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One of the main challenges in the tilapia culture in Malawi is the low growth rates and yields. This study aimed to compare iso-nitrogenous fish feeds concerning growth, feed utilization, and apparent digestibility of the redbreast tilapia (Coptodon rendalli) raised in pond-hapas and tanks. Coptodon rendalli fingerlings were stocked in hapas (1m² each) at 10 fish per hapa, each measuring 6.81± 0.33g, and reared for 70 days. The fish were fed on floating, sinking, and maize bran (control) feeds. In a parallel digestibility experiment, six aquarium glass tanks were stocked with 10 Coptodon rendalli fingerlings, each for 21 days. Fecal material was collected and transferred into conical flasks after one hour of feeding for storage at -20°C. Results showed significant differences in specific growth rate, weight gain, relative condition factor, final weight, and survival rate, with floating feeds yielding the highest values (P< 0.001). The fish displayed negative allometric growth, with a growth coefficient of b=1.84. Apparent feed conversion ratio and protein efficiency ratio varied significantly across treatments (P< 0.001). In the digestibility experiment, differences in protein digestibility were also significant (P< 0.001), while no significant differences were observed in fat (P = 0.22), ash (P = 0.53), and energy (P = 0.34) across treatments. Fish fed on floating feeds exhibited better growth, feed utilization, and digestibility, highlighting the need to enhance the use of floating feeds in aquaculture [ABSTRACT FROM AUTHOR]

Projected growth in insect production as alternative feedstuffs will yield novel by‐products that are potentially valuable for aquafeed applications. We analyzed the nutrient composition of three by‐products occurring from black soldier fly larvae production (exuvia, cocoon, imago) and the bioavailability of key nutrients for Pacific Whiteleg shrimp (Litopenaeus vannamei). Protein accounted for 317 g kg−1 in exuviae, 433 g kg−1 in cocoons, and up to 521 g kg−1 in adult flies (imagines). Considerable amounts of essential amino acids were detected in imago meal, which significantly matched the ideal dietary amino acid composition for penaeid shrimp (r2 = 0.66, p = 0.0076). Exuviae and cocoons contained moderate amounts of lipids (64–140 g kg−1), while imagines comprised 356 g kg−1 total lipid. Saturated fatty acids predominated in all insect materials (47%–83% of total fatty acids). Chitin concentration was highest in cocoons and exuviae (154 and 139 g kg−1) and low in imagines (51 g kg−1). A feeding trial with shrimp, L vannamei, revealed apparent digestibility coefficients of 20%–59% for protein, 24%–54% for energy, 25%–49% for carbon, and 27%–68% for copper. Defatting of imago meal increased the digestibility of protein, energy, and carbon by 77%, 64%, and 61%, respectively. Defatted imago meal can serve as a protein supplement for shrimp diets. [ABSTRACT FROM AUTHOR]

Abstract Projected growth in insect production as alternative feedstuffs will yield novel by‐products that are potentially valuable for aquafeed applications. We analyzed the nutrient composition of three by‐products occurring from black soldier fly larvae production (exuvia, cocoon, imago) and the bioavailability of key nutrients for Pacific Whiteleg shrimp (Litopenaeus vannamei). Protein accounted for 317 g kg−1 in exuviae, 433 g kg−1 in cocoons, and up to 521 g kg−1 in adult flies (imagines). Considerable amounts of essential amino acids were detected in imago meal, which significantly matched the ideal dietary amino acid composition for penaeid shrimp (r2 = 0.66, p = 0.0076). Exuviae and cocoons contained moderate amounts of lipids (64–140 g kg−1), while imagines comprised 356 g kg−1 total lipid. Saturated fatty acids predominated in all insect materials (47%–83% of total fatty acids). Chitin concentration was highest in cocoons and exuviae (154 and 139 g kg−1) and low in imagines (51 g kg−1). A feeding trial with shrimp, L vannamei, revealed apparent digestibility coefficients of 20%–59% for protein, 24%–54% for energy, 25%–49% for carbon, and 27%–68% for copper. Defatting of imago meal increased the digestibility of protein, energy, and carbon by 77%, 64%, and 61%, respectively. Defatted imago meal can serve as a protein supplement for shrimp diets.

