Banca de DEFESA: DEBORA REGINA DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: DEBORA REGINA DA SILVA
DATA: 10/09/2020
HORA: 09:00
LOCAL: Video Conferencia
TÍTULO:

Qualidade de oócitos de vacas leiteiras e produção de embriões a partir de oócitos maturados in vitro
com melatonina

PALAVRAS-CHAVES:

Heat stress. Oxidative stress. Cleavage rate.

PÁGINAS: 63
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
RESUMO:

Melatonin has potential to scavenger free radicals and presents anti-apoptosis properties, so its addition to the in vitro maturation (IVM) medium of oocytes may have potential to mitigate the effects of heat stress. The objectives were to verify if cleavage rate (CR) of embryos produced from oocytes aspirated of dairy cows during summer is ameliorated by the addition of melatonin to the IVM medium. We also aimed to associate oocyte quality to milk production and physiological parameters. Oocytes from Holstein cows (n=16, farm 1), crossbred Holstein x Zebu cows (n=18, farm 2; n=11, farm 3) were obtained by ovum-pick-up during summer in Brazil. Oocytes were IVM in medium containing 0, 10^-6 or 10^-4 mol/L of melatonin. The CR was evaluated on day 3 after in vitro fertilization (IVF). Rectal and superficial temperature, heart and respiratory rate, milk production, days in milk (DIM), and body condition score (BCS) were collected from cows. Temperature-humidity index (THI) was generated through measurement of environmental temperature and humidity. Holstein cows presented respiration rate more elevated than crossbred Holstein x Zebu cows. There was an interaction treatment x farm effect on CR (P=0.03). On farm 1, the concentration 10^-4 mol/L increased (P = 0.08) CR (70.0 ± 17.0%) compared to control (22.0 ± 15.6%). On farm 2, CR was increased (P = 0.08) by melatonin in the concentration 10^-6 mol/L (50.0 ± 20.3%) compared to control (20.0 ± 13.5%). The addition of melatonin on IVM medium may be a strategy to increment cleavage rate of embryos produced from lactating dairy cows during summer. However, the dose to be added differ according to animal genetic, being greater for Holstein than crossbreed cows.

 

 

 

MEMBROS DA BANCA:
Presidente - NADJA GOMES ALVES (Membro)
Interno - JOSE CAMISAO DE SOUZA (Membro)
Externo ao Programa - JOAO BOSCO BARRETO FILHO - DMV/FCA (Suplente)
Externo ao Programa - RENATO RIBEIRO DE LIMA - DES/ICE (Membro)
Externo à Instituição - JASMIN - UFRJ (Membro)
Externo à Instituição - MARCOS BRANDAO DIAS FERREIRA - EPAMIG (Suplente)