Utilizing of black cumin (Nigella sativa) flour to increase the immunity system of tilapia (Oreochromis niloticus) against Aeromonas hydrophila bacteria attack

ABSTRACT This study aims to determine dose of black cumin flour in fish feed diets which can improve the disease resistance of tilapia against the attack of A. hydrophila. This study was used tilapia juvenile with a size of 7 – 8 cm. This study was conducted from March – May 2021 and the experimental method is completely randomized design (CRD) with 5 treatments and 3 replications. The treatment used were addition of black cumin flour into fish feed with doses 0 (A), 20 (B), 35 (C), 50 (D), and 65 (E) g/Kg feed. The treatments fed by supplemental diets contained black cumin flour was conducted for 14 days, then a challenge test was carried out with the infection of A. hydrophila bacteria by immersion for14 days. A. hydrophila bacteria used to infect fish had a density of 108 CFU/mL. The Parameters used were total leukocyte, hematocrit, total leukocyte differential, clinical symptoms, survival rate and water quality. The result showed that black cumin flour was effective to increase the immunity system of tilapia. The dose of 50 g/Kg feed was effective showed increase the highest percentage increase in white blood cells of 64.56%, compared to treatments B, C, and E which showed an increase in white blood cells of 47.40%, 48.82% and 1.2%, respectively. Treatment A decreased the percentage of white blood cells by 19.52%. The 50 g dose of black cumin showed the highest percentage value of hematocrit and leukocyte differential in tilapia fry, respectively 34%, lymphocytes 84.3%, monocytes 6%, and neutrophils 9.7% with the fastest recovery period (4 days) and after the challenge test resulted in the highest survival rate of 95%. Keywords: Aeromonas hydrophila, tilapia juvenile, black cumin, immune system ABSTRAK Penelitian ini bertujuan untuk menentukan dosis tepung jintan hitam dalam formula pakan ikan yang dapat meningkatkan ketahanan tubuh ikan nila terhadap serangan bakteri A. hydrophila. Penelitian ini menggunakan benih ikan nila dengan ukuran 7-8 cm. Penelitian ini dilaksanakan pada bulan Maret – Mei 2021 dan metode eksperimen yang digunakan adalah model Rancangan Acak Lengkap dengan lima perlakuan dan tiga ulangan. Perlakuan yang digunakan adalah penambahan tepung jintan hitam pada pakan dengan dosis 0 (A), 20 (B), 35 (C) 50 (D) dan 65 (E) g/Kg pakan. Pemeliharaan ikan uji yang diberikan perlakuan yang mengandung tepung jintan hitam dilakukan selama 14 hari, setelah itu dilanjutkan uji tantang menggunakan bakteri A. hydrophila dengan metode immersi selama 14 hari. Bakteri A. hydrophila yang digunakan untuk menginfeksi ikan memiliki kepadatan 108 CFU/mL. Parameter yang digunakan yaitu leukosit, hematokrit, differensial leukosit, gejala klinis, kelangsungan hidup dan kualitas air. Hasil penelitian memperlihatkan tepung jintan hitam dapat meningkatkan ketahanan tubuh ikan nila. Dosis jintan hitam 50 g per 1 kg pakan paling efektif, terlihat dari persentase peningkatan sel darah putih tertinggi sebesar 64.56%, dibandingkan perlakuan B, C, dan E yang masing masing menunjukan peningkatan sel darah putih sebesar 47.40%, 48.82% dan 1.2%. Perlakuan A mengalami penurunan persentase sel darah putih sebesar 19.52%. Dosis jintan hitam 50 g menunjukkan nilai persentase hematokrit dan differensial leukosit yang paling tinggi pada benih ikan nila, masing-masing sebesar 34%, limfosit 84.3%, monosit 6%, dan neutrofil 9.7% dengan masa pemulihan tercepat (4 hari) dan setelah di uji tantang menghasilkan kelangsungan hidup tertinggi yaitu sebesar 95%. Kata kunci: Aeromonas hydrophila, benih ikan nila, jintan hitam, sistem imu