Abstract Two feeding trials were performed to evaluate the apparent digestibility coefficients (ADCs) of dry matter, protein, and amino acids of three animal‐origin and four plant‐origin ingredients in Totoaba macdonaldi. In the first feeding trial, the animal‐origin ingredients were evaluated using totoaba juveniles with an initial weight of 529.7 ± 104.2 g, and for the second feeding trial 745.9 ± 210.6 g. Evaluated ingredients were: poultry by‐product meal, meat and bone meal, feather meal (FM), soy protein concentrate, soybean meal (SBM), corn gluten (CG), and wheat gluten (WG). Each experimental ingredient was evaluated in triplicate. ADCs of dry matter ranged from 35.9% for FM to 67.9% for poultry by‐product, while the protein ADCs values ranged from 41.7% for CG to 83.2% for poultry by‐product. Fish meal ADC (79.6%) was similar to poultry by‐product but significantly higher than WG and soy protein concentrate (72.5% and 72.6%, respectively). The ADCs for lysine were significantly higher for WG, sardine meal, poultry by‐product, and SMB (94.5%, 79.8%, 79.4%, and 79.4%, respectively). Based on the results from the present study, poultry by‐product, WG, and soy protein concentrate are the most promising alternative ingredients (i.e., to the fishmeal) for the formulation of totoaba grow‐out feeds.

Two feeding trials were performed to evaluate the apparent digestibility coefficients (ADCs) of dry matter, protein, and amino acids of three animal‐origin and four plant‐origin ingredients in Totoaba macdonaldi. In the first feeding trial, the animal‐origin ingredients were evaluated using totoaba juveniles with an initial weight of 529.7 ± 104.2 g, and for the second feeding trial 745.9 ± 210.6 g. Evaluated ingredients were: poultry by‐product meal, meat and bone meal, feather meal (FM), soy protein concentrate, soybean meal (SBM), corn gluten (CG), and wheat gluten (WG). Each experimental ingredient was evaluated in triplicate. ADCs of dry matter ranged from 35.9% for FM to 67.9% for poultry by‐product, while the protein ADCs values ranged from 41.7% for CG to 83.2% for poultry by‐product. Fish meal ADC (79.6%) was similar to poultry by‐product but significantly higher than WG and soy protein concentrate (72.5% and 72.6%, respectively). The ADCs for lysine were significantly higher for WG, sardine meal, poultry by‐product, and SMB (94.5%, 79.8%, 79.4%, and 79.4%, respectively). Based on the results from the present study, poultry by‐product, WG, and soy protein concentrate are the most promising alternative ingredients (i.e., to the fishmeal) for the formulation of totoaba grow‐out feeds. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology / Shuisheng Shengwu Xuebao is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The apparent digestibility coefficients (ADCs) of Tenebrio molitor meal (TMM), Hermetia illucens meal (HIM), Clostridium autoethanogenum protein (CAP), Methylococcus capsulatus meal (MCM), Chlorella vullgaris meal (CVM), Cottonseed protein concentrate (CPC) and Peruvian fishmeal (PFM) were determined in juvenile hybrid grouper (Epinephelus fuscoguttatus♀xEpinephelus lanceolatu♂). A basal diet (including 50% fishmeal) and seven test diets (700 g/kg of the basal diet and 300 g/kg of each test ingredient) were formulated with 0.1% yttrium oxide (Y2O3) as an inert marker. The juvenile hybrid groupers, with initial average body weight of (9.95±0.50) g, were randomly distributed into 0.3 m³ fiberglass tanks, each tank with 30 fish. The faeces samples were collected twice-daily by siphoning following feeding fish after five days of domestication. The ADCs of dry matter of seven test ingredients were ranked as CVM>TMM=CAP=CPC>HIM=MCM=PFM (P<0.05). CVM showed the highest ADCs of dry matter (DM), crude protein (CP) and most amino acids (including methionine and threonine) except crude lipids (CL), whereas HIM had the relatively lower ADCs of DM, CP and most amino acids except CL. CAP had a higher lysine digestibility than the other six test ingredients, and was only lower than CVM in the ADC of CP. The ADC of DM in PFM was significantly lower than that in CVM (P<0.05), and showed no differences with that in CAP (P>0.05). Besides, PFM showed a lower ADC of CP than the ADCs of CP in CVM, CAP and MCM (P<0.05), and showed a lower ADC of lysine than that in CAP as well as a lower ADC of threonine than those in CAP and CVM (P<0.05). Overall, this study showed the advantage of CVM and CAP among the seven protein sources on the digestibility of feed available in hybrid grouper. [ABSTRACT FROM AUTHOR]

