PERSPECTIVE: Rooster Spermatozoa Cryopreservation and Quality Assessment.

Unsuccessful rooster fertility following cryopreservation may be linked to specific changes in spermatozoa quality, which can be determined using various methods. These determinations also facilitate the design of improved freezing and thawing processes. Here, we update the current state of methodologies available for the assessment of rooster semen quality after cryopreservation. Computer-assisted sperm analyses (CASA) is one of the main systems used to analyse motion parameters of spermatozoa (total motility, progressive motility and motion parameters). Moreover, fluorescent techniques and flow cytometry can improve the assessment of various aspects of semen quality (viability, acrosome status, mitochondrial potential, lipid peroxidation, DNA damage, lipid peroxidation and cell debris removal) using specific fluorescent markers such as ethidium bromide, Yo-Pro-1, Annexin V, propidium iodide, SYBR-14, PNA, JC-1, BODIPY, acridine orange and DRAQ5. Transmission electron microscopy also yields valuable information on spermatozoa ultrastructure. The application of these techniques to rooster spermatozoa is reviewed in relation to specific freezing techniques, the effects of cryoprotective agents (CPAs) and extenders, and the determination of spermatozoa quality after cryopreservation.