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ZHOU Jian
,
ZHAO Zhongmeng
,
HUANG Zhipeng
,
ZHAO Han
,
LI Qiang
,
ZHANG Lu
,
KE Hongyu
,
SU Xutao
,
XIAO Yu
,
DU Jun
2021, 42(2):162-169.
DOI: 10.19663/j.issn2095-9869.20191231001
Abstract:
To evaluate the quality characteristics of red swamp crayfish, Procambarus clarkii, crayfish from pond and paddy field cultures were used to compare the muscle, amino acid, and fatty acid compositions between the two culture models. The results showed that there was no significant difference in crude protein and crude fat between the two culture models (P>0.05). The muscle moisture content of crayfish in the pond culture was significantly higher than that in the paddy field culture (P>0.05), while the total ash content was significantly lower than that in the paddy field culture (P<0.05). Seventeen amino acids, including seven essential amino acids and four flavor amino acids, were detected in the muscle and hepatopancreas of the crayfish in the two culture models. There was no significant difference in the muscle WEAA/WTAA values between the two culture models (P>0.05), while the hepatopancreatine WEAA/WTAA values in the pond culture model were significantly higher than those in the paddy field model (P<0.05). According to the amino acid and chemistry score, the first limiting amino acids in the muscle and hepatopancreas were sulfur-containing amino acid (methionine and cysteine), while the second limiting amino acid in the muscle was valine and that in the hepatopancreas was leucine. In addition, 20 and 24 fatty acids were detected in the muscle and hepatopancreas of crayfish, respectively. Palmitic acid (C16:0) was the highest saturated fatty acid in the muscle and hepatopancreas, and oleic acid (C18:1n9c) was the highest monounsaturated fatty acid. The muscle and hepatopancreas of crayfish in the pond and paddy field models have higher edible and nutritional values.
To evaluate the quality characteristics of red swamp crayfish, Procambarus clarkii, crayfish from pond and paddy field cultures were used to compare the muscle, amino acid, and fatty acid compositions between the two culture models. The results showed that there was no significant difference in crude protein and crude fat between the two culture models (P>0.05). The muscle moisture content of crayfish in the pond culture was significantly higher than that in the paddy field culture (P>0.05), while the total ash content was significantly lower than that in the paddy field culture (P<0.05). Seventeen amino acids, including seven essential amino acids and four flavor amino acids, were detected in the muscle and hepatopancreas of the crayfish in the two culture models. There was no significant difference in the muscle WEAA/WTAA values between the two culture models (P>0.05), while the hepatopancreatine WEAA/WTAA values in the pond culture model were significantly higher than those in the paddy field model (P<0.05). According to the amino acid and chemistry score, the first limiting amino acids in the muscle and hepatopancreas were sulfur-containing amino acid (methionine and cysteine), while the second limiting amino acid in the muscle was valine and that in the hepatopancreas was leucine. In addition, 20 and 24 fatty acids were detected in the muscle and hepatopancreas of crayfish, respectively. Palmitic acid (C16:0) was the highest saturated fatty acid in the muscle and hepatopancreas, and oleic acid (C18:1n9c) was the highest monounsaturated fatty acid. The muscle and hepatopancreas of crayfish in the pond and paddy field models have higher edible and nutritional values.
FAN Ying
,
WANG Xiaolu
,
YU Xiaoqing
,
LIU Hongjun
,
YE Haibin
,
WANG Shuxian
,
DIAO Jing
,
HU Fawen
,
JIAN Yuxia
2021, 42(1):63-73.
DOI: 10.19663/j.issn2095-9869.20191111001
Abstract:
The present study aimed to assess the effect of Bacillus licheniformis on the growth, intestinal digestive enzymes activity, non-specific immunity and resistance against Aeromonas salraonicida in the fat greenling (Hexagrammos otakii). A total of 270 H. otakii with an average initial body weight of (22.0±2.0) g/tail were randomly allocated to three groups (the control group and two experimental groups with different B. licheniformis levels) with three parallels per group and 30 fish per parallel. Fish in the control group were fed a basal diet consisting of albumen, and the ones in the two experimental groups were fed basal diets supplemented with 5×107 (0.5%) or 1×108 CFU/g (1.0%) B. licheniformis, respectively. After 50 days, fish were infected with A. salraonicida, and the cumulative mortality rate was determined within 14 days. The specific growth rate was found to be significantly higher in fish fed diets containing B. licheniformis when compared with the control group (P<0.05). Furthermore, the activities of SOD, CAT, and T-AOC in the serum of H. otakii in the experimental groups were significantly increased compared with the control group (P<0.05). Conversely, the MDA levels in the experimental groups were decreased compared with the control group (P<0.05). The GSH-Px activity in the 1.0% B. licheniformis group was lower than that in the control group, but the activity in the 0.5% B. licheniformis group was higher than that in the control group. The activities of GS, MDH, and HK in the serum of fish in the experimental groups were increased compared with the control group (P<0.05). Compared with the control group, AST and ALT activities in the serum of fish in the experimental groups were decreased (P<0.05) and CHE and ADA activities were higher than those in the control group (P<0.05). The activities of trypsin, amylase and lipase in the intestines of fish in the experimental groups were increased to different degrees, with the highest activity observed in the 1.0% B. licheniformis group (P<0.05). The bacterial challenge test revealed that the 14 day cumulative mortality rate in the 1.0% B. licheniformis group was only 35.55% (P<0.05). The results obtained in the present study revealed that B. licheniformis can increase growth, activities of intestinal digestive enzymes, and non-specific immunity, as well as enhance resistance against A. salraonicida in H. otakii.
The present study aimed to assess the effect of Bacillus licheniformis on the growth, intestinal digestive enzymes activity, non-specific immunity and resistance against Aeromonas salraonicida in the fat greenling (Hexagrammos otakii). A total of 270 H. otakii with an average initial body weight of (22.0±2.0) g/tail were randomly allocated to three groups (the control group and two experimental groups with different B. licheniformis levels) with three parallels per group and 30 fish per parallel. Fish in the control group were fed a basal diet consisting of albumen, and the ones in the two experimental groups were fed basal diets supplemented with 5×107 (0.5%) or 1×108 CFU/g (1.0%) B. licheniformis, respectively. After 50 days, fish were infected with A. salraonicida, and the cumulative mortality rate was determined within 14 days. The specific growth rate was found to be significantly higher in fish fed diets containing B. licheniformis when compared with the control group (P<0.05). Furthermore, the activities of SOD, CAT, and T-AOC in the serum of H. otakii in the experimental groups were significantly increased compared with the control group (P<0.05). Conversely, the MDA levels in the experimental groups were decreased compared with the control group (P<0.05). The GSH-Px activity in the 1.0% B. licheniformis group was lower than that in the control group, but the activity in the 0.5% B. licheniformis group was higher than that in the control group. The activities of GS, MDH, and HK in the serum of fish in the experimental groups were increased compared with the control group (P<0.05). Compared with the control group, AST and ALT activities in the serum of fish in the experimental groups were decreased (P<0.05) and CHE and ADA activities were higher than those in the control group (P<0.05). The activities of trypsin, amylase and lipase in the intestines of fish in the experimental groups were increased to different degrees, with the highest activity observed in the 1.0% B. licheniformis group (P<0.05). The bacterial challenge test revealed that the 14 day cumulative mortality rate in the 1.0% B. licheniformis group was only 35.55% (P<0.05). The results obtained in the present study revealed that B. licheniformis can increase growth, activities of intestinal digestive enzymes, and non-specific immunity, as well as enhance resistance against A. salraonicida in H. otakii.
JING Tingsen
,
ZHOU Mingrui
,
LI Zhe
,
LI Yulin
,
SUN Wenbo
,
LIANG Juntian
,
WANG Xinliang
,
YE Hua
,
CHENG Tingshui
,
LUO Hui
2021, 42(5):149-157.
