Factors affecting weight at first service of Holstein Friesian heifers born and reared in a tropical environment (I. Mohamed Elfagir, A. M. Abu Nikhaila, T. A A, M. Khair Abdallah, & A. Mousa Younis Waniss, Trans.). (2026). Yemeni Journal of Agriculture & Veterinary Sciences, 7(1), 9-15. https://doi.org/10.70022/yjavs.v7i1.3004