Superovulatory response and in vivo production of embryos in Santa Inês ewes in function of FSH dosage

Author(s)

Giovanna Serpa Maciel

• Document type: Master's Dissertation
• Press: Jaboticabal. 2016-06-29.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2016-05-16
• Advisor: Maria Emilia Franco Oliveira; Marcus Antônio Rossi Feliciano; Wilter Ricardo Russiano Vicente

Abstract

The aim of this study was to evaluate the effect of exogenous FSH dose in gonadotropin treatment on superovulatory response and in vivo production of embryos in sheep. Twenty four Santa Inês ewes were submitted to synchronization of estrus with intravaginal progesterone device (CIDR®) inserted into D0 and remained until D8. At the start of the protocol (D0) and in the removal of the intravaginal device was administered 0.125 mg of PGF2a synthetic analog (Sincrocio®). The gonadotrophin treatment was initiated 48 hours prior to removal of progesterone (D6) when the females were randomly divided into three groups according to the total dose of exogenous porcine FSH: G200 (n = 8) - 200 mg; G133 (n = 8) - 133 mg; and G100 (n = 8) - 100 mg. The total doses been administered in 8 applications at intervals of 12 hours. On D6, the females received 300 IU eCG. Were performed B mode ultrasonography and color Doppler, in order to verify follicular growth of ovulatory wave, area of vascularization of the follicular wall and the moment of ovulation. Six days after the the onset of estrus, the embryos were collected and assessed morphologically and regarding the percentage of apoptotic cells. Was performed Kruskal Wallis test and Dunns post-test, and the rates were compared using Chi-square test. The variable area of the follicular vascularization was compared between treatments and moments by ANOVA with repeated measures in time and Tukey post-test, with correlation analysis (Pearson) for the number of follicles and area of the vascularization. The significance level used for the statistical tests was 5% (P> 0.05). The duration of estrus of sheep was lower in G200 compared to G133 and similar to G100 (P = 0.0218). The ovulatory moment occurred later in G200 (P = 0.0037); reduction of the size of the preovulatory follicle and rate of reduction of the size of preovulatory follicles were higher (P = 0.0027 and 0.0024, respectively) for sheep of the G200 compared to G100, though similar to G133. The area of the follicle vascularization varied with relation to moments, gradually increasing with a peak between 216 and 232 hours and then declined (P <0.001). The ovulation rate and anovulatory failures showed statistical differences between groups (P = 0.016), the G100 showed higher ovulation rate in relation to the G1333 and similar to G200 and the G100 showed the lowest value of anovulatory failures in relation to G133 and similar to G200. The number of non-fecundated structures and unfertilized rate were higher in animals pertaining to G100 (P = 0.008 and 0.0477, respectively) compared to the G200 and similar to G133; the number of viable embryos and viability rate was higher (P = 0.038 and 0.0493, respectively) for sheep of the G200 compared to G133, though similar to G100; the percentage of apoptotic cells was higher in the group G100. It was concluded that the dose of 200 mg showed the best results of the studied variables and is therefore not indicated the use of smaller doses of FSH (100 mg and 133 mg) in superstimulation ovulatory treatments in Santa Inês ewes. (AU)

• FAPESP's process: 14/04614-6 - Effect of the dose of FSH in gonadotrophic superstimulation on superovulatory response and in vivo production of embryos in Santa Inês ewes
• Grantee: Giovanna Serpa Maciel Feliciano
• Support Opportunities: Scholarships in Brazil - Master