Sex ratio of bovine embryos produced in vitro

Reproductive biotechnologies are important tools that help to increase production rates, providing high gains in animal production. In this sense, in vitro embryo production stands out because it is the biotechnique that enables the highest number of offspring per female, which is reflected in rapid genetic gain, a reduction in the interval between generations and a rapid increase in the herd. However, there are several reports that this technique causes sexual disproportion of the embryos, with more male embryos being observed, which can be detrimental given the need for a certain gender, according to each production system. Knowledge of the factors involved in the process of sex disproportion in bovine embryos produced in vitro will help to improve the technique, improve cattle farming, increase rates and reduce production costs. The aim of this review is to discuss the main factors involved in sex ratio deviation, as well as the importance of this for livestock farming.