Received July 02, 2025
Accepted February 20, 2026

Objective: This study aimed to evaluate the effects of different heterologous in vitro fertilization (he-IVF) media on embryonic development in red-rumped agoutis (Dasyprocta leporina) using guinea pig oocytes as a model. Considering the species’ ecological and biotechnological relevance, optimizing IVF conditions is essential to improve assisted reproductive technologies for conservation and research. Methods: Epididymal spermatozoa from four red-rumped agoutis were selected and capacitated before co-incubation with in vitro matured guinea pig oocytes. Three IVF media were tested: human tubal fluid (HTF), Toyoda-Yokoyama-Hoshi (TYH), and Tyrode's albumin lactate pyruvate (TALP). After six hours of fertilization, presumptive zygotes were cultured and evaluated on Days 2 and 5 for cleavage, morphology, assessments of oocyte-sperm interaction, and number of cells. In addition, reactive oxygen species (ROS) levels, and mitochondrial membrane potential assessments were performed to analyze oxidative stress during early development. Results: Among the tested media, TALP significantly improved cleavage rates (P < 0.05) and resulted in a higher proportion of embryos with eight or more cells on both D2 and D5 of culture (P < 0.05). Embryos derived from TALP also showed reduced oxidative stress, evidenced by lower ROS levels and decreased mitochondrial membrane potential compared to the other groups (P < 0.05). Conclusion: TALP proved to be the most effective medium for supporting he-IVF using red-rumped agouti sperm, enhancing both developmental kinetics and cellular quality. These results contribute to the refinement of IVF protocols and represent an important step toward developing homologous embryo production systems in this neotropical species.