Comparison of slow freezing and vitrification methods for Venda cockerel’s spermatozoa

Comparison of slow freezing and vitrification methods for Venda cockerel’s spermatozoa

Masindi L. Mphaphathi, Dibungi Luseba, Ben Sutherland, Tshimangadzo L. Nedambale

Agricultural Research Council, Animal Production Institute, Germplasm Conservation & Reproductive Biotechnologies, Irene, RSA; Tshwane University of Technology, Faculty of Science, Department of Animal Sciences, Pretoria, RSA; University of the Free State, Department of Animal, Wildlife and Grassland Sciences, Bloemfontein, RSA

An improvement in avian semen cryopreservation is essential and has the potential to improve the cryo-gene banking efficiency. This study compared two cryopreservation methods (slow freezing and vitrification) and the effect of different thawing/warming temperatures (5℃, 25℃ and 41℃) on Venda cockerel’s spermatozoa. Semen samples from Venda cockerels were diluted with modified Kobidil+ extender supplemented with 8% dimethyl sulfoxide. Semen from each ejaculate was stained with nigrosin/eosin for viability examination. The cryopreserved samples were either slow cooled in 0.25 mL straw or vitrified in a solid surface vitrification (SSV) device. Semen straw or cryovial was stored in liquid nitrogen container. The straw or cryovial with sperm was thawed or warmed at 5?C, 25?C and 41℃ and analysed by a Computer-Aided Sperm Analysis (CASA). There was a significant difference in live/normal sperm between the semen donors. Cockerels spermatozoa cryopreserved by slow freezing (43%) and thawed at 5?C had a significantly higher survival and motility rate compared to vitrification (2.5%) method. In conclusion, there was higher rate of live/normal morphology sperm. Cryopreservation process reduces sperm motility and velocity rate regardless of cryoprevervation method and thawing or warming temperatures. However, slow freezing was a better method to maintain motility of spermatozoa following cryopreservation.

DOI: 10.4236/ojas.2012.23028