to be particularly affected, an outcome opposite to that of the brain (modulation operated by dietary PUFA). Full article

A 65-day study was undertaken to test the effects of two doses (10 and 20 mg/kg) of dietary fumonisin Bs (FB) on the rabbit male reproduction system. Body and testicular weight was not affected by the intoxication, neither the fatty acid composition of the testicular total phospholipids; the testis histological analysis failed to reveal any toxic effect. The FBs increased the testicular concentration and activity of reduced glutathione and glutathione peroxidase and decreased initial phase lipid peroxidation (conjugated dienes and trienes) in a dose dependent manner. Sperm morphology and chromatin condensation were monitored on Feulgen-stained smears. No significant differences were observed between the treatment groups and between sampling time points. The live cell ratio in the sperm (as assessed with flow cytometry) was not different among groups at any of the five sampling timepoints and was also identical within groups. Similarly, the spermatozoa membrane lipid profile was also identical in all three groups after the total intoxication period. In summary, it was demonstrated that FBs in an unrealistic and unjustified high dose still do not exert any drastic harmful effect on the leporine, male reproduction system, meanwhile slightly augmenting testicular antioxidant response. Full article

Twenty-four adult rabbit bucks (n = 6 per treatment) were fed a basal diet supplemented with 0 (control), 50, 100, and 150 mg proline/kg dry matter (DM) diet for 12 weeks to determine possible usefulness for alleviating the negative impact of environmental heat stress on redox status, haemato-biochaemical attributes and semen quality. There were significant dose–response effects, with increments in levels of dietary proline (LDP) quadratically improving red blood cell counts (p = 0.017), rectal temperature (p = 0.009), and respiratory rate (p < 0.001). Increasing LDP cubically affected superoxide dismutase activity in blood plasma (p = 0.012) and total antioxidant capacity in both blood and seminal plasma (p < 0.001 and p = 0.006, respectively). The optimal response was observed at 30 and 80 mg proline/kg DM for blood and seminal plasma, respectively. With regards to homeostasis indexes, increments in LDP cubically modified blood plasma concentrations of total protein (p = 0.002) and albumin (p < 0.001), with an optimal response found at 70 mg proline/kg DM. A linear relationship (p = 0.005) was also observed between LDP and blood plasma glucose concentrations, with the optimal response being found at 100 mg proline/kg DM. Increasing LDP also showed positive effects on reproductive traits, with quadratic increases in blood plasma testosterone and cortisol concentrations (p < 0.001; optimal responses at 50 and 60 mg proline/kg DM, respectively), a positive linear relationship with in libido, ejaculate volume, sperm concentration and total sperm count (p < 0.001 for all; optimal responses observed at 100 mg proline/kg DM) and a quadratic increase in total functional sperm fraction (p < 0.001; optimal response at 70 mg proline mg/kg DM). Hence, the optimal positive effects of dietary proline supplementation on redox status, blood metabolites, and reproductive traits of rabbit bucks may be achieved at 50–100 mg/kg DM. Full article

The cryopreservation process adversely affects sperm function and quality traits, causing some changes at biochemical and structural levels, due to mechanical, thermal, osmotic, and oxidative damage. Supplementation with curcumin nanoparticles could prevent and even revert this effect and could enhance the post/thawed sperm quality in the rabbit. The study amid to explore the effect of curcumin (CU) and curcumin nanoparticles (CUNPs) supplementation in semen extender on post/thawed rabbit sperm quality. Twelve fertile, healthy rabbit bucks were included, and the ejaculates were collected using artificial vaginas. Rabbit pooled semen was cryopreserved in tris-yolk fructose (TYF) extender without any supplement (control group) or extender supplemented with CU at levels of 0.5, 1 or 1.5 µg/mL (CU0.5, CU1.0, and CU1.5, respectively) or CUNPs at levels of 0.5, 1, 1.5 (CUNPs0.5, CUNPs1.0, and CUNPs1.5, respectively) and was packed in straws (0.25 mL) and stored in liquid nitrogen (−196 °C). Results revealed that CUNPs1.5 had a positive influence (p < 0.05) on post-thawing sperm progressive motility, viability, and membrane integrity as compared with the other groups. Percentages of dead sperm, abnormalities, early apoptotic, apoptotic, and necrotic sperm cells reduced (p < 0.05) in CUNPs1.5 as compared to other treatments. Using 1.5 µg/mL of CUNPs significantly improved total antioxidant capacity (TAC), GPx, while MDA and POC reduced (p < 0.05) in CU1.5 in comparison with other groups. SOD values were enhanced (p < 0.05) in CUNPs1.0 and CUNPs1.5 in relation with other treatments. Conclusively, the addition of curcumin and its nanoparticles to the extender can improve the post-thawed quality of rabbit sperm via redox signaling and reduce the apoptosis process. Full article

Conditions of pet rabbit breeding colonies and breeder practices are undocumented and very little is known about the pet rabbit sales market. Here, multiple methods were employed to investigate this sector of the UK pet industry. A freedom of information request sent to 10% of councils revealed confusion and inconsistency in licensing conditions. Data from 1-month of online sale adverts (3446) identified 646 self-declared breeders, of which 1.08% were licensed. Further, despite veterinary advice to vaccinate rabbits from five weeks, only 16.7% rabbits were vaccinated and 9.2% of adult rabbits were neutered. Thirty-three breeders completed a questionnaire of which 51.5% provided smaller housing than recommended, the majority housed rabbits singly and bucks were identified as most at risk of compromised welfare. However, most breeders provided enrichment and gave a diet compliant with recommended guidelines. Mini-lops and Netherland dwarfs were the most commonly sold breeds, both of which are brachycephalic, which can compromise their health and wellbeing. From sales data extrapolation, we estimate that 254,804 rabbits are purposefully bred for the UK online pet sales market each year. This data is the first of its kind and highlights welfare concerns within the pet rabbit breeding sector, which is unregulated and difficult to access. Full article