Improving and sustaining the health and productivity of dairy cows require integrated strategies that combine management and appropriate nutrition. This review adopts two complementary perspectives: optimizing periparturient management to support high productivity without compromising animal health and improving gestational nutrition to produce healthy replacement heifers. Several studies have examined how maternal nutritional and metabolic status before and after calving influence postpartum reproduction, productivity, placental development, and offspring health. Prepartum energy status is a key determinant of early postpartum ovarian function, with a timely first ovulation associated with adequate insulin-like growth factor-I exposure during follicular development. Insufficient β-carotene intake in energy-prioritized feeding systems adversely affects ovarian resumption. Uterine recovery is also nutrition-sensitive; cows with endometritis exhibit signs of impaired liver function, whereas delayed uterine involution is associated with inefficient ruminal nitrogen utilization. Supplementation with lysine, the first limiting amino acid in corn-based diets, further promotes uterine recovery. From a developmental perspective, maternal insulin resistance is associated with low birth weight and altered endocrine profiles in calves, which are indicative of long-term metabolic vulnerability. In contrast, lysine supplementation during the dry period supports neonatal protein synthesis and growth. Furthermore, in growing primiparous cows, greater milk yield during early pregnancy was associated with reduced anti-Müllerian hormone concentrations in female calves, suggesting a lower ovarian reserve. Collectively, these findings highlight the importance of gestational and peripartum nutritional management not only for improving dairy cow fertility and productivity but also for optimizing the health and reproductive potential of the next generation.

Artificial insemination (AI) is the predominant reproductive technology in Japanese cattle breeding, particularly for genetic improvement of dairy and beef cattle. This review outlines the historical development, current status, and recent advances in semen production technologies for AI in Japan and addresses the remaining challenges and future directions. The adoption of AI accelerated after the Act on Improvement and Increased Production of Livestock was implemented in 1950, with frozen semen replacing liquid semen by the mid-1960s. Advances in cryobiology and genomic selection have improved breeding efficiency; however, fertility issues persist. In dairy cattle, conception rates have declined primarily due to high milk yield, negative energy balance, and heat stress. In beef cattle, particularly Japanese Black cattle, conception rates remain stable overall, but subfertile sires still occur despite normal post-thaw semen quality. Studies on sperm motility, acrosomal integrity, and genomic variants have identified a single nucleotide polymorphism (SNP) marker linked to extreme subfertility in Japanese Black bulls. Japan has developed innovative technologies such as the two-layer semen straw (FCMax), which enhances post-thaw sperm function through in-straw dilution and supplementation. Field trials have suggested potential improvements in conception rates; however, large-scale validation studies are still ongoing. Furthermore, sexed semen technology has been widely adopted in Japan and achieved conception rates comparable to those of conventional semen. Emerging challenges include labor efficiency in large-scale farms, prompting interest in improved thawing protocols or liquid semen alternatives. Future priorities include integrating genomic tools, refining cryobiological techniques, and implementing practical innovations to sustain cattle reproduction in evolving production systems.

To efficiently produce high-quality bovine calves by transferring embryos obtained from in vitro fertilization (IVF), it is important to evaluate their ability to conceive and their ability to develop into normal litters. In this study, we aimed to clarify the effects of timing and morphology of blastomere cleavage on the gene expression status of bovine IVF embryos. Bovine IVF embryos were classified in four categories, which were divided according to the time of the first blastomere cleavage and the presence or absence of direct cleavage. In addition, the gene expression profiles of these embryos were examined. The timing and morphology of the blastomere cleavage was involved in pre-implantation development and gene expression status of bovine IVF embryos. Our results indicate the possibility of multiple evaluations for bovine IVF embryos and the selection of the most suitable embryos for embryo transfer.