Comparison of density gradient and single layer centrifugation of stallion spermatozoa: Yield, motility and survival

• Published in: Equine veterinary journal 2009, Vol.41 (1), p.53-58
• Main Authors: Morrell, J.M, Dalin, A.M, Rodriguez-Martinez, H
• Format: Article
• Language: English
• Subjects: Animal and Dairy Science; Animals; cell death; centrifugation; Centrifugation, Density Gradient - methods; Centrifugation, Density Gradient - veterinary; colloidal centrifugation; density; density gradient centrifugation; Ejaculation; horse; Horses - physiology; Husdjursvetenskap; Male; new methods; Population Density; Semen Preservation - methods; Semen Preservation - veterinary; single layer centrifugation; Specimen Handling - veterinary; Sperm Count - veterinary; sperm motility; Sperm Motility - physiology; sperm survival; sperm yield; spermatozoa; Spermatozoa - cytology; Spermatozoa - physiology; spermatozoa survival; stallion spermatozoa; stallions; TECHNOLOGY; TEKNIKVETENSKAP; Time Factors; Tissue and Organ Harvesting - methods; Tissue and Organ Harvesting - veterinary; Veterinary Science; Veterinärmedicin; yields
• ISSN: 0425-1644; 2042-3306; 2042-3306
• DOI: 10.2746/042516408X322139

Summary Reasons for performing study: A new, simpler, technique of colloidal centrifugation has recently been developed, designated single layer centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal centrifugation, density gradient centrifugation and single layer centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (38 ejaculates) were processed by the 2 methods of colloidal centrifugation. For both uncentrifuged and centrifuged samples, sperm yield was calculated and subjective sperm motility assessed over several days to provide an estimate of sperm survival. Some stored semen samples, held at 4°C overnight, were also available for testing. Results: For fresh, extended semen, a similar recovery yield of motile spermatozoa was seen for the 2 methods of preparation for single layers and density gradients, respectively. Sperm motility and survival rate were significantly improved by colloidal centrifugation compared to unprocessed ejaculate, without any significant difference between methods (SLC vs. gradient). However, the yield was reduced by 18–20% when cold‐stored semen was used for centrifugation compared to fresh semen; and more variation between ejaculates was observed than for fresh ejaculates. Again, sperm motility and sperm survival were improved in the centrifuged sperm preparations compared to stored, unprocessed ejaculates. Potential relevance: The 2 colloid centrifugation techniques produce equivalent sperm preparations in terms of sperm quality. However, the SLC method would be more practical and convenient for use in the field.