Dietary manipulations play an important role in improving the rabbit behaviour and performance and mitigating the negative effects of heat stress (HS) in rabbits. Thus, this study was designed to determine the modulatory role of thyme essential oil (TEO) in improving the blood metabolites, antioxidant status, immunological response, ovarian activity, reproductive traits and fecundity of rabbit does kept under high environmental stress. A total of 100 nulliparous does were used and randomly assigned into five treatments of 20 does each. The basal diet fed to the experimental groups contained TEO at levels of 0, 50, 100, 150 and 200 mg/kg diet for the 1st, 2nd, 3rd, 4th and 5th groups, respectively. The period of TEO treatment was one month during an experimental period of three months during the summer season. Results showed that TEO at a level of 100 mg/kg diet decreased (p ≤ .001) MDA, while increased (≤.001) total proteins (TPs), albumin (AL), globulin (GL), blood haemoglobin, total antioxidant capacity (TAC), haematocrit (Ht) and glutathione (GSH). Conversely, the TEO treatment did not affect GSH peroxidase and superoxide dismutase (SOD). Immunological variables (IgG and IgM), milk production, ovulation rate (OR) and normal embryos percentage were significantly improved by 100 mg TEO/kg diet supplementation. The reproductive variable of stressed rabbit does fed TEO were significantly higher than those in the control diet. Collectively, dietary TEO supplementation can alleviate the negative influences of heat stressed-female rabbits, via enhancing the antioxidant capacity and immunological parameters.

Objective: The potential of extra virgin olive oil (EVOO), betaine (BET), and ginger (GIN), as natural antioxidants, in reducing negative effects of heat stress on physiological responses, antioxidant capacity, semen quality and fertility of bucks under heat stress were investigated.Methods: Forty adult Animal Production Research Institute line rabbit bucks were distributed randomly into four experimental treatments of ten rabbits each. The first treatment was fed the commercial pellet diet (CPD) without supplementation and served as a control. The other three treatments were fed CPD supplemented with EVOO (300 mg), BET (1,000 mg), and GIN (200 mg) per kg diet for 3 consecutive months during the summer season.Results: Supplementation of EVOO, BET, or GIN improved (p<0.05) the sexual desire, progressive motility, vitality, intact acrosome and membrane integrity, sperm cell concentration, sperm outputs and fertility. Seminal plasma total proteins, globulin, total antioxidant capacity, glutathione and glutathione S-transferase, and initial fructose increased (p<0.05), while total lipids, aspartate and alanine aminotransferases and malondialdehyde decreased (p<0.05) compared with the control. In comparing the natural antioxidants treatments, GIN evoked the largest improvement.Conclusion: The inclusion of GIN (200 mg/kg diet) appeared to improve the sexual desire, semen quality and oxidative stress of bucks. This may be a beneficial supplement for the management of rabbit bucks used in natural mating or artificial insemination.

Animal husbandry development is influenced by various factors, with heat stress (HS) being a significant factor. The aim of this experiment was to explore the potential of natural antioxidants such as vitamin C (VITC), vitamin E (VITE), lycopene (LYC), and allicin (AL) in enhancing growth, immune function and maintaining the redox status of fattening rabbits under HS. Male weaning rabbits (n = 150, 5 weeks of age) were randomly assigned to 5 groups. The rabbits were fed a basal diet (control group) or supplemented with 40 mg of vitamin E (VE40), 5 mg of vitamin C (VC5), 150 mg of lycopene (LYC150), or 150 mg of allicin (AL150) per kg of diet, respectively, under summer Egyptian conditions. The overall temperature humidity index (THI) value was 29.76, indicating severe HS during the experimental period. The findings indicated that all dietary supplemented groups showed significant improvements in live body weight at 8 weeks (P < 0.0001) and 11 weeks (P < 0.05) of age compared to the control group. The feed conversion ratio (FCR) was improved with all additives (P < 0.05), while feed intake and carcass traits were not affected by the treatments (P > 0.05). The AL group had the highest dressing percentage compared to the other groups (P < 0.05). Feeding stressed rabbits with antioxidant supplements resulted in a higher hemoglobin concentration compared to the control group (P < 0.05). Aspartate transaminase (AST), triglycerides, and creatinine levels were decreased with all additives as compared to the control group (P < 0.05). Total protein and albumin were significantly higher in AL group than in other groups (P < 0.05). The serum Immunoglobulin G (IgG) was significantly increased, while tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), and interferon gamma (IFN-γ) were decreased by all feed additives (P < 0.05). Immunoglobulins (IgA and IgM) did not differ among all experimental groups (P > 0.05). Serum total antioxidant capacity (TAC) and glutathione (GSH) levels were higher in all supplement groups compared to the HS group (P < 0.05). All dietary supplements significantly reduced malondialdehyde (MDA) levels in liver tissues and blood serum compared to the control group (P < 0.05). Collectively, allicin emerged as a potent shield against heat stress, bettering lycopene and vitamins E and C in safeguarding the well-being of growing rabbits.

Red tilapia eggs one day post fertilization (dpf) were exposed to coenzyme Q10 (CoQ10) at rates of 0, 5, and 10 mg/L for control, treatment 2 (C5), and treatment 3 (C10), respectively, without exchanging water and until the larval mouth-opening stage. Fertilized eggs of red tilapia exposed to different concentrations of CoQ10 were hatched at rates (p > 0.05) between 38 to 54.67%. The yolk-sac diameter at the 2nd day post hatching (dph), ranged from 1.85 to 1.87 mm in depth and 1.63 to 1.88 mm in width and was not altered by the CoQ10 treatments. Similarly, red tilapia survival (p > 0.05) ranged from 22.67 to 32%. On 6 dph, a slight percentage (2.08%) of survived fishes exposed to high CoQ10 dose (C10) exhibited larval deformation in the form of an axial curvature of the spine in the abdominal and caudal region. Larvae displayed a normal structure of the esophagus folds in all fish groups, and larvae in the C5 group displayed the longest folds and widest muscularis layer, followed by fishes in the C10 group and the control. Red tilapia fry on 30 dph treated with CoQ10 possessed higher antioxidant potentials in terms of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) compared to the control. In conclusion, treating Red tilapia fertile eggs with 5 mg/L CoQ10 improves the growth, gut structure, and antioxidant efficiency of the produced larvae.