Effect of dietary valine levels on the growth performance, feed utilization and immune function of juvenile golden pompano,Trachinotus ovatus

Abstract

This experiment was designed to investigate the effects of dietary valine on the growth performance, feed utilization, digestive enzymes, serum antioxidant and immune indices of juvenile Trachinotus ovatus and determine its valine requirement. Six diets with different concentrations of L‐valine (15.0, 16.6, 18.6, 20.7, 23.5 and 25.4 g/kg dry diet, defined as diet Val‐1 to Val‐6.), were formulated to contain 430 g/kg crude protein with fish meal, soybean meal, peanut meal and precoated crystalline amino acids. Each diet was randomly assigned to triplicate treatments of 20 fish (the initial body weight was 5.34 ± 0.03 g) for 8 weeks. The results indicated that the final body weight and percent weight gain (PWG) increased with increasing valine concentration up to 18.6 g/kg (diet Val‐3), whereas the diets containing higher valine concentration reduced the growth performance significantly (p < .05). Moreover, the protein efficiency ratio, body protein deposition (BPD), muscle protein content, intestinal amylase and pepsin activities, serum T‐AOC, LZM activities, IgM, complement 3 and complement 4 concentration had a similar trend with PWG, and the trend of feed conversion ratio, serum AST, ALT activities, urea and MDA content was opposite. Meanwhile, the lipid contents of whole fish and muscle in diet Val‐6 were particularly lower than other diets (p < .05). The survival rate of diet Val‐1 was lowest in this study and was significantly lower than diet Val‐2 (p < .05). The results of polynomial regression based on PWG and BPD indicated that the optimal dietary valine requirement for Trachinotus ovatus reared in seawater‐floating net cages was 19.87–20.17 g/kg valine of dry diet, correspondingly 46.22–46.91 g/kg of dietary protein.

Effect of dietary isoleucine level on growth, protein retention efficiency, haematological parameter, lysozyme activity and serum antioxidant status of fingerlingChanna punctatus(Bloch)

“…Deficiency of dietary isoleucine led to slow growth and feed utilization efficiency in this and other species including chinook salmon, O. tshawytscha (Chance, Mertz, & Halver, ); channel catfish, I. punctatus (Wilson, Poe, & Robinson, ); milk fish, Chanos chanos (Borlongan & Coloso, ); rainbow trout, O. mykiss (Rodehutscord et al, ); mrigal, C. mrigala (Ahmed & Khan, ); rohu, L. rohita (Khan & Abidi, ; Murthy & Varghese, ); grass carp, C. idella (Shang et al, ); common carp, Cyprinus carpio (Zhao et al, ); catla, C. catla (Zehra & Khan, ); golden pompano, T. ovatus (Huang et al, ); blunt snout bream, M. amblycephala (Ren et al, ). In the present study, fish fed the dietary isoleucine‐deficient diet Ile 4 exhibited deficiency signs such as reduce weight and poor feed conversion.…”

“…Different statistical and mathematical models of expressing essential amino acid requirement are used in several studies (Castillo & Gatlin, ; Huang et al, ; Khan & Abidi, ; Ren et al, ; Zehra & Khan, ). Use of non‐linear model broken line is recommended to be more appropriate to describe the response for evaluating results from dose–response experiment and also allow the complex physiological response of living organism (NRC, ).…”

“…The amount of isoleucine contributed by casein and gelatin in the experimental diets was 3.8 and 0.2 g/kg dry diet, respectively. The range of isoleucine in the trial diets was fixed as per the requirement of other fish species (Huang et al, ; NRC, ; Rahimnejad & Lee, ; Ren et al, ; Zehra & Khan, ; Zhao et al, ). The analysed isoleucine concentrations of the diet were 3.8, 7.5, 11.3, 15.1, 19.3, 23.2 and 27.4 g/kg dry diet and labelled as Ile 4 , Ile 8 , Ile 12 , Ile 16 , Ile 20 , Ile 24 and Ile 28, respectively.…”

“…Among the essential amino acids, branched‐chain amino acids (BCAAs) participate in lipolysis, lipogenesis, glucose metabolism, glucose transportation, intestinal amino acid transport, benefiting embryo growth and immunity (Zhang, Zeng, Ren, Mao, & Qiao, ). Isoleucine (Ile), the branched‐chain amino acids (BCAAs) is involved in protein synthesis, growth, maintain nitrogen balance, tissue building, energy production (Ahmed & Khan, ; Huang et al, ; Khan & Abidi, ), insulin biosynthesis and secretion (Kimball & Jefferson, ), immune response and digestion (Zhao et al, ). Dietary isoleucine deficiency or excess results in retardation of growth and feed conversion (Ahmed & Khan, ; Huang et al, ; Liu et al, ; Millamena, Teruel, Kanazawa, & Teshima, ; Rodehutscord, Becker, Pack, & Pfeffer, ; Zhao et al, ).…”

“…Isoleucine requirements have already been defined for chinook salmon, Oncorhynchus tshawytscha ; channel catfish, I. punctatus ; rainbow trout, Oncorhynchus mykiss ; mossambique tilapia, Oreochromis mossambicus ; rohu, Labeo rohita ; white sturgeon, Acipenser transmontanus ; red sea bream, Pagrus major ; European sea bass, Dicentrarchus labrax ; gilthead seabream, Sparus aurata ; turbot, Psetta maxima ; Atlantic salmon, S. salar ; mrigal, Cirrhinus mrigala ; grass carp, Ctenopharyngodon idella (NRC, ); catla, Catla catla (Zehra & Khan, ); golden pompano, T. ovatus (Huang et al, ); blunt snout bream, M. amblycephala (Ren et al, ); red drum, S. ocellatus (Castillo & Gatlin, ).…”