This project aims to verify if short periods of holding time (period of time that the sperm remains in contact with seminal plasma at 17ºC before being subjected to cryopreservation at -196 ° C), can replace long periods (24 hours). To perform this experiment, six ejaculates will be collected from 6 boars (n=36). After semen analyses, it will be extended in BTS and allocated into treatments: T0 (centrifuged after extended), T4 (4 hours contact with seminal plasma at 17 ° C), T8 (8 hours contact with seminal plasma at 17 ° C), T12 (12 hours contact with seminal plasma at 17 ° C) and T24 (8 hours contact with seminal plasma at 17 ° C). After the holding time, the samples will centrifuged (500 x g / 10 min) and the pellets will suspended in a freezer extender of boar semen to a final concentration of 300 x 106 spermatozoa/mL, subsequently packaged into 0.5 ml straws and cryopreserved by an automatic system. After thawing, samples will be evaluated by motility characteristics (CASA), plasma and acrosomal membrane integrity, mitochondrial membrane potential and fluidity of plasma membrane lipids by flow cytometer. Data will be submitted to analysis of mixed models (PROC MIXED), using the SAS (2002).
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