ABSTRAKPenelitian dilakukan untuk mengevaluasi pengaruh substitusi meat bone meal (MBM) dengan tepung defatted maggot (Hermetia illucens) (TDM) pada persentase bobot, panjang relatif organ pencernaan, dan status Escherichia coli usus puyuh. Penelitian ini menggunakan 285 ekor puyuh betina berumur 6 minggu dengan rata-rata bobot 153,3±3,7 g. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan 3 perlakuan, 5 ulangan, dan masing-masing ulangan terdiri atas 19 ekor puyuh. Perlakuan yang diberikan ialah P1 = 0% TDM dalam ransum, P2 = 3,1% TDM dalam ransum (menggantikan 50% protein MBM), dan P3 = 6,18% TDM dalam ransum (menggantikan 100% protein MBM). Pengukuran organ pencernaan dilakukan dengan menimbang bobot masing-masing organ pencernaan dan dibandingkan dengan bobot hidup dikalikan 100%. Pengukuran panjang relatif dihitung dengan membandingkan panjang organ dengan bobot hidup dan dikalikan 100. Perhitungan konsentrasi E. Coli menggunakan metode pengenceran menurut Waluyo (2005). Hasil penelitian menunjukkan pengaruh yang tidak nyata pada persentase dan panjang relatif organ pencernaan. Tepung defatted maggot memiliki kemampuan sebagai antimikrob alami yang dapat menurunkan jumlah koloni Escherichia coli usus puyuh sebesar 99,99% seiring dengan peningkatan tepung defatted maggot sampai sebesar 6,18% dalam ransum. Dapat disimpulkan bahwa tepung defatted maggot (Hermetia illucens) dapat digunakan sampai sebesar 6,18% dalam ransum sebagai alternatif pengganti MBM dalam ransum puyuh tanpa mengganggu kesehatan puyuh. Kata kunci: Escherichia coli, meat bone meal, organ pencernaan, puyuh, tepung defatted maggot ABSTRACT This study was designed to evaluate the effect of substitution of Meat Bone Meal (MBM) with defatted maggot (Hermetia illucens) meal (DMM) on weight and length of digestive organs and the status of Escherichia coli in quailintestine. This study used 285 female quails aged six weeks with an average weight of 153.3±3.7 g. This experiment used Completely Randomized Design with three treatments, five replications, and each replication consisteds of 19 quails. The treatments were P1 = 0% DMM in diet, P2 = 3.1% TDM in diet (to substitute 50% of MBM protein), and P3 = 6.18% TDM in diet (to substitute 100% of MBM protein). The measurement of the digestive organs was performed by weighing each of the digestive organ and compared with the live weight multiplied by 100%. The measurement of the relative length was calculated by comparing the length of the organs by live weight and multiplied by 100%. The calculation of the concentration of E. coli used the method of dilution according to Waluyo (2005). The results showed that there was no significant effect on the percentage and the relative length of digestive organs. Defatted maggot meal has the activity as a natural antimicrobial that can decrease the Escherichia coli in quail intestine by 99.99% along with the increase in defatted maggot meal to 6.18% in diet. It can be concluded that protein from defatted maggot (Hermetia illucens) meal can be used up ...