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Photodynamic therapy as an antimicrobial treatment of domestic rooster's semen: analysis of different pre-irradiation time, light irradiance and light radiant exposure

Grant number: 18/02849-7
Support type:Scholarships in Brazil - Master
Effective date (Start): March 01, 2019
Effective date (End): September 30, 2020
Field of knowledge:Agronomical Sciences - Veterinary Medicine
Principal Investigator:Ricardo Jose Garcia Pereira
Grantee:Gabriel Augusto Novaes
Home Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil


Brazilian poultry industry stands out in agribusiness once the country became the second largest global producer and the world's biggest exporter of chicken meat. Therefore, biotechnology innovations that enhance poultry breeding are highly relevant, in particular artificial insemination (IA). However, it is not rare that poultry ejaculates exhibit high levels of microorganism since cloaca is a common pathway for semen, urine and feces. In an attempt to control this contamination many semen extenders used in birds have antibiotics in their formula, an approach that have been lately challenged by some researchers because of its implications regarding bacterial resistance. Thus, aiming to create alternatives to the use of antibiotics, our laboratory initiated a research to adapt non-thermal light therapies to reduce contamination of semen from chicken roosters (Projeto IC FAPESP nº 2017/04457-6). Our preliminary data confirmed the antimicrobial potential of these therapies, but also stressed the need for adjustments to define an efficient protocol that controls the seminal microbiota without impairment of spermatozoa. Hence, in order to better adjust the photodynamic therapy (PDT) for poultry semen, this study proposes to investigate how alterations in pre-irradiation time with methylene blue (AM), in light radiant exposure (J/cm2), and light irradiance (mW/cm2) will affect sperm viability and bacteria in semen. Lastly, we will assess PDT effects on fertility (in vivo) of semen samples after irradiation.