Characteristics and cryopreservation of stallion spermatozoa

Advances in the cryopreservation of salmonid semen and suitability for a production-scale artificial fertilization program

During the past decade, semen cryopreservation techniques in salmonid fish have progressed to where fertilization rates obtained with preserved sperm approach those produced with fresh sperm. Recent advances in the collection, dilution and storage of salmonid spermatozoa are reviewed. The problems encountered during the development and examination of artificial insemination programs in warm-blooded animals are contrasted with those encountered in fish. This paper discusses the advantages of artificial fertilization, and the manner in which advances in cryopreservation techniques could aid in the development and expansion of concentrated, production-scale artificial fertilization programs in salmonid fish.

Effect of glycerol on motility, viability, extracellular aspartate aminotransferase release and fertility of stallion semen before and after freezing

The effect of different glycerol concentrations (0 to 5.3 per cent) on motility, viability and aspartate aminotransferase (AST) release of stallion spermatozoa was studied before and after deep-freezing. Addition of glycerol to a TRIS-fructose-egg yolk diluent used to extend stallion semen had no effect on motility and viability of spermatozoa and it did not increase AST release. Inclusion of glycerol in the extender only partially preserved the motility and viability of stallion semen during deep-freezing. A fertility trial revealed that concentrating stallion semen by centrifugation, followed by addition of the extender containing 7.5 per cent glycerol, had little effect on fertility and a 70 per cent conception rate was obtained in 10 mares after inseminations during one service period. Freezing and thawing horse spermatozoa, even in the presence of 7.5 per cent glycerol, significantly decreased the fertilisation rate.