DOI: 10.19663/j.issn2095-9869.20200421002
Abstract:
The aim of this study was to investigate the effects of fishmeal replacement by soy peptide protein on the growth performance, body composition, digestive enzymes activity, and antioxidant capacity of yellow catfish (Pelteobagrus fulvidraco). The control group (A0) received 30% fishmeal, and the experimental groups received soy peptide protein substitutes at 17%, 33%, and 50% (A17, A33, and A50), and four kinds (A0, A17, A33, and A50) of iso-nitrogen compound feeds were prepared. There were 4 replicates and 30 juvenile yellow catfish per group [average body weight: (3.7±0.6) g], and the experiment ran for 80 days. The results showed that there were no significant differences in the growth performance of A17 and the control group (P>0.05). The weight gain rate of A33 was significantly higher than the control group (P<0.05), but there were no other differences (P>0.05). In A50, the feed coefficient ratio was significantly higher than the other groups (P<0.05), while the weight gain rate, specific growth ratio, and protein efficiency ratio were significantly lower than the other groups (P<0.05). There were no differences in the viscerosomatic and hepatosomatic indexes (P>0.05). Soy peptide protein substitution did not affect the contents of water, ash, or crude protein in yellow catfish (P>0.05). However, when the level of soy peptide protein increased from 33% to 50%, the crude fat content decreased significantly (P<0.05). The activities of intestinal lipase and amylase were significantly higher in the treatment groups (P<0.05), and the activity of gastric amylase in A33 and A50 was significantly higher than the control group (P<0.05). Soy peptide protein substitution did not affect malondialdehyde (MDA) activity in the liver. In conclusion, when fishmeal replacement was less than 33%, the growth performance of yellow catfish increased and there were no adverse effects on the antioxidation capacity of the liver. This is the first study to explore the effects of soy peptide protein replacement on P. fulvidraco growth and provides a reference for feed preparation and soy peptide protein use.
The aim of this study was to investigate the effects of fishmeal replacement by soy peptide protein on the growth performance, body composition, digestive enzymes activity, and antioxidant capacity of yellow catfish (Pelteobagrus fulvidraco). The control group (A0) received 30% fishmeal, and the experimental groups received soy peptide protein substitutes at 17%, 33%, and 50% (A17, A33, and A50), and four kinds (A0, A17, A33, and A50) of iso-nitrogen compound feeds were prepared. There were 4 replicates and 30 juvenile yellow catfish per group [average body weight: (3.7±0.6) g], and the experiment ran for 80 days. The results showed that there were no significant differences in the growth performance of A17 and the control group (P>0.05). The weight gain rate of A33 was significantly higher than the control group (P<0.05), but there were no other differences (P>0.05). In A50, the feed coefficient ratio was significantly higher than the other groups (P<0.05), while the weight gain rate, specific growth ratio, and protein efficiency ratio were significantly lower than the other groups (P<0.05). There were no differences in the viscerosomatic and hepatosomatic indexes (P>0.05). Soy peptide protein substitution did not affect the contents of water, ash, or crude protein in yellow catfish (P>0.05). However, when the level of soy peptide protein increased from 33% to 50%, the crude fat content decreased significantly (P<0.05). The activities of intestinal lipase and amylase were significantly higher in the treatment groups (P<0.05), and the activity of gastric amylase in A33 and A50 was significantly higher than the control group (P<0.05). Soy peptide protein substitution did not affect malondialdehyde (MDA) activity in the liver. In conclusion, when fishmeal replacement was less than 33%, the growth performance of yellow catfish increased and there were no adverse effects on the antioxidation capacity of the liver. This is the first study to explore the effects of soy peptide protein replacement on P. fulvidraco growth and provides a reference for feed preparation and soy peptide protein use.
2022, 43(1):97-105.
DOI: 10.19663/j.issn2095-9869.20200710001
Abstract:
Turbot (Scophthalmus maximus) is an economically important marine fish species in northern China. With the unceasingly amplification of farming scale and great improvement of intensivism in recent years, turbot diseases have been occurring frequently. Bacillus cereus YB1 could be used as a candidate probiotic strain, which has animal safety for turbot at a certain concentration. The present study aimed to investigate the effect of B. cereus (YB1) on growth performance, liver immune enzyme activity, intestinal digestive enzyme activity, and intestinal tissue structure of juvenile S. maximus, and would provide new probiotic strains for turbot aquaculture. A total of 720 healthy juveniles with an average body weight of (3.6±0.7) g were randomly divided into 4 groups with 3 replicates per group and 60 fish per replicate. The fish in the 4 groups were fed diets containing YB1 at a viable count of 0 (control), 105, 106, and 107 CFU/g at (21±2)℃, respectively, and the experiment lasted for 50 days. Results showed that the weight gain rate (WGR) and specific growth rate (SGR) were significantly higher in juvenile turbot fed diet supplemented with 107 CFU/g of YB1 than those of the fish fed the control diet (P<0.05). The amount of protease and amylase increased by 57.86% and 82.37%, respectively in 106 CFU/g group, and were significantly higher than those in the control group (P<0.05). Lipase content of fish in 107 CFU/g was significantly higher than that of the control group (P<0.05). Catalase activity in fish fed diets supplemented with YB1 was not significantly different from fish in the control group. Malondialdehyde content of juveniles fed 106 CFU/g YB1 dietary supplement was decreased by 42.03%, and was significantly lower than that in the control group (P<0.05). SOD activity of fish fed YBI increased compared with that of the control, however, the increase was not significant (P>0.05). YB1 led to a significant increase in the height and number of folds in the intestinal mucosa of turbot (P<0.05). Intestinal muscularis thickness was significantly increased in the 106 CFU/g YB1 dietary supplement group than in the control group; it was 68.91% higher than that of the control group at the end of the experiment. In this study, B. cereus (YB1) could promote the growth of juvenile turbot, improve the activities of digestive and liver immune enzymes in their intestine, and improve the structure of intestine. This study shows that B. cereus (YB1) can be used in turbot aquaculture, with a recommended dosage of 106 CFU/g.
Turbot (Scophthalmus maximus) is an economically important marine fish species in northern China. With the unceasingly amplification of farming scale and great improvement of intensivism in recent years, turbot diseases have been occurring frequently. Bacillus cereus YB1 could be used as a candidate probiotic strain, which has animal safety for turbot at a certain concentration. The present study aimed to investigate the effect of B. cereus (YB1) on growth performance, liver immune enzyme activity, intestinal digestive enzyme activity, and intestinal tissue structure of juvenile S. maximus, and would provide new probiotic strains for turbot aquaculture. A total of 720 healthy juveniles with an average body weight of (3.6±0.7) g were randomly divided into 4 groups with 3 replicates per group and 60 fish per replicate. The fish in the 4 groups were fed diets containing YB1 at a viable count of 0 (control), 105, 106, and 107 CFU/g at (21±2)℃, respectively, and the experiment lasted for 50 days. Results showed that the weight gain rate (WGR) and specific growth rate (SGR) were significantly higher in juvenile turbot fed diet supplemented with 107 CFU/g of YB1 than those of the fish fed the control diet (P<0.05). The amount of protease and amylase increased by 57.86% and 82.37%, respectively in 106 CFU/g group, and were significantly higher than those in the control group (P<0.05). Lipase content of fish in 107 CFU/g was significantly higher than that of the control group (P<0.05). Catalase activity in fish fed diets supplemented with YB1 was not significantly different from fish in the control group. Malondialdehyde content of juveniles fed 106 CFU/g YB1 dietary supplement was decreased by 42.03%, and was significantly lower than that in the control group (P<0.05). SOD activity of fish fed YBI increased compared with that of the control, however, the increase was not significant (P>0.05). YB1 led to a significant increase in the height and number of folds in the intestinal mucosa of turbot (P<0.05). Intestinal muscularis thickness was significantly increased in the 106 CFU/g YB1 dietary supplement group than in the control group; it was 68.91% higher than that of the control group at the end of the experiment. In this study, B. cereus (YB1) could promote the growth of juvenile turbot, improve the activities of digestive and liver immune enzymes in their intestine, and improve the structure of intestine. This study shows that B. cereus (YB1) can be used in turbot aquaculture, with a recommended dosage of 106 CFU/g.
