Dietary β-glucans and mannanoligosaccharides improve growth performance and intestinal morphology of juvenile pacu Piaractus mesopotamicus (Holmberg, 1887)

Abstract

The objective of this study was to evaluate the effect of increased levels (0.0, 0.1, 0.2, 0.4, and 0.8%) of a combination of β-glucans and mannanoligosaccharides (MOS) in isonitrogenous (23% of digestible protein) and isoenergetic (13.38 MJ of digestible energy kg-1) pacu diets, corresponding to five treatments and four replicates. A 30-day feeding trial was conducted to assess the effects on growth performance, hematological parameters, and intestinal morphology. Fish (n = 160, 30.92 ± 0.46 g) were distributed randomly in 20 aquaria (300 L) with a recirculating water system with controlled temperature (26.20 ± 0.32°C) and fed four times a day until apparent satiation. A quadratic effect (P < 0.05) was observed for weight gain (WG), feed conversion ratio (FCR), and protein efficiency ratio (PER). The hepatosomatic and viscerosomatic indexes, hematocrit, hemoglobin, mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC) did not show differences (P > 0.05) among treatments. Pacu fed β-glucans and MOS at 0.1 and 0.2% resulted in the greatest (P < 0.05) villus height and perimeter. The diet containing 0.2% β-glucans and MOS promoted the best growth response, feed efficiency, and intestinal morphology, without detrimental effects on the hematological parameters for juvenile pacu.

Growth, physiological and immune responses of Arapaima gigas (Arapaimidae) to Aeromonas hydrophila challenge and handling stress following feeding with immunostimulant supplemented diets

“…On one hand had no effect on hematocrit, MCHC, MCV, respiratory burst of leukocytes, total protein, albumin and number of eosinophils. Similarly, P. mesopotamicus supplemented with a combination of 1-8% of β-glucan and mannanoligosaccharides for 30 days, did not change the number of erythrocytes, hematocrit, hemoglobin, MCHC, VCM, and total plasma protein levels [9]. In H. huso supplemented with 1-2% of S. cerevisiae in the diet, for 42 days, no changes in plasma levels of total proteins, glucose, erythrocytes, hematocrit, hemoglobin, MCHC, MCV and Table 3 Plasma biochemical parameters and blood immune parameters of Arapaima gigas, after 30 days feeding the experimental diets.…”

“…Supplementation with 0.1% of S. cerevisiae in the Table 2 Growth performance parameters of Arapaima gigas fed the experimental diets for 30 days. diet of O. niloticus [23] and 2% in the diet of Huso huso [24], as well as 2% of β-glucan combined with mannanoligosaccharides in the diet of Piaractus mesopotamicus [9] improved fish growth performances. The previous studies indicated that S. cerevisiae-based products were efficient in promoting fish growth and potentially viable for aquaculture use from the production viewpoint.…”

“…However, with the development of global aquaculture, several problems have arisen, including the deterioration of water quality, parasitic and bacterial diseases [1,3,4,7]. Diets supplemented with immunostimulants based on Saccharomyces cerevisiae, which contain beta-glucan polysaccharide, mannanoligosaccharides and chitin have been recommended for improvement in fish production [7][8][9][10]. Diets supplemented with immunostimulants may improve fish performance by establishing the intestinal microbiota and better preparing fish immune system.…”

“…Diets supplemented with immunostimulants may improve fish performance by establishing the intestinal microbiota and better preparing fish immune system. As a consequence, fish are more resistant to stress, including parasitic and infectious diseases [6][7][8][9][10]. Aquate Fish™ ® is a commercial feed additive that may play a role in the fish defense systems.…”

Performance of pacu juveniles fed diets supplemented with L-carnitine

“…Fish fed 2,000 mg kg -1 L-carnitine had taller and less-thick villi (Table and Figure 3), which represents an adaptation of the tissue to the food, suggesting an improvement in the surface area for the absorption of nutrients (Hisano et al, 2018). In pacu, the intestinethe main organ for nutrient digestion and absorption in fish -is medium sized and lined by folds, which are distributed longitudinally, being wider and more complex in the median portion, where there is a greater nutrient absorption (Corrêa, 2016).…”