Effect of follicular aspiration at the onset of progesterone-based timed artificial insemination on the follicular dynamics and fertility of early postpartum Japanese black cows

Predisposing factors, diagnostic and therapeutic aspects of persistent endometritis in postpartum cows

A certain level of endometrial bacterial infection and inflammation is involved in bovine uterine involution during the puerperal period. Factors that hamper normal uterine involution expose the uterine environment to pathological conditions, causing different endometritis levels. The lack of proper diagnostic tools extends the time to conception. Efforts have been made to elucidate the postpartum uterine environment, including bacterial flora, changes in transient endometrial inflammation, and the pathophysiology of endometritis, to improve bovine reproductive performance. E. coli and Trueperella pyogenes in the uterus are likely to cause persistent infection, and Mycoplasma bovigenitalium infection is associated with dystocia and cytological endometritis in postpartum dairy cows. Due to the widespread use of cytobrush as a diagnostic tool for bovine subclinical endometritis (SE) that enables quantification of the degree of inflammation, we found that endometritis at week 5 postpartum was associated with delayed first ovulation. Approximately 30% of open cows have SE during the postpartum period, and cows with low blood glucose during prepartum have a high risk of developing SE. Additionally, cows with purulent vaginal discharge do not always have endometritis but only vaginitis and/or cervicitis. Intrauterine infusion of polyvinylpyrrolidone-iodine (PVP-I) improves fertility and promotes endometrial epithelial cell regeneration after inducing transient uterine inflammation, suggesting that PVP-I could be a good alternative to antibiotics. In conclusion, prepartum management to prevent glucose deficiency, prompt diagnosis to identify causative agents and intrauterine inflammation levels, and appropriate treatment to minimize antimicrobial resistance is beneficial for tackling endometritis and improving reproductive performance in bovine herds.

International perspectives on the impacts of reproductive technologies on food production in Asia

The greatest numbers of domestic animals are raised in Asia. The Asian animal industry is characterized by the involvement of a high percentage of the population, mostly smallholders, of which 95 % rear domestic animals. In exploring the best ways to formulate sustainable society, it is essential to make the most of livestock products by applying appropriate reproductive technologies. There is no doubt that reproductive technologies such as AI and ET have made a great contribution to increase the number of excellent animals. Although more advanced cutting edge reproductive technologies have become available and some of them have indeed a potential of revolutionary changes in livestock industry, the most important problem for increasing productivity concerns the maintenance of optimum nutrition and prevention of heat stress to support reproductive performance and increased supply of animal proteins. International societies should be involved in binding together developed and newly developing countries in the construction of a novel model for future livestock rearing management that suits diverse environmental circumstances.