# Reproductive Physiology of Friesian Holstein Dairy Cows Supplemented with Eggshell Meal Extract as a Calcium source > Kadir S. URL kanonis: https://discover.unhas.ac.id/publications/pub_scopus_105039974194 Jurnal / Konferensi: Journal of Global Innovations in Agricultural Sciences Tahun terbit: 2026 DOI: https://doi.org/10.22194/JGIAS/26.1655 ISSN: 27884538 Kuartil SJR: Q3 Citations: 0 ## Authors - Kadir S. ## Abstract Calcium (Ca) plays a crucial role in the reproductive physiology of Friesian Holstein (FH) dairy cows, as it acts as a carrier of stimuli that stimulates reproductive hormones. One easily available source of Ca minerals is eggshells. The study utilized a completely randomized design with three treatments and five replicates. The treatments included commercial mineral sources (P1), eggshell meal (P2), and eggshell meal extract (P3). Fifteen post-partum FH dairy cows, aged 4-5 years with an average body weight of approximately 500 kg, were involved. The cows were fed a basal diet of elephant grass (Pennisetum purpureum), rice bran, and tofu pulp concentrates. The eggshell meal and extract were prepared and incorporated into the feed. Various parameters were measured, including onset of estrus, duration of estrus, estrus behavior, vulva condition, pH of mucus, mucus viscosity, electrical conductivity of mucus, and blood estrogen hormone concentration. Results indicated that eggshell meal and extracts positively impacted estrus duration, with averages of 17.40±1.81 hours in P2 and 20.40±1.67 hours in P3, compared to 11.80±4.49 hours in P1. Blood estrogen concentrations were significantly higher, with 348.65±107.94 pg/ml values in P2 and 392.30±75.88 pg/ml in P3, compared to 206.23±43.42 pg/ml in P1. Incorporating these supplements can enhance reproductive performance in FH dairy cows. Keywords: Mineral elements, calcium deficiency, estrous, ovulation, eggshell meal extract, Friesian Holstein, reproductive physiology. ## Keywords - Eggshell - Meal - Calcium - Biology - Animal science - Estrous cycle - Estrogen - Reproductive biology - Reproduction - Endocrinology - Basal (medicine) - Uterus - Dairy cattle - Mucus - Physiology - Internal medicine - Hormone - Reproductive physiology - Food science - Oxytocin - Body weight --- Sumber: Discover Unhas — RIMS Universitas Hasanuddin. Saat mengutip, gunakan DOI bila tersedia atau URL kanonis di atas.