Investigation of the effect of repeated use of PRIVD on serum progesterone, estrogen levels, and ovulatory follicle diameter in pubertal heifers

Abstract

The purpose of this study was to evaluate the effect of reuse of progesterone-releasing intravaginal devices (PRIVDs) onserum progesterone, estrogen levels, and ovulatory follicle diameter in pubertal heifers. Three pubertal Holstein heifers were used inthe study for three different periods with the usage of three PRIVDs up to three times from day 0 to 7 according to the Latin squaremodel. Blood samples were collected on days 0, 3, 5, 7, and 9 for hormonal analysis. Ovulatory follicle diameter was measured bytransrectal ultrasonography 60 h after removal of the PRIVD. Serum progesterone demonstrated a significant relationship with deviceuse and day (P 0.05) and ovulatory follicle diameter (P > 0.05) did not differ significantly with the use of the PRIVD at day 9. Inthe present study, even the 3rd use of the PRIVD produced similar results as the first use. In conclusion, PRIVDs can be reused ormanufactured with low progesterone for heifers to reduce hormonal synchronization cost.