Effect of equilibration time in plasmatic membrane integrity and cinetic of boar spermatozoa

• Grant number: 17/20796-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2018
• End date: February 28, 2019
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: André Furugen Cesar de Andrade
• Grantee: Matheus Pasini Martins
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The cryopreservation of boar semen, still have great possibility of growth in the participation of artificial inseminations worldwide. Many characteristics favor an application of cryopreservation at the commercial level, such as greater durability of the dose used, allowing the modern swine breeding to take better advantage of a breeder's genetic capacity. However, despite still presenting low fertility rates, compared with in natura or refrigerated semen, that diminish their large-scale on field use, these disadvantages could be corrected with the development and improvement of preservation techniques. Among the techniques with potential to decrease cytoplasmic damage in spermatozoa is the equilibrium time, especially when the technique is performed at 5 ° C. Therefore, the present project aims to evaluate the influence of the equilibrium time at the protocols of cryopreservation of boar semen, due to the characteristics of plasma membrane integrity, such as the kinetics of swine spermatozoa. For this purpose, five boars of a commercial hybrid line will be used. Four ejaculates of each animal 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, concentration and sperm morphology. After the analysis, 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 morphofunctionality, such as kinematics (CASA) and membrane integrity by flow cytometry. For the statistical analysis, the effects obtained from the experimental procedures will be analyzed with previous verification of the residues normality and homogeneity of the variances. The original or transformed data will be submitted to PROC MIXED using the SAS program (v. 9.3). (AU)