Relationship between Progesterone and Oestradiol-17β Concentrations and Embryonic Loss in Frisian Cows under Egyptian Condition.

The objective of this study was to determine the association between circulating (Progesterone, oestradiol-17β and P4/E2 ratio) concentrations and embryonic loss in Friesian cows under Egyptian condition. On day 25 by both progesterone (P4) level and sonography, 65.71% (69/105) cows continued their gestation normally and 17.14% (18/105) cows didn't conceive. While, 17.14% (18/105) of inseminated cows showed high progesterone level firstly and decline before day 25 suspecting early pregnancy loss, EPL. Also, 5 cows (7.25%) of the pregnant cows lost their feti from day 25 to day 45 (late pregnancy loss, LPL) were detected. Blood progesterone concentrations (P4 ) increased significantly in cows diagnosed pregnant (P<0.05) compared to low P4 in cows lost pregnancy (8.03 & 8.98 ng/ml vs. 4.4 & 4.9 ng/ml respectively), starting from day 4 to day 7after AI. Cows with LPL showed increasing P4 concentration in the first 25 days and got down on days 28 and 40 accompanied with embryonic loss. concentrations of estradiol were increased significantly(P<0.05) in cows with EPL starting from days 4 to 21 after AI compared to cows diagnosed pregnant. P4/E2 ratio was significantly (P<0.05) higher in cows diagnosed pregnant starting from days 4 to 40 after AI compared to cows loss their embryos early from days 4 to 25 after mating, while LPL cows has highest P4/E2 ratio during 25 days post AI and declined on days 28 to 40 in Friesian cows. It can concluded that the percentage of EPL was 17.14% and the percentage LPL was 7.25% during the first 45 days post mating in Friesian dairy cows raised in Sakha Experimental Station. [ABSTRACT FROM AUTHOR]