Equine semen microbiology and its implications on the endometrium after artificial insemination

• Grant number: 23/15862-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2024
• End date: November 30, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Eneiva Carla Carvalho Celeghini
• Grantee: Maria Fernanda Lema Carneiro
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Controlled reproduction in horses is fundamental to the economic growth of the equine industry and the preservation of genetic integrity. Endometritis, inflammation of the endometrium, negatively impacts the reproductive capacity of mares. The etiology of endometritis is diverse and can be associated with both infectious and non-infectious causes. The possibility of uterine contamination by semen, due to the presence of microorganisms that may be pathogenic, is a cause for concern, considering the few studies in the literature. The proposed study aims to evaluate uterine contamination in mares by microorganisms present in semen and its relationship with persistent post-breeding endometritis after artificial insemination. For this experiment, at least 8 stallions and a cycle of 20 mares will be used, with ages ranging from 3 to 15 years and different breeds, undergoing follicular and uterine monitoring every 12 hours until ovulation, by palpation and ultrasound, with ovulation being induced (follicle e35mm). Insemination will be performed with cryopreserved semen immediately after ovulation is detected. At the same time, endometrial samples will be collected for microbiological and cytological evaluation and the mares will be inseminated with cryopreserved semen. The semen will be thawed to prepare the inseminating dose, and samples will be separated for microbiological evaluation. 48 hours after AI, endometrial samples will be collected again for microbiological and cytological evaluation. Pregnancy diagnosis will be performed by ultrasound 14 days after AI. The data will be evaluated by ANOVA. Fertility will be assessed using the Fisher test, considering p d0.05.