In Vitro Development of Holstein and Japanese Black Breeds Embryo

Abstract

Two experiments were conducted with 3,457 oocytes, aspirated from the ovaries of slaughtered Holstein and Japanese Black breeds cows to compare the use of superovulated cow serum (SCS) and fetal calf serum (FCS) supplementation into medium for in vjtro development (experiment I) and the effect of different source of oocytes (experiment 11). The endpoint was development to cleavage on day 2 and to blastocyst up to day 9 after msermnabon. In experiment I, oocytes were matured and cultured m vltro (after fertilization) in TCM-199 supplemented with 5% SCS or 5% FCS. The cleavage rate of zygotes cultured in medium supplemented with 5% SCS was higher (P<0,05) than 5% FCS (5621860, 65,3% vs 4451742, 60,0%). The blastocyst production rate was sigdicantly higher (PC0,Ol) in SCS treatment than FCS (2321860, 27,0% vs 1241742, 16,7%). In experiment 11, 956 oocytes collected from Holstein breed and 899 oocytes from Japanese Black breed were matured, fertilized and cultured in vitro in medium supplemented with 5% SCS. The mean oocyte number and blastocyst production per ovary were 12,O (956180) and 3,2 (252180) for Holstein breed, 15,0 (899160) and 3,l (184160) for Japanese Black breed. The cleavage rate of zygotes derived from Holstein and Japanese Black breeds ovaries was not significantly different (6351956. 66,4% vs 5691899, 63,3%, respectively). However, the blastocyst production rate was sigdicantly higher (P<0,01 in Holstein than Japanese Black breeds (252/956, 26,4% vs 1841899, 20%). These results indicated that the developmental rate to biastocysts of embryos cultured m vitro differ from breed to breed.