The Replacement Of Fish Meal With Yeast Culture And Cottonseed Protein Concentrate In Diets Of Pacific White Shrimp(Litopenaeus Vannamei)

Due to the increasing demand,unstable supply and rising price of fish meal,it has become a hot research topic to find a new protein source to decrease fish meal inclusion in shrimp diet for the sustainable development of Pacific white shrimp culture.This study investigated the effects of replacing fish meal with yeast culture and cottonseed protein concentrate on the growth performance,feed utilization,biochemical indices,intestinal histology and flesh quality of Litopenaeus vannamei.The obtained results can provide a reference for the development and application of low fish meal diet for Litopenaeus vannamei.1 Effects of yeast culture substituting fishmeal on growth,nonspecific immunity,intestinal and hepatopancreatic histology of Litopenaeus vannameiThis study investigated the effects of yeast culture(YC)substituting fishmeal(FM)on growth,non-specific immunity,intestinal and hepatopancreatic histology of Litopenaeus vannamei.Based on the control diet with fishmeal content of 200 g/kg,YC was used to decrease dietary FM to 200,160,120 and 80 g/kg(FM20,FM16,FM12,FM8),respectively.Then,the four diets were fed to shrimp(2.78±0.10 g)for 8 weeks.The results showed that the growth performance of shrimp decreased with the increase of the ratio of yeast culture replacing fish meal.Compared with the control group,the weight gain of FM8 group was reduced by 12.22%,and the feed conversion ratio was increased by 0.21(P < 0.05),while there was no significant difference between FM16 and FM12 groups and the control group(P > 0.05).Protein and lipid retention in FM12 and FM8 groups were decreased(P < 0.05),and hepatopancreatic activities of superoxide dismutation(SOD)and alkaline phosphatase(AKP)were increased and malondialdehyde(MDA)content was decreased in FM12 group(P < 0.05).In FM8 group,the crude protein digestibility,hepatopancreatic protease and amylase activity,the intestinal villi length and width were decreased(P < 0.05),and hepatic corpuscle was observed with atrophy and irregular lumen shape.In conclusion,yeast culture can replace 40 g/kg fish meal with 200 g/kg fish meal without adverse effects on growth performance,non-specific immunity,intestinal and hepatopancreas histology of Litopenaeus vannamei.2 Effects of cottonseed protein concentrate substituting fishmeal in high fish meal diet on growth and flesh quality of Litopenaeus vannameiThis study investigated the effects of replacing dietary fish meal with cottonseed protein concentrate(CPC)on growth and flesh quality of Litopenaeus vannamei.The control diet was formulated to contain 560 g/kg fish meal(CPC0),then,20%,40%,60%,80% and 100% of dietary fish meal were replaced by CPC with inclusion of 130.2,260.4,390.7,521 and 651.3 g/kg,respectively(CPC20,CPC40,CPC60,CPC80 and CPC100).The six isonitrogenous diets were fed to shrimp with initial body weight of(1.2±0.1 g)for56 days.With the increase of fish meal replacement by CPC,the growth performance and feed intake of shrimp tended to decrease.Compared to the control group,the weight gain was decreased by 15.1%,21.7% and 33.8%(P < 0.05),while feed conversion ratio was increased by 0.15(P > 0.05),0.18(P < 0.05)and 0.23(P < 0.05)in CPC60,80 and 100 groups,and the meat yield in were also significantly decreased in the three groups(P <0.05).In flesh quality,water-holding capacity,hardness,chewiness,adhesiveness,SOD activity and free umami amino acid content of flesh in CPC80 and 100 groups were significantly decreased(P < 0.05),while MDA content in flesh was significantly increased(P < 0.05),but there were no significant differences in flesh color,proximate composition,main amino acids and main fatty acids among all the groups(P > 0.05).In conclusion,in the diet containing 560 g/kg fish meal,cottonseed protein concentrate can successfully replace 224 g/kg(40%)fish meal without negative effects on growth performance and flesh quality of Litopenaeus vannamei.3 Effects of cottonseed protein concentrate substituting fishmeal in practical diet on growth and flesh quality of Litopenaeus vannameiThis study investigated the effects of replacing fish meal with cottonseed protein concentrate in practical diet on growth and flesh quality of Litopenaeus vannamei.The control diet was designed to contain 200 g/kg fish meal(FM20),then dietary fish meal was reduced to 150,100,50 and 0 g/kg(FM15,FM10,FM5 and FM0)by cottonseed protein concentrate inclusion with the supplementation of microencapsulated amino acids and cholesterol.The five isonitrogenous and isolipid diets were fed to shrimp with initial body weight of(1.2±0.1 g)for 56 days.Compared to the control group,the weight gain FM5 and FM0 groups was decreased by 13.3%,16.2%(P < 0.05),while feed conversion ratio was increased by 0.11,0.13(P < 0.05).The survival of the two groups and the meat yield of FM10,FM5 and FM0 groups were also significantly lower than those of the control(P < 0.05).In terms of flesh quality,no significant differences in flesh texture characteristics,flesh color,proximate composition,main amino acids,main fatty acids,MDA content and SOD activity were found among all the groups(P > 0.05).In conclusion,with the supplementation of limited amino acids and cholesterol,cottonseed protein concentrate can successfully replace 100 g/kg(50%)fish meal in practical diet containing200 g/kg fish meal without adverse effects on growth performance and flesh quality of Litopenaeus vannamei.