Nutritional evaluation of rapeseed protein isolate as fish meal substitute for juvenile turbot (Psetta maxima L.) — Impact on growth performance, body composition, nutrient digestibility and blood physiology

Insects are emerging as a sustainable alternative to fishmeal and fish oil in aquafeeds. This study assessed the effect of graded incorporation levels of defatted yellow mealworm (Tenebrio molitor) protein meal on juvenile rainbow trout (Oncorhynchus mykiss) growth performance, body composition, and apparent nutrient digestibility. The trial comprised five dietary treatments: control diet with 25% fishmeal, and four experimental diets with yellow mealworm protein meal at 5%, 7.5%, 15%, or 25%, which corresponded to a fishmeal replacement of 20%, 30%, 60%, or 100%, respectively. After 90 days, the graded incorporation of insect protein meal led to a significant stepwise increase in final body weight, and a significant improvement of specific growth rate, feed conversion ratio, and protein efficiency ratio compared to the control treatment. Regardless of the incorporation level, the insect protein meal had no effects on fish whole-body composition and apparent digestibility coefficients of dry matter, protein, fat, phosphorus, and energy. Protein, phosphorus, and energy retention significantly increased in fish fed the diets with an insect protein meal. In conclusion, the yellow mealworm protein meal could effectively replace 100% of fishmeal in the diet of juvenile rainbow trout with positive effects on its overall zootechnical performance.

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Dietary replacement of fish meal by defatted and fermented soybean meals with taurine supplementation for pompano fish: effects on growth performance, nutrient digestibility, and biological parameters in a long-term feeding period

Journal of Animal Science ◽

10.1093/jas/skaa367 ◽

2020 ◽

Vol 98 (12) ◽

Author(s):

Hung Phuc Nguyen ◽

Thinh Van Do ◽

Hau Duc Tran

Keyword(s):

Growth Performance ◽

Soybean Meal ◽

Fish Meal ◽

Basal Diet ◽

Nutrient Digestibility ◽

Biological Parameters ◽

Feeding Period ◽

Taurine Supplementation ◽

Fermented Soybean

Abstract A 16-wk growth trial was conducted to examine the effects of dietary replacement of fish meal by defatted soybean meal (SBM) and fermented soybean meal (FSBM) with taurine supplementation on growth performance, nutrient apparent digestibility coefficient (ADC) and biological parameters of pompano fish. The FSBM was produced by fermenting SBM with Lactobacillus spp. Seven isonitrogenous and isoenergetic diets were formulated to replace 35% or 50% of fish meal by SBM or FSBM with taurine supplementation. The diets are denoted as follows: FM, SBM35, SBM35T, FSBM35T, SBM50, SBM50T, and FSBM50T. The FM (the basal diet) contained fish meal as a main source of dietary protein. Taurine was supplemented to SBM35T, FSBM35T, SBM50T, and FSBM50T at the level of 15 g/kg diet. Pompano juveniles with an initial body weight (BW) of 80 g reared in floating net cages were fed the experimental diets twice daily for 16 wk. Results showed that the final BW, weight gain, and feed conversion ratio of fish fed SBM35 and SBM50 were significantly lower than those of fish fed FM (P < 0.05), indicating that the replacement of fish meal by SBM at the rate of 35% in the diet is excessive for pompano. Supplementation of taurine to the SBM-included diets significantly increased growth performance and feed utilization (P < 0.05); however, these diets did not restore the performance back to a level equivalent to that of fish offered the basal diet. Meanwhile, fish fed FSBM35T had comparable growth and feed performances to those fed FM. Hematocrit values, total biliary bile acid levels, whole body lipid contents, and tissue taurine concentrations of fish fed SBM35 and SBM50 were the lowest among the treatments, but these parameters were improved by taurine supplementation and FSBM inclusion in the diet. Taurine supplementation increased lipid ADC, and SBM fermentation slightly enhanced both lipid and protein ADCs of the fish. These findings suggest that the combination of FSBM and taurine supplementation is an effective way to improve growth performance, nutrient digestibility, and biological parameters, and that FSBM with taurine supplementation can replace 35% of fish meal in pompano diets without any negative effects on growth and feed performances in a long-term feeding period.

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Combined Effects of Citric Acid and Phytase Supplementation on Growth Performance, Nutrient Digestibility and Body Composition of Labeo rohita Fingerlings

Aquaculture Studies ◽

10.4194/aquast656 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Maryam Iqbal ◽

Muhammad Afzal ◽

Atif Yaqub ◽

Khalid Mahmood Anjum ◽

Komal Tayyab

Keyword(s):

Body Composition ◽

Citric Acid ◽

Growth Performance ◽

Labeo Rohita ◽

Antinutritional Factors ◽

Nutrient Digestibility ◽

Whole Body ◽

Canola Meal ◽

Feed Conversion ◽

Plant Materials

Aquaculturists have been concentrating their efforts to design aquafeeds using agro by-products to reduce feed costs. However, the presence of a wide variety of antinutritional factors (ANFs) in plant materials is one of the major obstacles. For this purpose, a 2x2 factorial experiment was established to evaluate the suitability of canola meal with citric acid (CA) and phytase (PHY) supplementation for growth performance, nutrient digestibility and body composition of Labeo rohita fingerlings. Five isocaloric and isonitrogenous diets; D1 (control; without CA and PHY), D2 (CA 15 g/kg+PHY 1000 FTU/kg), D3 (CA 30 g/kg+PHY 1000 FTU/kg), D4 (CA 15 g/kg+PHY 2000 FTU/kg) and D5 (CA 30 g/kg+PHY 2000 FTU/kg) were fed to fish (mean initial weight 7.61±0.31 g) in triplicates for 90-days. The growth performance was significantly increased while feed conversion ratio was decreased with D3 compared to control and other CA and PHY supplemented groups (P<0.05). Furthermore, higher digestibility (%) of nutrients (dry matter, crude protein and ash) and improved whole-body composition was also exhibited by fish fed with D3 (P<0.05). Hence, the above results elucidate that supplementation of 30 g/kg CA with 1000 FTU/kg PHY could be a useful approach for improved growth performance, nutrients digestibility and body composition of L. rohita.

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