Erratum to: 56 SINGLE LAYER CENTRIFUGATION THROUGH PURESPERM® 80 IMPROVES QUALITY OF CRYOPRESERVED DOG SPERMATOZOA

Abstract

Density gradient centrifugation with PureSperm® (PureSperm® 40 + PureSperm® 80; Nidacon International, Mölndal, Sweden) has been satisfactorily used to enhance the quality of dog semen samples; however, no studies have been performed on the effect of single layer centrifugation (SLC) with PureSperm® on frozen–thawed dog semen. The aim of this study was to investigate if SLC with PureSperm® 80 can improve the post-thaw semen quality of dog. Semen from 5 dogs was collected by digital manipulation. Two ejaculates from each dog were centrifuged with Tris-based extender, supernatant was removed, and sperm pellet was suspended to a final concentration of 300–400 × 106 sperm mL–1 with CaniPROTM Freeze A plus 20% egg yolk at 22°C. Extended semen was cooled to 5°C within an hour and then diluted to a final concentration of 150–200 × 106 sperm mL–1 in CaniPROTM Freeze B plus 20% egg yolk at 5°C, loaded in 0.5-mL plastic straws and frozen horizontally in ranks placed 4 cm above the surface of liquid nitrogen vapors for 10 min, after which they were directly placed in liquid nitrogen. After 24 to 48 h of storage, straws were thawed in a water bath at 37°C for 30 s. After thawing, semen samples were divided in 2 aliquots: one of them was used as control and the other one was processed by SLC PureSperm® 80. Assessment of sperm motility (assessed by computerized-assisted semen analysis), morphology (Diff-Quick staining), and viability [triple fluorescent stain of propidium iodine/isothiocyanate-labeled peanut (Arachis hypogaea) agglutinin/Rhodamine 123] were evaluated in control and treated semen samples. Data were studied by ANOVA. Results are expressed as mean ± SEM. Significant (P < 0.001) differences were found between SLC-treated and control semen for sperm motility (percentage of total motile spermatozoa: 93.65 ± 0.05 v. 83.79 ± 0.13; percentage of progressive motile spermatozoa: 79.38 ± 6.66 v. 54.61 ± 16.11), morphology (86.45 ± 0.01 v. 83.51 ± 0.01), and viability (percentage of viable sperm with an intact acrosome: 58.32 ± 0.04 v. 36.50 ± 0.17; percentage of viable sperm with an acrosome reaction: 2.81 ± 0.01 v. 9.74 ± 0.21). Based on our results, we can conclude that SLC with PureSperm® 80 is an alternative and successful method for improving the quality of frozen–thawed dog spermatozoa, selecting good-quality spermatozoa (motile, morphologically normal, viable, and acrosome intact spermatozoa) from the rest of the semen sample.