Effect of cooling rate on sperm quality of cryopreserved Andalusian donkey spermatozoa

The aim of this study was to evaluate the effect of different cooling rates on post-thaw quality of cryopreserved donkey spermatozoa. Eighteen ejaculates from six adult Andalusian donkeys (three ejaculates per donkey) were collected using an artificial vagina. Pooled semen samples (two ejaculates per pool) were divided into three aliquots, and frozen in Gent freezing extender using three different cryopreservation protocols (P): P1 (conventional slow freezing, as control): semen pre-cooled in an Equitainer for 2 h and frozen in liquid nitrogen (LN2) vapour; P2 (controlled pre-freeze cooling rate): semen pre-cooled at a controlled rate for 73 min and frozen in LN2 vapour; and P3 (rapid freezing) semen frozen immediately in LN2 vapour. After thawing at 37 °C for 30 s, semen samples were assessed for motility, morphology, acrosome and plasma membrane integrity; spermatozoa were also tested for DNA integrity. Significant (P < 0.01) differences were found between the cryopreservation protocols for all sperm parameters evaluated, except for DNA integrity. Semen samples frozen using P2 showed significantly (P < 0.01) higher values for sperm motility, morphology, sperm membrane integrity, and acrosome integrity. On the contrary, P3 reduced sperm motility (P < 0.01) and increased the percentage of spermatozoa with damaged plasma membrane (P < 0.001). In our study, we demonstrated that the sperm of Andalusian donkey is particularly sensitive to the cooling rate used before freezing. Furthermore, Andalusian donkey semen can be successfully cryopreserved using controlled cooling rates combined with freezing in LN2 vapour.Fil: Demyda-Peyrás, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad de Córdoba; EspañaFil: Bottrel, M.. Universidad de Córdoba; EspañaFil: Acha, D.. Universidad de Córdoba; EspañaFil: Ortiz, I.. Universidad de Córdoba; EspañaFil: Hidalgo, M.. Universidad de Córdoba; EspañaFil: Carrasco, J.J.. Centro de Selección y Reproducción Animal; EspañaFil: Gómez Arrones, V.. Centro de Selección y Reproducción Animal; EspañaFil: Gósalvez, J.. Universidad Autónoma de Madrid; EspañaFil: Dorado, J.. Universidad de Córdoba; Españ

Differences in preservation of canine chilled semen using simple sperm washing, single-layer centrifugation and modified swim-up preparation techniques

This study compared the efficacy of simple sperm washing (SW), single-layer centrifugation (SLC) and modified swim-up (SU) techniques in the preparation of dog spermatozoa for cooling. Eighteen ejaculates, collected from three dogs (six per dog), were pooled (three ejaculates per pool) and divided into three aliquots: (1) one aliquot was washed and cooled at 5°C for 72h, considered as control (SW-control), (2) the second aliquot was selected by SLC through Androcoll-C and subsequently cooled in the same way as the SW-control samples (SLC-AC) and (3) the last aliquot was selected by a modified SU method with Androcoll-C and cooled as mentioned above (SU-AC). Assessment of sperm motility, sperm morphology, sperm membrane integrity and acrosome integrity were performed on aliquots of fresh semen and chilled-rewarmed samples. Sperm membrane integrity and progressive motility were significantly (P0.05). The recovery rates were not significantly (P>0.05) different between SW-control, SLC-AC and SU-AC samples. Our results confirm that SU-AC may be a successful method for the preparation of dog spermatozoa for cooling.Fil: Dorado, J.. Universidad de Córdoba; EspañaFil: Gálvez, M.J.. Universidad de Córdoba; EspañaFil: Demyda-peyrás, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad de Córdoba; EspañaFil: Ortiz, I.. Universidad de Córdoba; EspañaFil: Morrell, J.M.. Swedish: Sveriges Lantbruksuniversitet; SueciaFil: Crespo, F.. Ministerio de Defensa. Fondo de Explotación de los Servicios de Cría Caballar y Remonta. Centro Militar de Veterinaria de la Defensa; EspañaFil: Gósalvez, J.. Universidad Autónoma de Madrid; EspañaFil: Hidalgo, M.. Universidad de Córdoba; Españ