The use of Folltropin® diluted in a slow release carrier (MAP5®) previously to the follicular aspiration increases the efficiency of the in vitro embryo production programs in Holstein donors

The study evaluated the effect of the donor superstimulation prior to the ovum pick-up (OPU) with different FSH-P (Folltropin®; Tecnopec) doses diluted in a slow release carrier (hyaluronic acid, MAP5®, Bioniche) in the in vitro embryo production (IVP). A total of 90 non-lactating Holstein donors was distributed into four different groups: Control (CON; n=22); Folltropin 200 mg (FOLL; n=23); MAP5/Folltropin 200 mg (M200, n=22) and MAP5/Folltropin 300 mg (M300, n=23). On a random day of the estrous cycle (Day 0) all cows received an intravaginal progesterone device (P4; Primer®, Tecnopec) and 2mg of estradiol benzoate (BE, RIC-BE®, Tecnopec), intramuscular (IM). On Day 4 and Day 5, the FOLL group received four decreasing doses of Folltropin IM; the MAP5 groups (40mg/mL) received a single dose (IM) on Day 4 AM. The CON group received same protocol, however, with no superstimulatory treatment. The P4 devices were removed on D7 AM and cows were submitted to OPU. Immediately before the OPU, all visible follicles were quantified and classified according to their diameter [small ( 10 mm) follicles]. Data were analyzed by orthogonal contrast using the GLIMMIX procedure of SAS. The contrasts established were: C1 (Superstimulation effect): CON vs. (FOLL+M200+M300); C2 (MAP5 effect): FOLL vs (M200+M300); C3 (dose effect): M200 vs. M300. A greater (C1: P<0.0001) proportion of medium follicles was observed in animals submitted to superstimulation [FOLL: 64.3 (301/468); M200: 67.9 (347/511); M300: 66.5% (300/451)] compared to CON group (19.2%, 68/355). Also, greater number of aspirated follicles (CON: 16.1 ± 1.1; FOLL: 20.4 ± 1.4; M200: 23.2 ± 2.3; M300: 19.6 ± 1.6; C1: P = 0.01), total oocytes retrieved (CON: 13.1 ± 1.0; FOLL: 16.5 ± 1.2; M200: 19.5 ± 2.1; M300: 15.4 ± 1, 4: C1: P = 0.01), viable oocytes (CON: 9.3 ± 0.7; FOLL: 12.2 ± 1.2; M200: 15.6 ± 1.7, M300: 11.4 ± 1.2; C1: P = 0.02), cleavage rate [CON 75.6 (155/205); FOLL: 85.1 (239/281); M200: 79.6 (273/343); M300: 79.4% (210/263); C1: P=0.002] and blastocysts per OPU session (CON: 2.4 ± 0.5; FOLL: 3.7 ± 0.7; M200: 4.7 ± 0.7; M300: 3.1 ± 0.6; C1: P = 0.06) were observed in females submitted to the superstimulation treatment compared to the CON group. Additionally, cows of the M200 group obtained greater recovery rate [M200: 84.0 (429/511) vs. M300: 78.7% (355/451); C3: P = 0.009), higher number of viable oocytes (M200: 15.6 ± 1.7 vs. M300: 11.4 ± 1.2 C3: P = 0.04) and blastocysts per OPU session (M200 4.7 ± 0.7 vs M300: 3.1 ± 0.6, C3: P = 0.06) compared to animals of the M300 group. In conclusion, the administration of Folltropin, associated or not with MAP5®, previously to OPU increases the efficiency of in vitro embryo programs in non-lactating Holstein cows. Additionally, the use of 200mg of Folltropin associated with MAP5 was sufficient to achieve superior results in in vitro embryo programs in nonlactating Holstein cows.