2021, 42(2):96-103.
DOI: 10.19663/j.issn2095-9869.20200213001
Abstract:
Apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in white fish meal, Peruvian red fish meal, meat and bone meal, corn gluten meal, soybean meal, peanut meal, cottonseed meal, and rapeseed meal were determined for juvenile tiger puffer (Takifugu rubripes) with initial mean body weight of 37.90 g. A reference diet and test diets that consisted of a 70 : 30 mixture of the reference diet to test ingredient were used with 0.1% Y2O3 as an external indicator. White fish meal, Peruvian red fish meal and soybean meal had higher ADCs of dry matter, dry matter ADCs ranged in 43.35%~70.54% among ingredients tested. Protein ADCs of feed ingredients ranged in 50.91%~92.78%, meat and bone meal had significantly lower ADCs of protein compared with that of white fish meal, Peruvian red fish meal, soybean meal, peanut meal, rapeseed meal and distillers dried grains with solubles (DDGS) (P<0.05). Amino acid ADCs generally reflected protein digestibility. ADCs of lipid were relatively high in the ingredients tested. Energy ADCs of feed ingredients ranged in 30.58%~90.01%, white fish meal, Peruvian red fish meal, soybean meal and peanut meal had significantly higher ADCs of energy (76.26%~90.01%). Phosphorus ADCs of feed ingredients ranged in 9.13%~68.14%, white fish meal, Peruvian red fish meal had significantly higher ADCs of phosphorus among ingredients tested. In conclusion, ADCs of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in white fish meal, Peruvian red fish meal were higher, while ADCs of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in meat and bone meal and DDGS were lower compared with that other tested ingredient for tiger puffer. Soybean meal and peanut meal had higher ADCs of protein and essential amino acids in plant protein ingredients. Resultant digestibility data may provide useful information to commercial tiger puffer feed industry.
Apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in white fish meal, Peruvian red fish meal, meat and bone meal, corn gluten meal, soybean meal, peanut meal, cottonseed meal, and rapeseed meal were determined for juvenile tiger puffer (Takifugu rubripes) with initial mean body weight of 37.90 g. A reference diet and test diets that consisted of a 70 : 30 mixture of the reference diet to test ingredient were used with 0.1% Y2O3 as an external indicator. White fish meal, Peruvian red fish meal and soybean meal had higher ADCs of dry matter, dry matter ADCs ranged in 43.35%~70.54% among ingredients tested. Protein ADCs of feed ingredients ranged in 50.91%~92.78%, meat and bone meal had significantly lower ADCs of protein compared with that of white fish meal, Peruvian red fish meal, soybean meal, peanut meal, rapeseed meal and distillers dried grains with solubles (DDGS) (P<0.05). Amino acid ADCs generally reflected protein digestibility. ADCs of lipid were relatively high in the ingredients tested. Energy ADCs of feed ingredients ranged in 30.58%~90.01%, white fish meal, Peruvian red fish meal, soybean meal and peanut meal had significantly higher ADCs of energy (76.26%~90.01%). Phosphorus ADCs of feed ingredients ranged in 9.13%~68.14%, white fish meal, Peruvian red fish meal had significantly higher ADCs of phosphorus among ingredients tested. In conclusion, ADCs of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in white fish meal, Peruvian red fish meal were higher, while ADCs of dry matter, crude protein, crude lipid, gross energy, phosphorus and amino acids in meat and bone meal and DDGS were lower compared with that other tested ingredient for tiger puffer. Soybean meal and peanut meal had higher ADCs of protein and essential amino acids in plant protein ingredients. Resultant digestibility data may provide useful information to commercial tiger puffer feed industry.
WANG Xiaoyan
,
LI Baoshan
,
SUN Yongzhi
,
WANG Chengqiang
,
LI Lu
,
SUN Xiaoyu
,
WANG Dan
,
ZUO Zhen
,
LI Peiyu
,
HUANG Bingshan
,
WANG Jiying
2024, 45(3):76-86.
DOI: 10.19663/j.issn2095-9869.20230213002
Abstract:
The complete intestinal structure is important to ensure the rapid and h ealthy growth of fish. However, the feed composition, aquaculture water environment, intestinal microbial population, and other factors may affect the intestinal health of fish. Intestinal health problems caused by feed ingredients are mainly due to the antinutrient factors contained in raw materials. Antinutritional factors contained in high-level soybean meal can cause oxidative damage to the intestine, thus, inducing soybean meal-induced enteritis (SBMIE), which leads to a decreased appetite and the slow growth of fish. Alleviating the damage of soybean meal to the fish intestinal tract and improving intestinal health through nutrition are essential methods for ensuring the sustainable development of the feed industry, which has significant ecological and economic significance. As a functional amino acid, arginine is a precursor to the synthesis of bioactive substances, such as urea, glutamic acid, creatine, proline, polyamine, and nitric oxide. Arginine modulates metabolic regulation, including growth, immunity, intestinal barrier, and endocrine regulation. It plays a vital role in the immune regulation, maintenance, and protection of the intestinal mucosal structure and function. It has been reported that arginine is beneficial for repairing intestinal mucosal injury in poultry and aquatic animals. In this study, the carnivorous marine economic fish Sebastes schlegelii (54.97±0.12) g were used to investigate the repair effect and mechanism of arginine on SBMIE. This study aimed to provide a scientific basis for the application of arginine for maintaining the intestinal health of fish and provide a reference for the application of plant protein to the compound feed of the carnivorous economic fish S. schlegelii. The purpose of this study was to investigate the repairing effects of arginine on the growth performance, arginine metabolism, intestinal structure, antioxidant performance, relative expression levels of intestinal tight junction protein genes (occludin, clnd15, and zo-1), and inflammatory factor-related genes (il-1β, il-8, il-15, and tlr8) and anti-inflammatory factor-related gene (il-12b) of S. schlegelii with SBMIE. S. schlegelii were fed high-level soybean meal (40%) for 28 days to induce SBMIE. SBMIE-S. schlegelii weighing (54.97±0.12) g were used as the study animals. Four isonitrogen and isoenergetic experimental feeds were formulated. The basic formula was supplemented with 30% soybean meal, arginine 0 supplementation as the control group (D0), and 1%, 2%, and 3% arginine supplementation as the treatment groups, named D1, D2, and D3, respectively. Each diet group had three replicates, and each replicate consisted of 40 fish. The fish were randomly placed in 12 homemade cages (60 cm × 60 cm × 90 cm). The experiment lasted for 6 weeks. The experimental fish were fed twice a day (08:00 and 17:00), with the initial feeding amount being 1% of the body weight, and the feeding amount being adjusted according to the feeding situation. During the experiment, the bottom of the cages was cleaned, and the water was changed every day to maintain the water temperature at 18~22 ℃, the dissolved oxygen at > 6 mg/L, the pH at 7.6~8.2, the ammonia nitrogen content at < 0.05 mg/L, and the nitrite nitrogen content at < 0.05 mg/L. The light cycle was the natural cycle. The results showed that the weight gain rate of the fish in the D2 and D3 groups was significantly higher than that in D0 group (P<0.05). The hepatosomatic and viscerosomatic indexes of the fish in the arginine treatment groups were significantly lower than those in the D0 group, and the condition factor was significantly higher than that in the D0 group (P<0.05). There was no significant effect on the survival rate (P>0.05). Diamine oxidase (DAO) activity, NO content, and iNOS activity values in the serum of the treatment groups were significantly lower than those in the D0 group (P<0.05). The serum T-NOS activity in the D2 and D3 groups was significantly lower than that in the D0 group (P<0.05). The duplicature height in the treatment groups was significantly higher than that in the D0 group, while no significant difference was found in the duplicature number and muscle thickness (P>0.05). In group D0, the intestinal mucosa lamina propria widened, and the number of goblet cells increased, while in groups supplemented with arginine, the intestinal mucosa was intact, and the problems mentioned above improved significantly. Intestinal total antioxidant capacity (T-AOC) in arginine supplementation groups was significantly increased, and the highest value was found in group D2 (P<0.05). The malondialdehyde content in groups D2 and D3 was decreased significantly compared to that in the D0 group (P<0.05). The relative expression of occludin mRNA in each treatment group was significantly upregulated compared to that in the D0 group (P<0.05). The relative expression level of clnd15 mRNA in the D2 group was significantly higher than that in the D0 and D1 groups (P<0.05). The relative expression level of zo-1 mRNA in group D1 was significantly higher than that in the other groups (P<0.05). The relative expression levels of IL-1β, IL-15, and TLR8 mRNA were downregulated in all treatment groups, while the relative expression of IL-12b mRNA was upregulated (P<0.05). No significant differences were found in IL-8 mRNA relative expression (P>0.05). In conclusion, under the conditions of this experiment, the growth and antioxidant performances of S. schlegelii with SBMIE were significantly increased, arginine metabolism and the intestinal structure were improved significantly, and the relative expression of intestinal tight junction protein and anti-inflammatory factor-related genes was upregulated, while that of inflammatory factor-related genes was downregulated, with arginine supplementation in a high-level soybean meal diet. Arginine (2% best) was effective in repairing SBMIE of S. schlegelii. The results of this study provide a theoretical basis for the mechanism of repairing SBMIE with arginine.
