Search

The present study aimed to evaluate the dietary effects of Clostridium butyricum culture (CC) or sodium butyrate (SB) on the growth, feed utilization, serum indicators, intestinal histology and microbiota of largemouth bass (Micropterus salmoides). CC and coated SB (50%) were supplemented to a low fish meal diet (245 g/kg) (control diet) at the inclusion levels of 1 g/kg and 2 g/kg, to form five iso-nitrogenous and iso-lipidic diets (control, CC-1, CC-2, SB-1, and SB-2). Then, the five diets were fed to largemouth bass with initial body weight of 70.2 ± 0.1 g. After 8 weeks of feeding, dietary supplementation of 1 g/kg CC increased the weight gain (WG) by 7.4% (P 0.05), when compared to the control. The muscle composition was not significantly affected by the inclusion of CC or SB (P > 0.05). Dietary inclusion of CC or SB significantly reduced serum diamine oxidase activity and increased lysozyme activity (P

To investigate the impact of dietary inclusion of ferulic acid (FA) on growth performance, physiological and biochemical functions and hepato-intestinal health, three iso-nitrogenous and iso-lipidic diets supplemented with 0 mg/kg, 100 mg/kg, and 200 mg/kg FA were fed to Megalobrama amblycephala (9.75 ± 0.04 g) for 8 weeks. The growth performance, physiological and biochemical parameters, antioxidant capacity and the expression of genes were assessed on 4th and 8th week. The results indicated that 100 mg/kg FA inclusion significantly enhanced the weight gain rate (on week 4 and 8), feed intake (on 4th week), protein efficiency ratio (on week 8) and condition factor (on week 4) (P

The aim of this trial was to investigate the effects of dietary protein and lipid levels on growth performance and flesh quality of largemouth bass (Micropterus salmoides). A 3 × 3 two-factor design was used, including three crude protein levels of 46%, 50%, 54% (P46, P50, P54) and three crude lipid levels of 8%, 12%, 16% (L8, L12, L16). Thus, a total of nine diets (P46/L8, P46/L12, P46/L16, P50/L8, P50/L12, P50/L16, P54/L8, P54/L12 and P54/L16) were prepared and fed to large-size largemouth bass with initial body weight of 109.7 g for 84 days. At the same dietary protein level, weight gain rate (WGR), protein efficiency rate (PER), viscerosomatic index and polyunsaturated fatty acids (PUFAs) percent in flesh showed an increasing trend with increasing the dietary lipid level, while feed conversion ratio (FCR) showed a decreasing trend. At P46 and P50, whole fish crude protein, muscle crude protein, total collagen content, hardness, springiness, chewiness and shear force increased, and steaming loss and freezing loss decreased with increasing the dietary lipid level, while the above indicators showed an opposite trend at P54. At P50, the protein retention (PR) of 16% crude lipid group was significantly higher than that in the 8% and 12% crude lipid groups (P 0.05). The P50/L16 group showed the highest PER, PR, whole fish protein, muscle protein, total collagen, PUFAs, muscle hardness, springiness, chewiness, shear force and the lowest steaming loss. In conclusion, based on growth performance and flesh quality, the appropriate dietary protein and lipid requirements for large-size largemouth bass were 50% and 16%, respectively.

