Effects of diets containing Bacillus subtilis and Lactococcus lactis bacteria on cellular hematology and digestive enzymes of tiger Oscar (Astronotus ocellatus Agassiz, 1831)

Oscar fish (Astronotus ocellatus), is one of the most popular aquarium fish, which needs more attention to provide health in breeding conditions. Due to the expansion of the use of probiotic bacteria in the aquaculture industry this research was conducted to evaluate the effects of Lactococcus lactis and Bacillus subtilis on digestive enzymes and hematology as health indices of Oscar. The experiment was set up with 300 juveniles with an average weight of 8.96 ± 0.03 (gr) and a length of 8.23 ​​± 0.02 (cm) during 70 days with a diet containing the two mentioned bacteria in 9 treatment groups of CFU/g 1010 bacterial ​​concentration as 150, 300 and 450 mg added bacteria per kg of food and equal mixtures of both bacteria as 75, 150 and 225 mg per kg of food and were compared with control treatment. At the end of rearing period the results of the blood indices showed an increase in red blood cells, hemoglobin and hematocrit values ​​in treatment 3 (LL450) (P<0.05). Also, the results of the activity of digestive enzymes, including amylase, lipase and protease, in the treatments receiving bacterial added diets, especially in treatment 3 (LL450), statistically was differing from control (P<0.05).