Intestinal histology and stereology in rainbow trout (Oncorhynchus mykiss ) administrated with nanochitosan/zeolite and chitosan/zeolite composites

Abstract

In previous study, the effects of synthesized chitosan/zeolite and nanochitosan/zeolite composites on rainbow trout growth, digestive enzyme activities and some biochemical parameters were shown. In this study, the effects of experimental diets based on the previous study on the rainbow trout intestinal histology and stereology were assessed: control diet (no zeolite and composite), T1 diet (14.28 g/kg zeolite), T2 diet (0.05 g/kg chitosan included in zeolite), T3 diet (0.5 g/kg chitosan included in zeolite), T4 diet (5 g/kg chitosan included in zeolite), T5 diet (0.05 g/kg nanochitosan included in zeolite), T6 diet (0.5 g/kg nanochitosan included in zeolite), T7 diet (5 g/kg nanochitosan included in zeolite). The experiment was conducted for 60 days. Results showed that supplemental diets did not have side effect on the normal structure of intestinal segments but administration of T1 and T4 diets had slight negative effects on structural maintenance in the middle part of intestine. Acidic mucin producing goblet cell percentage was also higher in nanocomposites‐administrated groups in comparison with the control group. Enhanced villus height, density and finally absorption surface area in different parts of rainbow trout intestine were mainly shown in T7 group. Meanwhile, higher thickness of tunica mascularis in different regions were noted in treatment groups especially in T7 group. The number of intraepithelial mononuclear leukocytes in fish intestine received treatment diets was also higher than control group. In conclusion, nanochitosan/zeolite composites in comparison with zeolite and chitosan/zeolite composites were more effective to improve histological structure of rainbow trout intestine.

A Detailed Study of Rainbow Trout (Onchorhynchus mykiss) Intestine Revealed That Digestive and Absorptive Functions Are Not Linearly Distributed along Its Length

“…Moreover, goblet cell density is strongly affected by several external factors comprising nutrition, physiology and immunology [24,25], and this must be considered as a possible source of variability. On the contrary, our finding of goblet cells producing different mucous substances agrees with previous results in several teleost fish, including rainbow trout [4,8,10]. Interestingly, the significant increase of acid glyconjugates observed in the anterior intestine, the increase of villus branching and the appearance of vacuolized enterocytes in the pyloric caeca all occurred in correspondence with the increase of lipid concentration in the diet.…”

“…This distal intestine is the major site of macromolecules absorption in most fish species, including salmonids [7]. In addition, only a few studies have been performed on rainbow trout intestine report quantitative data [10], while most of them are based on qualitative observations [6]. Finally, these studies are rarely carried out in animals raised in optimal and standardized conditions and do not consider the relationship between intestinal morphology and fish growth.…”

Dietary limonCitrus × latifoliafruit peel essential oil improves antioxidant capacity of tambaqui (Colossoma macropomum) juveniles

“…The alterations in the intestinal morphology of tambaqui can be associated with possible beneficial effects also observed in several studies that presented an increase in the absorption surface area in the intestinal mucosa (Ferreira et al., 2016; Goulart et al., 2018; Hamidian et al., 2018). The dietary effects on gut morphology highlighted here are thus directly linked to EOCL.…”

Growth and physiological responses of juvenile amberjack (Seriola dumerili) fed pellet diets bound by different binders

“…Because villus density represents absorption surface in fish intestine, several studies have attempted to determine the influence of dietary factors on villus density in small intestine (Hamidian et al, 2018;Merrifield et al, 2011; M. A. Ramos et al, 2017).…”