Comparison of continuous and pulse administration of probiotic bacteria potency of Lactobacillus sp., Bacillus thuringiensis and B. cereus in the basal diet on biochemical parameters of Lates calcarifer

This study was conducted with the aim of determining the effect of different probiotics administration on alterations in biochemical parameters of juvenile sea bass (Lates calcarifer). Four hundred and twenty sea bass with an average weight of 34 ± 4.5 g were prepared and randomly divided into seven groups with three replications (40 fish in each replication) and fed with experimental diets for 90 days. The experimental treatments included: group 1 (T1): different Lactobacillus plantarum sp.; group 2 (T2): L. plantarum sp., L. bulgaricus, L. acidophilus and L. rhamnosus in a combined form (combination of lactobacilli); group 3 (T3): the combination of diets 1 and 2 as well as Bacillus cereus and B. thuringiensis which was administered to fish every two weeks; group 4 was the control group without probiotics (C4). In addition, groups 5, 6 and 7 (T5, T6 and T7) were similar to groups 1, 2 and 3 which were continuously fed to fish. The results showed that there was a significant increase in blood serum cholesterol at the end of the experiment in T7 compared to the control group. The calcium level in T3 showed the highest amount compared to other treatments. All treatments showed a decreased amount of total protein at the end of the experiment compared to the control (C4). Moreover, the highest value was related to T6. T7 exhibited the highest amount of triglycerides and glucose at the end of the experiment. In case of liver enzymes, the lowest serum ALP level was found in T1 and the lowest AST in T6, while serum ALT level did not display any significant difference in any group. In cases of Cpk and HDL, the lowest values belonged to T1. In general, it can be concluded that the use of a mixture of probiotics in a pulse administration can cause positive effects on the blood biochemical parameters of L. calcarifer.