Studies of ovarian and uterine physiology and improvement of assisted reproductive technologies to elevate reproductive efficiency in cattle: hormone assays

• Grant number: 20/10659-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2020
• End date: April 30, 2021
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Roberto Sartori Filho
• Grantee: Felipe Pinheiro Bittar
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 18/03798-7 - Studies on ovarian and uterine physiology and improvement of Assisted Reproduction Technologies to increase reproductive efficiency in cattle, AP.TEM

Abstract

The present proposal aims at obtaining an scholarship for an undergraduate student to help with experiments that aim to clarify physiological aspects related to ovulation and pregnancy maintenance in bovine females submitted to artificial insemination (AI) or embryo transfer (ET). In addition, it is intended to develop strategies to increase efficiency and / or simplify the use of fixed-time artificial insemination (FTAI) or embryo production protocols. The project will be developed at the Luiz de Queiroz School of Agriculture - Esalq, USP in partnership with the Federal University of Paraíba, FMVZ - Botucatu, FEALQ, Texas A&M University, Alta Genetics do Brazil, Londrina State University, University of Wisconsin-Madison and private companies. It is a project with a series of experiments that will require numerous hormone assays, some of which are not well established in our laboratory. The Department of Animal Science at ESALQ has equipment for hormonal dosages by ELISA and Chemiluminescence techniques. In this project, the fellow will be mainly involved in the collection and processing of blood samples for the measurement of plasma progesterone. It is intended that the fellow gets involved in laboratory analysis (P4) at ESALQ, and we intend to send him to the USA to follow the dosages performed there. Blood samples from cows and heifers will be collected in Vacutainer tubes, containing heparin to obtain plasma. After harvesting, the blood will be centrifuged at 1700 X g for 15 min at 4oC and the plasma stored at -20oC for later use. P4 concentrations will be compared using the ELISA test, according to Rasmussen et al. (1996) with the Chemiluminescence technique (commercial kit from Immulite). The comparisons will be made regarding precision, accuracy, cost and time spent in the tests, to evaluate the cost-benefit of each technique.