BIOTECHNOLOGY IN THE REGULATION OF PRODUCTIVE AND REPRODUCTIVE STATUS AND HEALTH IN DAIRY COWS

Primary objective for the project is to perform systematic field trials of biotechnological procedures for the control of reproduction in dairy farms in RS. All biotechnological procedures are based on the combination of synthetic prostaglandin F2alpha, gonadotrophin releasing-hormone, pituitary gonadostimulins, and synthetic progesterone. All of them are aimed for one of the following goals: 1) induction and synchronization of estrus, 2) ovulation, 3) follicular wave control, and 4) luteal development and 5) luteal regression control. Efficiency of biotechnological procedures is evaluated by the following data: production and reproductive farm records, body condition score, sex hormones determination in blood serum and milk, animals health and welfare evaluation. Effects of selenium on placental retention in cows that were induced to parturition using synthetic prostaglandin is also going to evaluated. Following data are going to be used for selenium effects evaluation: blood plasma parameters (Gpx, progesteron, estradiol, cortisol, T3, T4), full blood parameters (Gpx, Se, Hb, differ-ential leucocytes formula), pathohystology of placentomas (hystochemistry of T cells and/or macrophages subpopulations). At the wery end an optimal strat-egy for reproduction control on dairy cow farms in RS is going to be recommended.