Effects of a high-energy diet on oocyte quality and in vitro embryo production in Bos indicus and Bos taurus cows

Abstract

The effects of different dietary energy levels [100 and 170% for maintenance (M) and high energy (1.7M), respectively] on metabolic, endocrine, and reproductive parameters were evaluated in nonlactating Bos indicus (Gir; n=14) and Bos taurus (Holstein; n=14) cows submitted to ultrasound-guided ovum pick-up followed by in vitro embryo production. The oocyte donor cows were housed in a tiestall system and fed twice daily (0800 and 1600 h). Twenty-one days before the beginning of the experiment, the animals were fed with a maintenance diet for adaptation followed by the experimental diets (M and 1.7M), and each cow underwent 9 ovum pick-up procedures 14 d apart. The recovered oocytes were cultured in vitro for 7 d. We measured glucose and insulin concentrations and performed glucose tolerance tests and the relative quantification of transcripts (PRDX1, HSP70.1, GLUT1, GLUT5, IGF1R, and IGF2R) from the oocytes recovered at the end of the experimental period. No interactions were observed between the effects of genetic groups and dietary energy level on the qualitative (viable oocytes, quality grade, and oocyte quality index) and quantitative (oocytes recovered) oocyte variables. There were no effects of dietary energy level on the qualitative and quantitative oocyte variables. However, Bos indicus cows had greater numbers of recovered structures, viable oocytes, and A and B oocyte grades as well as better oocyte quality index scores and lower DNA fragmentation rates compared with Bos taurus donors. In vitro embryo production (cleavage and blastocyst rates and number of embryos) was similar between diets, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Moreover, Bos indicus cows on the 1.7M diet showed lower transcript abundance for the HSP70.1, GLUT1, IGF1R, and IGF2R genes. All cows fed 1.7M diets had greater glucose and insulin concentrations and greater insulin resistance according to the glucose tolerance test. In conclusion, increasing dietary energy did not interfere with oocyte numbers and quality, but the 1.7M diet reduced in vitro embryo production in Bos indicus cows after 60 d of treatment. Finally, Bos indicus cows had greater oocyte quality, greater numbers of viable oocytes and greater in vitro embryo yield than Bos taurus.

Effect of seasonality on the quality of bovine oocytes selected by the brilliant cresyl blue method

“…Success in in vitro bovine embryo production is directly related to the quality of the gametes used, which is largely influenced by nutrition (Sales et al, 2015). In general, oocyte donors receive a controlled diet without significant changes in quantity and composition throughout the year, which makes it a negligible factor in the variation of the process.…”

Endocrine and metabolic differences between Bos taurus and Bos indicus cows andimplications for reproductive management

“…More oocytes were recovered (37.1 vs. 15.4), more embryos were produced (7.3 vs. 1.1), and a greater blastocyst rate was obtained (28.3 vs. 14.1%) from Nelore than Holstein heifers. In another study (Sales et al, 2015), Gir cows had a greater number of oocytes recovered by ovum pickup (OPU; 23.4 vs. 14.9), better quality of oocytes demonstrated by greater cleavage rates (73.6 vs. 40.8%), greater number of blastocysts (3.8 vs. 0.7) and better blastocyst rates (36.7 vs. 12.1%) than Holstein donors.…”

Impacts of Macronutrients on Gene Expression: Recent Evidence to Understand Productive and Reproductive Performance of Livestock

“…Interestingly, supplementation of sunflower seeds or sunflower oil had a positive effect on milk yield and milk composition in lactating goats (Morsy et al, 2015). Although having an association with bronchiolitis (Sawahata et al, 2010) and cytotoxic activity (Yunita et al, 2013), Sauropus androgynus is traditionally consumed by several Southeast Asian countries and is believed to be an enhancer of milk production during lactation (Bunawan et al, 2015). When feeding S. androgynus leaf extract to lactating mice, it enhanced the expression of two prominent genes (prolactin and oxytocin) regulating milk production and subsequently, increased milk production (Soka et al, 2010) suggesting their potential use to increase milk production in livestock ruminants (Gabbi et al, 2015).…”

“…Interestingly, Sales et al, found different dietary energy levels have no influence on the oocyte numbers and quality. In addition, high energy diet intake for a long period may decrease the in vitro production of embryos in Bos indicus cows by causing a hyperinsulinemic state and inducing the downregulation of cellular metabolism genes (Sales et al, 2015).…”