Comparative Assessment of Follicular Activity, Oocyte Recovery and Embryo Production in Friesian Heifers and Adult Cows Following Different OPU Intervals

Study was conducted to evaluate the influence of donor age and Ovum pick-up (OPU) session interval on follicular dynamics, oocyte recovery and in vitro embryo production in Friesian cattle. A total of ten clinically healthy Friesian females were included in the study and categorized into two age groups: heifers aged 12–25 months and adult cows aged 8–10 years. OPU was performed at two different intervals, i.e., 14 days (Group A) and 21 days (Group B) to determine the effects of collection frequency on ovarian response and subsequent embryo production. Selected oocytes were subjected to in vitro maturation, fertilization, and embryo culture procedures. The number of follicles aspirated, oocytes recovered, oocyte recovery rate, cleavage rate, and blastocyst production were recorded and compared according to donor age and OPU interval. The study was executed during the winter season from November to February to minimize the potential confounding effects of environmental heat stress on follicular development and embryo production. The findings of the study are expected to provide useful information regarding the selection of appropriate donor age and OPU frequency for optimizing oocyte yield and embryo production in Friesian cattle. The results may contribute to the development of efficient OPU-based IVEP protocols for enhanced reproductive performance and genetic dissemination in dairy cattle.

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