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Improvement of alternative techniques to radioimmunoassay for hormone assays using samples from studies on anovulatory condition and influence of insulin on reproduction in dairy cows

Grant number: 15/07446-0
Support type:Scholarships abroad - Research
Effective date (Start): September 01, 2015
Effective date (End): August 31, 2016
Field of knowledge:Agronomical Sciences - Veterinary Medicine - Animal Reproduction
Principal Investigator:Roberto Sartori Filho
Grantee:Roberto Sartori Filho
Host: Milo Wiltbank
Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
Local de pesquisa : University of Wisconsin-Madison (UW-Madison), United States  

Abstract

In addition to studying the physiology and reproductive biotechnologies in Holstein cows associated with Grants number 2014/03580-0 and 2014/22885-7, we intend to develop robust tests for ELISA's hormone assay to replace the Radioimmunoassay technique, which has presented many difficulties in implementation and importation in Brazil. The objective of this proposal is to evaluate and compare assays for measurement of plasma or serum progesterone (P4), estradiol (E2) and insulin concentrations for use in experiments and allow physiologic understanding of the true hormone concentrations, as well as to understand the quality and limitations of each test. The techniques used for dosage of P4, E2 and insulin are radioimmunoassay, ELISA and chemiluminescence. Blood will be sampled from the animals involved in the project 2014/22885-7 and 2014/03580-0, and a minimum of 100 samples will be analyzed per assay. Concentrations of plasma and serum will be compared. Data analysis will be performed by analysis of variance, logistic regression and correlation test. The projects involved in the proposal are: 2014/03580-0, that aims to evaluate the role of insulin in the modulation of follicular and luteal function, and to understand the influence of insulinogenic diet on embryo production, on the expression of liver enzymes (Cytochrome P450 2C, 3A and aldo-keto reductase 1C and 1D) and on the circulating concentrations of P4 in non-lactating Holstein cows. The proposal 2014/22885-7, aims to estimate the incidence of anovulatory condition in dairy cattle, and to understand the mechanism, identify the risk factors and the factors involved in the establishment and maintenance of pregnancy in cows in anovulatory condition. When returning to Brazil, after 12 months, the goal is to establish a Partnership Laboratory for the scientific community with various options of hormone assays. Several publications will be produced during this period. In addition, in relation to projects, we hope to better understand how diet can influence embryo production, and to identify risk factors and management techniques to decrease the incidence of anovulatory condition, and find measures to increase the fertility of dairy cows affected by this condition.