Supplementing rooster sperm with Cholesterol-Loaded-Cyclodextrin improves fertility after cryopreservation.

Little is known about the effects of Cholesterol-Loaded Cyclodextrin (CLC) on post-thaw semen quality in chicken. The aim of the present study is to investigate the efficacy of CLC levels (0, 1, 2 and 3 mg/mL Schramm diluent) on post-thawed semen quality and fertility in two breeds of chicken Pradu Hang Dum (native chicken) and Rhode Island Red. Semen samples of each breed were pooled, divided into 4 aliquots and diluted with Schramm diluents, cooled to 5 °C when DMF was added (6% of final volume). Semen straws were subjected to cryopreservation using the liquid nitrogen vapor method. Post-thawed sperm motility, viability, acrosome integrity, mitochondrial function, and the Malondialdehyde (MDA) level were determined. The fertility of frozen semen was tested by inseminating laying hens. Post-thaw motility between Pradu Hang Dum and Rhode Island Red was no different; but Rhode Island Red had a higher semen viability and live cell intact acrosomes than Pradu Hang Dum (P < 0.05). The percentage of high functioning mitochondria in the Pradu Hang Dum was higher than the Rhode Island Red. CLC at 2 and 3 mg/mL supplementation was associated with improved viability of frozen semen; that is, acrosome integrity and mitochondrial function (P < 0.01), albeit having no effect on MDA levels. The sperm with 1 mg/mL CLC yielded a significantly better fertility (P < 0.01). CLC (1 mg/mL) improved the quality of frozen rooster semen. There was no interaction among breeds and CLC on post-thaw semen quality and fertility.

Chuaychu-Noo N ，Thananurak P ，Chankitisakul V ，Vongpralub T ... -  《-》

Effect of cholesterol-loaded cyclodextrin on cryosurvival and fertility of cryopreserved carp (Cyprinus carpio) sperm.

Addition of cholesterol-loaded cyclodextrin (CLC) to the diluents of mammalian semen increased stability and rigidity of phospholipid hydrocarbon chains of plasma membrane during sperm cryopreservation process. CLC has been tested successfully as cryoprotectant in various livestock sperm cryopreservation protocols but its efficacy for cryopreserving of fish sperm has not previously been tested. In the present study, different cholesterol loaded cyclodextrin concentrations were evaluated for the cryopreservation of carp (Cyprinus carpio) sperm. Sexually mature fish were induced to spermiation and ovulation with Ovopel. The extenders were prepared by using 300 mM glucose and 10% DMSO supplemented with different concentrations of CLC (0.5, 1.0, 1.5, 2.0, 2.5, and 3.0mg per 120×10(6) spermatozoa) and without CLC (control). The pooled semen was diluted separately at a ratio of 1:3 (v/v) by using CLC extenders. Diluted semen placed into 0.25 ml straws were equilibrated at 4°C for 15 min and frozen in liquid nitrogen vapor. Fertilization was conducted using a ratio of 1×10(5) spermatozoa/egg. Fresh sperm with no treatment showed the greatest sperm motility, duration of motility, viability, and fertilization results compared to the other tested cryopreserved and control groups (p<0.05). Supplementation of 1.5 mg CLC to the extender showed the best cryoprotective effect for sperm motility, duration of motility, and viability against freezing damage in comparison to extenders containing 2.5 mg, 3.0 mg CLC, and control group (p<0.05). Cryopreserved sperm containing 1.5 mg CLC provided greater result in term of fertilization success when compared to other extenders containing 0.5, 2.5, and 3.0 mg CLC or control (p<0.05). The amount of CLC effected post-thaw sperm quality and fertility as a dose-dependent manner. It is concluded that treatment of cholesterol-loaded cyclodextrin for carp sperm cryopreservation significantly improves cell cryosurvival and fertilization.

Yildiz C ，Yavas I ，Bozkurt Y ，Aksoy M ... -  《-》

Effects of k-carrageenan supplementation or in combination with cholesterol-loaded cyclodextrin following freezing-thawing process of rooster spermatozoa.

