Efeito da somatotropina bovina recombinante (rbST) na produção in vivo e na maturação in vitro de oócitos bovinos da raça Sindi / Effect of recombinant bovine somatotropin (rbST) on the in vivo production and in vitro maturation of bovine oocytes of the Sindi breed

A fim de avaliar o efeito de diferentes doses da rbST sobre a dinâmica folicular, a produção e a maturação in vitro de oócitos, 20 vacas Sindi, divididas em três grupos, receberam um dispositivo de progesterona intravaginal, estradiol e PGF2α, além de 2mL de solução salina (grupo controle), 250 (grupo rbST 250) ou 500mg de rbST (grupo rbST 500). Cinco dias depois, realizou-se a ovum pick up, e os complexos cumulus-oócitos (CCOs) recuperados foram selecionados, classificados e maturados in vitro. Os dados de contagem foram comparados pelo procedimento glht (General Linear Hypothesis Test), e os dados em porcentagem foram submetidos ao qui-quadrado, no programa estatístico R, onde as diferenças foram consideradas significativas quando P<0,05. Não houve diferença (P>0,05) entre os grupos quanto à quantidade de folículos e à taxa de maturação. Os grupos rbST 250 e rbST 500 foram significativamente superiores (P<0,05) ao grupo controle em relação ao número de folículos grandes (0,42±0,20 vs. 0). O grupo rbST 500 apresentou maior (P<0,05) porcentagem de oócitos viáveis (91,52%) do que os grupos controle (67,85%) e rbST 250 (53,33%). A rbST aumenta o número de folículos grandes, e 500mg de rbST aumentam a porcentagem de oócitos viáveis em vacas Sindi.(AU)

In order to evaluate the effect of different doses of rbST on the follicular dynamics, production, and in vitro maturation of oocytes, 20 Sindhi cows were divided into three groups, receiving an intravaginal progesterone device, estradiol and PGF2α, and 2mL of solution saline (Control Group), 250 (rbST 250 Group) or 500mg rbST (rbST 500 Group). Five days later, the ovum pick up was performed, and the cumulus-oocyte (CCO) complexes recovered were selected, classified, and matured in vitro. The counting data were compared by the glht (General Linear Hypothesis Test) procedure, and the percentage data were submitted to Qui- square, in the statistical program R, where differences were considered significant when P< 0.05. There was no difference (P> 0.05) between the groups regarding follicle quantity and maturation rate. The rbST 250 and rbST 500 groups were significantly higher (P< 0.05) than the Control group in relation to the number of large follicles (0.42±0.20 versus 0). The rbST 500 group presented higher (P< 0.05) percentage of viable oocytes (91.52%) than the Control (67.85%) and rbST 250 (53.33%) groups. rbST increases the number of large follicles and 500mg rbST increases the percentage of viable oocytes in Sindhi cows.(AU)

Efeito do óleo essencial do Croton nepetifolius Baill na penetração cervical em ovelhas mestiças de Dorper e Santa Inês / Effect of the essential oil of Croton nepetifolius Baill on cervical penetration in crossbred Dorper and Santa Inês ewes

A fim de se avaliar o uso do óleo essencial de Croton nepetifolius Baill (OECn) na penetrabilidade cervical em ovelhas mestiças, 40 ovelhas foram distribuídas ao acaso em quatro grupos (n=10): controle, misoprostol, OECn50 e OECn100 (50 e 100µg do OECn, respectivamente). Após a sincronização do estro, utilizando CIDR e eCG (200UI), a profundidade de penetração da cérvix foi mensurada utilizando-se uma pipeta de inseminação artificial de bovino graduada, no período de zero até 72h após a retirada do CIDR. Os resultados foram expressos em média ± erro-padrão, submetidos à ANOVA seguida do teste de Tukey, enquanto os dados, em porcentagem, foram submetidos aos testes de Fisher ouqui-quadrado. Nenhuma diferença significativa (P>0,05) foi encontrada quanto ao grau de penetrabilidade cervical. Quanto ao tempo de passagem, os grupos misoprostol e OECn100 apresentaram um menor tempo de penetrabilidade às 60h(1,7±0,6 e 1,5±0,6min, respectivamente), quando comparados ao grupo controle (4,1±0,6min), que não diferiu significativamente do grupo OECn50 (2,3±0,6min). Portanto, o óleo essencial de Croton nepetifolius Baill pode ser utilizado para encurtar o tempo de penetrabilidade cervical em ovelhas submetidas à sincronização estral.(AU)

In order to evaluate the use of the essential oil of Croton nepetifolius Baill (EOCn) on cervical penetration in crossbred ewes, 40 ewes were randomly allocated into four groups (n= 10): CONTROL, MISOPROSTOL, EOCn50 and EOCn100 (50 e 100µg of the EOCn, respectively). After estrus synchronization, using CIDR and eCG (200IU), depth of cervical penetration was measured using artificial insemination gun for bovine species which was graduated and used from 0 to 72h after CIDR removal. Results were expressed as mean ± standard error mean, submitted to ANOVA and Tukey test while data in percentage were submitted to Fisher or Chi-Square test. No significant difference (P> 0.05) was observed at grade of cervical penetration. Concerning trespassing time, MISOPROTOL and EOCn100 groups presented a lower trespassing time at 60h (1.7±0.6 and 1.5±0.6min, respectively) than CONTROL group (4.1±0.6min), which did not differ significantly from EOCn50 (2.3±0.6min) group. Therefore, the essential oil of Croton nepetifolius Baill can be used to shorten the cervical penetration time in estrus synchronized ewes.(AU)

Quercetin influences in vitro maturation, apoptosis and metabolically active mitochondria of goat oocytes.

SummaryThe present study aimed to investigate the effect of quercetin as an alternative antioxidant to cysteamine on in vitro maturation. Oocytes were collected from goat ovaries, destined for in vitro maturation and distributed into three groups: CIS group, oocytes were immersed in MIV base medium; in Groups Q4 and Q8, oocytes were immersed in the medium of the CIS group, adding 4 µM or 8 µM of quercetin, respectively, and cultured for 24 h at 38.5°C with 5% CO2. The CIS and Q4 groups presented the same percentage of expanded cumulus cells, but the per cent in the Q8 group was significantly lower than that of the other groups (P<0.05). The oocyte retraction rate in the Q8 group was higher (P<0.05) than in the CIS and Q4 groups. Treatment with 8 µM of quercetin presented a lower proportion of expanded oocytes than the CIS group and 4 µM of quercetin (P<0.05). The percentage of MII oocytes was higher in the Q4 group than in the CIS group (P<0.05), but the percentages in the CIS and Q8 groups were similar. The rate of apoptosis was higher in the CIS group than in the other groups (P<0.05). In addition, oocytes matured with 4 µM quercetin showed higher mitochondrial activity than matured oocytes in the CIS and Q8 groups (P<0.05). In conclusion, 4 µM of quercetin can be used as an alternative to cysteamine in the in vitro maturation of goat oocytes.