Studies of ovarian and uterine physiology and improvement of assisted reproduction technologies to increase reproductive efficiency in cattle

Abstract

Experiments are being carried out to help clarify physiological aspects related to ovulation and maintenance of pregnancy in bovine females submitted to artificial insemination (AI) or embryo transfer (ET). In addition, studies are evaluating strategies to increase the efficiency and/or simplify the use of timed artificial insemination (TAI) or embryo production protocols. The project proposes carrying out dozens of balanced experiments within six main themes, three of which are on reproductive physiology (1 - Mechanisms involved in maintaining pregnancy; 2 - Ovarian, uterine and endocrine changes in response to different treatments or hormone concentrations; 3 - Ovarian dynamics and embryo quality in TAI protocols) and three others focused on reproductive biotechnologies (4 - Reproductive efficiency in Nellore cows and heifers submitted to TAI protocols; 5 - Reproductive efficiency in dairy cows submitted to TAI protocols; 6 - In vivo embryo production in superovulated cows inseminated with refrigerated sexed sperm, both in beef and dairy cattle. In these experiments, more than 20,000 animals are being used, where there are sperm evaluations of the semen used, transrectal ovarian and uterine ultrasonographic examinations, blood samples for hormone assays and uterine flushings (when relevant) to study the dynamics and ovarian and uterine functions, embryo quality and fertility. Within the theme, the Post-Doctoral fellow will be involved in numerous activities, focusing on helping with hormonal assays, ultrasound evaluations and writing scientific articles, but with greater involvement with the experiment entitled "Validation of the sperm binding test and characterization of the uterine tube epithelial cell culture in vitro to predict fertility in bulls".