Growth, biochemical response and liver health of juvenile barramundi (Lates calcarifer) fed fermented and non-fermented tuna hydrolysate as fishmeal protein replacement ingredients

Abstract

Conventional aquaculture feed materials available in Australia are expensive, which has prompted the search for alternatives that would be cost-effective and locally available. The present study was undertaken in order to maximize the use of a tuna hydrolysate (TH), which was produced locally from the tuna-processing discards. The growth performance, biochemical status, antioxidant capacity and liver health of juvenile barramundi (Lates calcarifer) were assessed. Two series of isonitrogenous and isocaloric diets labelled as TH50, TH75 (non-fermented tuna hydrolysate) and FTH50, FTH75 (fermented tuna hydrolysate) were formulated to replace FM at 50% and 75%, respectively. A basal diet without the TH supplementation was used as a control. The experimental diets were fed to the triplicate groups of fish three times a day for 56 days. The results of the experiment revealed that fish fed on both fermented and non-fermented TH-containing diets significantly reduced (p < 0.05) the final body weight, weight gain and specific growth rate compared to the control. The highest apparent digestibility coefficients for dry matter, protein and lipid were obtained in the control group, and decreased with the increasing level of TH in the diets. However, the whole-body proximate compositions and the blood biochemical indices of fish were not affected by the TH inclusion in the diets. The fish fed on TH diets of TH50, FTH50 and TH75 exhibited reduced (p < 0.05) glutathione peroxidase (GPx) activity compared to the control; whereas the FTH75 exhibited no difference with the control. The excessive inclusion of TH in the diets of TH75 and FTH75 resulted in cytoplasmic vacuolization, with an increased amount of lipid accumulation, and necrosis in the liver tissue. These results indicated that the replacement of the FM protein with TH at 50% and 75% inclusion levels negatively affected the growth performance, feed utilization, and digestibility in juvenile barramundi; and it also increased the potential risk of hepatic failure in the fish. Further investigation is, therefore, required in order to optimize the TH levels in the fish diets which would be suitable for the growth of fish, as well as for maintaining the enhanced biochemical response in juvenile barramundi.

Impact of varied combinatorial mixture of non-fishmeal ingredients on growth, metabolism, immunity and gut microbiota of Lates calcarifer (Bloch, 1790) fry

“…Despite the health promoting capacity of TH, its inclusion percentage was not enhanced in any of the diets. A previous study by Siddik et al, highlights the negative impacts of excess inclusion of TH in juvenile barramundi diet that include reduced growth performance, feed utilisation and digestibility, cytoplasm vacuolization, necrosis and lipid accumulation in hepatic tissue 43 . Proximate composition analysis showed a considerable increase in ash% with the replacement of FM in each subsequent diet formulation.…”

Dietary tuna hydrolysate modulates growth performance, immune response, intestinal morphology and resistance to Streptococcus iniae in juvenile barramundi, Lates calcarifer

“…FPH containing free amino acids and suitable peptides has a substantial role in maintaining good health of fish 32 . However, the use of FPH in aqua-feeds must be at the appropriate level as higher inclusion of FPH may negatively influence the growth and feed utilization in fish 1 , 33 . In Japanese flounder, Paralichthys olivaceus 16% or higher inclusion of fish hydrolysate in the diet resulted in significant reduction in growth 34 .…”

“…Lates calcarifer , a euryhaline carnivorous fish species commonly known as barramundi or Asian sea bass, is widely cultured throughout the Indo-Pacific region and Australia 1 , 2 . Currently, the commercial farming of this species is well established in ponds, net cages and recirculating aquaculture systems (RAS) in both fresh and saline water.…”

Bioprocessed poultry by-product meals on growth, gut health and fatty acid synthesis of juvenile barramundi, Lates calcarifer (Bloch)

“…The PBM was sieved through a 0.5mm size mesh sieve and was used as the raw material for bioprocessing. The fermentation of PBM was completed following a technique described in our earlier study [32]. In short, PBM was weighed and Baker’s yeast, Saccharomyces cereviceae (Instant dried yeast, Lowan) was added at 10% and Lactobacillus casei in the form of skim milk product (Yakult, cell density of 3 × 10 6 CFU ml −1 ) was added at 5% of the weight of PBM.…”

“…Throughout the experimental period of 42 days, fish were fed to satiation the respective diets three times a day at 0800, 1200 and 1700 h. About 1.5 h after feeding, uneaten feed was removed carefully by siphoning, transferred to aluminium cups, and dried to a constant weight in order to calculate the feed conversion ratio. The growth performance, feed utilization and body indices parameters of juvenile barramundi were calculated using the equations describe previously [32].…”