Stress responses of transportation on red tilapia which given feed containing chromium

ABSTRACTThis study was conducted to evaluate stress responses of transportation on red tilapia Oreochromis sp. which given feed containing chromium. Three isonitrogenous and isocaloric experimental feeds were prepared, these diets were control (without chromium), CrPic 1 mg/kg, and CrYst 2 mg/kg supplementation in feed, all group were arranged triplicate. Satiation feeding was done three times a day. After a 60-day feeding experiment, the experimental fishes were fasted and distributed in polyethylene bags (N=60 fish/bag) containing 3 L of water, subjected to condition of transport simulation for 13 hours. Survival rate, levels of plasma cortisol, blood glucose, superoxide dismutase (SOD), and malondialdehyde (MDA) enzyme were observed at before transportation, after transportation, one day, and two days after transportation. The result showed that chromium supplementation reduced the levels of plasma cortisol before and after transportation, one day, and two days after transportation. Also, it decreased blood glucose compared with control significantly before transportation and one day after transportation. The SOD enzyme concentration increased significantly after fish was fed with feed containing chromium for 30 days, while the MDA enzyme concentration increased significantly after two days of transportation. However, there was no significant difference in the survival of red tilapia between treatments. The best result was obtained in the treatment of fish which fed with feed containing chromium. CrPic supplementation 1 mg/kg and CrYst 2 mg/kg increased the body resistance in red tilapia by decreasing the negative effect of stress while transportation. Keywords: stress, transportation, red tilapia, chromium ABSTRAKPenelitian dilakukan untuk mengevaluasi respons stres transportasi ikan nila merah Oreochromis sp. yang diberikan pakan yang mengandung kromium. Pada penelitian ini digunakan tiga jenis pakan, terdiri atas pakan tanpa suplementasi kromium (kontrol), pakan bersuplementasi kromium pikolinat (CrPic 1 mg/kg), dan kromium yeast (CrYst 2 mg/kg), semua perlakuan diulang sebanyak tiga ulangan. Pemberian pakan sebanyak tiga kali sehari dan dilakukan secara at satiation. Setelah 30 hari pemeliharaan, ikan uji dipuasakan dan didistribusikan dalam plastik polietilen (N=60 ekor ikan/kantong plastik) yang berisi 3 L air, dilakukan dengan simulasi transportasi selama 13 jam. Parameter yang diamati pada penelitian ini adalah kelangsungan hidup, kortisol, glukosa darah, enzim superoksida dismustase (SOD), dan malondialdehida (MDA) saat sebelum transportasi, sesaat setelah transportasi, sehari, dan dua hari setelah transportasi. Hasil yang didapatkan adalah suplementasi kromium menurunkan konsentrasi kortisol secara signifikan sebelum transportasi, sesaat, sehari, dan dua hari setelah transportasi. Suplementasi kromium menurunkan glukosa darah secara signifikan pada saat sebelum transportasi dan sehari setelah transportasi. Konsentrasi enzim SOD meningkat secara signifikan setelah pemberian pakan bersuplementasi kromium selama 30 hari, sedangkan konsentrasi enzim MDA meningkat secara signifikan setelah dua hari transportasi pada ikan yang diberi pakan bersuplementasi kromium. Namun, tidak ada perbedaan yang signifikan pada kelangsungan hidup ikan nila merah antarperlakuan. Hasil terbaik diperoleh pada perlakuan ikan dengan suplementasi kromium. Suplementasi 1 mg/kg CrPic dan 2 mg/kg CrYst dapat meningkatkan daya tahan tubuh pada budidaya ikan nila merah dengan menurunkan pengaruh negatif stres akibat transportasi. Kata kunci: stres, transportasi, nila merah, kromium