Holding time and equilibration time: Its effects on cryopreserved boar spermatozoa

• Grant number: 19/01124-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: March 18, 2019
• End date: July 17, 2019
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: André Furugen Cesar de Andrade
• Grantee: Marina da Silva Passarelli Zanatta
• Supervisor: Marc Yeste Oliveras
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Universitat de Girona, Spain
• Associated to the scholarship: 17/10821-2 - Evaluation of equilibration time on boar semen cryopreservation protocols: a physiological and morphofunctional study, BP.MS

Abstract

The use of cryopreserved semen in modern swine production accounts for only 1% of all artificial inseminations performed worldwide, hence, its applicability is still very restricted, demanding more studies aiming at improving this biotechnology, which would lead to its full implementation into the commercial level. On this path, several techniques have been developed and applied in recent decades in order to improve the freezability of semen, such as changing cryopreservation protocols, the use of specific fractions of the ejaculate, holding time as well as the application of equilibration time. Thus, the aim of the present project is to evaluate the application of the equilibration time in boar semen cryopreservation protocols and deepen the understanding of this action in relation to the physiology and morphofunctional of swine spermatozoa. For this purpose, five boars of a commercial hybrid line will be used. Twenty ejaculates will be collected by the gloved-hand technique. After collection, semen samples will be analyzed for motility characteristics by the computerized system for semen analysis and concentration. Semen samples will be subjects to a 24 hours period of holding time. After the holding time period, samples will be destined to the cryopreservation procedure, remaining under equilibration time (5°C) for periods of 0, 2 and 4 hours. After cryopreservation, 4 straws will be thawed at 37° C for 30 seconds for analyzes of sperm physiology and morph functionality, such as kinematics (CASA), determination of free cysteine radicals in the sperm head, the immunoprecipitation against HSP70 and Western-blot assessments. For the statistical analysis, the SAS software (v. 9.3) will be used and the data will be analyzed for variance and normality of the residues. Data that does not meet the assumptions will be processed and submitted to the PROC MIXED. The averages will be analyzed by the Tukey test and the ideal time of equilibrium will be obtained through a polynomial regression equation. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PASSARELLI, MARINA DA SILVA; PINOTI PAVANELI, ANA PAULA; RAVAGNANI, GISELE MOURO; MARTINS, MATHEUS PASINI; PEDROSA, ANA CAROLINA; MASSAMI KITAMURA MARTINS, SIMONE MARIA; DE ALCANTRA ROCHA, NATHALIA RAISSA; BITTAR RIGO, VICTOR HENRIQUE; YASUI, GEORGE; YESTE, MARC; et al. Effects of different equilibration times at 5 degrees C on boar sperm cryotolerance. Animal Reproduction Science, v. 219, AUG 2020. (16/24690-4, 19/01124-1, 17/10821-2)