Biological responses in mullet Mugil liza juveniles fed with guar gum supplemented diets

Abstract

a b s t r a c tThis study aimed to evaluate the effects of adding guar gum, a non-starch polysaccharide, to the diet of Mugil liza juveniles. The juveniles (mean weight = 0.38 ± 0.01 g) were fed one of three diets with increasing supplement levels (4%, 8%, and 12%) and a control diet without additional gum for 60 days, in order to evaluate the effects on zootechnical performance, proximate composition, liver parameters, morphological alterations to the intestinal tract, and modulation of gastrointestinal microbiota. The animals fed 8% and 12% gum presented a significantly lower mean final weight, weight gain, specific growth rate, food intake rate, and protein intake rate than the control. Adding gum to the diets also reduced the dry matter, crude protein, and carcass fat levels. All treatments with added gum resulted in increased liver glycogen, and the cholesterol levels were significantly reduced in fish fed 4% and 8% supplement levels. No intestinal morphological alterations were observed in the animals. However, a modulating effect was noted on the microbial community, altering the bacterial quantity and composition throughout the tract segments. The use of guar gum is not recommended in Mugil liza diets, at least above 4%.

Exogenous enzyme complex prevents intestinal soybean meal-induced enteritis in Mugil liza (Valenciennes, 1836) juvenile.

“…The mullets in the present study exhibited distribution of bacteria along the gastrointestinal tract similar to previous works (Ramos et al 2015a(Ramos et al , 2015b. Bacteria were more abundant in the stomach than in intestinal sections; the authors identify that this microbial pattern could indicate that M. liza utilizes the bacterial biomass for its own growth, similar to ruminant animals, whose nutrition relies mainly on bacterial-fermentable products and the microbial biomass present in the forestomach (Hill et al 2008).…”

Gut Microbiota and Energy Homeostasis in Fish

“…A limited number of studies show that modifying the diet of the fish can result in alterations of the gut microbiota, but this is not always the case. Diets containing guar gum, (non-starch polysaccharide) fed to the omnivorous mullet, Mugil liza (100) or soy proteins to the carnivorous rainbow trout (101) induce alterations in the bacterial quantity and composition in the GIT. In zebrafish, administration of dietary nucleotides results in modifications of the microbiota and reduction in fatty acid oxidation in muscle and liver as well as lower inflammatory tone (102).…”

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

“…Similar results have been reported in several fishes, that is, Enes et al (2013) reported that plasma cholesterol did not decrease in white sea bream, Diplodus sargus by GG supplementations at 4-12% to diet. In addition, liver cholesterol increased by feeding 12% GG-supplemented diet in mullet (L. R. V. Ramos et al, 2015). In aquatic animals, dietary cholesterol is absorbed by the stomach and intestine, and it is influenced by several factors such as dietary fat composition, bile acid secretion, and activity of cellular transporters in digestive tracts (Lammert & Wang, 2005).…”