ABSTRACT.- Reproduction is crucial in the efficiency of grazing-based beef production systems. There are different ways to improve reproductive indices in cattle, such as through herd management, nutrition and/or genetics. It was shown that different levels of herbage allowance and the use of crossbred cows could improve the follicular and uterine characteristics that translate into higher cow fertility. Our study aimed to evaluate the follicle size, oocyte quality, and changes in follicular fluid composition and uterine gene expression in crossbred and purebred cycling beef cows grazing native pastures at two different levels of herbage allowance for three years. The experimental design was a complete randomized block with two replications. © 2024 Elsevier B.V. All rights reserved.