Influence of adding zeolite loaded with different charges to semen extender on sperm quality in rabbits after cryopreservation.

The aim of the present study was to investigate the effect of supplementing rabbit semen extender with zeolite loaded with different charges (Z+ or Z-, Z±) on sperm cryopreservation. Semen was collected from six healthy, fertile New Zealand rabbit bucks using an artificial vagina. The collected ejaculates were pooled and diluted with a tris-yolk fructose (TYF) extender supplemented with Z± (+16, +12, +8, -16, -12, and -8) at a concentration of 1% for a final sperm concentration of 25 × 106 sperm cells/mL. The diluted semen samples were then cryopreserved in 0.25 mL straws and stored in liquid nitrogen for 1 month. To evaluate sperm quality, we examined sperm progressive motility, vitality, morphological abnormalities, and plasma membrane integrity. In addition, apoptotic rates were determined using flow cytometry and by examining sperm ultrastructure under a transmission electron microscope (TEM). Moreover, total antioxidant capacity and markers of lipid peroxidation were measured in the extender after thawing. Addition of Z± had a positive effect on progressive motility, vitality, and membrane integrity after an equilibration period and post-thawing as compared with the controls (P < 0.05). Z± supplementation, particularly with a strong negative charge, also decreased the percentages of apoptotic and necrotic sperm cells compared to controls (P < 0.05), as shown both by flow cytometry and TEM. This was not associated with any marked effects on the oxidative biomarkers in the extender. In conclusion, addition of Z± to semen extender improved post-thawing sperm quality by improving sperm characteristics, decreasing apoptosis, and minimizing sperm damage during cryopreservation.

Influence of allicin administration on reproductive efficiency, immunity and lipid peroxidation of rabbit does under high ambient temperature.

This study investigated the effect of daily oral administration with allicin levels (0, 5 and 10 mg/kg of female body weight), 30 days pre-insemination, on reproductive performance in vivo and in vitro, immunity, and oxidative stress of rabbit does under high ambient temperature. Niliparous NZW does (n = 105) were randomly divided into three groups (35 in each) treated with 0, 5 and 10 mg allicin dissolved in 2 ml distilled water, respectively, for 30 days pre-insemination. At the end of treatment (30 days), does were artificially inseminated with fresh diluted semen of 20 fertile NZW bucks. Reproductive performance and ovulatory response parameters were determined. Serum biochemicals, enzyme activity, immunoglobulins (IgG and IgM) and antioxidant status were determined on day 30 of treatment. Serum progesterone and prolactin were determined pre-insemination (30 days of treatment), on 15 days of pregnancy and 7 days post-partum. Results showed that both allicin levels increased live litter size, and bunny viability rat and litter size at birth and weaning. Allicin levels increased ovulation rate and improved embryo quality. Number of total follicles decreased only with 10 mg allicin. Progesterone increased pre-insemination, 15 days of pregnancy and 7 days post-partum progesterone by allicin levels. Prolactin pre-insemination and on day 7 post-partum increased with 10 mg allicin. Serum total proteins, albumin, globulin, IgG and IgM increased, while glucose, aspartate and alanine aminotransaminases, and thiobarbituric acid reaction decreased by both allicin levels. In conclusion, the mechanism by which allicin administration 30 days pre-insemination to improve the reproductive performance of rabbit does is based on that allicin can play an important role, as a natural exogenous antioxidant, increasing immune response and reducing lipid peroxidation.