Replacement Fish Meal By Protein Blends In Practical Diets For Siberian Sturgeon (Acipenser Baerii Brandt) Under Ideal Protein Concept

In this study, the effect of partial or total substitution fishmeal with animal or vegetable protein blend was studied in juvenile Siberia sturgeon (Acipenser baerii Brandt)on feedintake, growth performances, body composition,nitrogen and phosphorus discharge and flesh quality under 2 ideal protein concepts.Under the same concept,the effect of different protein level were also studied on growth performances.4 experiments was respectively summarized as follows:Experiment 1. Replacement Fish Meal by Rendered Animal Protein Blend in Practical Diets for Siberian Sturgeon (Acipenser baerii Brandt)under ideal protein concept. The effect of animal protein blend (APB, including meat & bone meal, MBM: 35%; poultry by-product meal, PBM: 40%; hydrolysed feather meal, HFM: 5%; spray dried blood meal, BM: 20%) as a partial or total replacement of fishmeal (FM) was studied in juvenile Siberia sturgeon (Acipenser baerii Brandt) in an eight-week growth trial. Six extruded experimental diets were formulated. The experiment was conducted with 6 treatment groups. 4 replicates for one group,20 fish for one replicate. 48.3% and 40% of fishmeal(FM)were used in control diets with crude protein at 40% and 36%, respectively. 75% or 100% of FM will be replaced by MP in other 4 diets, in which lysine, methionine, and threonine will be balanced under ideal protein concept (Dlys/DP=6.5;Dmet/DP=2.4; Dthr/DP=4.2)by crystallized amino acid (Lys-H2SO4, 65 %;DL-Met. 98% and L-Thr. 98%), respectively. Accordingly the six diets were named as FM40, BAP75-40, BAP40, FM36, BAP75-36, BAP36, respectively. 0.1% of Yttrium oxide(Y₂O₃)as inner marker for digestibility determination was designed for nitrogen and phosphorus excretion. Fish body composition and serum somatotrpic axis hormone GH and IGF-I were determined.The results showed that with the increasing of the Substitution , ADC of dry matter ,crude protein and gross phosphorus decreased;substitution of 75% or 100% fishmeal with MP, either at dietary 40% CP or at dietary 36% CP, did not result in the decrease of SGR,nitrogen retention and phosphorus retention (P>0.05). But the feed intake in 36% CP was higher than that in 40% CP, and the feed efficiency in 36% CP was lower than that in 40% CP(P<0.05);there was no significant difference for Non-faecal N excretion/N intake,but it's contrary for Non-faecal P excretion/ P intake,and decreased with the increasing of the Substitution.;there were no significant differences on fish body and liver composition for substitution or protein level, but it's contrary on muscle crude lipid for substitution level.Experiment 2.Total Replacement Fish Meal by vegetable Protein Blend in Practical Diets for Siberian Sturgeon (Acipenser baerii Brandt) under ideal protein concept. The effect of rendered vegetable protein blend (including BVP40, soybean meal: 61.5% and wheat gluten meal:38.5% ; BVP36, soybean meal:62.1%; wheat gluten meal:37.9%) as a total replacement of fishmeal (FM) was studied in juvenile Siberia sturgeon (Acipenser baerii Brandt) in an eight-week growth trial.Four extruded experimental diets were formulated. 48.3% and 40% of fishmeal (FM) were used in control diets with crude protein at 40% and 36%, respectively. FM will be totally replaced by BVP, in which lysine, methionine, and threonine will be balanced under ideal protein concept by crystallized amino acid (Lys-H2SO4, 65 %;DL-Met. 98% and L-Thr. 98%), respectively. Accordingly the 4 diets were named as FM40, BVP40, FM36, BVP36, respectively. 0.1% of Yttrium oxide (Y₂O₃) as inert marker for digestibility determination was designed for nitrogen and phosphorus excretion. Fish body composition and serum somatotrpic axis hormone GH and IGF-I were determined.The results showed total substitution of fishmeal with BVP, either at dietary 40% CP or at dietary 36% CP, did not result in the decrease of FCR, nitrogen retention (P>0.05);but the feedintake in 36% CP and FM group was higher than that in 40% CP and BVP group,respectively; total substitution of fishmeal with BVP can decrease phosphorus discharge; Ash and phosphorus of fish body and crude lipid of liver for BVP group were significantly higher than FM group.Experiment 3. Replacement Fish Meal by animal or vegetable Protein Blend in Practical Diets for Siberian Sturgeon (Acipenser baerii Brandt) under ideal protein concept in a long-term. The diets FM40,BAP40 and BVP40 in the experiment 1 and 2 were chosen for further determining feedintake, growth performances , nitrogen and phosphorus discharge and flesh quality of Siberian Sturgeon (Acipenser baerii Brandt ) in an eight-week trial.The experiment was conducted with 3 treatment groups . 4 replicates for one group,14 fish for one replicate. The results showed that total substitution of fishmeal with BVP and BAP resulted in decreace of SGR and feedintake(P<0.05). Nitrogen and phosphorus discharge of BVP was lower than FM and BAP(P<0.05),and phosphorus retention of BVP was higher than FM and BAP(P<0.05). There were no significant differences on whole body composition among the 3 groups. The liver lipid of BVP fish was higher than FM and BAP(P﹤0.05); Total amino acids,essential amino acids,flavor creating amino acids, tasty amino acids and sweetish amino acids content of BVP fish flesh were all higher than the other 2 groups. It was higher on flesh MUFA and lower on flesh PUFA of BAP than FM and BVP(P﹤0.05).Experiment 4. Total Replacement Fish Meal by 2 vegetable Protein Blend in Practical Diets for Siberian Sturgeon (Acipenser baerii Brandt) under ideal protein concept. The effect of 2 vegetable protein blends (including BVP1, soybean meal:62.4% and wheat gluten meal:37.6% and RSM , soybean meal:28.8% ;rapeseed meal :28.8% and wheat gluten meal:42.4)as a total replacement of fishmeal (FM) was studied in juvenile Siberia sturgeon (Acipenser baerii Brandt) in an eight-week growth trial was studied. The experiment was conducted with 3 treatment groups,4 replicates for one group,20 fish for one replicate. 28.5% of fishmeal (FM) were used in control diets with crude protein at 36%. In other two diets,Lysine, methionine, and threonine was balanced by crystallized amino acid(Lys-H2SO4, 65 % ; DL-Met. 98% and L-Thr. 98%).All the diets are formulated under ideal protein concept(Dlys/DP=5.40; Dmet/DP=2.32; Dthr/DP=3.30).Accordingly the 3 diets were named as FM, BVP1, BVP2,respectively.The results showed that total replacement fishmeal by 2 vegetable proteins did not affect feedintake ,but SGR and feed efficiency decreased significantly(P﹤0.05).For 2 vegetable proteins, there were no differences on growth performance or feed efficiency. CF , VSI and HSI of BVP1 and RSM were lower than FM , significantly for HSI (P﹤0.05) but not significantly for CF and VSI.On the lipid content of the liver, 2 vegetable proteins were higher than FM significantly.,but there were no significant differences on fish body composition or blood indexes of various groups.