Simple Summary: This study evaluated the influence of coprophagic behavior on the fecal concentrations of lactic acid, short-chain fatty acids (SCFA) and branched fatty acids (BCFA), ammonia nitrogen, fecal pH, and the apparent digestibility coefficients of nutrients and fecal scores of adult dogs. Coprophagia is a common and undesirable behavior observed in dogs; however, little is known about its causes or possible consequences when analysis of the animal's feces is needed for experimental purposes. Therefore, this study evaluated the effect of coprophagy on digestibility, fecal pH, and fermentative metabolites. Twelve healthy dogs with a mean age of 3.50 ± 1.45 years were included and divided into two groups: coprophagic (COP) and non-coprophagic (NCOP). The study lasted 30 days, the last 6 days being used to collect feces for the analysis of the apparent digestibility of coefficients (ADC), fecal pH, and the concentration of short- and branched-chain fatty acids, ammonia, and fecal lactic acid. Statistical analysis was performed using the SAS software. No differences were observed for most variables, except for the ADC of nitrogen-free extract (NFE), which presented the highest average for the COP. This result should be interpreted with caution, as the NFE is estimated from calculations and was not determined in the laboratory; in addition, the results represent not only starch and sugars but also some parts referring to fibers. Therefore, coprophagy seemed not to influence the fecal variables analyzed. [ABSTRACT FROM AUTHOR]

Vegetable oil is progressively replacing fish oil (FO) in aquafeed production. However, the effect of oxidized vegetable oil is less reported. This study was done to investigate the effects of oxidized refined palm oil (RPO) on the growth performance, feed utilization, proximate and fatty acid profiles, apparent digestibility coefficients and oxidative stress of hybrid grouper juvenile (Epinephelus fuscoguttatus × E. lanceolatus). RPO was force-oxidized and introduced into diets at three oxidative levels to replace 50% of FO. Diets with FO and fresh RPO were served as controls. The peroxide value of the oxidized diets was measured as 14.73, 24.50, and 36.10 meq/kg for diets OxL, OxM, and OxH, respectively. These diets were fed to triplicate groups of hybrid grouper (initial body weight 9.91 ± 0.01 g) for 8 weeks. There was no significant difference in terms of growth performance, survival, feed utilization, and whole-body protein proximate composition in all treatments (p > 0.05). However, different dietary treatments affected the body fatty acids profile and fish-fed OxM diet achieved the highest body weight gain without significant difference (p > 0.05). In terms of hepaticsomatic index (HSI), fish-fed OxH showed a significantly lower value compared to other treatments. Similarly, the lowest apparent digestibility coefficients (ADC) of nutrients were observed in fish fed OxH diet. The oxidized diets caused significant lower blood cholesterol and high-density lipoprotein cholesterol (HDL) (p < 0.05). The oxidative stress in the liver as indicated by the significantly higher thiobarbituric acid-reactive substance (TBARS) value in fish fed all the oxidized diets while no significant changes on the muscle TBARS values. In conclusion, the oxidized RPO diets significantly affected the liver, the nutrient digestibility, and the blood total cholesterol and HDL. Furthermore, hybrid grouper can tolerate up to 20 meq/kg of oxidized RPO in the diet without compromising the growth.

This study aimed at optimizing the sedimentation method for stool collection in digestibility tests in pirarucu. In the first trial, juvenile fish (435.26 ± 10.80 g) received the reference diet with chromium oxide to determine the gastrointestinal transit time (GITT). In the second, the fish were fed the reference and two test diets (corn and soybean meal) for 15 days. The apparent dry matter, protein and phosphorus digestibility coefficients (ADC) were determined to verify the time of acclimatization to the experimental diets. The stool pattern was visually analysed on day 5 and 10 of acclimatization. The third trial evaluated the maximum stool collection time for reduced nutrient leaching 30 min, 1, 6 and 12 h after evacuation as well as the stool collected directly from the rectum. GITT was 5.5 h. ADC varied during the initial acclimatization and stabilized between days 8 and 10, corroborating a consistent visual pattern on day 10 than on day 5. Nutrient ADC increased with increased stool collection time, except with a 30‐min interval, which presented ADC similar to rectum samples. Pirarucu stool must be collected from day 10 for a 30‐min interval about 30 min after the second daily meal. [ABSTRACT FROM AUTHOR]

