| dc.description.abstract | We have developed a simple, economical and portable C02 incubator for production of bovine IVF embryos in the field. The incubator consists of a metallic chamber (29L x 26W x 21 H em); the bottom plate of this chamber is electrically heated to maintain the chamber temperature between 38.5 and 40.0°C. Incubations are carried out in a small plastic box (15L x 10W x 4H em) placed inside this chamber. The cover of this box is transparent to view the culture dishes and has an inlet at one end. Immediately below this inlet, at the bottom of the box, is a plastic dish (3 em diameter) for placing effervescent granules. Distilled water (5 ml) is added through the inlet into the plastic dish containing effervescent granules to generate C02, and the inlet is capped with a silicone stopper to maintain constant C02 level inside the box. To examine the amount of effervescent granules that should be added to maintain an optimum C02 levels for successful in vitro production of embryos, 0.25, 0.5 and 1.0g of effervescent granules (Tartaric acid, 420 mg; Carbonated hydrogen natrium 460 mg; Silicone fiber 10 mg per g of effervescent granules) were tested. Blastocyst production rate and the number of ICM and trophectoderm cells of the blastocysts produced were compared among treatment groups, as well as with embryos developed in a Sanyo C02 incubator (Controi:Sanyo electric Co. L TO., Osaka, Japan). Procedures for in vitro maturation of oocytes, in vitro fertilization and in vitro culture of cleaved embryos were as reported previously (Suzuki et al., Theriogenology 34:1051, 1 990); and all step of IVM, IVF and IVC were done in both incubators. More than 250 immature oocytes were allocated at random to each treatment. lmmunosurgery and a differential staining techniques (Iwasaki et al., J. Reprod. Fertil. 90:279, 1 990) were used to determine ICM and trophectoderm cells. Results are shown in Table 1. The number of ICM and trophectoderm cells from blastocysts produced in the control group were 30.1 ±6.6 and 79.3±21.3, respectively and were not different (P>0.05) from the other groups. These results suggest that the simple incubator developed in our laboratory can be successfully used for production of bovine IVF embryos and could be used at the farm level. | en |
