TY - JOUR
T1 - Effects of plant proteins on postprandial, free plasma amino acid concentrations in rainbow trout (Oncorhynchus mykiss)
AU - Larsen, Bodil Katrine
AU - Dalsgaard, Anne Johanne Tang
AU - Pedersen, Per Bovbjerg
PY - 2012
Y1 - 2012
N2 - Postprandial patterns in plasma free amino acid concentrations were investigated in juvenile rainbow trout
(Oncorhynchus mykiss) fed either a fish meal based diet (FM) or a diet (VEG) where 59% of fish meal protein
(corresponding to 46% of total dietary protein) was replaced by a matrix of plant proteins from wheat, peas,
field beans, sunflower and soybean. Blood samples were obtained from the caudal vein of 7 fish in each dietary
treatment group prior to feeding, as well as: 2, 4, 6, 8, 12, 24, 48 and 72 h after feeding (sampling 7 new
fish at each time point), and plasma amino acid concentrations were subsequently measured by HPLC. Nutrient
digestibility and ammonia excretion of the two experimental diets were measured in a parallel experiment
using a modified Guelph setup. Results showed that the appearance of most amino acids (essential
and non-essential) in the plasma was delayed in fish fed the VEG diet compared to those fed the FM diet. Essential
and non-essential amino acids furthermore appeared more or less synchronously in the plasma in fish
fed the FM diet, while the appearance was less synchronised in fish fed the VEG diet. Differences in plasma
concentrations between the two dietary treatment groups correlated largely with the amino acid content
of the two diets except for methionine, lysine and arginine, where the differences were more extreme than
what would be expected from differences in dietary concentrations. The apparent protein digestibility coefficient
was higher in the VEG diet than in the FM diet (93 versus 92%; t-test, Pb0.05), supporting that protease
inhibitors from plant protein ingredients were not the cause of the delay. The apparent digestibility coefficient
of carbohydrates (calculated as nitrogen-free extract (NFE)) was much lower in the VEG than in the
FM diet (51 versus 76%; t-test, Pb0.05). Combined with a higher NFE content in the VEG diet, this meant
that there was 2.7 times more indigestible NFE in the VEG than in the FM diet (6.1 versus 2.2 g 100−1 g
feed). Such difference may suggest that the uptake of amino acids (AA) was affected by dietary carbohydrates.
Total ammonia-nitrogen (TAN) excretion was slightly, but non-significantly, higher in VEG fed fish
than in FM fed fish (59 versus 55 mg TAN g−1 digested protein; t-test, P>0.05). In conclusion, the study
showed that amino acid uptake patterns are affected when replacing fish meal with plant based protein
ingredients
AB - Postprandial patterns in plasma free amino acid concentrations were investigated in juvenile rainbow trout
(Oncorhynchus mykiss) fed either a fish meal based diet (FM) or a diet (VEG) where 59% of fish meal protein
(corresponding to 46% of total dietary protein) was replaced by a matrix of plant proteins from wheat, peas,
field beans, sunflower and soybean. Blood samples were obtained from the caudal vein of 7 fish in each dietary
treatment group prior to feeding, as well as: 2, 4, 6, 8, 12, 24, 48 and 72 h after feeding (sampling 7 new
fish at each time point), and plasma amino acid concentrations were subsequently measured by HPLC. Nutrient
digestibility and ammonia excretion of the two experimental diets were measured in a parallel experiment
using a modified Guelph setup. Results showed that the appearance of most amino acids (essential
and non-essential) in the plasma was delayed in fish fed the VEG diet compared to those fed the FM diet. Essential
and non-essential amino acids furthermore appeared more or less synchronously in the plasma in fish
fed the FM diet, while the appearance was less synchronised in fish fed the VEG diet. Differences in plasma
concentrations between the two dietary treatment groups correlated largely with the amino acid content
of the two diets except for methionine, lysine and arginine, where the differences were more extreme than
what would be expected from differences in dietary concentrations. The apparent protein digestibility coefficient
was higher in the VEG diet than in the FM diet (93 versus 92%; t-test, Pb0.05), supporting that protease
inhibitors from plant protein ingredients were not the cause of the delay. The apparent digestibility coefficient
of carbohydrates (calculated as nitrogen-free extract (NFE)) was much lower in the VEG than in the
FM diet (51 versus 76%; t-test, Pb0.05). Combined with a higher NFE content in the VEG diet, this meant
that there was 2.7 times more indigestible NFE in the VEG than in the FM diet (6.1 versus 2.2 g 100−1 g
feed). Such difference may suggest that the uptake of amino acids (AA) was affected by dietary carbohydrates.
Total ammonia-nitrogen (TAN) excretion was slightly, but non-significantly, higher in VEG fed fish
than in FM fed fish (59 versus 55 mg TAN g−1 digested protein; t-test, P>0.05). In conclusion, the study
showed that amino acid uptake patterns are affected when replacing fish meal with plant based protein
ingredients
U2 - 10.1016/j.aquaculture.2011.11.028
DO - 10.1016/j.aquaculture.2011.11.028
M3 - Journal article
SN - 0044-8486
VL - 326
SP - 90
EP - 98
JO - Aquaculture
JF - Aquaculture
ER -