Developmental Speed Affects the Cryotolerance of In Vitro Produced Buffalo (Babalus Bubalis) Embryos

• Published in: Italian journal of animal science Vol. 12; no. 4; p. e80
• Main Authors: Boccia, Lucia, Rosa, Anna De, Attanasio, Laura, Neglia, Gianluca, Vecchio, Domenico, Campanile, Giuseppe, Zicarelli, Luigi, Gasparrini, Bianca
• Format: Journal Article
• Language: English
• Published: Bologna Taylor & Francis 01-01-2013; Taylor & Francis Ltd; PAGEPress Publications; Taylor & Francis Group
• Subjects: Abattoirs; Buffalo; Buffalo, Embryo, Developmental speed, Vitrification, Cryotop; Cold tolerance; Cryotop; Developmental speed; Dimethyl sulfoxide; Embryo; Embryos; Ethylene glycol; Oocytes; Pregnancy; Sucrose; Vitrification
• ISSN: 1828-051X; 1594-4077; 1828-051X
• DOI: 10.4081/ijas.2013.e80

The aim of this study was to evaluate whether the developmental speed affects the cryotolerance of in vitro produced buffalo embryos. In Experiment 1, abattoir-derived oocytes were in vitro matured, fertilized and cultured. The embryos produced by Say 7 of culture were vitrified at the tight morula (TM), early blastocyst (EBL), blastocyst (BL), expanded-blastocyst (XBL) and hatched-blastocyst (HBL) stage. The embryos were vitrified by cryotop in 16.5% ethylene glycol (EG) and 16.5% dimethyl sulfoxide (DMSO) and 0.5 M sucrose. Embryos were warmed in 0.25 M sucrose for 1 min and then in 0.15 M sucrose for 5 min and cultured in vitro for 24 h, to evaluate post-culture viability. In Experiment 2, ovum pick-up (OPU) was carried out on lactating buffaloes to produce embryos that were vitrified-warmed and transferred into synchronized recipients. The lowest (P<0.01) survival rates were recorded with TM (22.4%) and the highest (P<0.01) with HBL (84.5%), whereas intermediate results were observed with EBL, BL and XBL (54.5, 64.7, 67.9%, respectively). Pregnancy rate on both Days 25 and 45 was significantly higher (P<0.05) for faster (XBL and HBL) developing embryos (75.0% and 62.5%, respectively) than for the slower (TM, EBL and BL) developing counterparts (36.4% and 0, respectively). Interestingly, pregnancies to term were only recorded when HBL were transferred (20%). In conclusion, it was demonstrated that the chronology of development is a major factor affecting the cryotolerance of in vitro produced buffalo embryos.