In previous studies of apparent digestibility coefficients (ADCs), the association between apparent digestion and protein metabolism from different protein sources has long been ignored. To develop nutritionally adequate diets, this study evaluated the effects of different protein sources (fermented soybean meal [FSM], rapeseed meal [RSM], Antarctic krill powder [AKP] and fish protein hydrolysate [FPH]) on the growth performance, ADCs and expression of genes related to protein metabolism in Chinese perch. The experimental feed was composed of 300g kg‐1 test ingredients and 700g kg‐1 reference feed (RF). After the feeding trial, FPH was found to achieve the best growth performance of Chinese perch and had significantly higher ADCs of dry matter and gross energy than all other ingredients. Besides, FPH was the only ingredient with crude protein ADC exceeding 90% and the highest crude lipid ADC, while RSM had the lowest crude protein and crude lipid ADC. FPH showed the highest ADC of amino acids except for serine and tyrosine, and RSM showed the lowest amino acid ADC except for methionine. FPH resulted in the lowest expression of mtor, s6k, murf1, mafbx, pept2 and lat2 and the highest expression of gdh and ast in the muscle. The transcription level of cat significantly increased in the gut of the FSM group compared with that in the RF group. These findings imply that FPH may be a promising ingredient to be incorporated into the formulated diet of Chinese perch. [ABSTRACT FROM AUTHOR]

An eight‐week growth trial and a four‐week digestibility trial was undertaken to assess the impact of DL‐methionine and phytase supplementation on growth performances, apparent digestibility coefficients (ADC), phosphorus retention and digestive enzyme activities of Penaeus vannamei. Five treatment groups in three replicates fed with a control diet (fishmeal 200 g/kg), and four low fishmeal (50 g/kg) diets with soy protein concentrate‐soybean meal protein viz., SPC1 (without supplementation), SPC 2 (DL‐methionine), SPC 3 (Phytase) and SPC4 (DL‐methionine and phytase). SPC 2 had significantly improved (p <.05) the weight gain (5.79 ± 0.12), FCR (1.53 ± 0.06) and SGR (3.21 ± 0.06) than other low fishmeal diets, but not significantly different to that of SPC 4 and control. SPC 2 also showed significantly higher protease activity. P retention was significantly higher in SPC 2 than SPC 1, SPC 3 and control, however, not significantly different from SPC 4. Faecal phosphorus load was significantly reduced in SPC 2 than SPC 1 and control. Protein digestibility was significantly higher in SPC 2 and SPC 4, whilst phosphorus digestibility was significantly higher in SPC 4. Thus, it is concluded that the supplementation of DL‐methionine is essential for the overall better performances of P. vannamei in low fishmeal diets and phytase for improving phosphorus digestibility. [ABSTRACT FROM AUTHOR]

Coprophagia is a common and undesirable behavior observed in dogs; however, little is known about its causes or possible consequences when analysis of the animal’s feces is needed for experimental purposes. Therefore, this study evaluated the effect of coprophagy on digestibility, fecal pH, and fermentative metabolites. Twelve healthy dogs with a mean age of 3.50 ± 1.45 years were included and divided into two groups: coprophagic (COP) and non-coprophagic (NCOP). The study lasted 30 days, the last 6 days being used to collect feces for the analysis of the apparent digestibility of coefficients (ADC), fecal pH, and the concentration of short- and branched-chain fatty acids, ammonia, and fecal lactic acid. Statistical analysis was performed using the SAS software. No differences were observed for most variables, except for the ADC of nitrogen-free extract (NFE), which presented the highest average for the COP. This result should be interpreted with caution, as the NFE is estimated from calculations and was not determined in the laboratory; in addition, the results represent not only starch and sugars but also some parts referring to fibers. Therefore, coprophagy seemed not to influence the fecal variables analyzed.

