296 LIPIDIC CONTENT IN JERSEY BLASTOCYSTS COMPARED WITH HOLSTEIN AND IVP EMBRYOS

The objective of this study was to compare the ultrastructure of bovine embryos from different breeds and origin in terms of lipid contents. Jersey and Holstein embryos produced in vivo were obtained from superovulated donors by non-surgical method 7 days after AI. Embryos produced in vitro (Holstein cross breed) were obtained from cumulus-oocytes complexes (COC) aspirated from slaughterhouse ovaries. The COC were matured and fertilized in vitro. The zygotes were cultivated in vitro for 7 days in SOFaa media. Embryos produced in vivo (Holstein n = 5; Jersey n = 5) and in vitro (n = 5) classified as blastocyts grade II were fixed in Karnovsky solution immediately after embryo recovery or embryo culture and prepared for microscopic electronic evaluation. Ultrastructure of inner cell mass and trophoblast cells was analyzed. Morphometry on electron microscopy was performed using a point-count method in random samples of electron micrographs of each embryo category. The data were analyzed by chi square test. The volume density occupied by number of lipid droplets was greater in Jersey and in vitro-produced embryos compared with Holstein embryos (24.3% ± 11.7; 28.4% ± 19.6 and 9% ± 6.68, respectively, P < 0,05).