Prostaglandins vis-à-vis bovine embryonic mortality: a review

Decline in fertility in bovines is attributed to various reproductive problems viz. anoestrus, repeat breeding, abortions and post parturient disorders. Among these, repeat breeding has been an important cause for reducing the animals' fertility and life-time productivity. Many researchers have reported embryonic mortality as a major cause of repeat breeding arising due to premature corpus luteum lysis. Prostaglandin F2 α released from the uterus causes alterations in luteal blood flow, induces luteal lysis, and hence reduces progesterone secretion from the bovine corpus luteum. Therefore various strategies have been tried to modulate prostaglandin F2 α synthesis and secretion in order to prolong the lifespan of CL. Administration of cyclooxygenase inhibitors which include non-steroidal anti-inflammatory drugs acting by competitive inhibition of key enzymes of prostaglandin synthesis is one such method. Feeding of diet rich in polyunsaturated fatty acids during critical period significantly reduces prostaglandin synthesis. Other drugs, which are potential candidates for reducing prostaglandin synthesis, include oxytocin receptor antagonist, recombinant bovine somatotropin, lysophosphatidic acid and prostaglandin F synthase inhibitors. To conclude, there is much scope of using various compounds to reduce prostaglandins synthesis during the critical period of pregnancy for improving the embryo survival rate.