https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:28510 Thu 13 May 2021 04:21:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:39099 0.05) sperm concentration (1.20 ± 3.68x109 sperm/ml) than the EE samples (1.11 ± 3.51x109 sperm/ml). The percentage live sperm in the fresh semen samples did not differ among Namaqua Afrikaner (67.76 ± 1.94percent), Dohne Merino (68.59 ± 1.94percent) and Dorper (72.82 ± 1.98percent) rams. The percentage live sperm for all three breeds dropped considerably after freezing to 17.76 ± 2.03percent, 17.86 ± 2.03percent and 22.72 ± 2.07percent respectively. It remained constant for all the breeds from 7 until 90 days after freezing, indicating that length of storage should not have an effect on percentage live sperm for semen collected via AV or EE. Percentage live sperm of the frozen-thawed semen of the Namaqua rams was lower than that of the Dorper rams, indicating that the Namaqua semen collected via EE did not freeze as well as that of the Dorper semen. In conclusion, neither fresh nor frozen-thawed Dorper and Dohne Merino semen collected via EE did differ significantly. Furthermore, except for semen volume, Dorper and Dohne Merino semen collected via AV did not differ significantly whether evaluated as fresh or frozen-thawed semen. However, both Dorper and Dohne Merino rams produced semen with higher motility and a higher percentage live sperm post-thaw when the semen samples were collected via an AV than via EE. From these results it can therefore be postulated that if Namaqua semen were collected via AV it could have a higher post-thaw percentage live sperm than if semen was collected via EE. Advanced further studies are necessary to investigate the reason for the lower post-thaw survival rate of sperm of the Namaqua Afrikaner rams. This is necessary as semen stored in a cryobank for breeding and conservation purposes for this endangered breed has to be of high quality. Such resources as cryobanks are expensive and funds cannot be wasted on preserving inferior samples that could not fertilize an ovum when needed. The low percentage of live sperm obtained with the frozen-thawed samples in this, as well as other studies on indigenous breeds, is an indication that further research is needed into more suitable freezing protocols. It can be concluded that Namaqua Afrikaner semen cannot be frozen successfully for the purpose of storage in a cryobank, when using a freezing protocol based on Triladyl® as extender. Furthermore, any increase in post-thaw survival rate of sperm will be beneficial and it is therefore suggested that all efforts be made to solve the problem of the Namaqua Afrikaner rams that do not want to ejaculate into an artificial vagina.]]> Thu 13 May 2021 00:06:08 SAST ]]>