Dear Adewuyi

when flushing donor cows it is important to make sure that the female is is in good health status otherwise she may not be able to produce fertile embryos - same for recipients heifer as surrogates

After flushing you must proceed (according to OIE regulation) to wash the embryo 10 times with a sterile washing /holding media

commercial (flushing+ holding) media contains already little amount of antibiotics and fungicide . But not enough to iradicate desease, only to avoid contamination .

use as well sterile embryo transfer sheaths and sterile sanitary cover

wish you the best succes in your ET program

sincerely

Determination of the quantity/dosage of the antibiotics to be added to the embryo aliquot could be complex as one would want to prevent the negative effect that the antibiotics might pose to the development of the embryo. However, the male and female cow could be pretreated with appropriate dosage of the antibiotics before donation and crossing is carried out. My submission.