The complete intestinal structure is important to ensure the rapid and h ealthy growth of fish. However, the feed composition, aquaculture water environment, intestinal microbial population, and other factors may affect the intestinal health of fish. Intestinal health problems caused by feed ingredients are mainly due to the antinutrient factors contained in raw materials. Antinutritional factors contained in high-level soybean meal can cause oxidative damage to the intestine, thus, inducing soybean meal-induced enteritis (SBMIE), which leads to a decreased appetite and the slow growth of fish. Alleviating the damage of soybean meal to the fish intestinal tract and improving intestinal health through nutrition are essential methods for ensuring the sustainable development of the feed industry, which has significant ecological and economic significance. As a functional amino acid, arginine is a precursor to the synthesis of bioactive substances, such as urea, glutamic acid, creatine, proline, polyamine, and nitric oxide. Arginine modulates metabolic regulation, including growth, immunity, intestinal barrier, and endocrine regulation. It plays a vital role in the immune regulation, maintenance, and protection of the intestinal mucosal structure and function. It has been reported that arginine is beneficial for repairing intestinal mucosal injury in poultry and aquatic animals. In this study, the carnivorous marine economic fish Sebastes schlegelii (54.97±0.12) g were used to investigate the repair effect and mechanism of arginine on SBMIE. This study aimed to provide a scientific basis for the application of arginine for maintaining the intestinal health of fish and provide a reference for the application of plant protein to the compound feed of the carnivorous economic fish S. schlegelii. The purpose of this study was to investigate the repairing effects of arginine on the growth performance, arginine metabolism, intestinal structure, antioxidant performance, relative expression levels of intestinal tight junction protein genes (occludin, clnd15, and zo-1), and inflammatory factor-related genes (il-1β, il-8, il-15, and tlr8) and anti-inflammatory factor-related gene (il-12b) of S. schlegelii with SBMIE. S. schlegelii were fed high-level soybean meal (40%) for 28 days to induce SBMIE. SBMIE-S. schlegelii weighing (54.97±0.12) g were used as the study animals. Four isonitrogen and isoenergetic experimental feeds were formulated. The basic formula was supplemented with 30% soybean meal, arginine 0 supplementation as the control group (D0), and 1%, 2%, and 3% arginine supplementation as the treatment groups, named D1, D2, and D3, respectively. Each diet group had three replicates, and each replicate consisted of 40 fish. The fish were randomly placed in 12 homemade cages (60 cm × 60 cm × 90 cm). The experiment lasted for 6 weeks. The experimental fish were fed twice a day (08:00 and 17:00), with the initial feeding amount being 1% of the body weight, and the feeding amount being adjusted according to the feeding situation. During the experiment, the bottom of the cages was cleaned, and the water was changed every day to maintain the water temperature at 18~22 ℃, the dissolved oxygen at > 6 mg/L, the pH at 7.6~8.2, the ammonia nitrogen content at < 0.05 mg/L, and the nitrite nitrogen content at < 0.05 mg/L. The light cycle was the natural cycle. The results showed that the weight gain rate of the fish in the D2 and D3 groups was significantly higher than that in D0 group (P<0.05). The hepatosomatic and viscerosomatic indexes of the fish in the arginine treatment groups were significantly lower than those in the D0 group, and the condition factor was significantly higher than that in the D0 group (P<0.05). There was no significant effect on the survival rate (P>0.05). Diamine oxidase (DAO) activity, NO content, and iNOS activity values in the serum of the treatment groups were significantly lower than those in the D0 group (P<0.05). The serum T-NOS activity in the D2 and D3 groups was significantly lower than that in the D0 group (P<0.05). The duplicature height in the treatment groups was significantly higher than that in the D0 group, while no significant difference was found in the duplicature number and muscle thickness (P>0.05). In group D0, the intestinal mucosa lamina propria widened, and the number of goblet cells increased, while in groups supplemented with arginine, the intestinal mucosa was intact, and the problems mentioned above improved significantly. Intestinal total antioxidant capacity (T-AOC) in arginine supplementation groups was significantly increased, and the highest value was found in group D2 (P<0.05). The malondialdehyde content in groups D2 and D3 was decreased significantly compared to that in the D0 group (P<0.05). The relative expression of occludin mRNA in each treatment group was significantly upregulated compared to that in the D0 group (P<0.05). The relative expression level of clnd15 mRNA in the D2 group was significantly higher than that in the D0 and D1 groups (P<0.05). The relative expression level of zo-1 mRNA in group D1 was significantly higher than that in the other groups (P<0.05). The relative expression levels of IL-1β, IL-15, and TLR8 mRNA were downregulated in all treatment groups, while the relative expression of IL-12b mRNA was upregulated (P<0.05). No significant differences were found in IL-8 mRNA relative expression (P>0.05). In conclusion, under the conditions of this experiment, the growth and antioxidant performances of S. schlegelii with SBMIE were significantly increased, arginine metabolism and the intestinal structure were improved significantly, and the relative expression of intestinal tight junction protein and anti-inflammatory factor-related genes was upregulated, while that of inflammatory factor-related genes was downregulated, with arginine supplementation in a high-level soybean meal diet. Arginine (2% best) was effective in repairing SBMIE of S. schlegelii. The results of this study provide a theoretical basis for the mechanism of repairing SBMIE with arginine.
DING Zhirong
,
CHEN Fang
,
ZHANG Guanrong
,
XU Jianzhao
,
GUAN Junfeng
,
MA Yongcai
,
XIE Dizhi
,
LI Yuanyou
2023, 44(5):45-55.
