Relationship Between Results of Embryo Recovery, Feeding Management and Ratio of Blood Urea Nitrogen to Blood Glucose in Japanese Black Cows With Superovulatory Treatment

Abstract

The connection that blood-biochemical values and the results of embryo recovery collected from Japanese Black cows (n=30) have with the rates of NFC and DIP (NFC/DIP) in the feed were examined using regressionanalysis. Blood urea nitrogen (BUN, P<0.05) and the ratio of BUN to blood glucose (B/G, P<0.01) atthe initiation of superovulatory treatment showed a negative correlation with the number and rate of transferableembryos. The B/G level showed a negative correlation with the ratio of NFC/DIP in the feed. Moreover, the number of cows with ad>70% rate of transferable embryos significantly increased (P<0.05) when the valuesof BUN and B/G were <13mg/dl and <0.2, respectively. When the feed was changed at the time of estrusbefore superovulation treatment, the number and rate of transferable embryos were significantly higher in thehigh NFC/DIP group (NFC/DIP>5) than in the low NFC/DIP group (P<0.05).