Protocolo J-Synch Em Bovinos Da América Do Sul: Manuscrito De Revisão

Abstract

Artificial insemination and TFAI protocols have been the main strategies used for the genetic advancement of herds. Some of these protocols aim adaptations for the period of follicular development during the proestrus of the reproductive cycle of bovine heifers because many authors have reported the pre-ovulatory estradiol concentrations exposure from that period as inductor of the pregnancy success and the development of the fetus. The new 6d protocol with the use of estradiol and progesterone (named J-Synch) bases on the concept estradiol may play a role in the establishment, development, and support of the embryo directly through the induction of endometrial receptors and regulation of histotrophic secretion and indirectly through the subsequent luteal phase that prepares the uterine environment to support the embryo. An analysis of research findings was made on several platforms using keywords. The first researches comparing J-Synch with conventional protocols achieved excellent end results for pregnancy success, but no difference was obtained among treatments, which shows that this protocol can be as conventional as others. It was possible to observe that some factors may influence the effectiveness of J-Synch, including the use of eCG compared to the conventional protocol; estrus detection; the time to perform the IATF; the appropriate nutritional quality status that varies in different seasons; the type of semen that may be used (either conventional or sexed-sorted); and the presence of CL at protocol starts. It was concluded the J-Synch protocol has many opportunities to improve the pregnancy rate for IATF under several conditions approached.