DILUTION AND FREEZING OF OVINE SEMEN

Abstract

Nine experiments were conducted to dilute the ram semen' and evaluation of the revival of the frozen semen. During the present work, the effects of 5 different extenders, method of addition of extender, glycerol level, and duration of equilibration period, cooling' rate, freezing rate and thawing rate were studied. Results recommended using triscitric-fructose-egg yolk-glycerol-extender or skim [ilk• tris--citric-fructoseegg yolkglycerol-extender on one-step at dilution' rate 1:6 (v/v) after fast cooling the fresh semen from 30--32°C to 15°C over 10 minutes, and 14.5% glycerol level, equilibration period of 4.5h, freezing rate from 4.0°C to -16.5°C over 4 minutes and thawing the frozen semen at 100°C/4 second then at 42°C/5 second with tris#citric• acid-fructoseegg yolk-glycerol--extender or 100°C/5 second then at 42°C/5 second with skim milk-tris--citric acid-fructoseegg yolk-• glycerol-extender. This protocol resulted in over 77.9% and 86.8% postthawing recovery rate for motility as of initial and equilibrated semen respectively, with the first extender and 75.9 and 82.8% respectively, for the second extender.