Apparent Digestibility Of Ten Protein Feed Igredients And Dietary Of Dietary Exogenous Enzymes Inclusion On Feed Utilization For Largemouth Bass,Micropterus Salmoides

Research one:Apparent digestibility of ten protein feed ingredients for largemouth bassIn this experiment,Y₂O₃ was used as an external indicator,and the exper-imental diet was prepared according to the proportion of 70%basic diet and 30%test raw materials.The feeding trial was conducted to investigate the apparent digestibility coef-ficients（ADC）of nutrients in commonly used protein sources for largemouth bass,in-cluding animal protein sources,Peruvian brown fish meal（BFM）,Peruvian white fish meal（WFM）,China fish meal（CFM）,pet-grade poultry by-product meal（PBP）and por-cine haemoglobin powder（PHP）,and plant protein sources,soybean meal（SM）,dehulled soybean meal（DSM）,fermented soybean meal（FSM）,corn gluten meal（CGM）and pea-nut meal（PM）.Largemouth bass（Micropterus salmoides）with an initial body weight of（23.35±0.82）g were fed three replicates of each diet with 100 fish per replicate.Apparent satiating diet was fed twice a day（7:00 and 16:00）.The apparent digestibility of dry mat-ter of 10 protein raw materials ranged from 69.46%to 96.42%.The apparent digestibility of dry matter of BFM was the highest（96.42%）,and that of CFM was the lowest（69.46%）.The apparent digestibility of dry matter of five animal protein raw materials was above90%.The apparent digestibility of dry matter of BFM and WFM was significantly higher than that of CFM,PBP and PHP（P<0.05）.The apparent digestibility of dry matter of PM was significantly higher than that of SM,DSM,FSM and CGM（P<0.05）.The ap-parent digestibility of crude protein of the 10 protein raw materials was 89.08%-97.30%.In animal protein raw materials,the apparent digestibility of crude protein of WFM was97.30%,which was significantly higher than that of other feed raw materials（P<0.05）;The apparent digestibility of crude protein of BFM,CFM and PBP was significantly higher than PHP（P<0.05）.The apparent digestibility of crude protein of DSM,FSM and PM was significantly higher than SM and CGM（P<0.05）.The apparent digestibility of total phosphorus of largemouth bass to the 10 protein ingredients was 36.35%-80.25%.The digestibility of largemouth bass to 10 kinds of protein was consistent with that of crude protein,and there were significant differences among different amino acids.This study showed that largemouth bass has high digestibility of protein for ingredients of both animal and plant origin.Compared with plant protein,animal protein sources can provide more lipid for fish.Poultry meat powder and peanut meal are the high quality activity of the black bass and the raw material of the plant protein,which can be used to replace some fish powder in the feed of the black bass,and reduce the cost of feed.At the same time,the diet designed for largemouth bass should be selected on the basis of amino acid balance and price.Research two:Effects of dietary exogenous enzyme inclusion on growth performance and feed utilization of largemouth bassThis study was conducted to evaluate the effects of exogenous enzymes inclusion on growth performance,body composition and feed efficiency of largemouth bass.The diet with 25%fish meal was considered as the control（CON）,and another five isonitrogenous and isolipidic diets were formulated with the inclusion of neutral protease,keratinase,cellulase,phytase and complex enzymes,which named NP,KER,CEL,PHY and COM,respectively.Largemouth bass with an initial body weight of（39.65±0.15）g was used as the experiment subjects for 57d.Each diet was set up with 3 replicates with30 fish in each replicate.Two times a day（7:00 and 16:00）.The results showed that the addition of different enzymes could significantly promote the growth of largemouth bass,and the final body weight（FBW）,weight gain rate（WGR）and specific growth rate（SGR）of KER,CEL and COM groups were significantly higher than CON（P<0.05）.Compared with CON,the addition of enzyme preparation increased the FI（P<0.05）;at the same time,the FI of COM group was significantly higher than that of the other four enzyme treatment groups（P<0.05）.The addition of enzyme preparation had no significant effect on feed efficiency（FER）and protein efficiency（PER）（P<0.05）.Compared with CON,PHY and COM significantly increased protein deposition rate（PRR）and fat deposition rate（LRR）（P<0.05）;the addition of NP and KER had no significant effect on LRR（P<0.05）,but significantly increased PRR（P<0.05）.Protein apparent digestibility and fat apparent digestibility of different enzyme preparation groups were significantly higher than those of CON（P<0.05）,the apparent digestibility of protein in COM group was significantly higher than that in other groups（P<0.05）;The apparent digestibility of fat in KER,CEL and COM groups was significantly higher than NP and CON（P<0.05）.In summary,the supplementation of exogenous enzymes,especially keratinase,cellulase and complex enzyme,in high plant protein diet,can effectively promote the digestion and absorption of nutrients,improve feed utilization and elevate growth performance of large-mouth bass.