scholarly journals Dietary arginine affects growth, gut morphology, oxidation resistance and immunity of hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂) juveniles

2018 ◽  
Vol 120 (3) ◽  
pp. 269-282 ◽  
Author(s):  
Mingjuan Wu ◽  
Xiaoyi Wu ◽  
Senda Lu ◽  
Yujie Gao ◽  
Wei Yao ◽  
...  

AbstractAn 8-week growth trial was conducted to evaluate the effects of dietary arginine (Arg) levels on growth, gut morphology, oxidation resistance and immunity of hybrid grouper (Epinephelus fuscoguttatus♀×Epinephelus lanceolatus♂) juveniles. Seven isoenergetic (1465 kJ (350 kcal)/100-g DM), isoproteic (53·5 % of DM) and isolipidic (7 % of DM) experimental diets were formulated to contain graded Arg levels ranging from 1·9 to 4·7 % (dry weight) at approximately 0·5 % increments. Each diet was randomly assigned to triplicate groups of 16 juvenile fish (average initial body weight: 11·7 (sd 0·1) g) and was administered twice daily (08.00 and 16.00 hours). After the growth trial, all remaining fish were fed their prescribed diets for 2 d and then exposed to 4·5 mg Cu2+/l water for 36 h. Results showed that growth performance and feed utilisation of experimental fish were significantly affected by different dietary Arg levels. Weight gain % (WG%) of fish was increased as dietary Arg increased, reaching a peak value at 3·8 % dietary Arg level, and when dietary Arg level increased to 4·7 % WG% was reduced. Fish fed 1·9 and 2·2 % dietary Arg levels had higher daily feed intake compared with fish fed other dietary Arg levels. Feed conversion ratios in fish fed 1·9, 2·2, 2·7 and 4·7 % dietary Arg levels were higher than those in fish fed 3·1, 3·8 and 4·1 % dietary Arg levels. Protein efficiency ratio and protein productive value (PPV) increased with an increase in dietary Arg, up to a peak value at 3·8 % dietary Arg level, above which these parameters declined. On the basis of quadratic regression analysis of weight gain % (WG%) or PPV against dietary Arg levels, the optimal dietary Arg requirement for hybrid grouper was estimated to be 3·65 %. Fish fed 3·8 % dietary Arg had higher whole-body and muscle protein contents compared with fish fed other dietary Arg levels. Fish fed 3·8 and 4·1 % dietary Arg levels had higher levels of mRNA for insulin-like growth factor-I and target of rapamycin in the liver compared with fish fed other dietary Arg levels. Hepatic S6 kinase 1 mRNA expression in fish fed 3·8 % dietary Arg level was higher than that in fish fed any of the other dietary Arg levels. Gut morphology, hepatic antioxidant indices and immune indices in serum and head kidney were significantly influenced by dietary Arg levels. In conclusion, the optimal dietary Arg requirement for hybrid grouper was estimated to be 3·65 %, and suitable dietary Arg supplementations improved gut morphology and oxidation resistance of hybrid grouper.

2020 ◽  
pp. 1-12
Author(s):  
Zhiyu Zhou ◽  
Xiaoyi Wu ◽  
Delbert M. Gatlin ◽  
Xiao Wang ◽  
Wei Mu ◽  
...  

Abstract A 6-week growth trial was conducted to evaluate the influences of dietary valine (Val) levels on growth, protein utilisation, immunity, antioxidant status and gut micromorphology of juvenile hybrid groupers. Seven isoenergetic, isoproteic and isolipidic diets were formulated to contain graded Val levels (1·21, 1·32, 1·45, 1·58, 1·69, 1·82 and 1·94 %, DM basis). Each experimental diet was hand-fed to triplicate groups of twelve hybrid grouper juveniles. Results showed that weight gain percentage (WG%), protein productive value, protein efficiency ratio, and feed efficiency were increased as dietary Val level increased, reaching a peak value at 1·58 % dietary Val. The quadratic regression analysis of WG% against dietary Val levels indicated that the optimum dietary Val requirement for hybrid groupers was estimated to be 1·56 %. Gut micromorphology and expression of growth hormone in pituitary, insulin-like growth factor 1, target of rapamycin and S6 kinase 1 in liver were significantly affected by dietary Val levels. In serum, fish fed 1·58 % dietary Val had higher superoxide dismutase, catalase, lysozyme activities and IgM concentrations than fish fed other dietary Val levels. Fish fed 1·58 % dietary Val had higher expression of NF-E2-related factor 2 in head kidney than fish fed other dietary Val levels. Generally, the optimum dietary Val requirement for maximal growth of hybrid groupers was estimated to be 1·56 % of DM, corresponding to 3·16 % of dietary protein, and dietary Val levels affected growth, protein utilisation, immunity and antioxidant status in hybrid groupers.


2020 ◽  
Vol 4 (1) ◽  
pp. 52-56
Author(s):  
Wei Kang Chor ◽  
Victor Charlie Andin ◽  
Chitra Devi Gopalakrishnan ◽  
Amierah Amer ◽  
Shaheera Mohamed ◽  
...  