DOI: 10.19663/j.issn2095-9869.20230110004
Abstract:
Trachinotus ovatus, commonly known as golden pompano, is a euryhaline warm water carnivorous fish. It has the characteristics of fast growth, simple feeding, delicious meat, strong stress resistance, and high survival rate. It can accept compound feed throughout its growth. It is popular among fish breeders and consumers because of its moderate specifications and affordable price. With an annual output of 240 000 tons, it has become one of the most important marine fish breeding species in the southern coastal areas of China. As a marine carnivorous fish, it has specific requirements relating to the levels and sources of dietary protein and fat, and a strong dependence on fish meal and fish oil, which are limited resources with high prices, which also determines its high feed cost. However, compared with other rare sea fish, its price is low and the profit margin of breeding is low (2–4 CNY/kg), thus, easily leading to the loss of breeding enterprises and individual businesses. Therefore, it is necessary to develop efficient and low-cost compound diets and reduce the supplemental level of fish meal oil in diets to solve the bottleneck problem of golden pompano fish breeding. Previous studies have shown that T. ovatus subjected to a high efficiency and low fish meal diet exhibited excellent growth and health in pond cage culture. To further evaluate the application effect of this feed in deep-sea cage culture, an experimental feed (crude protein 47.66%, crude fat 7.98%) based on the formula feed of a low fish meal diet was produced by a feed company with a large-scale production process (feed production using large machinery and mass production in a feed mill with an hourly output that can reach more than 10 t using equipment such as oil sprayer machines, where the fat source is added by spraying). A commercial feed from a well-known brand was used as the control diet (crude protein 47.75%, crude fat 9.63%). Large-sized golden pompano (mean body weight ~262 g) were provided by Yangjiang Haina Fisheries Limited and kept for 2 weeks at the deep-sea cage breeding base in Dasuo Island, Yangjiang (12–20 m depth, about 15 km offshore) to adapt to the test environment. During the temporary feeding period, a well-known commodity was used for feed. Overall, 150 000 healthy large-sized golden pompano with neat specifications (initial body weight ~260 g) were selected and randomly assigned to six deep-sea cages (HDPE C60 floating cages, circumference 60 m, 25 000 fish per cage). Each feed was provided in three parallel cages for 33 days (April 29 to May 31, 2021). During breeding, full food was provided twice a day (07:00 and 17:00). During the experiment, the seawater temperature was 20.00~29.00 ℃. Dissolved oxygen was 6.30~7.80 mg /L. The results showed that the growth performance of fish was not statistically different between the two groups (P>0.05). However, compared with the control group, the weight gain rate and specific growth rate of fish-fed experimental diets increased by 14.43 % and 8.19 %, respectively, and the average daily weight gain increased by 0.68 g. In terms of muscle nutrition and texture characteristics, the muscle lipid contents of the fish-fed experimental diets were significantly higher than those of fish-fed control diets (P<0.05), but the muscle moisture content significantly decreased (P<0.05). The edible quality and texture characteristics of muscle were comparable between the two groups (P>0.05). Compared with the control group, the serum protein, triglyceride, total cholesterol, and low-density lipoprotein contents, as well as the activity of aspartate aminotransferase, of fish fed the experimental diet were significantly decreased (P<0.05), and the hepatic total cholesterol content of the experimental group was significantly decreased (P<0.05). There was no significant difference in liver antioxidant capacity between the two groups (P>0.05). In addition, the feed cost per 1 kg of fish receiving the experimental diet was 18.80% lower than that of fish receiving the control diets, and its culture benefit was increased by 62.12%. The results showed that the experimental diet (high efficiency and low fish meal diet) not only promoted growth, but also improved the muscle fat level and serum lipid metabolism of the fish. These results indicate that the high efficiency and low fish meal diet can be applied in the culture of golden pompano within deep-sea cages. In this study, a high efficiency and low fish meal diet for T. ovatus was developed by using amino acid balance technology and fatty acid precision nutrition technology in deep-sea cage large-scale culture. Through the analysis of growth performance, serum biochemical parameters, liver lipid metabolism, and antioxidant properties, it was found that the growth promoting effect of test material was comparable to that of commercial material, and could improve the muscle quality and liver health of golden pompano. Use of the experimental diet could also reduce the cost of breeding, improve the economic benefits, and result in high economic value. The results indicate that the experimental high efficiency and low fish meal diet for T. ovatus has a good application effect and excellent market development prospects, and also has important practical guiding significance for the large-scale production and application of high efficiency low fish meal compound feed, solving the problem of aquaculture bottleneck and facilitating deep-sea golden pompano culture.
Trachinotus ovatus, commonly known as golden pompano, is a euryhaline warm water carnivorous fish. It has the characteristics of fast growth, simple feeding, delicious meat, strong stress resistance, and high survival rate. It can accept compound feed throughout its growth. It is popular among fish breeders and consumers because of its moderate specifications and affordable price. With an annual output of 240 000 tons, it has become one of the most important marine fish breeding species in the southern coastal areas of China. As a marine carnivorous fish, it has specific requirements relating to the levels and sources of dietary protein and fat, and a strong dependence on fish meal and fish oil, which are limited resources with high prices, which also determines its high feed cost. However, compared with other rare sea fish, its price is low and the profit margin of breeding is low (2–4 CNY/kg), thus, easily leading to the loss of breeding enterprises and individual businesses. Therefore, it is necessary to develop efficient and low-cost compound diets and reduce the supplemental level of fish meal oil in diets to solve the bottleneck problem of golden pompano fish breeding. Previous studies have shown that T. ovatus subjected to a high efficiency and low fish meal diet exhibited excellent growth and health in pond cage culture. To further evaluate the application effect of this feed in deep-sea cage culture, an experimental feed (crude protein 47.66%, crude fat 7.98%) based on the formula feed of a low fish meal diet was produced by a feed company with a large-scale production process (feed production using large machinery and mass production in a feed mill with an hourly output that can reach more than 10 t using equipment such as oil sprayer machines, where the fat source is added by spraying). A commercial feed from a well-known brand was used as the control diet (crude protein 47.75%, crude fat 9.63%). Large-sized golden pompano (mean body weight ~262 g) were provided by Yangjiang Haina Fisheries Limited and kept for 2 weeks at the deep-sea cage breeding base in Dasuo Island, Yangjiang (12–20 m depth, about 15 km offshore) to adapt to the test environment. During the temporary feeding period, a well-known commodity was used for feed. Overall, 150 000 healthy large-sized golden pompano with neat specifications (initial body weight ~260 g) were selected and randomly assigned to six deep-sea cages (HDPE C60 floating cages, circumference 60 m, 25 000 fish per cage). Each feed was provided in three parallel cages for 33 days (April 29 to May 31, 2021). During breeding, full food was provided twice a day (07:00 and 17:00). During the experiment, the seawater temperature was 20.00~29.00 ℃. Dissolved oxygen was 6.30~7.80 mg /L. The results showed that the growth performance of fish was not statistically different between the two groups (P>0.05). However, compared with the control group, the weight gain rate and specific growth rate of fish-fed experimental diets increased by 14.43 % and 8.19 %, respectively, and the average daily weight gain increased by 0.68 g. In terms of muscle nutrition and texture characteristics, the muscle lipid contents of the fish-fed experimental diets were significantly higher than those of fish-fed control diets (P<0.05), but the muscle moisture content significantly decreased (P<0.05). The edible quality and texture characteristics of muscle were comparable between the two groups (P>0.05). Compared with the control group, the serum protein, triglyceride, total cholesterol, and low-density lipoprotein contents, as well as the activity of aspartate aminotransferase, of fish fed the experimental diet were significantly decreased (P<0.05), and the hepatic total cholesterol content of the experimental group was significantly decreased (P<0.05). There was no significant difference in liver antioxidant capacity between the two groups (P>0.05). In addition, the feed cost per 1 kg of fish receiving the experimental diet was 18.80% lower than that of fish receiving the control diets, and its culture benefit was increased by 62.12%. The results showed that the experimental diet (high efficiency and low fish meal diet) not only promoted growth, but also improved the muscle fat level and serum lipid metabolism of the fish. These results indicate that the high efficiency and low fish meal diet can be applied in the culture of golden pompano within deep-sea cages. In this study, a high efficiency and low fish meal diet for T. ovatus was developed by using amino acid balance technology and fatty acid precision nutrition technology in deep-sea cage large-scale culture. Through the analysis of growth performance, serum biochemical parameters, liver lipid metabolism, and antioxidant properties, it was found that the growth promoting effect of test material was comparable to that of commercial material, and could improve the muscle quality and liver health of golden pompano. Use of the experimental diet could also reduce the cost of breeding, improve the economic benefits, and result in high economic value. The results indicate that the experimental high efficiency and low fish meal diet for T. ovatus has a good application effect and excellent market development prospects, and also has important practical guiding significance for the large-scale production and application of high efficiency low fish meal compound feed, solving the problem of aquaculture bottleneck and facilitating deep-sea golden pompano culture.
