Influence of temperature and time during ovary transportation on in vitro embryo production efficiency in the buffalo species (Bubalus bubalis).

The aim of this study was to evaluate the influence of temperature during ovary collection/transportation and that of the time interval between ovary collection and processing in the laboratory, on in vitro embryo production efficiency in buffalo species. A retrospective analysis of data collected over the last 4 years in our lab was carried out on 3461 oocytes, recovered over 120 replicates. No differences in oocytes developmental competence were observed in relation to the time interval between ovary collection and processing in the laboratory (3-6 h). On the contrary, a correlation was found between oocyte developmental competence, evaluated in terms of cleavage and blastocyst rate, and temperature during ovary collection/transportation. In particular, lowering temperature during ovary transportation significantly improved both cleavage (74.6 % vs 65.8 and 63.1 % for temperature ranges of 25-30 degrees C, 30-34 degrees C and 34-37 degrees C, respectively; P<0.05) and blastocyst rates (30.9 % vs 21.8 and 22.7 % for temperature ranges of 25-30 degrees C, 30-34 degrees C and 34-37 degrees C, respectively; P<0.05). It was concluded that extending the time interval between ovary collection and processing to 6 h is not detrimental for buffalo oocyte developmental competence. Furthermore, lowering temperature during ovary collection and transportation increases the in vitro embryo production efficiency in buffalo species.