Protein synthesis in gilthead sea bream: response to partial fishmeal replacement

Abstract

The present study aimed to measure tissue protein synthesis in sea bream fed isonitrogenous diets that contained 63, 55 and 50 % fishmeal; in the latter two diets, 16 and 27 % of the fishmeal protein was replaced with plant protein. Over a 35 d period, there were no differences in feed intake, growth or feed efficiency among the three diets. Protein metabolism was then measured in the liver and white muscle tissue as rates of protein synthesis and as the capacity for protein synthesis before feeding (0 h) and at different times after feeding (4-48 h). Diet did not have a significant effect on protein synthesis or on the capacity for protein synthesis in either tissue. The capacity for protein synthesis was not affected by time after feeding, and overall mean values were 81·02 (SE 1·68) and 4·07 (SE 0·94) mg RNA/g protein for the liver and white muscle, respectively. Liver and white muscle fractional rates of protein synthesis were significantly higher at 4 -8 h, intermediate at 12 h and were not different among pre-feeding (0 h), 24 and 48 h. Overall, the indices of protein metabolism measured at various times over 48 h following feeding were closely aligned with measurements of feeding, growth and growth efficiency established over a longer time scale. Key words: Protein synthesis: Specific dynamic action: Fishmeal replacementThe development of sustainable aquaculture is partly dependent on sustainable aquafeeds and the replacement of some or all of the protein and oil derived from marine sources (1 -3) . Strategies include the use of protein and oil sources derived from agriculture production as well as consideration of organic and certified ingredients that may include those of marine origin (4,5) . While considerable knowledge exists about the use of alternative protein sources in aquafeeds, the majority of this has been obtained from long-term growth experiments. Protein turnover is clearly of central importance to growth but only a few studies on fish have investigated protein turnover (6) , protein synthesis and protein degradation, in relation to dietary modification; even fewer have investigated the effect of replacing fishmeal on protein synthesis (7 -10) . Protein turnover reflects dietary protein in relation to how closely it matches quantitative and qualitative amino acid requirements (11 -13) .Low or imbalanced amino acid supply tends to initially stimulate protein synthesis in the liver in order to maintain protein synthesis and growth in the skeletal muscle (9) . Prolonged feeding at a low intake of amino acids will down-regulate protein synthesis so that liver rates decrease to be the same or lower than on a higher-quality protein source and skeletal muscle protein synthesis cannot be sustained and will be depressed (11,14) . When an alternative dietary protein is of high quality, muscle protein synthesis may not be affected by protein sources used, as in barramundi (Lates calcarifer) fed lupin meal to replace 45 % of the fishmeal protein (15) . In contrast, wholeanimal protein synthe...

Protein synthesis in crustaceans: a review focused on feeding and nutrition

“…At their peak, rates were 2-4 times higher, depending on the tissue, than at pre-feeding (Figure 3). There are strong similarities with post-prandial protein synthesis in fish including the rapid peak, its relative magnitude and how this is of longer duration in muscle [38,39]. In continuously fed animals protein synthesis was similar to pre-feeding rates in all tissues except the claw muscle and was similar to the peak rate.…”

“…Depending on the number of abiotic, biotic and specific nutritional factors some tissues have a pronounced post-prandial peak whereas others have more sustained plateau [2,39]. If unfed and peak rates of protein synthesis are measured, a daily protein synthesis value can be accurately calculated [39]; this was used to calculate daily SRE values of 38% for the marine protein feeds and 32% for the purified feed (Figure 5b).…”

“…If unfed and peak rates of protein synthesis are measured, a daily protein synthesis value can be accurately calculated [39]; this was used to calculate daily SRE values of 38% for the marine protein feeds and 32% for the purified feed (Figure 5b).…”

Feeding in hatcheries

“…European seabass (Dicentrarchus labrax), along with gilthead sea bream (Sparus aurata), are important Mediterranean and southern European aquaculture species (Enes et al, 2011;Carter et al, 2012). Combined production was just under 0.3 million metric tonnes in 2011 (FAO, 2014).…”

The Adaptive Response of Protein Turnover to the Energetic Demands of Reproduction in a Cephalopod

“…Incorporation times of 1-2.5 h following injection of 1.6 and 1.8 mL 3 Hphenylalanine 100 g Ϫ1 into the base of the arms are suitable for using the flooding dose method with dumpling squid (Carter et al 2009). Therefore, each individual was weighed immediately before injection to calculate dose (1.8 mL 100 g Ϫ1 ) and injected with a solution of 150 mM L-phenylalanine and L-(2,6-3 H)phenylalanine (Amersham Pharmacia Biotech) in 0.2 mm filtered seawater at pH 7.4 (Carter et al 2009(Carter et al , 2012. Following injection, animals were returned to aerated seawater at 20ЊC for 96-115 min to allow incorporation of L-(2,6-3 H)phenylalanine into the tissues.…”