Efficiency of nonsurgical collection of embryos from superovulated cows on day 5

Nonsurgical collection of embryos from superovulated cows on day 5 (day 0 = day of onset of estrus) yielded fewer embryos than expected in comparison with the yield of oocytes collected surgically on day 1 and of embryos collected surgically on day 3. The yields were 16.5 oocytes, 16.8 embryos and 2.9 embryos and/or oocytes on days 1, 3 and 5, respectively. The low yield on day 5 was not explained by retention of embryos, as only 3 of 58 cows flushed were later found to be still pregnant. Key words: Superovulation, embryos, embryo recovery, bovine