https://www.selleckchem.com/products/pilaralisib-xl147.html 00 and 25.99 months of age. Heifers that calved in autumn had the highest MY1, whereas calving in summer was related to the lowest milk production (p less then 0.001). The risk of culling within 50 days in milk in first lactation (n = 21,225) increased along with first calving age, e.g. heifers that first calved after 30 months of age were 5.52-times more likely to be culled compared to heifers that calved before 22 months of age (p less then 0.001). Calving difficulty was related to higher culling risk in early lactation (p less then 0.001). Heifers that required caesarean section were 24.01-times more likely to leave the herd within 50 days after first calving compared to heifers that needed no assistance (p less then 0.001). Conclusion Reproductive performance of replacement heifers is closely linked to longevity and milk production in dairy herds.Objective MicroRNAs (miRNAs) are the most abundant small RNAs. Approximately 2000 annotated miRNAs genes have been found to be differentially expressed in ovarian follicles during the follicular development. Many miRNAs exert their regulatory effects on the apoptosis of follicular granulosa cells (FGCs) and follicular development (FD). However, accurate roles and mechanism of miRNAs regulating apoptosis of FGCs remain undetermined. Methods In this review, we summarized the regulatory role of each miRNA or miRNA cluster on FGCs apoptosis and FD on the bases of 41 academic articles retrieved from PubMed and web of science and other databases. Results Total of 30 miRNAs and 4 miRNAs clusters in 41 articles were reviewed and summarized in the present article. 29 documents indicated explicitly that 24 miRNAs and miRNAs clusters in 29 articles promoted or induced FGCs apoptosis through their distinctive target genes. The remaining 10 miRNAs and miRNAs of 12 articles inhibited FGCs apoptosis. were reported in all articles. MiRNAs exerted modulation actions by at least