Partial Replacement of Fishmeal with Seafood Discards for Juvenile Penaeus japonicus: Effects on Growth, Flesh Quality, Chemical and Fatty Acid Composition

Abstract

The present study was designed to assess the influence of fishmeal replacement with increasing percentages of fresh seafood discards (0, 25, 50 and 75%) in diets for Penaeus japonicus on growth performance, physical characteristics and the chemical and fatty acid composition of shrimp flesh. Each diet was administered for 108 days, and the trial was assayed in triplicate. The final body weight and the specific growth rate were significantly higher (p < 0.05) in shrimps fed with 75% fishmeal replacement as compared to 25%, while the abdomen weight and the total length were the highest (p < 0.01). Moreover, 75% replacement showed a significantly (p < 0.05) lower value of hardness and a greater crude protein and lipid content as compared to the 0% replacement. The shrimps fed with high levels of seafood discards (50 and 75%) showed a lower saturated fatty acid concentration and, in turn, a greater amount of polyunsaturated fatty acids in shrimp meat significantly (p < 0.05) affected the lower atherogenic and thrombogenic indices. In conclusion, replacing 75% of fishmeal with seafood discards provided satisfactory results. An economic analysis based on ESG indicators and PESTLE methodology is provided in order to show the socio-economic and governance impacts affecting the replacement of shrimps’ diet with fish discard.

Status of Fishery Discards and By-Products in Greece and Potential Valorization Scenarios towards a National Exploitation Master Plan

“…The rising gap between supply and demand has prompted the search for sustainable alternatives, such as discarded fish species and fish processing by-products that have been reported to have high nutritional value by Saleh et al (2022) [ 33 ] and Khiari et al (2022) [ 34 ]. From a nutritional standpoint, fish meal produced from discards and processing by-products have been evaluated for the diets of Atlantic salmon ( Salmo salar ) [ 35 ], rainbow trout ( Oncorhynchus mykiss ) [ 36 , 37 ] red drum ( Sciaenops ocellatus ) [ 38 , 39 ], olive flounder ( Paralichthys olivaceus ) [ 40 ], Nile tilapia ( Oreochromis niloticus ) [ 41 ], kuruma shrimp ( Penaeus japonicus ) [ 42 ], juvenile turbot ( Scophthalmus maximus ) [ 43 ], red seabream ( Pagrus major ) [ 44 , 45 ], juvenile longfin yellowtail ( Seriola rivoliana ) [ 46 ], river catfish ( Hemibagrus nemurus ) [ 47 ], and European seabass ( Dicentrarchus labrax ) [ 48 ], with promising results for partial and total industrial fish meal substitution. Data from the proximate composition analysis of Mediterranean fish species with relatively low economic value suggest that the nutritional profile is comparable to industrially produced fish meal; therefore, the concept of a fish meal processing chain could present a viable solution for the valorization of discards and fish by-products.…”