Welfare and quality of farmed trout fed high plant protein diets. 1 Growth performance and quality traits

摘要

Abstract This study was performed to evaluate the effects of high levels of inclusion of plant protein sources to replace fish meal in rainbow trout ( O. mykiss ) diets on growth performance and quality characteristics. Two isoproteic (44.8%) and isolipidic (19.6%) extruded diets were fed to eight groups of trout (IBW 106.6g) for 103 days. Diet FM, containing only fish meal as protein source, was used as control treatment and compared to diet PV80, where a plant protein mix (pea protein concentrate and wheat gluten) was included to replace 80% of fish meal protein. Growth performance (FBW: 318.5g; SGR: 1.06%) and feed to gain ratio (0.79) of the fish were not affected by dietary treatment (p>0.05). Dry matter and protein ADCs, measured in vivo after stripping, resulted higher in fish fed the high vegetable protein diet relative to the fish meal one (p vs 1.72, p vs 91.18%, p vs 1.07%, p vs 8.82%, p vs 2.88%, p vs 6.41%, p post mortem (5.56 vs 6.44, p 0.05). Higher dry matter (28.2 vs 26.8g/100g, p vs 1.31mg/g, p post mortem firmness measured by the Shear force of raw muscle resulted higher in fish fed the plant protein based diet (4.06 vs 3.30N, p post mortem (4.24 vs 2.95N, p<0.05) resulted not affected by the dietary treatment. In summary, data show that even if the growth performance of rainbow trout fed a diet in which fish meal was largely replaced by high quality plant proteins resulted similar, some major quality traits such as dressing out, fillet composition and texture can be significantly affected by dietary treatment.