Effectiveness of Strychnos ligustrina Bl. extract as feed supplementation to increase immune system of Nile Tilapia (Oreochromis niloticus) wich againts Streptococcus agalactiae

One of the problems of intensive cultivation of tilapia is the attack of Streptococcosis disease caused by Streptococcus agalactiae bacteria. To prevent it is necessary to prevent the use of natural antibiotics that is Strychnine bush extract. Research with the title Effectiveness of Strychnine bush Extract (Strychnos ligustrina Bl.) On Feed against Tilapia Resistant Immune Response (Oreochromis niloticus) Infected with Streptococcus agalactiae bacteria was carried out at Fishery Laboratory of the Faculty of Agriculture and Animal Husbandry of University of Muhammadiyah Malang on 25 August to 16 September 2017. The material used is extract of songga wood and fish tilapia size 9-12 cm as many 80 tails divided into 20 aquariums, where each aquarium contains 4 tails and Streptococcus agalactiae bacteria. The purpose of this research is to know the effect of giving Strychnine bush extract to the dosage to get the dose of songga extract of wood which is effective to give the best influence to the nile tilapia (Oreochromis niloticus) immune response covering hematocrit level, leukocrit level, leukocyte count and phagocytosis activity. The method used in this research is the experimental method using Completely Randomized Design (RAL), then the data is analyzed by using ANAVA. In this research, there were five treatments with various dosages, namely treatment (K: 0%), (A: 5%), (B: 10%), (C: 15%) and (D: 20%), each treatment was repeated four times. The main parameters used are hematocrit level, leukocrit level, leukocyte count and phagocytosis activity. As a supporting parameter is water quality and MIC (Minimum Inhibitation Concentration) test. The results showed that dosage of Strychnine bush extract did not affect the level of hematocrit and leukocrit level, but significant effect on leukocyte count with the highest value at treatment B with 10% dose is 11,9 × 105 cell / mm3. Giving extract also significant effect on phagocytosis activity with the highest phagocytosis value at treatment B with dose of 10% that is 32%