This experimental research purposely seeks to explore the effect of supplementing k-carrageenan (k-CRG) or CLC (cholesterol-loaded cyclodextrins) or the combined effect of k-CRG and CLC as supplements of antioxidants to an extender for rooster semen freezing. A total of 75 neat pooled ejaculates were collected twice a week from twenty-five (25) commercial line arbor acres broiler roosters (30 wks) during the experimental period. In each replicate, semen samples (n= 15, three ejaculates per rooster) were pooled and divided into nine equal aliquots, and each aliquot was diluted with one of the following extender supplemented with k-CRG, CLC, and k-CRG + CLC after which it was subjected to cryopreservation process using the "pellet" method. In study I, the supplementation of extenders with k-CRG was in five equal aliquots as follows; (0.2, 0.4, 0.6, 0.8) mg/mL and control group (k-CRG 0) mg/mL while in Study II, there was a combination of both k-CRG + CLC (0.4 mg/mL + 1.5 mg/mL, respectively), 0.4 mg/mL k-CRG, 1.5 mg/mL CLC and control group. Sperm quality parameters, endogenous antioxidant enzymes, lipid peroxidation (MDA) and ROS were all assessed after the freeze-thaw process. Our findings in study I indicated that at post-thaw, an optimum 0.4 mg/mL k-CRG supplementation in the extender improved semen quality parameters, endogenous enzymes, MDA and ROS in comparison to the control group. Interestingly prior to the freeze-thaw process, it was depicted in study II that combined k-CRG + CLC (0.4 mg/mL+1.5 mg/mL) inclusion in the extender provided maximum protection to sperm quality parameters, endogenous enzymes, MDA and ROS in comparison to 1.5 mg/mL CLC and control group at post-thaw. Besides, there was also a significant difference observed in the extenders supplemented with combined k-CRG + CLC (0.4 mg/mL +1.5 mg/mL) when compared to 0.4 mg/mL k-CRG for semen quality parameters and endogenous antioxidant enzymes (SOD, CAT, and GPx) but no significant difference was observed for MDA and ROS. Also, there was a significant difference observed in the extender supplemented with 1.5 mg/mL CLC when compared to the control group for semen quality parameters, SOD, CAT, and MDA but no significant difference for GPx and ROS at post-thaw. In conclusion, k-CRG at an optimal dosage of 0.4 mg/mL proved effective for improving post-thaw sperm quality but its combined addition k-CRG + CLC at an optimal concentration of (0.4 + 1.5) mg/mL in the extender provided greater protection to the rooster spermatozoa at post-thaw.

Li W ，Appiah MO ，Zhao J ，Liu H ，Wang J ，Lu W ... -  《-》

Effect of organic selenium dietary supplementation on quality and fertility of cryopreserved chicken sperm.

Oxidative stress due to cryopreservation has been considered as a major factor in sperm damage. Supplementation of the diet with different concentrations of organic selenium has been proposed to improve the quality of fresh and frozen-thawed semen in different breeds of roosters. Sixteen Pradu Hang Dum (Thai native) and 16 Rhode Island Red roosters were used in this study. Four levels of selenium supplementation between 0 and 0.9 ppm were examined. After 14 days of feeding, semen samples were collected twice a week and the fresh semen was evaluated. Then semen from each group was pooled and cryopreserved. The fertility of frozen-thawed semen was determined by inseminating 48 layer hens. Supplementation of diets with 0.3, 0.6 and 0.9 ppm selenium improved the fresh semen in terms of sperm viability and normal morphology (P < 0.01). Sperm concentration increased (quadratically, P < 0.001) with increasing dietary selenium levels. Meanwhile, post-thawed semen quality in terms of sperm motility, viability, live with intact acrosome and functioning mitochondria improved significantly with selenium treatments of 0.6 and 0.9 ppm, and lipid peroxidation was decreased (P < 0.001) and fertility improved (P < 0.05) with those levels of selenium treatment. In addition, there were differences between breeds with respect to some fresh or frozen semen quality parameters (P < 0.05). In conclusion, the breed affected both fresh and frozen semen. Even there were no statistically significant differences in the parameters from groups 0.6 and 0.9 ppm on frozen-thawed semen quality, but the highest sperm concentration was found in 0.6 ppm. Therefore selenium supplementation of diets at 0.6 ppm was recommended to improve the quantity and quality of fresh and frozen semen.

Chauychu-Noo N ，Thananurak P ，Boonkum W ，Vongpralub T ，Chankitisakul V ... -  《-》

Effect of cholesterol or cholesteryl conjugates on the cryosurvival of bull sperm.

Amorim EA ，Graham JK ，Spizziri B ，Meyers M ，Torres CA ... -  《-》