[Developmental competence of Dromedary camel oocytes fertilized in vitro by frozen-thawed ejaculated and epididymal spermatozoa]

ABSTRACT

The present study aimed to compare the in vitro fertilizing capacity of frozen-thawed ejaculated and epididymal spermatozoa in order to standardize the semen preparation protocol for camel in vitro fertilization [IVF]. Semen samples were collected from 7 Dromedary camels by means of artificial vagina [AV]. Ten cauda epididymes were obtained from slaughtered adult camels, isolated, incised and rinsed for obtaining the sperm rich fluid. Ejaculated and epididymal spermatozoa were processed for cryopreservation. Fresh and frozen-thawed ejaculated and epididymal spermatozoa were evaluated for motility, livability, membrane and acrosomal integrities. Frozen-thawed ejaculated and epididymal spermatozoa were used to fertilize camel mature oocytes in vitro. The results showed that, the progressive motility of freshly collected epididymal spermatozoa was significantly [P<0.05] higher than ejaculated spermatozoa [49.25 +/- 1.75 vs. 38.50 +/- 1.50%, respectively]. The viability index of epididymal spermatozoa was significantly [P<0.05] higher than that of ejaculated spermatozoa [96.63 +/- 2.45 vs. 84.00 +/- 4.08, respectively]. The post-thaw acrosome and membrane integrities of epididymal spermatozoa were significantly [P<0.05] higher than those of ejaculated spermatozoa. Morula and blastocyst rates of camel oocytes in vitro fertilized by frozen-thawed epididymal spermatozoa [59.4 +/- 0.8, 19.12 +/- 0.7 and 10.29 +/- 0.7%, respectively] were significantly [P<0.05] higher than those fertilized by frozen-thawed ejaculated spermatozoa [48.27 +/- 3.1, 11.63 +/- 1.1 and 5.43 +/- 0.8%, respectively]. In conclusion, the Dromedary camel frozen epididymal spermatozoa have the capacity to endure cryopreservation, fertilize oocytes and produce embryos in vitro better than ejaculated sperm