Replacement Of Fish Meal By FSM,MM,MBM And SBC In Diets For GIFT Tilapia (Oreochromis Niloticus)

The growth experiment was conducted to study effects of substituting fish meal(FM)with fish steak(FSM),meat meal(MM),meat and bone meal(MBM)and spray-dried blood meal(SBC)on growth performance,body composition,antioxidant capacity and immunity,digestive enzymes activity and apparent digestibility coefficient(ADC)of tilapia.The control group(D1)diet contained 12%FM,and the replaced diet contained 4%,8%,12%of FSM(D2,D3,D4),MM(D5,D6,D7),MBM(D8,D9,D10)and 2%,4%of SBC(D11,D12)respectively equivalent replacing FM in the control group diet(FSM,MM and MBM fish meal replacement ratio of 33.3%,66.7%and 100%;SBC 16.7%,33.3%).Twelve isonitrogenoursly,isolipidicly,isophosphorously(the MBM test add the same amount of phosphorus),and equivalent Lys and Met and diets were formulated by supplemented with oil,phosphorus and coated Lys and Met.1080 tilapia(initial body weight 24.91 ±0.10g)were randomly divided into 12 treatments with 3 replicates in each treatment and 30 fish per replicate.After an 56-day trial,the results show that:(1)There were no significant differences between the control group(Dl)and the replacing group(D2-D12 on weight gain rate(WGR),specific growth rate(SGR),feed conversion rate(FCR),condition factor(CF),viscera index(VIS)and the carcass protein and moisture(P>0.05).The carcass lipid significantly decreased of FSM,MM and MBM(P<0.05),while it was no significant differences of SBC.(2)The pepsin activity gradually decreased of FSM and SBC(P>0.05),it gradually increased of MM and MBM(P>0.05).No significant differences were observed on the MBM test for the intestinal protease activity(P>0.05),while it gradually increased of FSM,MM and SBC(P<0.05).The intestinal amylase activity decreased significantly(P<0.05),while the lipase activity was not significantly different(P>0.05).(3)The serum SOD gradually decreased of FFM and MM,while the serum SOD increased and then decreased of MBM and SBC.The serum MDA gradually increased of FSM and MM,while it decreased significantly of MBM and SBC.The serum lysozyme decreased significantly of FSM and MM,while it increased significantly of MBM and SBC.The Apparent digestibility experiment used chromium oxide(Cr2O3)as exogenous indicator.The basal feed was according to the control group feed of the growth experiment,the experimental feed was 69.5%of basal feed + 30%of measured raw materials + 0.05%of Cr2O3.Tilapia(initial body weight 152.36 ± 2.3 8g)were randomly divided into 6 groups with 3 replicates in each group and 20 fish per replicate,excrement collection for 15 days.The results showed that:(1)The ADC of dry matter of SBC was highest,MBM was lowest,there were no significant differences between FSM,MM and FM.(2)The ADC of protein of SBC was highest,then FM,and then MM,then FSM,MBM was lowest.(3)The ADC of lipid of FM was highest,then FSM,MM,MBM,SBC was lowest.In conclusion,(1)According to the growth,FSM,MM and MBM could total replace FM in tilapia diet,SBC could partial relace FM by 33.3%.(2)According to the organism antioxidant capacity and immunity,FSM,MM and MBM could replace FM no more than 66.7%in tilapia diet,SBC could partial relace FM by 33.3%.(3)Comprehensively,FSM,MM and MBM could replace FM no more than 66.7%in tilapia diet,SBC could partial relace FM by 33.3%.