To investigate the effects of dietary different lipid levels on the growth performance, feed digestibility, antioxidant status, and fillet fatty acid compositions of juvenile hybrid sturgeon (Acipenser baerii Brandt ♀ A. schrenckii Brandt ♂), four isonitrogenous (42% crude protein) experimental diets were formulated with various lipid levels at 5% (D05), 10% (D10), 15% (D15) and 20% (D20), respectively. Hybrid sturgeon with an initial body weight of (152.83±0.67) g were randomly divided into 4 groups with 3 replicates in each group and 25 fish per replicate for a 12- week trial. The results showed that dietary different lipid levels had significant effect on the growth performance of juvenile hybrid sturgeon. Among them, final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) in D15 group were significantly higher than those in D05, D10 and D20 groups (P<0.05). Feed efficiency (FE) in D15 group was significantly higher than that in D05 and D10 groups (P<0.05). With the enhanced dietary lipid level, viscerasomatic index (VSI), hepatosomatic index (HSI) and crude fat in fillet and liver increased significantly (P<0.05). Dietary different lipid levels had no significant effects on the apparent digestibility of dry matter (ADCd) and protein (ADCp) (P>0.05). The apparent digestibility of fat (ADCf) in D10, D15 and D20 groups was significantly higher than that in the D05 group (P<0.05). The highest apparent digestibility of energy (ADCe) was in D15 group, which was significantly higher than that in D05 and D10 groups (P<0.05). When the dietary lipid level increased from 5% to 20%, the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and myeloperoxidase (MPO) were boosted (P<0.05) while glutathione peroxidase (GSH-Px) activity reduced significantly (P<0.05) in serum of juvenile hybrid sturgeon. The activities of the four liver function indicators, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactic dehydrogenase (LDH), also showed an increasing trend (P<0.05). There was a significant positive linear correlation between the content of fillet fatty acids and the fatty acid content in the diets (R2>0.90, P<0.05). These results revealed that the optimal lipid level in the diet of juvenile hybrid sturgeon was 15%, and P/E was 23.54 mg/kJ. [ABSTRACT FROM AUTHOR]

Androgen action generates sex-related differences that include changes in the gut microbiota composition. Hypoandrogenism and hyperandrogenism in males and females, respectively, are associated with the prevalence of metabolic disorders. Our recent work showed that male androgen receptor knockout (ARKO) mice developed high-fat diet (HFD)-dependent sarcopenic abdominal obesity, hyperglycemia, and hepatic steatosis, leading to early death. The ARKO mice also exhibited alterations in intestinal microbiota but did not experience metabolic abnormalities when administered with antibiotics. Here, we show that time-dependent changes in feed efficiency (ratio of body weight gain to food intake) and weight of dried feces-to-food ratio could be good markers for changes in gut microbiota. Turicibacter spp., Lactobacillus spp., and L. reuteri increased in the gut in both HFD-fed ARKO and castrated mice having metabolic abnormalities. HFD-fed ARKO mice showed increased plasma levels of aspartate, but not alanine, aminotransferase. Changes in the gut microbiome appear to provoke androgen deficiency-induced metabolic diseases, leading to early mortality.

Due to increasing demand of ingredients of animal origin, studies on the availability of nutrients in ingredients of plant origin are worthy in carnivorous species including bullfrog. This study aimed to determine apparent digestibility coefficients (ADCs) of amino acids (AAs) in three ingredients as plant protein sources (soybean protein concentrate (SPC), corn gluten meal 60 % (CGM), soybean meal (SM)) and two ingredients as plant energy sources (corn grain (CG) and wheat bran (WB)) which commonly use in bullfrog diets. A reference diet and five test diets containing 69.5 % of the reference diet, 30 % of each test ingredient and 0.5 % of chromium (III) oxide as an inert marker were prepared. Among plant protein ingredients, CGM showed better digestibility of essential amino acids (EAAs) (> 80 %) at the three post-metamorphic (initial, growing and finishing) phases of bullfrog development, except tryptophan which presented a low digestibility at growing and finishing phases. Among plant energy ingredients, CG presented better digestibility of AAs at both initial and growing phases than WB which showed better digestibility only at finishing phase. It was observed that methionine and lysine are the most limiting EAAs in tested ingredients, indicating that additional amounts of these AAs should be supplemented when these ingredients are used in bullfrog diets.

