Effect of gas atmosphere on the development of bovine embryos .using a simple portable incubator

Abstract

The objective of this study was to examine the effect of gas atmosphere on the development of IVMFC of bovine embryos in a simple portable carbon dioxide incubator under negative and positve pressure of air. Incubation was carried out in small plastic boxes (15L X lOW X 4H em). For C02 production, 0.25 g of effervescent gran­ ules in distilled water were used for successful IVMFC. In experiment I, the blastocyst rate observed in treatment 1 with negative pressure was higher (p < 0.05) than that in treatment 2 and 3 (43.5% and 42.9%, 23.9% and 4.8% for treatment 1 (i) and (ii), 2, 3, respectively). In ex­ periment II (treatment 1), the survival rate of simple incubator-produced blastocysts, following cryopresevation with 1.8M EG +0.05M T in the absence of PVP had no difference from that in 5% PVP. It was observed that the rate in 5% PVP was higher (p <O.Ol) than that in 20% PVP and higher (p <0.05) than that in 10% PVP (81.8%, 67 .5%, 56.5%, 6.3%; without PVP, 5% PVP, 10% PVP, and 20% PVP, respectively). In experiment The authors wish to thank Japanese Veterinary Medical Association and Japan Racing Association, Tokyo, Japan for financial assistance. II (treatment 2) , the comparative survival rate of blastocysts and hatched blastocysts produced by a simple incubator did not show any significant dif­ ference between program freezer and deep freezer. In experiment II (treatment 3) , the total cell num­ ber and live and dead ratio of blastocysts from a simple incubator showed no significant difference between program freezer and deep freezer. In ex­ periment III, the pH of culture medium in all the gas treatments was compared with C02 incubator and there was no significant difference. These results suggest that gas atmosphere with the negative pressure of air in a simple portable incubator increased the blastocyst formation rate. Hence, it can be successfully used for production of bovine IVMFC embryos and could be used at farm level.