P-146: Fertility and Flow Cytometric Evaluations of Frozen-Thawed Rooster Semen in Cryopreservation Medium Containing Low Density Lipoprotein

Background: Frozen-thawed rooster semen is not reliable for use in artificial insemination in commercial stocks. Low density lipoprotein (LDL) has been assessed for effectiveness as a cryoprotectant in the extender to improve the quality of frozen-thawed rooster semen. Although LDL has been evaluated in a few studies in other species for semen cryopreservation, to date, no study has been conducted that examines this cryoprotectant for freezing fowl semen. Thus, this study aims to analyze the effects of different concentrations of LDL (0, 2, 4, 6, and 8%) in a Beltsville extender for cryopreservation of rooster spermatozoa. Materials and Methods: In experiment one, motion parameters, membrane integrity, acrosome integrity, apoptosis status, and mitochondria activity were assessed after freeze-thawing. The highest quality of frozen-thawed semen was selected to be used for evaluation of the fertility rate in experiment two. Semen was collected from six roosters, twice weekly, then extended in a Beltsville extender that contained different concentrations of LDL as follows: 0 (control), 1% (BLDL1), 2% (BLDL2), % (BLDL4), 6% (BLDL6), and 8% (BLDL8). Results: Supplementation of the Beltsville extender with 4% LDL produced the most significant percentage of motility (43.1 ± 1.3), membrane integrity (59.4 ± 2.1), mitochondria activity (49.1 ± 1.19), and viable spermatozoa (45 ± 2.28) compared to control treatment with the results of 22.7 ± 1.3, 38.4 ± 2.1, 40.25 ± 1.19, and 37.8 ± 2.28 for motility, membrane integrity, mitochondria activity, and viability, respectively. In experiment two, more significant percentage of fertility rate was observed for frozen-thawed semen in the extender supplemented with 4% LDL (49.5 ± 1.6) compared to the control (29.2 ± 2.9). Progressive motility and acrosome integrity were not affected by LDL levels in the extenders Conclusion: The results showed that supplementation of the Beltsville extender with 4 % LDL resulted in higher quality of frozenthawed rooster sperm.