الفهرس 
Freezing Semen ExtendersOnly 14 pages are availabe for public view
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Abstract
This study was carried out at the Laboratory of Physiology and Biotechnology, Animal Production Department, Faculty of Agriculture, Mansoura University, in cooperation with Animal production Department, Faculty of Agriculture, Tanta University, Egypt during the period from May 2019 to February 2020. The aim of this study was to evaluate the effect of adding zeolite nanoparticles loaded with different charges in semen extender on rabbit sperm cryopreservation. Also, to test the theory whether artificial insemination of doe rabbits by fresh semen dilution with extender supplementation with different charges affects the sexual ratio of newborns or not. Six healthy, fertile rabbit bucks were used, and the ejaculates were obtained using an artificial vagina. Only those ejaculates that scored ≥70% for mass motility, progressive motility, liveability, and membrane integrity, ≤15% abnormality and sperm concentration of 100x106 sperm cells/ml were selected for the experiment. Semen of all bucks were pooled and diluted in a tris-yolk fructose (TYF) extender supplemented with zeolite nanoparticles loaded with different charges (+16, +12, +8, -16, -12 and -8) at concentration 1% for a final sperm concentration of 25 x 106 sperm cells/ ml. Diluted semen was packed in straws (0.25 ml) and stored in liquid nitrogen (-196 °C) for one month. After thawing, semen of each treatment was evaluated for sperm quality parameters, including sperm progressive motility, livability, morphological abnormalities and plasma membrane integrity. Apoptosis using flowcytometry and sperm ultrastructure by transmission electron microscope were also examined. Total antioxidant capacity and lipid peroxidation markers were determined in extender after thawing. Finally, the effect of supplementation zeolite nanoparticles loaded with different charges to rabbit semen extender on conception and kindling rates, litter size and sex ratio were checked in vivo using Seventy New Zealand white rabbits receptive females. Results showed that: 1- Addition of zeolite nanoparticles loaded with different charges had a positive effect (P<0.05) on sperm characteristics (progressive motility, livability and membrane integrity) after equilibration period and post-thawing as compared with the control. 2- It was interested to note that rabbit semen diluted with extender supplemented with zeolite nanoparticles loaded with positive charges (+16, +12 and +8) gave the higher progressive motility, vitality and membrane integrity after equilibration period. However, the lower abnormality after equilibration period was recorded with the treatment of zeolite nanoparticles with negative charges (-12 and -16). While, progressive motility, vitality and abnormality showed the best improvement in post-thawed rabbit buck semen diluted with extender supplemented with zeolite nanoparticles loaded with (+16) or (-16) charges. 3- Percentage of viable sperm increased (P < 0.05), while percentages of early apoptotic, apoptotic and necrotic sperm cells decreased (P < 0.05) in treatments of zeolite nanoparticles loaded with different charges as compared to control either by flowcytometry or transmission electron microscope. 4- It was interested to note that rabbit semen diluted with extender supplemented with zeolite nanoparticles loaded with negative charges (-16, and -12) gave the higher percentage of viable sperm and lower percentages of apoptotic and necrotic sperm. However, the lower percentage of early apoptotic sperm was recorded with the treatment of zeolite nanoparticles with positive charges (+12 and +8). While, positive charge (+16) or negative charge (-16) gave the higher percentage of intact sperm and lower percentages of apoptotic and necrotic sperm when examined with TEM. 5- In contrary, total antioxidants capacity in extender decreased (P < 0.05) and malondialdehyde and H2O2 concentration increased (P < 0.05) in treatments of zeolite nanoparticles loaded with different charges compared to control. 6- fertility trail showed insignificant effect on conception and kindling rates and litter size of rabbit does artificially mated by fresh extended semen supplemented with zeolite nanoparticles loaded with different charges. 7- Effect of extended fresh rabbit semen supplemented with zeolite nanoparticles loaded with different charges was not significant effect on sex ratio of bunnies born.