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This study assessed the impact of replacing fish meal (FM) with a blend of corn gluten meal and meat meal (BCM) at a ratio of 1:2 on the growth performance, digestive enzyme activity, and nonspecific immune response of juvenile black rockfish (Sebastes schlegelii). Seven experimental diets were formulated. The control (BCM0) diet contained 65% FM. Subsequently, 10, 20, 30, 40, 50, and 60% FM in BCM0 diet were replaced with BCM, referred to as the BCM10, BCM20, BCM30, BCM40, BCM50 and BCM60, respectively. Each diet was randomly assigned to triplicate groups of 30 rockfish (initial body weight: 3.6 ± 0.01 g) for 8 weeks. The BCM0–BCM50 diets resulted in no significant differences in final body weight (FBW), weight gain (WG), and specific growth rate (SGR), whereas the BCM60 diet led to the lowest FBW, WG, and SGR. The feed consumption and feed efficiency of rockfish fed BCM10–BCM50 diets did not differ significantly from those of rockfish fed the BCM0 diet. Intestinal trypsin and lipase activities showed a linear decrease with increasing substitution levels of BCM in the experimental diets. Moisture levels increased with elevated BCM replacement in diets, whereas crude protein and lipid levels decreased with increased BCM replacement. Whole-body amino acid profiles of rockfish, except for glycine and proline content, were not significantly affected by diet. However, lysozyme and catalase activities exhibited quadratic responses to increasing dietary BCM levels, and superoxide dismutase activity and glutathione content showed a negative linear response. Overall, these results show that a blend of corn gluten meal and meat meal can replace up to 50% of dietary FM without adversely affecting the growth performance of juvenile rockfish. • A blend of corn gluten meal and meat meal (BCM) in a 1:2 ratio is a good protein source of protein for black rockfish. • Substituting up to 50% FM with BCM did not have adverse effects on growth and feed utilization. • Intestinal trypsin and lipase activities showed a linear decrease with increasing substitution levels of BCM. • With increased dietary BCM, plasma superoxide dismutase activity and glutathione concentration decreased linearly. [ABSTRACT FROM AUTHOR]

Fish meal (FM) is widely used as a main protein source in formulated feed for marine fish culture. However, the production of FM has shrunk or plateaued due to the overfishing and climate change in the wild. Meat meal (MM) is known as a good replacer for FM in fish feeds. Dietary replacement effect of MM for FM on the growth, feed consumption, feed utilization, body composition, hematology, and innate immune responses of rockfish was determined. A total of 630 fish (initial weight of 2.3 g) was randomly distributed into 21, 50 L flow-through tanks (30 fish/tank). Seven experimental diets were formulated. The control (MM0) diet contained 55% FM. Then, 10, 20, 40, 60, 80, and 100% FM in the MM0 diet were replaced with MM, referred to as the MM10, MM20, MM40, MM60, MM80, and MM100 diets, respectively. All experimental diets were allocated to triplicate groups of fish. Fish were hand-fed to visual satiation twice a day for 8 weeks. Increased substitution of FM with MM in diets resulted in decreased essential amino acids (EAA), such as lysine and threonine and the sum n-3 highly unsaturated fatty acids, but increased EAA, such as arginine and methionine, and the sums of saturated and monoene FA. Weight gain (9.8 g/fish) of fish fed the MM10 diet was significantly (P <.003) greater than that (8.8, 8.9, 8.2, and 7.9 g/fish, respectively) of fish fed the MM0, MM60, MM80, and MM100 diets. Specific growth rate (SGR) (2.93%/day) of fish fed the MM10 diet was significantly (P <.004) higher than that (2.79, 2.69, and 2.64%/day, respectively) of fish fed the MM0, MM80, and MM100 diets. Weight gain and SGR of fish fed the MM100 diet were (P <.05) significantly lower than those of fish fed the MM0 diet. Feed consumption (9.34 g/fish) of fish fed the MM10 diet was significantly (P <.002) higher than that (8.72, 8.59, 8.32, and 8.10 g/fish, respectively) of fish fed the MM0, MM60, MM80, and MM100 diets. Feed efficiency (1.04%) of fish fed the MM10, MM40, and MM60 diets was significantly (P <.009) higher than that (0.99, and 0.98%, respectively) of fish fed the MM80, and MM100 diets. Condition factor, protein efficiency ratio, protein retention, hematological parameters, and innate immune responses (lysozyme and superoxide dismutase activities) of fish was not significantly (P >.05) different among the experimental diets. The chemical composition, and AA and FA profiles of the whole-body fish were not influenced by the experimental diets. In conclusion, dietary substitution FM up to 80% with MM can be made without deteriorating growth performance of rockfish. However, the optimum substitution level of FM with MM in diets were estimated to be 18.5, and 18.2% based on regression analysis of weight gain and SGR of rockfish, respectively. • Substitution effect of fish meal with meat meal in diets on performance of rockfish was determined. • Weight gain and SGR of fish fed the MM100 diet were significantly lower than those of fish fed the MM0 diet. • Dietary substitution FM up to 80% with MM can be made without deteriorating growth performance of rockfish. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted to evaluate the potential of replacing fish meal with processed animal by-product meals, meat meal and blood meal (4:1 ratio), in practical diets for juvenile grouper (Epinephelus coioides). Eight isonitrogenous diets were formulated to contain 45% protein and 12% lipid. Fish meal was replaced by 0%, 10%, 20%, 30%, 40%, 60%, 80%, and 100% of meat meal and blood meal (4:1) mixture (diets 1–8). The diet with 100% fish meal (diet 1) or trash fish as feed (diet 9) were used as controls. Grouper juveniles were reared in 250-l circular fiberglass tanks maintained in a flow-through seawater system. Each dietary treatment was tested in quadruplicate groups of 25 fish per tank arranged in a completely randomized design. Fish were fed the diets twice per day at a daily feeding rate of 5–6% of biomass and trash fish at 10–12% of biomass for 60 days. Percentage weight gain, specific growth rate (SGR), survival, feed conversion ratio (FCR) and body composition of grouper juveniles were measured. There were no significant differences (P>0.05) in growth performance among fish fed diets 1–7 (0–80% fish meal replacement) with those fed diet 9 (trash fish as feed). However, fish fed diet 3 had significantly higher (P<0.05) growth than those fed diet 8 (100% fish meal replacement). Survival among fish fed the experimental diets did not significantly differ (96–100%) but was significantly higher (P<0.05) than survival (90%) of fish fed trash fish. These results showed that up to 80% of fish meal protein can be replaced by processed meat meal and blood meal coming from terrestrial animals with no adverse effects on growth, survival, and feed conversion ratio of E. coioides juveniles. [Copyright &y& Elsevier]