A review of carotenoid utilisation and function in crustacean aquaculture

Crustaceans are cultured extensively around the world in intensive farming systems. High-performance formulated feeds have been developed for crustacean aquaculture, which are often supplemented with a number of natural and synthetic carotenoid sources. Studies over a number of years have consistently shown that dietary carotenoid supplementation is beneficial for crustacean aquaculture across a range of commercially relevant parameters. Most obvious is the effect on pigmentation, where carotenoid inclusion levels in feeds and duration of feeding diets with carotenoids have been optimised across many species to improve product colour, and subsequently quality and price. However, beneficial effects of carotenoid inclusion have increasingly been demonstrated on other parameters. This review updates the recent progress in our understanding of dietary carotenoid utilisation and storage, and the combined effects of diet, genetics and environment on crustacean pigmentation. In addition, the range of other physiological benefits this class of molecules brings to these animals is summarised. These include improvements in survival, growth, reproductive capacity, disease resistance and stress resistance. © 2015 Wiley Publishing Asia Pty Ltd

Used of microbial phytase to replace inorganic phosphorus in sex-reversed red tilapia: 1 dose response

Sex-reversed red tilapia of average initial body weight 5.5 g were fed seven practical diets containing 0, 500, 1,000, 2,000 and 4,000 units of microbial phytase/kg and two diets containing 0.2 and 0.3% feed grade dicalcium phosphate (DCP) (but no microbial phytase), respectively. The experiment was carried out in 235- l glass aquaria filled with 180 l water and attached with a closed-recirculating water system with 0.8 l/min flow rate. The experimental period was 10 weeks. All experimental diets were formulated with plant-based protein of 30% and 6% fat. Results indicated an improvement in apparent digestibility coefficient of phosphorus (ADCP) in fish given phytase supplemented feed. There was no difference in ADCP when 1,000 unit phytase/kg diet or higher phytase levels (2,000 and 4,000 unit phytase/kg diet) or 0.2 and 0.3% DCP were supplemented. A significant increase was noted for hemoglobin in tilapia that received 1,000 unit phytase/kg diet or higher levels compared to the control. Serum phosphorus ma kedly increased when the fish were given feeds with 1,000 unit phytase/kg diet and over, while the supplementation of 500 unit phytase/kg diet and over increased serum zinc level. Higher levels of phosphorus were retained in bone whereas lower levels of phosphorus presented in the feces of tilapia fed feeds supplemented with phytase. Growth performance was markedly influenced when the fish were given feed with 4,000 unit phytase/kg diet

The supplementation of phytase RONOZYME P on the growth and the utilisation of phosphorus by sex-reversed red tilapia (Oreochromis niloticus Linn.)

Abstract The effect of phytase supplementation to a low fish meal based diet on growth performance and phosphorus utilisation was investigated in sex-reversed red tilapia. Diets were prepared without phytase or inorganic phosphorus supplementation, with phytase, with supplemented inorganic phosphorus and with both phytase and supplemental inorganic phosphorus. Available phosphorus was set below requirement and the total phosphorus set to meet requirement for tilapia. After 8 weeks, there were significant differences in weight gain and protein utilisation between diets. There was an effect of phytase addition and inorganic phosphorus supplementation on bone phosphorus and whole-body phosphorus (p<0.05). A significant effect was also observed on phosphorus digestibility, phosphorus retention efficiency and phosphorus load of the water. Phosphorus digestibility and retention efficiency were significantly (p<0.05) higher, and phosphorus load of the water was significantly (p<0.05) lower in fish fed the phytase supplemented diet compared with diets containing supplemental inorganic phosphorus and the basal diet. In conclusion, phytase increased phosphorus availability, therefore reducing the need to add inorganic phosphorus and reducing phosphorus waste from low fish meal based diets for tilapia

The supplementation of phytase RONOZYME P on the growth and the utilisation of phosphorus by sex-reversed red tilapia (Oreochromis niloticus Linn.)

The effect of phytase supplementation to a low fish meal based diet on growth performance and phosphorus utilisation was investigated in sex-reversed red tilapia. Diets were prepared without phytase or inorganic phosphorus supplementation, with phytase, with supplemented inorganic phosphorus and with both phytase and supplemental inorganic phosphorus. Available phosphorus was set below requirement and the total phosphorus set to meet requirement for tilapia. After 8 weeks, there were significant differences in weight gain and protein utilisation between diets. There was an effect of phytase addition and inorganic phosphorus supplementation on bone phosphorus and whole-body phosphorus (p<0.05). A significant effect was also observed on phosphorus digestibility, phosphorus retention efficiency and phosphorus load of the water. Phosphorus digestibility and retention efficiency were significantly (p<0.05) higher, and phosphorus load of the water was significantly (p<0.05) lower in fish fed the phytase supplemented diet compared with diets containing supplemental inorganic phosphorus and the basal diet. In conclusion, phytase increased phosphorus availability, therefore reducing the need to add inorganic phosphorus and reducing phosphorus waste from low fish meal based diets for tilapia

Dietary nucleotide supplementation enhances immune responses and survival to Streptococcus iniae in hybrid tilapia fed diet containing low fish meal

AbstractA feeding trial was conducted to evaluate the effects of nucleotide (NT) supplementation in diet on immune responses and disease resistance of juvenile hybrid tilapia, Oreochromis niloticus×Oreochromis aureus. Nucleotide was added at 0, 120, 240, 360, 480 and 600mg NT/kg to low fish meal (6%) and high soybean meal (56%) basal diet for a total of 6 experimental diets. Each diet was fed to triplicate groups of tilapia (initial body weight 0.15±0.005g) in a recirculated freshwater rearing system for 10 weeks. Head kidney leukocyte superoxide anion production ratio was higher (P<0.05) in fish fed diets supplemented with ≥240mg NT/kg than that in fish fed the NT unsupplemented control diet. Fish fed the diet supplemented with 240mg NT/kg had higher plasma lysozyme activity than fish fed diets supplemented with ≤120mg NT/kg. The stimulation index (SI) of head kidney leukocyte stimulated with ConA was higher in fish fed diets supplemented with ≥120mg NT/kg than that in fish fed the control diet. The SI of leukocyte stimulated with PHA-P was higher in fish fed diets supplemented with ≥240mg NT/kg than in fish fed diets supplemented with ≤120mg NT/kg. After the feeding trial, 10 fish were randomly selected from each aquarium and were challenged with Streptococcus iniae for 7 days, higher survival (>80%) were observed in fish fed diets supplemented with NT than fish fed the NT unsupplemented control diet (56.7%). These results suggest that nucleotides supplemented at 120–240mg NT/kg in diet enhances immune responses and survival of tilapia fed low fish meal and high soybean meal diet