LIN Shengxiong
,
LI Xiao
,
LU Kangle
,
SONG Kai
,
LI Xueshan
,
LIN Yong
,
WANG Ling
,
ZHANG Chunxiao
2023, 44(5):56-68.
DOI: 10.19663/j.issn2095-9869.20221214002
Abstract:
A 9-week feeding trial was performed to investigate the effects of substituting fish meal (FM) with defatted mealworm Tenebrio molitor meal (TM) on the growth, body composition, serum immune index, as well as histology, barrier functions, digestive enzymatic activities, and microbial communities of the intestine of spotted seabass (Lateolabrax maculatus). In this study, the basal diet was formulated to contain 30% FM, and five experimental diets were formulated by replacing FM with TM at different levels: 0 (TM 0), 5% (5% TM), 10% (10% TM), 15% (15% TM), and 20% (20% TM). Juvenile spotted seabass (2.83±0.02) g were randomly assigned to five treatments with three replicates and 20 fish per replicate. The results showed that the weight gain rate, specific growth rate, and protein productive value of spotted seabass first increased and then decreased with an increase in TM. Among the treatments, there were no difference in the feed efficiency, feeding rate, survival, hepatosomatic index, abdominal fat ratio, or body composition (P>0.05), but the viscerosomatic index was higher in the 5% TM treatment than that in the 20% TM treatment (P<0.05). The serum lysozyme activity was induced in the 5% TM treatment compared to that in other TM treatments (P>0.05). Intestinal histomorphology of spotted seabass was altered with increased dietary TM levels. Compared with the FM treatment, the intestinal villus width, villus height, and muscular thickness were increased significantly in the 5% TM treatment, while all three indices were decreased significantly in the 20% TM treatment (P<0.05). Meanwhile, the expression of the pro-inflammatory gene IL-1β was significantly down-regulated in 5%–15% TM treatments compared to that in the FM and 20% TM treatments (P<0.05). A similar pattern was observed in the expression of the anti-inflammatory gene IL-4. The transcripts of genes associated with barrier functions (ZO-1 and Ocln) were significantly up-regulated in the 5% TM treatment (P<0.05). However, the activity of digestive enzymes (protease and lipase) was not different among all treatments (P>0.05). Furthermore, the alteration of intestinal microbial communities was observed with increasing dietary TM levels. Higher genus abundance of Bacillus was observed in the TM treatments compared to that in the FM treatment (P<0.05), and the relative abundance of Plesiomonas tended to decrease in the 5% TM and 10% TM treatments. In conclusion, substituting fish meal with 5% TM can improve the growth and intestinal health of spotted seabass, while 15% TM had no negative effects on fish. However, excess dietary TM (20%) inhibits growth, causes histopathological damage, and alters the composition of intestinal microbial community in L. maculatus. According to the results of the quadratic regression model, the level of fishmeal substitution by TM in the diet of spotted seabass should not be greater than 7.31%.
A 9-week feeding trial was performed to investigate the effects of substituting fish meal (FM) with defatted mealworm Tenebrio molitor meal (TM) on the growth, body composition, serum immune index, as well as histology, barrier functions, digestive enzymatic activities, and microbial communities of the intestine of spotted seabass (Lateolabrax maculatus). In this study, the basal diet was formulated to contain 30% FM, and five experimental diets were formulated by replacing FM with TM at different levels: 0 (TM 0), 5% (5% TM), 10% (10% TM), 15% (15% TM), and 20% (20% TM). Juvenile spotted seabass (2.83±0.02) g were randomly assigned to five treatments with three replicates and 20 fish per replicate. The results showed that the weight gain rate, specific growth rate, and protein productive value of spotted seabass first increased and then decreased with an increase in TM. Among the treatments, there were no difference in the feed efficiency, feeding rate, survival, hepatosomatic index, abdominal fat ratio, or body composition (P>0.05), but the viscerosomatic index was higher in the 5% TM treatment than that in the 20% TM treatment (P<0.05). The serum lysozyme activity was induced in the 5% TM treatment compared to that in other TM treatments (P>0.05). Intestinal histomorphology of spotted seabass was altered with increased dietary TM levels. Compared with the FM treatment, the intestinal villus width, villus height, and muscular thickness were increased significantly in the 5% TM treatment, while all three indices were decreased significantly in the 20% TM treatment (P<0.05). Meanwhile, the expression of the pro-inflammatory gene IL-1β was significantly down-regulated in 5%–15% TM treatments compared to that in the FM and 20% TM treatments (P<0.05). A similar pattern was observed in the expression of the anti-inflammatory gene IL-4. The transcripts of genes associated with barrier functions (ZO-1 and Ocln) were significantly up-regulated in the 5% TM treatment (P<0.05). However, the activity of digestive enzymes (protease and lipase) was not different among all treatments (P>0.05). Furthermore, the alteration of intestinal microbial communities was observed with increasing dietary TM levels. Higher genus abundance of Bacillus was observed in the TM treatments compared to that in the FM treatment (P<0.05), and the relative abundance of Plesiomonas tended to decrease in the 5% TM and 10% TM treatments. In conclusion, substituting fish meal with 5% TM can improve the growth and intestinal health of spotted seabass, while 15% TM had no negative effects on fish. However, excess dietary TM (20%) inhibits growth, causes histopathological damage, and alters the composition of intestinal microbial community in L. maculatus. According to the results of the quadratic regression model, the level of fishmeal substitution by TM in the diet of spotted seabass should not be greater than 7.31%.
2023, 44(5):69-79.