Yeast culture (YC) is a yeast-fermented product of enzymolysis soybean protein with plenty of small peptide and nucleotide. This study aimed to investigate the effects of YC as a substitute for fish meal (FM) on the growth, serum biochemical parameters, intestinal histology and microorganisms of hybrid snakehead (Channa argus ♂ × C. maculate ♀). In a basal diet containing 250 g/kg FM, YC was included at the levels of 0, 40, 80, 120 g/kg to replace 0, 29.5, 59.0 and 88.5 g/kg FM to form four isonitrogenous diets (CON, YC-40, YC-80 and YC-120). The four diets were fed to hybrid snakehead with initial body weight (9.2 ± 0.1 g) for 70 days. The results showed that there were no significant differences in weight gain (WG), feed conversion ratio, protein efficiency ratio (PER), protein retention (PR) and lipid retention (LR) among the three groups of CON, YC-40 and YC-80 groups (P > 0.05). However, the WG, PER, PR and LR in YC-120 group were significantly lower than those in the CON group (P 0.05). In serum biochemical parameters, superoxide dismutase activity and total antioxidant capacity in YC-40 and YC-80 groups were significantly increased, and total cholesterol content in YC-120 group was significantly decreased when compared to the control (P 0.05). Intestinal microbial analysis showed that the major intestinal microorganisms in all groups were Firmicutes, Spirochaetota, Proteobacteria and Actinobacteria. The relative abundance of Brevinema in YC-120 group was significantly higher than that in CON group (P

The purpose of this study was to analyze the affecting mechanism of Chlorella sorokiniana meal replacing fish meal on the growth performance and immune function of Pacific white shrimp, Litopenaeus vannamei by transcriptomics analysis. In a control diet containing 560 g % /kg fish meal, chlorella was used to replace 0 %, 20 %, 40 %, 60 %, 80 % and 100 % of dietary fish meal to form six iso-nitrogenous and iso-lipidic diets (C0, C20, C40, C60, C80, C100). The six diets were fed to white shrimp (1.37 ± 0.02 g) for 8 weeks. Compared to the control group, the final body weight (FBW), specific growth rate (SGR) and feed efficiency (FE) of the C20 group were significantly improved (P 0.05). When the replacement level of fish meal by chlorella was ≥ 60 %, the FBW, SGR and FE of shrimp were significantly decreased (P

The present study aimed to investigate the dietary effects of replacing fishmeal (FM) with cottonseed protein concentrate (CPC) on the growth, flesh quality and gossypol residue of Pacific white shrimp (Litopenaeus vannamei). Based on a diet containing 560 g/kg FM, CPC was used to replace 0%, 20%, 40%, 60%, 80% and 100% of dietary FM with CPC inclusion of 0, 130.2, 260.4, 390.7, 521 and 651.3 g/kg, respectively (CPC0, CPC20, CPC40, CPC60, CPC80 and CPC100). Then, the six isoproteic diets were used to feed shrimp with initial body weight of 1.20 ± 0.05 g in low salinity water (0.5–1.0‰) for 56 days. The results showed that the growth performance of shrimp was not significantly affected by the replacement of 20%, 40% of dietary FM with CPC (P > 0.05). Compared to the control, the weight gain was decreased by 15.1%, 21.7% and 33.8% (P 0.05), 0.18（P

This study was conducted to investigate the effects of adding bile acids to low fishmeal diet on the growth, nutrient utilization and serum biochemical parameters of Pacific white shrimp, Litopenaeus vannamei. First, a positive and a negative control diet were formulated to contain 200 g/kg fishmeal (FM20) and 140 g/kg FM (FM14), respectively. Then, bile acids were added to FM14 diet at the inclusion levels of 75 (BA75), 150 (BA150) and 300 (BA300) mg/kg. The five isoproteic and isolipidic diets were fed to shrimp with initial weight of 1.09 ± 0.01 g for 56 days. The results showed no significant difference in survival among all the groups (>90 %). Compared to FM20 group, the weight gain (−12.9 %), body crude protein content, apparent digestibility of dry matter and protein, bile acid content in hepatopancreas and serum were decreased significantly, while feed conversion ratio (FCR) was increased by 0.17 in FM14 group (P 0.05), reaching the similar levels to FM20 group (P > 0.05). Especially, the FCR of BA150 group was significantly lower (−0.16) than that of FM14 group (P

