Synchronization effect of follicular wave growth in the production of buffalo oocytes

This study aims to investigate the effect of different protocols of follicular wave synchronization of bubaline oocytes donor regarding the number of follicles, the recovery rate, the number and quality of oocytes produced. 12 adult buffallo were used under different protocols that resulted in the aspiration of follicles guided by ultrasound (OPU) 3 to 4 days after the emergence of follicular wave. Each animal was tested at least three times for each treatment. The treatments were: Treatment 1 (T1): animals not filed with OPU held in random day of the estrous cycle; Treatment 2 (T2): follicular wave reset prior to aspiration of all ovarian follicles, performing the OPU 3-4 days later; Treatment 3 (T3): placement of intravaginal progesterone device for 6 days, together with 2 mg of estradiol benzoate, 50 mg of progesterone and 150μg of prostaglandin, the OPU done at the implant removal; Treatment 4 (T4): similar to T3, however, T4 was applied, 100mg of FSH, 36-48 hours prior to OPU. At the OPU procedure, animals were evaluated for the number and size of follicles, classifying them into small (2-5mm), medium (6-9mm) and large (≥9mm). After collection, the oocytes were processed and classified according to morphological characteristics: Grade A, Grade B, Grade C, Grade D, expanded or naked. Statistical analysis was performed under ANOVA / Duncan test or KruskalWallis test and the significance level was P 0.05); but it was lower than T3 (10.44 ± 0,92b) and T4 (b- 11.39 ± 0.67 P 0.05) between treatments. The synchronization treatments using hormones (T3, T4) or not (T2) did not alter the average number of follicles, as they did not differ from T1 (P u003e 0.05). There was no difference between the total number of follicles observed at the moment of OPU and between different treatments (P u003e 0.05). However, comparing the number of follicles between the same treatments, we noticed a higher number of small follicles in relation to medium and large follicles (P u003c 0.05). It was concluded that the proposed protocols were not efficient to improve the number and quality of the OPU recovered structures.