Italian Journal of Animal Science (Nov 2013)

Developmental speed affects the cryotolerance of in vitro produced buffalo (Bubalus bubalis) embryos

  • Lucia Boccia,
  • Anna De Rosa,
  • Laura Attanasio,
  • Gianluca Neglia,
  • Domenico Vecchio,
  • Giuseppe Campanile,
  • Luigi Zicarelli,
  • Bianca Gasparrini

DOI
https://doi.org/10.4081/ijas.2013.e80
Journal volume & issue
Vol. 12, no. 4
pp. e80 – e80

Abstract

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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.

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