INTERAÇÕES AMBIENTAIS E GENÉTICOS AFETAM A PRODUÇÃO in vitro DE EMBRIÕES BOVINOS

Abstract

In the quest to know the factors that interfere with the in vitro production of bovine embryos, treatments, influences and strategies that can improve the oocyte quality of donors and embryo production have been studied, making the processes viable under adverse conditions. Thus, the objective was to evaluate retrospective data about in vitro production of bovine embryos (IVP), to establish and determine environmental, genetic, and geographic location factors that impact the rate of oocyte recovery, oocyte quality and quantity of bovine embryos derived from of in vitro production. Data were collected from the company Samvet Embriões®, (Morrinhos, Goiás, Brazil). It is, therefore, a retrospective uncontrolled study with exploratory data analysis. Data from 2017 to 2021 were collected using a Microsoft Excel® spreadsheet. The analyzed breeds were: Nelore, Brahman, Brangus, Girolando, Gir, Guzolando, Holstein, Jersey, Brown-Swiss, Senepol and Tabapuã. The season year effect, donor race and geographic location on the in vitro production of bovine embryos was evaluated. Regarding the variables: Oocyte quality in trms of grade I, grade II, grade III, proportion in grade I (Pgi), proportion in grade II (Pgii), proportion in grade III (Pgiii), number of non-viable oocytes (NV), percentage of number of non-viable oocytes (Pnv),number of viable oocytes (V), proportion of oocyte production (OV), Total number of oocytes (TOTAL), number of cleaved (CLI),percentage of cleaved (Pcli), number of in vitro matured oocytes (IVM), number of produced embryos (EP), and percentage of produced embryos (Pembriao) were also evaluated. The season of the year factor had no significant effect on the percentage of breed-independent bovine embryos. However, in winter there was a lower production of grade II oocytes. The donor breed had a significant effect on oocyte quality, on the number of viable and total oocytes. The interaction of latitude, longitude and altitude was significant in the number of viable and total oocytes. Thus, environmental, genetic, and geographic location factors impact the oocyte quality and embryo quantity in certain breeds.