Effects of dietaryLactobacillus plantarum(KC426951) in biofloc and stagnant-renewal culture systems on growth performance, mucosal parameters, and serum innate responses of Nile tilapiaOreochromis niloticus

Effects of dietaryLactobacillus plantarum(KC426951) on growth and innate responses of Nile tilapiaOreochromis niloticuswere evaluated in biofloc technology system and stagnant-renewal culture system (SRCS). The 90-day-long experiment contained four treatments: SRCS without probiotic (T1), SRCS with probiotic (T2), biofloc without probiotic (T3), and biofloc with probiotic (T4). The administration dose of probiotic was 2 x 10(8) CFU kg(-1)diet. At the end of experiment, the mean final weights, specific growth rates, feed conversion ratios, and total biomass were significantly (P < 0.05) better in BFT treatments, with no significant effect of probiotic on these parameters in both culture systems. Meanwhile, skin mucosal parameters including total protein (TP), lysozyme (LYZ), alkaline phosphatase (ALP), and protease (PRO) activity were significantly enhanced following probiotic supplementation. T4 treatment displayed a significantly higher LYZ and ALP activity in mucus versus other treatments. Also, serum alternative complement activity was significantly heightened in probiotic-supplemented fish. Superoxide dismutase activity in T4 was detected higher than that of SRCS groups. The results of the current study demonstrated the enhancement of some mucosal and serum innate responses of Nile tilapia in both culture systems uponL. plantarum(KC426951) supplementation.