Effects of skim milk and tris extender on frozen-thawed canine sperm morphology

Abstract

This study was aimed to compare the effects of freezing dog semen in straws in 0.1 % fat bearing Skim Milk-Glucose (SMG) extender with the routinely used TRIS-Fructose-Citric acid (TFC) extender regarding the post-thaw motility, acrosome and total morphologic defects rate. Four German shepherd male dogs of 2-3 years under the same managemental conditions on a private kennel were used. Six ejaculates per each dog (total 24 ejaculates) were collected digital manipulation. Two extenders used were 20% egg yolk containing TFC and 10% egg yolk containing SMG extenders. Semen was divided into two split parts and one was extended with TFC and the other with SMG extenders at 26°C at a rate 1:1 and cooled to 5°C in an hour. Cooled semen samples were further extended with 10% (v/v) glycerol containing extender (for an hour) at equal rates (final glycerol rate 5%). Following glycerolisation semen samples were filled into 0.5 mL straws and equilibrated for an hour at 5°C. Straws were frozen at -110°C liquid nitrogen vapour for 7 min. Labeled straws were stored in separate canisters in liquid nitrogen at -196°C. Six straws for TFC extender and six straws for SMG extender were stored to be examined. Straws were thawed at 45°C for 60 sec. Post-thaw motility rate of TFC and SMG extended semen samples were, respectively 48.54±8.27 and 51.97±7.51%. Acrosome and total morphologic defect rates were 41.04±9.44and51.17±9.05% for TFC; 38.04±13.60 and 46.67±12.68% for SMGextender, respectively. It has been founded that when the post-thaw sperm traits of straws frozen dog semen was evaluated, SMG extender have been successful at least as much as TFC extender. © Medwell Journals, 2012.