DOI: 10.19663/j.issn2095-9869.20230213001
Abstract:
In recent years, with the increase of varieties and the expansion of scale in aquaculture, as well as the rapid development of the intensive and industrial aquaculture industry, the demand for fish meal has increased significantly. On the other hand, due to global warming and environmental pollution, marine resources have reduced and the production of high-quality fish meal is gradually decreasing. The soaring prices of fish meal increase the feed cost in the process of aquaculture, severely decrease the economic benefits of aquaculture farmers, greatly limit the use of fish meal in aquatic feed, and hinder the sustainable development of the aquaculture industry. Therefore, it has become an important research subject in the aquatic feed industry to find new fish meal substitutes and reasonably reduce the amount of fish meal in feed. Crickets have high nutrient concentrations (55%–73% crude protein, high unsaturated fatty acid levels, and sufficient essential amino acid (EAA) profiles). For cricket meal, as one of the new high-quality insect protein sources, the crude protein concentration is comparable to that of fish meal. Recent studies have shown that cricket meal can replace part of fish meal, and have achieved good results in Clarias gariepinus, Micropterus salmoides, and other aquatic animals. However, the application of cricket meal as a substitute for fish meal in the diets of yellow catfish has not been reported. In the present study, we investigated the effects on the growth performance, muscle composition, and serum biochemical indexes of yellow catfish by replacing different proportions of fish meal in the diets with cricket meal. The aim was to explore the feasibility of replacing fish meal in the diets of yellow catfish, and to provide a scientific reference for the future development and application of insect protein sources in aquatic feed. The cricket meal used in this study was a brown powder containing dry matter crude protein content of 63.40%, crude fat content of 15.50%, and crude ash content of 7.36%. Healthy juvenile yellow catfish with an average body weight of (2.0±0.13) g were randomly divided into five groups with three replicates and 30 fish per replicate. Five isonitrogenous and isoenergetic experimental diets were formulated by replacing 0%, 15%, 30%, 45%, and 60% of fish meal protein with cricket meal, named T0, T15, T30, T45, and T60 groups, respectively. The experimental fish were reared in an indoor recirculating aquaculture system for 10 weeks. By measuring growth performance, muscle amino acid content, and serum biochemical parameters, the appropriate replacement level of cricket meal in yellow catfish diets was investigated. The results showed that with increasing cricket meal content, the final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) of juvenile yellow catfish increased first and then decreased. The growth performance of FBW, WGR, and SGR in the T30 group was the highest and significantly higher than that of FBW, WGR, and SGR in the T0 group (P < 0.05), whereas the feed conversion rate (FCR) was significantly lower than that of T0 and T15 groups (P<0.05). The hepatosomatic index in the T30 group was higher than that in the T0 and T15 groups (P<0.05), and there was no difference between the T45 and T60 groups. There were no significant differences in the viscerosomatic index, feed intake, FCR, and survival rate among all groups (P>0.05). The EAA contents of the muscle arginine and valine in the T60 group were significantly higher than those in the T0 group (P<0.05). There were no significant differences in the contents of total flavor amino acid in muscle among all groups with different proportions of replaced cricket meal (P>0.05). Compared with the T0 group, the content of glucose (GLU) in the serum of the T30, T45, and T60 groups significantly increased (P<0.05), whereas the content of total cholesterol (TCHO) was significantly decreased (P<0.05). The activities of the serum superoxide dismutase and catalase in the T30 and T60 groups were significantly higher than those of the T0 group (P<0.05). In conclusion, under our experimental conditions, the growth performance and muscle amino acid composition of juvenile yellow catfish were not affected by replacing fish meal with cricket meal, and serum biochemical parameters and TCHO contents were increased. The optimal growth rate was achieved by replacing fish meal with 30% cricket meal. The results of indicate that cricket meal is an excellent substitute for fish meal and provides a theoretical reference for the application of cricket meal as a partial substitute for fish meal in aquatic animal diets.
In recent years, with the increase of varieties and the expansion of scale in aquaculture, as well as the rapid development of the intensive and industrial aquaculture industry, the demand for fish meal has increased significantly. On the other hand, due to global warming and environmental pollution, marine resources have reduced and the production of high-quality fish meal is gradually decreasing. The soaring prices of fish meal increase the feed cost in the process of aquaculture, severely decrease the economic benefits of aquaculture farmers, greatly limit the use of fish meal in aquatic feed, and hinder the sustainable development of the aquaculture industry. Therefore, it has become an important research subject in the aquatic feed industry to find new fish meal substitutes and reasonably reduce the amount of fish meal in feed. Crickets have high nutrient concentrations (55%–73% crude protein, high unsaturated fatty acid levels, and sufficient essential amino acid (EAA) profiles). For cricket meal, as one of the new high-quality insect protein sources, the crude protein concentration is comparable to that of fish meal. Recent studies have shown that cricket meal can replace part of fish meal, and have achieved good results in Clarias gariepinus, Micropterus salmoides, and other aquatic animals. However, the application of cricket meal as a substitute for fish meal in the diets of yellow catfish has not been reported. In the present study, we investigated the effects on the growth performance, muscle composition, and serum biochemical indexes of yellow catfish by replacing different proportions of fish meal in the diets with cricket meal. The aim was to explore the feasibility of replacing fish meal in the diets of yellow catfish, and to provide a scientific reference for the future development and application of insect protein sources in aquatic feed. The cricket meal used in this study was a brown powder containing dry matter crude protein content of 63.40%, crude fat content of 15.50%, and crude ash content of 7.36%. Healthy juvenile yellow catfish with an average body weight of (2.0±0.13) g were randomly divided into five groups with three replicates and 30 fish per replicate. Five isonitrogenous and isoenergetic experimental diets were formulated by replacing 0%, 15%, 30%, 45%, and 60% of fish meal protein with cricket meal, named T0, T15, T30, T45, and T60 groups, respectively. The experimental fish were reared in an indoor recirculating aquaculture system for 10 weeks. By measuring growth performance, muscle amino acid content, and serum biochemical parameters, the appropriate replacement level of cricket meal in yellow catfish diets was investigated. The results showed that with increasing cricket meal content, the final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) of juvenile yellow catfish increased first and then decreased. The growth performance of FBW, WGR, and SGR in the T30 group was the highest and significantly higher than that of FBW, WGR, and SGR in the T0 group (P < 0.05), whereas the feed conversion rate (FCR) was significantly lower than that of T0 and T15 groups (P<0.05). The hepatosomatic index in the T30 group was higher than that in the T0 and T15 groups (P<0.05), and there was no difference between the T45 and T60 groups. There were no significant differences in the viscerosomatic index, feed intake, FCR, and survival rate among all groups (P>0.05). The EAA contents of the muscle arginine and valine in the T60 group were significantly higher than those in the T0 group (P<0.05). There were no significant differences in the contents of total flavor amino acid in muscle among all groups with different proportions of replaced cricket meal (P>0.05). Compared with the T0 group, the content of glucose (GLU) in the serum of the T30, T45, and T60 groups significantly increased (P<0.05), whereas the content of total cholesterol (TCHO) was significantly decreased (P<0.05). The activities of the serum superoxide dismutase and catalase in the T30 and T60 groups were significantly higher than those of the T0 group (P<0.05). In conclusion, under our experimental conditions, the growth performance and muscle amino acid composition of juvenile yellow catfish were not affected by replacing fish meal with cricket meal, and serum biochemical parameters and TCHO contents were increased. The optimal growth rate was achieved by replacing fish meal with 30% cricket meal. The results of indicate that cricket meal is an excellent substitute for fish meal and provides a theoretical reference for the application of cricket meal as a partial substitute for fish meal in aquatic animal diets.
2023, 44(5):21-32.
