FERTILITY OF FROZEN CHICKEN SEMEN AFTER INTRAVAGINAL AND INTRAUTERINE INSEMINATIONS USING VARIOUS CONCENTRATIONS AND EQUILIBRATION TIMES OF DIMETHYLSULFOXIDE AND A RANGE OF FREEZING AND THAWING RATES

The use of dimethyl sulfoxide (DMSO) as a cryoprotective agent for freezing chicken semen was examined with respect to intravaginal (I.V.) and intrauterine (I.U.) inseminations. Semen diluted in DMSO was subjected to various freeze rates, equilibration times and thawing rates. Various concentrations of DMSO were examined as was the effect of diluting DMSO with phosphate buffer and Lake''s solution. There was no significant (P > 0.05) effect of rate of freeze (ranging from 1.3.degree.-7.2.degree. C/min) on fertility. Rapid thawing in an ice bath resulted in a longer (P < 0.05) duration of fertility than thawing at 1.degree. C/min, but had no effect on percent fertility during duration or percent hens fertile. Equilibration time and concentration of DMSO had no significant (P > 0.05) effects on fertility. There was an interaction between insemination route and Lake''s solution vs. phosphate buffer with respect to duration of fertility. I.U. insemination apparently resulted in superior fertility to I.V. inseminations with semen frozen in DMSO.