Table 1.
Composition of experimental feed addition with the graded level of dietary chitosan for the rearing of juvenile B. gonionotus.
Table 2.
Estimation of the proximate composition of control feeds and individual graded levels of dietary chitosan-treated feeds (dry matter basis) for rearing B. gonionotus.
Table 3.
Growth parameters of fish fed in indigenous feed ingredients formulated feeds with graded levels of dietary chitosan feeding trial for 60 days.
Fig 1.
Histological analysis of the effects of dietary chitosan on villus length in the intestine of B. gonionotus (A-E).
Fish were fed a (A) the control diet (0 g kg-1 feed), (B) T1 (1 g kg-1 feed), (C) T2 (2 g kg-1 feed) or (D) T3 (3 g kg-1 feed). (E) Dietary chitosan-treated intestinal villus length compared to that with the control is shown (n = 9). Different letter bars indicate significant variations in the intestinal villus length of fish (E) in different dietary chitosan groups at P < 0.05 (Statistix 10). Scale bar = 100 μm; image 4x; H & E 200.
Fig 2.
Assessment of the effects of dietary chitosan on the culturable autochthonous bacteria and autochthonous lactic acid bacteria levels (log CFU/g intestine) of B. gonionotus.
One-way ANOVA was performed to analyze the data of three replicate experiments, and the data in the columns varied significantly according to the least significant difference (LSD) at P < 0.05 (Statistix 10). Different letter bars indicate significant variations in the levels of the culturable autochthonous bacteria and autochthonous lactic acid bacteria of B. gonionotus in different groups at P < 0.05 (Statistix 10). Error bar = ±SD; n = 9.
Table 4.
Effects of graded levels of dietary chitosan on the growth of fish pathogenic bacterial strains collected from the laboratory.
Values are the mean ± SEM (N = 3).
Fig 3.
Assessment of the effects of dietary chitosan on the intestinal digestive enzymes (A, B and C) of fish.
Fish were reared with three doses of dietary chitosan for 60 days. Here, Control = 0 g kg-1 feed; T1 = 1 g kg-1 feed; T2 = 2 g kg-1 feed and T3 = 3 g kg-1 feed. One-way ANOVA was performed to analyze the data of three replicate experiments, and the data in the columns varied significantly according to the least significant difference (LSD) at P < 0.05 (Statistix 10). Different letter bars indicate significant variations in (A) protease, (B) lipase, and (C) amylase levels of the fish in different dietary chitosan groups at P < 0.05 (Statistix 10). Error bar = ±SD; n = 9.
Fig 4.
Assessment of the effects of dietary chitosan on the proximate body composition (A, B C and D) of fish.
Fish were reared with three doses of dietary chitosan for 60 days. Here, Control = 0 g kg-1 feed; T1 = 1 g kg-1 feed; T2 = 2 g kg-1 feed and T3 = 3 g kg-1 feed. One-way ANOVA was performed to analyze the data of three replicate experiments, and the data in the columns varied significantly according to the least significant difference (LSD) at P < 0.05 (Statistix 10). Different letter bars indicate significant variations in (A) moisture (%), (B) protein (%), (C) lipid (%), and (D) ash (%) contents of the fish in different dietary chitosan groups at P < 0.05 (Statistix 10). Error bar = ±SD; n = 9.
Table 5.
Mineral composition of the muscle of B. gonionotus fed diets with graded levels of dietary chitosan after a 2-month feeding trial.
Values are the mean ± SEM (N = 3).
Fig 5.
Assessment of the effects of dietary chitosan on the hematological parameters (A, B, C, D and E) of fish.
Blood was collected from thirty fish of each replication and 90 fish of each treatment for estimating the (A) red blood cell (RBC) count, (B) white blood cell (WBC) count, (C) glucose level, (D) hemoglobin level and (E) packed cell volume (PCV). One-way ANOVA was performed to analyze the data of three replicate experiments, and the data in the columns varied significantly according to the least significant difference (LSD) at P < 0.05 (Statistix 10). Different letter bars indicate significant variations in the RBC count, WBC count, glucose level, hemoglobin level and PCV (%) of the fish in different dietary chitosan groups at P < 0.05 (Statistix 10). Error bar = ±SD; n = 90.
Fig 6.
Histological analysis of the effects of dietary chitosan on the kidneys (A and B) and liver (C and D) of B. gonionotus.
Fish were fed a (A and C) control diet (chitosan at 0 kg-1 feed) or dietary chitosan at 1 g kg-1 (B and D). (A) shows an unclear renal corpuscle (arrow), glomerulus (asterisk), Bowman’s space (arrowhead) and proximal tubules. (B) represents a more well-defined renal corpuscle, glomerulus, Bowman’s space and proximal tubules than A. (C) shows unclear hepatocytes (arrow) with irregularly shaped nuclei (asterisk). (D) shows hepatocytes with regularly shaped nuclei. Six fish were considered for each treatment. Image 40×; scale bar = 50 μm; H & E 200; n = 9.