To alleviate the deleterious effect of heat stress during summer conditions on male rabbits' reproduction, 40 V Line adult rabbit bucks (on av. 8 mo old) were divided into 4 experimental groups and exposed to temperatures ranging from 23 to 36°C. Bucks in the 1 st , 2 nd , 3 rd , and 4 th group were supplemented with 0, 50, 100 or 150 mg of Chinese royal jelly (RJ)/kg twice per week, respectively, over a 20-wk period. Semen quality and blood biochemical constituents were evaluated. RJ at any dose exhibited a significant increase (P<0.05) in rabbits' sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the untreated controls. Plasma total protein, albumin, globulin, glucose and high density lipids (HDL) concentrations were significantly (P<0.05) boosted in the RJ groups compared to the controls. In contrast, RJ treatment resulted in a significant (P<0.05) reduction in plasma total lipids, triglycerides, cholesterol and low density lipids (LDL) concentrations. Treatment with RJ significantly boosted (P<0.05) testosterone concentration in the RJ groups to reach 110, 120 and 128%, respectively, of the control group. Improved kidney and liver functions were observed in the RJ bucks groups where plasma creatinine, urea concentrations, aspartate aminotransferase and alanine aminotransferase enzyme activities were significantly (P<0.05) decreased by RJ treatments. Treating bucks subjected to heat stress by different RJ doses increased (P<0.05) total antioxidant capacity to 106, 111 and 115% of basal, but significantly reduced (P<0.05) malondialdehyde and thiobarbituric acid reactive substances compared to the untreated. It was concluded that Chinese royal jelly supplementation for heat-stressed male rabbits can counteract summer infertility and improve their physiological status.

No abstract

The aim of the present study was to investigate the long-term effect of using bee venom (BV) on the reproductive performance, immune, and health status of rabbit does and its effect on their litters. Sixty mature does, from Spanish V-line rabbit stock, were randomly assigned to four homogeneous groups with 15 does each. The 1 st , 2 nd and 3 rd groups were injected twice weekly under the neck skin with 0.1 ml solution contains 0.1, 0.2 and 0.3 mg BV/rabbit respectively. The 4 th group served as a control group. From the results, litter size at birth, litter weight and survival rate at weaning age as well as milk yield were significantly (p ≤ 0.05) increased in BV groups than in the control group. Serum estradiol 17β (E2) was significantly (p ≤ 0.05) higher (15%) in the rabbit does treated with BV compared to the control group. The treated does with BV at any study doses showed a gradual and significant (p ≤ 0.05) decrease (12%) in serum progesterone levels (P4) compared to the control. They also showed a significant (p≤0.05) increase in conception (17%) and fertility rates (10%) compared to the control does. Treatment of rabbit does with BV caused a gradual and significant (p ≤ 0.05) reduction in both aspartate aminotransferase (AST) (16%) and alanine aminotransferase (ALT) (37%) liver enzyme activities. Additionally, results have shown that BV resulted in a gradual and significant (p ≤ 0.05) increase in total antioxidant capacity (TAC), antioxidative enzymes such as glutathione S-transferase (GST) and glutathione peroxidase (GPx), serum IgG, IgM and IgA levels with significant (p ≤ 0.05) decrease in malondialdehyde (MDA) and thiobarbituric acid reactive substances (TBARS) in BV groups compared to the control group. Results suggest that BV can be used in rabbit farming as an effective and safe alternative to artificial chemical drugs (sexualstimulants) to improve certain reproductive traits, immune response and health.

Sixty low-conception rate does aged 18 to 24 months (in four groups) were used to determine the effect of replacement of prostaglandin (PG) F2α (PGF2α) injection by oral administration with sunflower oil (Sun)

This study was conducted to assess the impacts of using two essential oils, rosemary and ginger, on growing rabbits’ performance, carcass traits, meat composition, blood biochemicals, and the redux status of growing New Zealand White (NZW) rabbits. A total of 120 unsexed NZW rabbits, 42-days-old, were assigned randomly to five experimental groups (n = 24, 6 replicates with 4 rabbits each). The first group received a basal diet (control), the second to fifth groups were dietary supplemented daily with rosemary essential oil (REO) and ginger essential oil (GEO) at doses of 0.25 and 0.5% for each supplementation (REO-0.25, REO-0.5, GEO-0.25, and GEO-0.5), respectively. The growth traits were studied for 7 weeks, from the 7th to the 13th week of the rabbits’ age. The results revealed that final body weight, weight gain, and average daily gain increased significantly (p < 0.01) in the REO-0.5 and GEO-0.5 treatments compared to the control group. Daily feed intake decreased (p = 0.005) in essential oil treatments. Meanwhile, the feed conversion ratio improved significantly (p = 0.001) in REO and GEO at the high doses compared to the control group. The weight percentages of liver and giblets increased (p < 0.001) with both treatments of REO and GEO compared to the control group. The dietary supplementation with REO and GEO did not affect (p > 0.05) the meat composition of Longissimus dorsi and hind leg muscles. Meanwhile, REO and GEO supplementation significantly decreased cholesterol levels in the rabbit meat. Thiobarbituric acid reactive substance concentrations decreased by 10 and 15% in the meat of REO-0.5 and GEO-0.5 treatments, respectively, compared to the other groups. In the same trend, REO and GEO treatments induced a significant (p = 0.001) reduction in the plasma cholesterol concentrations and triglycerides compared to the control. The total antioxidant capacity increased by 7.60% and the malondialdehyde decreased by 11.64% in the plasma of GEO-0.5 treatment than the control. Thus, the dietary supplementation of REO and GEO have a beneficial effect in improving the productivity and meat quality of growing rabbits.

