| Popis: |
Protein hydrolysates from poultry by-product (CPH) and poultry by-product plus swine liver (PHPPL) were evaluated for digestibility and attractiveness for Litopenaeus vannamei, their effect on growth as a substitute for salmon by-product meal. Initially, the apparent digestibility coefficient (ADC) of the protein hydrolysates was determined and their attractiveness was also evaluated. Subsequently, five diets with 0, 25, 50, 75 and 100 % substitution of the salmon by-product meal protein by PHPPL, were evaluated. The experiment was conducted for 42 days in a clear water system. For the digestibility assay, the protein hydrolysates had high ADC for protein, dry matter, energy, and essential amino acids for L. vannamei. However, PHPPL had better digestibility results than CPH, so it was used in the growth assay. No difference in the attractiveness of the tested ingredients was observed (p ≥ 0.05). In the growth assay, survival was no different (p ≥ 0.05) among shrimp fed the different protein replacement levels. However, we observed an increase in shrimp growth with the treatment of 25 % protein replacement. Diet with 50 % protein replacement promoted growth similar to that of the control diet with a subsequent decline of up to 100 % of protein replacement. Therefore, it can be concluded that up to 25 % of dietary protein replacement with PHPPL can improve shrimp growth. |