DOI: 10.19663/j.issn2095-9869.20230227001
Abstract:
Fish meal and fish oil are important sources of protein and lipid in feeds. The lack of fish meal and fish oil supply has become an important limiting factor for the aquaculture industry. The proportion of fish oil and fish meal used in commercial feeds for farmed fish and crustaceans is continually decreasing, while the carbohydrate content is increasing. Carbohydrates are one of the three major nutrients that provide energy for the body. They have a much lower production price than protein and fat. Starch is a polymeric carbohydrate made from glucose molecules; it is the most commonly used in aquatic feeds and can replace fish meal and fish oil to reduce feed cost. Therefore, it is important to fully explore the nutritional function of carbohydrates for aquaculture. Hypoxia is a common stress in aquaculture, and acute hypoxia may lead to massive mortality of cultured fish in a short period of time resulting in serious economic losses to aquaculture. Therefore, it is crucial to find ways to improve the acute hypoxia tolerance of fish. Fish mainly use glucose for energy under acute hypoxia. Hypoxia inhibits oxidative phosphorylation in mitochondria and activates the anaerobic glycolysis pathway. Glucose degrades to produce lactate and ATP. Carnivorous fishes have limited absorption and utilization capacities to feed carbohydrates, unlike omnivorous fishes. Dextrin is an intermediate starch hydrolysis product, with a molecular weight between starch and glucose; it has good adhesion properties and is more easily digested and absorbed than starch. Therefore, we hypothesized that the use of easily digestible carbohydrate in the feed is an effective way to improve the acute hypoxia tolerance of fish. Takifugu rubripes is loved by Japanese and Korean consumers owing to its delicious taste and high nutritional value. It is a characteristic species of Chinese mariculture fish. It is mainly cultured in a high-density factory, and the dissolved oxygen in the water often relies on water exchange and an oxygenation pump; its gill cover is degraded and is at risk of acute hypoxia. This study determined the effect of the addition of corn starch or dextrin (corn starch hydrolysate) to the feed on growth performance, acute hypoxia survival rate, metabolite content, and the hypoxia inducible factor (HIF) signaling pathway of T. rubripes after 8 weeks of feeding. There were no significant differences in weight gain, feed conversion ratio, hepatosomatic index, viscerosomatic index, condition factor, and body composition between the starch group and the dextrin group (P>0.05). However, the survival rate during acute hypoxia of the dextrin group was significantly higher than that of the starch group (P<0.05). There were no significant differences in the liver glycogen and lactate contents, and lactate dehydrogenase A4 (ldha) gene expression between the starch group and dextrin group (P>0.05) during normoxia. However, the lactate content and ldha gene expression were significantly higher in the liver of the dextrin group than those in the starch group (P<0.05) during hypoxia. This indicated that feeding dextrin strongly activated anaerobic glycolysis to provide more energy under hypoxia. The serum triglyceride (TG) content significantly increased in the dextrin group compared with the normoxia groups, although the TG content in the serum and liver significantly decreased in the starch group after acute hypoxia (P<0.05). This suggested that feeding starch promoted lipid catabolism and oxygen consumption. There was no significant difference in the total soluble protein content of the muscle between the starch group and the dextrin group (P>0.05) during normoxia. However, the total soluble protein content of the muscle decreased in the dextrin group compared with the starch group (P<0.05) after acute hypoxia. Meanwhile, the total muscle soluble protein content, and the gene expression of liver v-akt murine thymoma viral oncogene homolog 1 (akt1), and mechanistic target of rapamycin kinase (mtor) significantly decreased in the dextrin group after hypoxia compared with the normoxia group. However, the liver mtor gene expression significantly increased in the starch group after hypoxia (P<0.05). This data demonstrated that protein synthesis was inhibited in the dextrin group under hypoxia. Hypoxia inducible factor (HIF) is the most critical transcription factor in cellular response to hypoxic stress. The dextrin group had higher hypoxia inducible factor 1 subunit alpha like (hif-3α) gene expression in the liver and lower hypoxia inducible factor 1 subunit alpha a (hif-1α) gene expression in the muscle (P<0.05) compared with the starch group during normoxia. The gene expression of liver hif-1α and hif-3α and muscle hif-1α and vascular endothelial growth factor A (vegfa) significantly increased in the dextrin group compared with the starch group (P<0.05) during hypoxia. This proved that feeding dextrin strongly activated the HIF signaling pathway under hypoxia. In summary, replacing starch with easily digestible dextrin in the feed did not affect the growth performance. Instead, it activated the HIF signaling pathway and anaerobic glycolysis to provide more energy for fish. Meanwhile, feeding dextrin inhibited lipid catabolism and protein synthesis, and reduced oxygen consumption to improve the acute hypoxia tolerance of T. rubripes. The study provides important guidance for the formulation design of hypoxia-tolerant feed and healthy development of aquaculture.
Fish meal and fish oil are important sources of protein and lipid in feeds. The lack of fish meal and fish oil supply has become an important limiting factor for the aquaculture industry. The proportion of fish oil and fish meal used in commercial feeds for farmed fish and crustaceans is continually decreasing, while the carbohydrate content is increasing. Carbohydrates are one of the three major nutrients that provide energy for the body. They have a much lower production price than protein and fat. Starch is a polymeric carbohydrate made from glucose molecules; it is the most commonly used in aquatic feeds and can replace fish meal and fish oil to reduce feed cost. Therefore, it is important to fully explore the nutritional function of carbohydrates for aquaculture. Hypoxia is a common stress in aquaculture, and acute hypoxia may lead to massive mortality of cultured fish in a short period of time resulting in serious economic losses to aquaculture. Therefore, it is crucial to find ways to improve the acute hypoxia tolerance of fish. Fish mainly use glucose for energy under acute hypoxia. Hypoxia inhibits oxidative phosphorylation in mitochondria and activates the anaerobic glycolysis pathway. Glucose degrades to produce lactate and ATP. Carnivorous fishes have limited absorption and utilization capacities to feed carbohydrates, unlike omnivorous fishes. Dextrin is an intermediate starch hydrolysis product, with a molecular weight between starch and glucose; it has good adhesion properties and is more easily digested and absorbed than starch. Therefore, we hypothesized that the use of easily digestible carbohydrate in the feed is an effective way to improve the acute hypoxia tolerance of fish. Takifugu rubripes is loved by Japanese and Korean consumers owing to its delicious taste and high nutritional value. It is a characteristic species of Chinese mariculture fish. It is mainly cultured in a high-density factory, and the dissolved oxygen in the water often relies on water exchange and an oxygenation pump; its gill cover is degraded and is at risk of acute hypoxia. This study determined the effect of the addition of corn starch or dextrin (corn starch hydrolysate) to the feed on growth performance, acute hypoxia survival rate, metabolite content, and the hypoxia inducible factor (HIF) signaling pathway of T. rubripes after 8 weeks of feeding. There were no significant differences in weight gain, feed conversion ratio, hepatosomatic index, viscerosomatic index, condition factor, and body composition between the starch group and the dextrin group (P>0.05). However, the survival rate during acute hypoxia of the dextrin group was significantly higher than that of the starch group (P<0.05). There were no significant differences in the liver glycogen and lactate contents, and lactate dehydrogenase A4 (ldha) gene expression between the starch group and dextrin group (P>0.05) during normoxia. However, the lactate content and ldha gene expression were significantly higher in the liver of the dextrin group than those in the starch group (P<0.05) during hypoxia. This indicated that feeding dextrin strongly activated anaerobic glycolysis to provide more energy under hypoxia. The serum triglyceride (TG) content significantly increased in the dextrin group compared with the normoxia groups, although the TG content in the serum and liver significantly decreased in the starch group after acute hypoxia (P<0.05). This suggested that feeding starch promoted lipid catabolism and oxygen consumption. There was no significant difference in the total soluble protein content of the muscle between the starch group and the dextrin group (P>0.05) during normoxia. However, the total soluble protein content of the muscle decreased in the dextrin group compared with the starch group (P<0.05) after acute hypoxia. Meanwhile, the total muscle soluble protein content, and the gene expression of liver v-akt murine thymoma viral oncogene homolog 1 (akt1), and mechanistic target of rapamycin kinase (mtor) significantly decreased in the dextrin group after hypoxia compared with the normoxia group. However, the liver mtor gene expression significantly increased in the starch group after hypoxia (P<0.05). This data demonstrated that protein synthesis was inhibited in the dextrin group under hypoxia. Hypoxia inducible factor (HIF) is the most critical transcription factor in cellular response to hypoxic stress. The dextrin group had higher hypoxia inducible factor 1 subunit alpha like (hif-3α) gene expression in the liver and lower hypoxia inducible factor 1 subunit alpha a (hif-1α) gene expression in the muscle (P<0.05) compared with the starch group during normoxia. The gene expression of liver hif-1α and hif-3α and muscle hif-1α and vascular endothelial growth factor A (vegfa) significantly increased in the dextrin group compared with the starch group (P<0.05) during hypoxia. This proved that feeding dextrin strongly activated the HIF signaling pathway under hypoxia. In summary, replacing starch with easily digestible dextrin in the feed did not affect the growth performance. Instead, it activated the HIF signaling pathway and anaerobic glycolysis to provide more energy for fish. Meanwhile, feeding dextrin inhibited lipid catabolism and protein synthesis, and reduced oxygen consumption to improve the acute hypoxia tolerance of T. rubripes. The study provides important guidance for the formulation design of hypoxia-tolerant feed and healthy development of aquaculture.
