COMPARISONS BETWEEN 3 DIFFERENT EXTENDERS FOR CANINE INTRAUTERINE INSEMINATION WITH FROZEN-THAWED SPERMATOZOA

Ejaculates from 7 dogs were obtained on the same day and were pooled. This pooled semen was separated into 3 equal fractions and processed s imultaneously, the only difference being in the extender used for free zing. The extenders were laiciphos (containing laiciphos, egg yolk, di stilled water and glycerol- Group 1); Tes/Tris (containing Tes/Tris, e gg yolk, distilled water and glycerol- Group 2); and biociphos (contai ning biociphos with glycerol in it, egg yolk and distilled water- Grou p 3). Spermatozoa were conditioned in 0.5ml French straws and presente d normal characteristics before freezing and after thawing. The sperm concentration of the pooled was 683 x 10(6) sperm/ml; sperm motility w as above 95%, the percentage of live spermatozoa was above 95% and was of good quality and mobility. Characteristics of the spermatozoa afte r thawing were the same for spermatozoa frozen with laiciphos and Tes/ Tris. Mean sperm concentration was 201.5 +/- 4.95 x 10(6) sperm/ml, sp erm motility was 65%, the percentage of live spermatozoa was 80% and t he quality of motility was good. Spermatozoa frozen with biociphos had the following post-thaw characteristics: sperm concentration was 201 x 10(6) sperm/ml, sperm motility was 50%, the percentage of live sperm atozoa was 78% and the quality of mobility was medium. Abnormalities w ere less than 15% for all spermatozoa after thawing. Intrauterine arti ficial inseminations were performed by laparoscopic intrauterine insem ination twice at Days 3 and 5 after the estimated LH peak in 15 normal ly cyclic Beagle bitches (5 per group) presenting normal hormonal prof iles. There were no differences between groups. The females were insem inated with 1.0 ml of spermatozoa (concentration of 200 x 10(6) sperm/ ml) diluted with 1.0 mi of extender. A 60% pregnancy rate was obtained in bitches inseminated with frozen-thawed spermatozoa extended with l aiciphos or Tes/Tris and 100% in bitches inseminated with spermatozoa extended with biociphos. Females inseminated with laiciphos, Tes/Tris and biociphos had a mean Litter size of 5 +/- 2.6, 3 +/- 1 and 3.4 +/- 1.3 pups, respectively. This study demonstrated that post-thaw assess ment of sperm characteristics is not the best technique for evaluating sperm fertility after freezing of for assessing different semen exten ders.