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The aim of this study was to assess the digestible protein value of three novel poultry products (Pea/Lentil‐PM, Hen on Hen‐PM, and soybean meal (SBM)‐PM), then a growth trial with a 2 × 5 design was conducted where SBM‐PM was included at five levels: 0, 5, 10, 15, and 30% in both a fish meal (FM)‐based diet and a plant protein (PP)‐based diet. Thirty rainbow trout (initial size = 10.7 ± 0.15 g; Troutlodge Inc, Sumner, WA) per tank were stocked into a 15°C recirculating system. Fish in triplicate tanks were fed twice daily to apparent satiation for 12 weeks. SBM‐PM had no effect on final weight (p = 0.3665; FM 233 vs. PP 237) or growth rate (p = 0.4703; FM 2070% vs. PP 2097%). Significant interactions between dietary protein and SBM‐PM for both intake (p = 0.0080) and FCR (p = 0.0081) indicate increased intake of fish fed the plant protein‐based diet without SBM‐PM. Regression modeling of this effect yields a polynomial model with an R‐square of 0.78; p < 0.0001 explained by the relationships: PlantFCR=0.875−0.0087Inclusion+0.00062Inclusion2 and Plant intake=2.02−0.02Inclusion+0.0014Inclusion2, respectively. These values suggest that the SBM‐PM can be included up to 30% in rainbow trout feeds to reduce feed costs without negatively impacting performance. [ABSTRACT FROM AUTHOR]

The complete quantitative essential amino acid (EAA) requirements of aquacultured animals are largely unknown except for a handful of species. This is problematic because formulation of least-cost diets for target animals demands precise knowledge of EAA requirements. One way of approximating EAA requirements is to use correlations between whole-body and/or muscle EAA profiles using essential to total EAA ratios (A/E ratios). This method requires a reference, quantified EAA requirement, usually lysine (Lys). To systematically evaluate the A/E ratio method, muscle AA profiles were measured in 10 species of teleost and whiteleg shrimp. In fish, Lys represented the dominant muscle EAA measured, ranging between 7.06 and 9.58 g/100 g protein, whereas, in shrimp, arginine (Arg) was quantified as the principal EAA. For non-EAA, glutamate (Glu) and glutamine were consistently the NEAA recorded at highest levels whereas, in shrimp, Glu + Gln was highest followed by aspartate (Asp) plus asparagine (Asn). Except for Arg, which was twice that of fish (P < 0.05), whiteleg shrimp expressed similar muscle A/E profiles. Strength of relationship between muscle EAA levels and known requirements were all strongly and positively correlated for non-salmonid species. When using Lys as the reference EAA there were few semblances between measured and estimated EAA requirements. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the influence of krill meal (KM) inclusion at various levels (0%, 2.5%, 5%) in plant-based and animal-based feeds, that were fishmeal (FM) and fish oil (FO) free, on Atlantic salmon growth. A FM/FO feed containing 0% KM was the control. Using a 2 × 3 factorial approach, diets were randomly assigned to one of 28 0.5 m3 flow-through tanks (n = 4 tanks per diet) initially stocked with 60 fish (148.4 ± 12.9 g; 23.6 ± 0.8 cm; condition factor (K) = 1.16 ± 0.08) each. Salmon were fed for 90 days using automatic feeders ad libitum. On day 45, stocking densities were reduced to 45 fish per tank by the random removal of 15 individuals to remove any potential of density affecting growth through the trial end. Water temperature, oxygen saturation, pH, and salinity throughout the trial were 11.8 °C, 103.5%, 7.38, and 32.0 g L−1, respectively. Fish fed plant-based feed without KM were lighter (p < 0.05) than all other groups at day 45 and 90, but those fed a plant-based feed with KM had comparable growth and feed intake compared to that of fish fed the control diet. Irrespective of the presence of KM, animal-based feeds achieved comparable weight growth (p > 0.05) to the control and 5% KM plant-based groups, with KM increasing feed intake (p < 0.05). Between day 45 and 90, feed conversion ratios increased in all groups except the control and 0% KM plant-based group, while specific growth rates (SGRs) decreased for all except the 0% KM plant-based diet. Between-group differences (p < 0.05) were also noted for the thermal growth coefficient. No differences were recorded in visceral or intestinal weight, and whole-body lipid levels were identical, proportional for all groups. Although differences (p < 0.05) were apparent in the concentrations of individual fillet fatty acids between groups, a 75 g serving size of any treatment would be sufficient to exceed daily intake recommendations for EPA + DHA. This trial determined that benefit, in terms of feed intake and growth performance, was gained when KM was added to plant-based feeds. However, no such advantage was observed when KM was used with animal-based feeds. [ABSTRACT FROM AUTHOR]