Estimulación ovárica con FSH vía epidural en un protocolo de aspiración ecoguiada (OPU) en vaquillas mestizas alimentadas a base de forrajes con diferentes niveles de fibra

Abstract

The research was carried out on a commercial farm Juticaray, located in the city of Cañar, at altitude of 3230 meters above sea level. The response to ovarian stimulation with 250 International Units (IU) of Follicle-stimulating Hormone (FSH) applied epidurally was evaluated in crossbred Holstein heifers (n=8) levels with high (42 days) and low (28 days) levels. of fiber in their diet, on ovarian response, assessed according to the number of antral follicles observed on the day of ultrasound-guided aspiration (OPU); number and quality of cumulus oocyte complexes (COC's) recovered by the OPU technique. Four treatments were established: T0=control (28-day pasture); T1=28-day grass + 250 IU of FSH; T2=control (42- day pasture); T3=42 day grass + 250 IU of FSH. The forage mixture consumed by the heifers was made up of 80.08% grasses and 7.4% mainly legumes. Crude fiber levels were similar between 28- and 42-day-old pastures (P>0.005); However, the 28-day grass had higher values of humidity, crude protein and ash compared to the 42-day grass (P<0.05). The overall average number of follicles visualized on the day of the OPU was 20 ± 1.07 follicles, 76% were aspirated (15.2 ± 1.11 follicles visualized) and 60.5% of COCs were recovered. (12.1 COC's), when classifying 56.2% were suitable and 43.8% were not suitable. The % recovery of COCs from T3 was 17.6% more compared to its control (T2) and 8.2% compared to T1. Furthermore, T3 obtained 3 times more suitable COCs compared to T2. It is concluded that administering 250 IU improves the number of aspirated follicles and the number and quality of recovered COCs, regardless of the phenological age of the grass that the heifers consumed.