Average shrimp weight fed with LAB supplemented diet was higher than the control group, and the statistic analysis displayed
significant differences (p < 0.05) in % RGR, FCR and % survival between the supplemented and control groups. Improvement of FCR in LAB fed shrimp suggests that addition of L. plantarumincreases feed utilization effectively. However, the mechanism how LAB
improve growth and FCR is not clear. Bacterial peptidoglycan (PG) may play such role as supported by Itami et al. [30]. Kuruma shrimp (P. japonicus) fed with PG from Bifidobacteriumthermophilumsignificantly increased shrimp body weight and survival. Lactobacillus acidophilus and L. sporogenes significantly improved growth of Macrobrachiumrosenbergiipostlarvae, but not survival rate [31]. Similarly, P. indicus larvae fed with L. plantarumimproved FCR compared to the control fed with non-LAB diet [32]. Treatment of L. stylirostris infected by V. nigripulchritudowith LAB probiotic,P. acidilactici, significantly improved the survival of the shrimp in pond A (7%) and pond B (15%) with lower FCR correlated to the increase of hepatopranceas (storage organ) dry weight as well as specific activities of a- amylase and trypsin in the digestive gland by 35% and 55%, respectively in probiotic fed shrimp. The rise in total trypsin activity following morning feedingwas also enhanced by the probiotic treatment [17]. The increase of specific activities ofamylase,total protease and lipase were reported in relation to weight and survival enhancement of Indian white shrimp (Fenneropenaeus
indicus) fed with Bacillus spp by Ziaei-Nejad et al. [33]. Therefore, it is possible that the LAB probiotic may in some way stimulate shrimp endogenous enzymes, thus increase feed digestibility.