Effect of nucleotides supplementation to low‐fish meal feed on long‐chain polyunsaturated fatty acid composition of juvenile rainbow troutOncorhynchus mykiss

Abstract

A feeding trial was conducted to evaluate the effect of nucleotides supplementation to low‐fish meal feed on growth and fatty acid composition of rainbow trout. Six isonitrogenous (42% crude protein) and isolipidic (18% crude lipid) diets were formulated containing fish meal and plant ingredients as main protein sources. The control diet was a basal diet without supplementation of nucleotides, and five experimental diets were prepared by supplementing one of the five different nucleotides in the form of 5′‐monophosphate (0.15%), that is inosine (IMP), adenosine (AMP), guanosine (GMP), uridine (UMP) and cytidine (CMP) onto basal diet. Two hundred forty juvenile rainbow trout with an initial average body weight 9.8 g were randomly distributed into twelve aquaria. After 15 weeks of feeding period, growth performance and feed utilization of rainbow trout were not significantly different among dietary treatments. Dietary GMP, UMP and CMP tended to accumulate crude lipid in the muscle and whole fish body. Moreover, dietary GMP, UMP and CMP significantly increased hepatic 18:3n‐3 and long‐chain homologue 18:4n‐3 and 20:4n‐3 contents. Hepatic 18:2n‐6 content showed also increase in fish fed GMP, UMP and CMP diets, but decreased in long‐chain homologue 20:3n‐6 and 20:4n‐6 contents. Decrease in 20:4n‐6, 20:5n‐3 and 22:6n‐3 contents was also found in the muscle of fish fed IMP, GMP and CMP diets. The present study clearly showed that there was no positive effect of dietary nucleotides on growth of fish, but dietary nucleotides particularly GMP, UMP and CMP altered polyunsaturated fatty acid composition of rainbow trout.

Interactive effect of dietary fish oil and pyrimidine nucleotide supplementation on the fatty acid composition of juvenile rainbow trout Oncorhynchus mykiss : Enhancement of ARA and DHA contents in the fillet of fish fed‐supplemented diet

“…Interestingly, our present study clearly showed that dietary pyrimidine nucleotides modulated fatty acid composition in the muscle but not in the liver of rainbow trout mainly for 20:4 n ‐6 and 22:6 n ‐3 contents. This finding was also in accordance with our previous finding on fatty acid composition in the muscle of rainbow trout fed nucleotide‐supplemented diet (Ridwanudin et al, 2019). Liver is a main organ to synthesize fatty acid and convert into other fatty acid or fatty acid derivatives such as eicosanoids and deliver it to other organs via blood circulation (Turchini et al, 2009).…”

“…However, supplementation of 1.5 g/kg pyrimidine nucleotides in the present study did not show to increase growth performance or feed utilization of rainbow trout. This was also similar to our previous study which found that supplementation of 1.5 g/kg purified nucleotides to low fishmeal‐based diet did not affect growth of rainbow trout (Ridwanudin et al, 2019). No growth promotion effect of 1.0 g/kg dietary nucleotides was also found in the juvenile turbot Scophthalmus maximus L. when fish meal replaced by 300 to 500 g/kg soya bean meal in the diet (Peng et al, 2013).…”

“…High fish oil (HFO) diet contains 120 g/kg of fish oil as the sole of lipid source, whereas low fish oil (LFO) diet includes 40 g/kg fish oil, 60 g/kg linseed oil and 20 g/kg rapeseed oil (Table 1). Two purified pyrimidine nucleotides including uridine 5’‐monophosphate (UMP) and cytidine 5’‐monophosphate (CMP) disodium salt forms from Tokyo Chemical Industry, Tokyo, Japan, were then supplemented at 1.5 g/kg in to each group according to our previous study (Ridwanudin et al, 2019) respectively (Table 1). The remaining two diets were served as control diets (HFO‐Cont.…”

“…In aquaculture, investigations of dietary nucleotides on fatty acid in fish have also been reported in Beluga sturgeon Huso huso juvenile, rainbow trout and grass carp Ctenopharyngodon idellus respectively (Abtahi et al, 2013; Ridwanudin et al, 2019; Tie et al, 2019). In Beluga sturgeon juvenile, supplementation of nucleotides in fishmeal‐based diet resulted in decreasing total saturated fatty acid in the whole body (Abtahi et al, 2013).…”

Efficacy of Dietary Nucleotides (Nucleoforce™)on growth, haemato-immunological response and disease resistance in Pangasianodon hypophthalmus fish (Sauvage, 1878) in Egypt

“…Several literature heightened attention on the usage of nucleotides as Growth promotor feed additives that are needed particularly for enhancing fish body metabolism and for developing of immune and intestinal tissues. (Peng et al, 2013 andRidwanudin et al, 2019). Nucleotides are low molecular weight biological compounds that play major roles in most biological processes which Can occur as subunit nucleobases or as polymeric nucleic acids (low et al, 2003).…”