Banca de DEFESA: LARA NOGUEIRA SILENCIATO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LARA NOGUEIRA SILENCIATO
DATE: 27/01/2022
TIME: 08:00
LOCAL: INSTITUTO DE ZOOTECNIA
TITLE:

Effect of long-acting progesterone supplementation on embryonic, fetal, postnatal development and pregnancy loss in Nellore females

KEY WORDS:

Reproductive efficiency, TAI, early diestrus, progestin, pregnancy.

PAGES: 96
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUBÁREA: Produção Animal
SUMMARY:

SILENCIATO, Lara Nogueira. Effect of long-acting progesterone supplementation on embryonic, fetal, postnatal development and pregnancy loss in Nellore females. 2022. 87p. Thesis (Doctorate in Animal Science). Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, 2022. The present study aimed to evaluate the effects of long-acting injectable progesterone (P4LA), administered at the beginning of diestrus (seven days after insemination), on embryonic, fetal and postnatal development, as well as on pregnancy rate and gestaional loss in Nellore females. For that, two experiments were carried out, the first of which the objective was to determine the effects of P4LA supplementation on the pregnancy rate and on the gestational loss. Thus, 403 females (heifers and cows) were submitted to the same ovulation synchronization protocol to perform Timed Artificial Insemination (TAI). After performing the TAI, the animals were divided into two groups according to the score of body condition, cyclicity and calf presence so that in each group there was a similar proportion of females taking these three variables into account. The P4 group (GP4; n=208) consisted of females who received 150mg of P4LA (Sincrogest® Injectable, Ourofino, Cravinhos/SP), intramuscularly, in a single dose, and the Control group (CG; n=195) by females who received no hormonal supplementation after TAI. Pregnancy diagnosis was performed at 30 and 90 days post-TAI by transrectal ultrasonography. In the second experiment, the main objective was to evaluate the effect of P4LA supplementation on embryonic, fetal and postnatal development. For that, 119 pregnant females from experiment I were used. Blood samples were collected, on days 17 and 30 post-TAI, to determine the concentration of progesterone. Embryonic development was assessed at 30 days of gestation by ultrasonographic measurement of crown-to-rump length (CRL). To assess fetal development, the thoracic diameter (TOD) was measured at 45 days of gestation, taking the ultrasonographic measurement of the maximum distance between the lateral ends of the chest. Postnatal development was assessed by birth weight. Data from the two experiments were submitted to Pearson's linear correlation analysis, binary logistic regression and model adjustment for analysis of variance using the Wald test. The test statistic for the significance of the coefficients was performed by the Z test. Quantitative variables were compared using Student's t test at 5% probability. In experiment I, no significant difference was observed between the GP4 and CG groups for pregnancy rate and gestational loss (0.3 and 0.61, respectively). In experiment II, there was also no difference between groups supplemented or not with P4LA in relation to the concentration of progesterone measured on days 17 and 30 post-TAI (0.73 and 0.62, respectively) and no difference was observed for embryonic, fetal and postnatal development (0.59, 0.09 and 0.64, respectively). It is concluded that the use of P4LA at the beginning of diestrus was not an effective strategy to improve the pregnancy rate and reduce gestational loss, in addition to not interfering with the embryonic, fetal and postnatal development of Nellore females submitted to TAI.

BANKING MEMBERS:
Presidente - 1548043 - MARCO ROBERTO BOURG DE MELLO
Interno - 2142739 - RODRIGO VASCONCELOS DE OLIVEIRA
Interno - 2316004 - RONDINELI PAVEZZI BARBERO
Externo à Instituição - SÉRGIO TRABALI CAMARGO FILHO - PESAGRO-RIO
Externo à Instituição - ÂNGELO JOSÉ BURLA DIAS - UENF