A 25-week feeding trial was conducted to assess the growth performance, organoleptic quality, and to estimate the viability of nourishing hybrid grouper (Epinephelus fuscoguttatus x Epinephelus lanceolatus) with low-cost fish (LCF) and commercially compound feed (CCF). A group of 3600 juvenile fish (182g) were released in four sea cages and fed with either LCF or CCF in duplicate. At the end of the trial, the hybrid grouper provided LCF attained a significantly higher (P<0.05) final body weight (971.00±24.04g) than those fed with CCF (838.50±17.68g). While the estimated feed cost of hybrid grouper fed with LCF (RM7.84 ± 0.45) was lower than those fed with CCF (RM9.28 ± 0.37), no significant difference was found in the fish survival and there was no clear bias in consumer preferences for either fish fed with LCF or CCF (P>0.05). Although technicalities of fish fed with LCF suggest that LCF is more efficient than CCF, feeding LCF to high-value fish is an unsustainable practice as LCF is usually obtained through trawling – a destructive fishing method for the marine ecosystem. Therefore, feeding with CCF without the use of LCF as the source of protein for its fishmeal will contribute to sustainable aquaculture. In order to convince the local farmers in Sabah to adopt the practice of feeding CCF, future research should focus on completing the species-specific diet formulation to promote optimum growth, and find ways to reduce the CCF local selling price.


Author(s):  
Jorn Trommelen ◽  
Andrew M. Holwerda ◽  
Philippe J. M. Pinckaers ◽  
Luc J. C. van Loon

All human tissues are in a constant state of remodelling, regulated by the balance between tissue protein synthesis and breakdown rates. It has been well-established that protein ingestion stimulates skeletal muscle and whole-body protein synthesis. Stable isotope-labelled amino acid methodologies are commonly applied to assess the various aspects of protein metabolism in vivo in human subjects. However, to achieve a more comprehensive assessment of post-prandial protein handling in vivo in human subjects, intravenous stable isotope-labelled amino acid infusions can be combined with the ingestion of intrinsically labelled protein and the collection of blood and muscle tissue samples. The combined application of ingesting intrinsically labelled protein with continuous intravenous stable isotope-labelled amino acid infusion allows the simultaneous assessment of protein digestion and amino acid absorption kinetics (e.g. release of dietary protein-derived amino acids into the circulation), whole-body protein metabolism (whole-body protein synthesis, breakdown and oxidation rates and net protein balance) and skeletal muscle metabolism (muscle protein fractional synthesis rates and dietary protein-derived amino acid incorporation into muscle protein). The purpose of this review is to provide an overview of the various aspects of post-prandial protein handling and metabolism with a focus on insights obtained from studies that have applied intrinsically labelled protein under a variety of conditions in different populations.


2001 ◽  
Vol 85 (2) ◽  
pp. 213-218 ◽  
Author(s):  
Shi-Yen Shiau ◽  
Jia-Fen Hsieh

An 8 week feeding trial was conducted to determine the dietary K requirement for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus). Purified diets with eight levels (0, 1, 2, 3, 4, 5, 7, 10 g/kg diet) of supplemental K were fed to tilapia. Each diet was fed to three replicate groups of fish initially weighing a mean value of 0.77 (SE 0.01) g/fish in a closed, recirculating rearing system. Weight gain was higher (P<0.05) in fish fed the diets supplemented with 2, 3 and 4 g K/kg diet than in fish fed diet with 10 g K/kg diet and the unsupplemented control diet. Gill Na+-K+ ATPase activity was highest in fish fed the diets supplemented with 1–3 g K/kg diet, followed by fish fed the diet with 5 g K/kg diet and lowest in fish fed the diet with 10 g K/kg diet. Whole-body K content in fish were generally increased as the dietary K supplementation level increased. Analysis by polynomial regression of weight gain and gill Na+-K+ ATPase activity and by linear regression of whole-body K retention of the fish indicated that the adequate dietary K concentration for tilapia is about 2–3 g/kg diet.


2004 ◽  
Vol 91 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Shi-Yen Shiau ◽  
Li-Shan Lu

Two 8-week feeding trials were conducted to determine the dietary Na requirement for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus) reared in fresh water and seawater. In each experiment, NaCl was added to the basal diet at 0, 0·5, 1, 2, 3, 5, or 7g Na/kg diet (fresh water) and at 0, 0·2, 0·5, 0·8, 1·2, 1·5, 2, or 3g Na/kg diet (seawater). Each diet was fed to three replicate groups of fish, individual fish initially weighing 0·69 (se 0·01) g, in a closed, recirculating rearing system. In fresh water, the tilapia fed the diet supplemented with 2g Na/kg diet had significantly (P<0·05) greater weight gain than the fish fed the diets supplemented with ≥3 and ≤0·5g Na/kg diet. Feed efficiency (FE) in fish generally followed the weight-gain pattern. Gill Na+–K+ ATPase activity was highest in the fish fed the diets supplemented with 1–3g Na/kg diet, followed by the fish fed the diet with 7g Na/kg diet and lowest in the fish fed the unsupplemented control diet. In seawater, the weight gain, FE and gill Na+–K+ ATPase activity in fish were not affected by the dietary treatment. Analysis by polynomial regression of weight gain, by broken-line regression of gill Na+–K+ ATPase activity and by linear regression of whole-body Na retention of the fish reared in fresh water, indicated that the adequate dietary Na concentration for tilapia is about 1·5g/kg diet. The present study also suggests that no dietary Na is required for tilapia reared in seawater.


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