Influence of obesity and metabolic disturbs on the reproductive parameters of stallions

• Grant number: 24/10967-0
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2025
• End date: August 31, 2027
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Gabriel Augusto Monteiro
• Grantee: Gabriel Augusto Monteiro
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated researchers: Fernanda Saules Ignácio ; Frederico Ozanam Papa

Abstract

The neuroendocrine system relates by the secretion of chemical messengers, hormones and neurohormones, that determine the rhythms and intensity of the sperm and sexual hormones production.Moreover, the neural system communicates the nutritional statement to GnRH neurons by the detectionof nutrients and metabolic hormones. Obesity and energy deficiency or excess may significantlydisturb the reproductive activity. The present study aims to evaluate the influence of adiposity andmetabolic alterations on the testicular temperature and blood flow perfusion, on the hormonalconcentrations and on the kinetic and functional sperm parameters in the stallion. For the experimentaltrial, thirty-six stallions will be divided into three groups: Group 1 - Control (normal score and insulin);Group 2 - (obese but normal insulin); and Group 3 - (insulinemic dysregulation). Before the start ofthe experiment, animals will be submitted to a complete andrological exam and to a hormonal profileevaluation (LH, FSH, IGF-1, thyroid hormones, testosterone, estradiol and insulin). With thebeginning of the experiment, the following exams will be done weekly over six consecutive weeks:thermography, testicular doppler ultrasound evaluation and blood samples collection for LH, FSH,IGF-1, thyroid hormones, testosterone, estradiol and insulin dosages. Furthermore, seminal collectionswill be done within the same frequency for sperm kinetic (computerized sperm analysis - CASA),sperm morphology (differential interference contrast - DIC) and structural analysis of the sperm cell(flow cytometry). A semen aliquot will destinated to freezing and post thawing analysis of the sameparameters. For the statistical analysis, all data will be tested for normal distribution andhomoscedasticity of variance by Shapiro-Wilk and Bartlett tests, respectively. Means of parametricdata will be submitted to variance analysis (ANOVA) and differences compared by Tukey test (P,0.05)and non-parametric data will be submitted to Kruskal-Wallis (P<0.05). Statistical analysis will be runby software R (2018). (AU)