The study investigated the effects of replacing fish meal with cottonseed protein concentrate (CPC), Tenebrio molitor (TM) and Clostridium autoethanogenum protein (CAP) on physical pellet quality and growth, feed utilization of Pacific white shrimp (Litopenaeus vannamei). A control diet (FM) was designed to contain 200 g/kg fish meal, then, 60 g/kg CPC, TM and CAP were used to replace the same amount of fish meal, respectively, to form four diets by pelleting. After the evaluation of physical quality, the four diets were fed to shrimp with initial body weight of 7.72 ± 0.01 g for 6 weeks. The results indicated that pellet hardness and bulk density were significantly increased (P 0.05). In addition, the dissolution loss and powder content in CPC and CAP diets were significantly decreased (P 0.05). Hepatopancreas amylase activity in CPC and CAP groups was significantly higher than that in FM group (P 0.05). The hepatopancreas and intestinal histology were normal in all groups without obvious injury. In conclusion, in the pelleted feed containing 200 g/kg fish meal, the replacement of 60 g/kg fish meal with CPC and CAP improved the physical pellet quality and had no negative effects on growth performance and nutrient utilization, but the replacement of 60 g/kg fish meal with TM decreased the growth performance and nutrient utilization of Pacific white shrimp.

The study investigated dietary effects of replacing fish meal (FM) with Clostridium autoethanogenum powder (CAP) on growth, flesh quality and metabolomics of largemouth bass (Micropterus salmoides). The control diet contained 350 g/kg FM, and then dietary FM was decreased to 300 g/kg, 250 g/kg, 200 g/kg, 150 g/kg and 100 g/kg by CAP inclusion, respectively (FM-30, FM-25, FM-20, FM-15, FM-10). Then, the six diets were fed to largemouth bass with initial body weight of 110 g for 56 days. The high CAP inclusion (FM-10) decreased specific growth rate, flesh collagen, flesh hardness and increased feed conversion ratio (P

This study investigated the effects of replacing fish meal (FM) with fermented soybean meal (FSM) on the growth performance, serum biochemical indices, intestinal health, microbial community and disease resistance of largemouth bass (Micropterus salmoides). The basal diet was designed to contain 350 g/kg FM (control, FSM-0), and then, FM was decreased to 300 g/kg, 250 g/kg, 200 g/kg, 150 g/kg by the FSM inclusion of 75 g/kg (FSM-7.5), 150 g/kg (FSM-15.0), 225 g/kg (FSM-22.5) and 300 g/kg (FSM-30), respectively. The five diets were fed to largemouth bass with initial body weight of 21.2 ± 0.1 g for 8 weeks. The results showed that FSM-30 group presented lower weight gain, and FSM-22.5 and FSM-30 groups displayed higher feed conversion ratio than those of the control group (P 0.05). Compared with the control, the protein retention in FSM-30 group, the lipid retention in FSM-15, FSM-22.5 and FSM-30 groups, and serum superoxide dismutase activity and total antioxidant capacity in FSM-22.5 and FSM-30 groups were decreased (P

Micropterus salmoides is one of the most economically valuable fish species in China. Currently, information in the effect of probiotics-supplemented feed on M. salmoides is rare. Present study investigated the impact of supplementary Lactobacillus casei K17 with six treatments on growth performance, gut digestion, absorption and non-specific immune, and gut bacterial biota and metabolomics of M. salmoides. A total of 450 M. salmoides (114 day of age, average 33.0 ± 0.5 g) were randomly allocated into six groups for a 69-day rearing experiments. M. salmoides was given commercial feed supplemented with: 1) live L. casei K17 (1 × 109 CFU/g), 2) live L. casei K17 protected by skim milk powder (10 %), 3) heat-killed dead L. casei K17, 4) its fermentation supernatant, 5) skim milk powder (10 %), and 6) normal saline (0.85 % NaCl), designated as LB, MB, DB, FS, MG, and SG, respectively. MB and DB diets significantly increased body weight and growth rate, but decreased feed conversion ratio of M. salmoides (p