No abstract

This study was carried out to assess the effect of Boron supplementation on male rabbit's reproductive performance. A total of 20 V. Line (V.L) adult rabbit bucks were divided into four equal experimental groups (5 bucks for each). Groups 2, 3 and 4 were fed rations supplemented with 17.5, 35 and 70 mg boron/kg feed in the form of boric acid (100, 200 and 400 mg boric acid, respectively) over 8 weeks. The first group was served as a control group. Results obtained by the Boron groups revealed that adding Boron to rabbit bucks rations at any tested doses resulted in a non-significant increase in the ejaculate volume of male rabbit by approximately 25% above the control group. Adding Boron at any dose exhibited a significant increase (p#0.01) in sperm concentration, total sperm output, sperm motility, live sperm and normal sperm compared to the control group and the high Boron dose had the highest effect on previous measurements compared to the low and medium Boron doses. Opposite trend was shown in the reaction time (libido) and seminal plasma fructose concentration which showed a significant decrease in these parameters in the Boron treated groups compared to the control. Plasma total protein, glucose, total lipids and triglycerides concentration were boosted in the Boron groups compared to the control (p#0.01) for glucose and triglycerides measurements. On the contrary, treated male rabbits with Boron at any tested doses resulted in a significant reduction in plasma cholesterol concentration. Blood and seminal plasma AST and ALT enzymes activities showed a tendency to decrease by Boron treatments compared to the control group. Treating bucks by different Boron doses resulted in a significant increase (p#0.01) in Total Antioxidant Capacity (TAC) to reach 110, 128 and 163% of blood plasma and 114, 121 and 122% of seminal plasma compared to the control value. On the other side, adding Boron to bucks rations did not affect the activity of seminal plasma alkaline phosphatase enzyme. Blood testosterone hormone had a tendency to increase in the Boron groups compared to the control group but this increase was not significant. It could be concluded that feeding rabbit bucks on rations containing the studied Boron doses results in a significant improvement in semen quality characteristics and had a positive effect on their physiological status.

This study aimed to evaluate in vitro and in vivo dietary supplementation with different levels of natural or nano-zeolite forms on rumen fermentation patterns and nutrient digestibility. In the in vitro experiment, a basal diet (50% concentrate: 50% forage) was incubated without additives (control) and with natural zeolite (10, 20, 30 g/kg DM) or nano-zeolite (0.2, 0.3, 0.4, 0.5, 1.0 g/kg DM) for 24 h to assess their effect on ruminal fermentation, feed degradability, and gas and methane production using a semi-automatic system of in vitro gas production (GP). The most effective doses obtained from the in vitro experiment were evaluated in vivo using 30 Barki goats (26 ± 0.9 SE kg body weight). Goats were allocated into three dietary treatments (n = 10/treatment) as follows: control (basal diet without any supplementations), natural zeolite (20 g/kg DM diet), and nano-zeolite (0.40 g/kg DM diet). The in vitro results revealed that only the nano-zeolite supplementation form quadratically (p= 0.004) increased GP, and the level of 0.5 g/kg DM had the highest GP value compared to the control. Both zeolite forms affected the CH4 production, linear, and quadratic reductions (p < 0.05) in CH4 (mL/g DM), consistent with linear increases in truly degraded organic matter (TDOM) (p = 0.09), and propionate molar proportions (p = 0.007) were observed by nano zeolite treatment, while the natural form of zeolite resulted in a linear CH4 reduction consistent with a linear decrease (p = 0.004) in NH3-N, linear increases in TDOM (p = 0.09), and propionate molar proportions (p = 0.004). Results of the in vivo experiment demonstrated that the nutrient digestibility was similar among all treatments. Nano zeolite enhanced (p < 0.05) the total short-chain fatty acids and butyrate concentrations, while both zeolite forms decreased (p < 0.001) NH3-N compared to the control. These results suggested that both zeolite supplementation forms favorably modified the rumen fermentation in different patterns.