PROTEINS
Carnivorous fish feed formulation practice with rendered animal proteins: A review of 20 year research at Zhejiang University Yan Wang, Ocean College, Zhejiang University, Peng Li, North American Renderers Association
Aquaculture is one of the fastest growing sectors in agriculture. Feed technologies have been recognized as one of the major driving forces to the expansion of aquaculture worldwide. The rapidly growing demand for digestible proteins for aquacultured species has been resulting in the depletion and deficiency of dietary protein sources, especially fishmeal, which has been used as the most ideal protein source in aquafeed. In 2023, the market price of quality fishmeal skyrocketed to RMB 18,000-20,000 (USD 2,500-2,775) per metric ton due to the dramatically declined fishmeal production. Fishmeal deficiency becomes a challenge threatening the sustainability of aquaculture of crustacean and carnivorous fish, which traditionally rely on high levels of fishmeal in formulated feeds.
Rendered animal proteins to replace fishmeal Research on fishmeal replacement in aquafeed started in the mid-1970s, following the research on fishmeal replacement in chicken diet. Before 2005, hundreds of papers were published to assess the potential replacement of fishmeal with rendered animal protein ingredients, such as poultry byproduct meal (PBM), meat and bone meal (MBM), feather meal (FEM) and blood meal (BD), in shrimp and finfish diets. During this period, fishmeal replacement level with PBM, MBM, FEM and BM singularly or in combination, was examined in diets for various carnivorous fish species, including rainbow trout, barramundi, sunshine bass, yellowtail, grouper, red drum, hybrid striped bass, gilthead seabream, Australian silver perch, red snapper, silver
seabream, chinook salmon, palmetto bass, European eels and black sea turbot. Since 2000, supported by the Fats and Protein Research Foundation (FPRF), North American Rendered Association (NARA) and other local funding sources, we have been developing cost-effective formulation technologies to replace fishmeal inclusion with PBM, MBM, FEM and BD in diets for those local carnivorous fish commercially important for mariculture in China. Previous studies by other researchers showed the inclusion of 15% FEM in chinook salmon diets and 12% FEM in Japanese flounder diets as a fishmeal alternative did not result in significantly lower growth, and the inclusion of 24% MBM and 16% FEM in rainbow trout diet containing 30% fishmeal did not negatively influence fish growth. Red drum fed the diets with fishmeal replaced by PBM grew faster than that of the fish fed the diets with the same amount of fishmeal replaced by MBM. These studies all demonstrated nutritional values of PBM, MBM and FEM in carnivorous fish diets, but did not fully elucidate the efficiency of those three promising protein ingredients. Therefore, we conducted the first feeding trial to compare the efficacy of PBM, MBM and FEM as a single fishmeal alternative in cuneate drum diet and found PBM delivered the best performance to cuneate drum, followed by MBM and FEM. In latter studies, we confirmed similar findings with Malabar grouper. Those early findings allowed local aquafeed millers of drum and grouper to include PBM, MBM and FEM in
Aquafeed: Advances in Processing & Formulation Vol 15 Issue 4 2023
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