Complete Replacement Of Fish Meal By Poultry By-product Meal In Practical Diets Based Upon An Amino Acid Balance For Pacific White Shrimp Litopenaeus Vannamei

In the present study, the supplementing effects of crystalline or coated amino acids in diets with complete replacement of fish meal by poultry by-product meal on an amino acid balance were evaluated on the growth, body composition, and plasma, muscle amino acid contents of Pacific white shrimp(Litopenaeus vannamei). The main findings were as follows:1. Effects of fish meal replacement with poultry by-product meal in diets supplemented with crystalline EAA or/and NEAA on growth performance, body composition, plasma and muscle free amino acidsA 2×4 factorial experiment with two levels of dietary protein(32% and 40%) and four dietary treatments of amino acid supplementation was carried out to determine the effects of complete replacement of fish meal(FM) with poultry by-product meal(PBM) in diets on a basis of EAAs or EAA+NEAAs on the growth and body composition of Pacific white shrimp over an 8-week feeding trial. Four amino acid-treated diets were formulated and expressed as diet FM, diet PBM, diet PBM+EAA and diet PBM+EAA+NEAA respectively for each dietary protein level. The weight gain rate(WGR) in PBM+EAA and PBM+EAA+NEAA groups were higher than that in PBM group(P<0.05), but lower than that of control(P<0.05) for each dietary protein level. Changes in FCR was just the opposite of WGR(P<0.05). No difference in WGR between PBM+EAA and PBM+EAA+NEAA groups(P<0.05) was observed. The shrimp fed the diets containing 40% protein level had higher WGR(P<0.05), body protein content(P<0.05), but lower body lipid content(P<0.05) compared to those shrimp fed diets containing 32% protein level. Free plasma EAA/NEAA was positively linearly correlated with dietary EAA/NEAA. Specific growth rate of shrimp was positively correlated with the concentrations of plasma free methionine or phenylalanine. Plasma free methionine, phenylalanine and lysine concentrations of PBM group were lower than that in control group(P<0.05), but there were no significant differences in muscle free amino acid concentrations(P>0.05). Feeding a diet with PBM+EAA or PBM+EAA+NEAA does not lead to a growth comparable to feeding the basal diet. The diets supplemented with NEAAs do not help in improving the growth of shrimp.2. Effects of fish meal replacement with poultry by-product meal in diets supplemented with coated EAA or/and NEAA on growth performance, body composition, plasma and muscle amino acidsA 2×6 factorial experiment with two levels of dietary protein(32% and 40%) and six amino acid treatments was conducted to determine the effects of complete replacement of fish meal(FM) with poultry by-product meal(PBM) in diets on a basis of EAAs or EAA+NEAAs on the growth and body composition of Pacific white shrimp over an 8-week feeding trial. Six amino acid-treated diets were formulated and expressed as diet FM, diet PBM, PBM+ crystalline EAA, diet PBM+ coated EAA, diet PBM+ crystalline EAA+ crystalline NEAA and diet PBM+ coated EAA+ coated NEAA respectively for each dietary protein level. For each dietary protein level, WGR in groups of PBM+ crystalline EAA and PBM+ crystalline EAA+ crystalline NEAA were higher than that in PBM group(P<0.05). No difference in WGR between group PBM+ coated EAA and control groups at 32% dietary protein level(P>0.05) was observed. The WGR both in group PBM+ crystalline EAA in group PBM+ crystalline EAA+ crystalline NEAA was not different(P>0.05), but was lower than those in group PBM+ coated EAA and group PBM+ coated EAA+ coated NEAA groups(P<0.05). The WGR value in group of PBM+ coated EAA was significantly higher than those in group PBM+ coated EAA+ coated NEAA(P<0.05). Changes in FCR was just the opposite of WGR(P<0.05). The shrimp fed the 40% protein diets had higher WGR, body protein content, but lower body lipid content(P<0.05) compared to those shrimp fed 32% protein diets. Free amino acid concentrations in plasma of groups PBM+ coated amino acids were generally lower than those in groups PBM+ crystalline amino acids(P<0.05). There were no differences in muscle amino acid concents(P>0.05) except glutamate, glycine and proline across dietary treatments(P<0.05). Feeding a diet with PBM+ coated EAA can lead to a growth comparable to feeding the basal diet at 32% dietary protein level.