Effect of dietary encapsulated organic salts (Na‐acetate, Na‐butyrate, Na‐lactate and Na‐propionate) on growth performance, haemolymph, antioxidant and digestive enzyme activities and gut microbiota of juvenile narrow clawed crayfish, Astacus leptodactylus leptodactylus Eschscholtz, 1823

Abstract

A 63‐day experiment was done to study the effects of four levels (5, 10, 20 and 50 g/kg) of encapsulated organic salts (Na‐acetate, Na‐butyrate, Na‐lactate and Na‐propionate) on the growth indices and haemato‐immunological responses of crayfish Astacus leptodactylus leptodactylus (4.38 ± 0.08 g). Crayfish were distributed at 51 1,000‐L tanks (17 treatments at triplicate). The highest values of final weight (27.86 g), specific growth rate (2.94% body weight per day) and survival rate (96%) were observed in the crayfish fed the 20 g/kg of encapsulated Na‐propionate diet (p < .05). The highest activities of phenoloxidase (7.4 U/min), superoxide dismutase (7.80 U/min) and lysozyme (9.40 U/min) were observed in the gut of crayfish fed the 20 g/kg of encapsulated Na‐propionate diet (p < .05), as well as the highest activities of alkaline protease (10.70 U/mg), lipase (9.10 U/mg), amylase (9.60 U/mg) and the lactobacillus count (p < .05). Broken line regression model of SGR and phenoloxidase activity suggested that the optimum dietary levels of encapsulated Na‐acetate, Na‐butyrate, Na‐lactate and Na‐propionate could be 30.7, 31.8, 31.4 and 33.5 g/kg, respectively, in crayfish reared in culture conditions.

Effects of Microencapsulated Organic Acid and Their Salts on Growth Performance, Immunity, and Disease Resistance of Pacific White Shrimp Litopenaeus vannamei

“…Several studies reported improved growth performance, nutrient utilization and immune response in crustaceans fed a microencapsulated blend of organic acid or acid salts. Safari et al [61] reported the efficacy of an encapsulated blend of Na-butyrate, Na-lactate and Na-propionate on growth performance and survival of crawfish at 20 g/kg. The OS blend used in the present study contains Ca-propionate, Ca-formate and Na-acetate, and showed higher feed intake compared to those fed the OA diets.…”

Effects of dietary short‐chain fatty acid salts on the growth performance, digestive, antioxidant and immune enzyme activities, immune‐related gene expression and resistance to Vibro parahaemolytics infection in juvenile ridgetail white prawn ( Exopalaemon carinicauda )

“…The type and dose of SCFA salts have important effects on the growth performance of aquatic animals. Supplements of SA (3.07%), SP (3.18%) and SB (3.35%) in the diet can improve SGR, survival rate and FE of Astacus leptodatylus (Safari et al, 2020). A significant improvement in growth performance was achieved with an inclusion level of butyric acid (0.5%) in Lates calcarifer (Alamifar et al, 2019) and microencapsulated SB (0.03%) in C .…”

“…To evaluate the effects of SA, SP and SB on specific growth rate, survival rate, feed efficiency and relative percent survival, the individuals from each group were weighed and calculations were made according to a previous report (Safari et al, 2020): Specific growth rate (SGR, %/day) = 100 × (In (final body weight) – In (initial body weight))/feeding days; Survival rate (SR, %) = 100 × final survival individuals/initial individuals; Feed efficiency (FE) = (final body weight − initial body weight)/feed intakes; Relative percent survival (RPS) = (mortality rate in control group − mortality rate in immunized group)/ mortality rate in control group …”

“…Acute hepatopancreatic necrosis disease (AHPND) is one of the significant diseases widely observed in shrimp, caused by Vibrio parahaemolyticus (Raja et al, 2017). Maintaining the health status of shrimps is crucial to their successful aquaculture and appropriate diet additives can be good methods for improving their physical condition (Safari et al, 2020). Precautionary administration of chemicals such as antibiotics has been routinely practiced in aquaculture (Hoseinifar, Safari, et al, 2017; Hoseinifar, Sun, et al, 2017), though the overuse of antibiotics in aquaculture is harmful to human and animal health, and to the aquaculture environment (Cabello, 2006).…”

“…SCFAs and their salts are “generally regarded as safe” compounds (Ng & Koh, 2017; Tian et al, 2017) and a number of researchers have found that SCFAs as feed additives in the aquafeed production industry have positive effects on aquatic animals such as zebrafish ( Dnio rerio ) (Zhang et al, 2020), common carp ( Cyprinus carpio L.) (Safari et al, 2017), Li topenaeus vannamei (Silva et al, 2015), juvenile turbot ( Scophthalmus maximus L.) (Wei et al, 2017), juvenile grass carp ( Ctenopharyngodon idellus ) (Liu et al, 2016) and barramundi ( Lates calcarifer ) (Alamifar et al, 2019). SCFAs modulate the physiological status of aquatic animals in four ways by improving (1) feed quality (reducing pH and the harmful bacteria count); (2) intestine functions (incremental increase in enzyme activity, nutrient digestibility, mineral solubility and gut health); (3) faeces traits (reduced phosphorus load and microbiota count) and (4) water quality (Ng & Koh, 2017; Safari et al, 2020). To the best of our knowledge, no information is available in the literature about the use of SCFA salts as supplements in the diet of juvenile E. carinicauda .…”