Determination of reproductive parameters in gilts using cryopreserved spermatozoa in extender with NETs inhibitor or antioxidants

• Grant number: 25/05529-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2025
• End date: October 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: André Furugen Cesar de Andrade
• Grantee: Luan Mendes de Oliveira Bezerra
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/09891-0 - Small molecules and miRNAs as cryotolerance and fertility biomarkers in boar semen, AP.R

Abstract

In swine production, artificial insemination (AI) is the main biotechnology currently employed; however, the use of cryopreserved semen still presents challenges, particularly in maintaining fertility and sperm function when compared to chilled semen. Among the main factors that can affect sperm viability are the damages caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS), as well as the immune response of the female reproductive tract, especially NETosis-the formation of neutrophil extracellular traps. In this context, the use of antioxidants and NETosis inhibitors in the semen thawing medium aims to minimize cellular damage and improve pregnancy and fertility rates. Therefore, this study will evaluate the effects of thawing extenders containing an antioxidant (BHT) and/or a NETosis inhibitor (PGE¿) on the reproductive parameters of gilts (pregnancy rates, litter size, fertility, and embryonic viability). The results may contribute to improving the use of frozen semen, overcoming the limitations associated with low fertility and the impact of the uterine immune response after insemination.Therefore, this study will evaluate a protocol using an ovulation inducer, performing transrectal ultrasonography to monitor follicular growth and determine the optimal time for fixed-time AI (FTAI) with cryopreserved semen. Additionally, Doppler ultrasonography will be used to identify changes in uterine blood flow patterns in the different proposed treatments. Furthermore, the effects of thawing extenders containing an antioxidant (BHT) and/or a NETosis inhibitor (PGE) on reproductive parameters of gilts (pregnancy rates, litter size, fertility, and embryonic viability) will be assessed. The results may contribute to improving the use of frozen semen by overcoming the limitations associated with low fertility and the impact of the uterine immune response post-insemination. Combining FTAI with an improved thawing medium could enhance reproductive efficiency and increase productivity in the sector.