Analysis of circulating microRNAs during early gestation in Japanese-Black cattle

We found four circulating miRNAs showing high levels in plasma of pregnant Japanese Black cows. Since these miRNAs are less affected by the measurement system due to hemolysis, it was suggested that they may be used as markers for early pregnancy diagnosis in cattle. The Japanese-Black (JB) cattle were subjected to controlled estrus, and artificially inseminated (AI) according to the AM–PM rule following detected estrus twice daily. Peripheral blood from a total of seven AI cows was collected on day 21 (day 0 being the date of AI) to compare circulating miRNA levels in four pregnant and three non-pregnant statuses.