An 8‐week feeding trial was performed to examine the potential of total replacement of fish meal with animal by‐products with or without enzymatic components in juvenile genetically improved farmed tilapia (GIFT) diets, Oreochromis niloticus, (mean initial weight, 19.71 ± 0.28 g), reared in RAS system. Five isonitrogenous and isoenergetic diets were formulated with fish meal for the diets with total replacement of the isonitrogenous amounts of enzymatic fish meal (E‐FM), chicken liver meal (CLM), enzymatic chicken liver meal (E‐CLM), dried porcine solubles (DPS) and enzymatic dried porcine solubles (E‐DPS) respectively. The results indicated that the weight gain rate (WGR) and specific growth rate (SGR) in the FM group were significantly higher than the E‐FM and E‐CLM groups (p <.05), but the specific growth rate (SGR) in the E‐CLM group lower than the E‐FM group. The feed conversion ratio (FCR) in FM and CLM was significantly lower than the E‐FM, E‐CLM and E‐DPS groups (p <.05), and no significant difference was observed among the FM, CLM and DPS groups (p >.05). The values of the protein retention efficiency (PRE) and protein efficiency ratio (PER) in FM, CLM and DPS groups were significantly higher than the E‐CLM group (p <.05). The values of feed intake ratio (FIR) in FM and CLM groups were significantly lower than the E‐FM, E‐CLM and E‐DPS groups (p <.05). There was no significant difference in the whole body contents of moisture, crude lipid and crude ash among the FM and E‐CLM groups (p >.05). The whole body contents of crude protein in the FM group were significantly higher than the E‐FM, CLM, E‐CLM DPS and E‐DPS groups (p <.05). The apparent digestibility coefficients (ADC) of dry matter, crude protein and crude lipid in the FM, E‐FM, E‐CLM and E‐DPS groups were not significantly different (p >.05). The serum glucose(GLU), total cholesterol (TCHO) and triglycerides (TG), or the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were not affected by the different treatments (p >.05). There was no significant difference in serum total protein (TP) or albumin (ALB) and between the FM group and other groups (p >.05). There was no significant difference in the serum urea nitrogen (BUN) content in the FM, CLM, E‐CLM and DPS groups (p >.05). Fish fed with the CLM and DPS diets had significantly lower hepatic GHR1, IGF1 and IGF2 gene mRNA expression levels than in fish fed the FM diet (p <.05). The present data showed that 6% of dietary fish meal can be totally replaced by the chicken liver meal and dried porcine solubles with no effect on the growth performance of GIFT strain tilapia. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology / Shuisheng Shengwu Xuebao is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A feeding trial was conducted to examine the potential of enzyme‐treated feather meal (EFM) as a fishmeal substitute in the diet of turbot. Fishmeal (650 g/kg) was incrementally replaced (0, 160, 320, 480, 640 and 800 g/kg) by EFM (0, 80, 160, 240, 320, 400 g/kg) to prepare six experimental diets (Control, EFM8, EFM16, EFM24, EFM32 and EFM40). Diet EFM24 was supplemented with lysine and methionine to form seventh diet (EFM24 + AA). The eighth diet was formulated with 240 g/kg steam‐processed feather meal to replace 480 g/kg fishmeal (SFM24). Eight diets were each fed to triplicate groups of juvenile turbot (37.47 g) in a recirculating aquaculture system for 7 weeks. The results showed that fish fed diet EFM24 grew better than those fed SFM24 (p <.05). The growth performance, body composition and serum biochemical indices of fish fed diet EFM8 were not statistically different compared to the control treatment (p >.05). However, further increase in fishmeal replacement (32%–80%) affected negatively growth, nutrients digestibility, serum biochemical indices and body composition (p <.05). Supplementation of lysine and methionine (EFM24 + AA) significantly improved growth performance and diet utilization compared to EFM24 (p <.05). Altogether results suggested that the EFM could comprise 80 g/kg in a diet for juvenile turbot by concurrent reduction of the fishmeal content by 160 g/kg without lysine and methionine supplementation. [ABSTRACT FROM AUTHOR]

A series of trials were conducted with Pacific white shrimp Litopenaeus vannamei, to evaluate the efficiency of two salmon meals as compared to anchovy meal. The basal diet contained 200 g/kg anchovy meal, which was systematically replaced (0%, 50%, 75% and 100%) with salmon meal on an isonitrogenous basis. Another two diets were formulated with a hydrolysed salmon meal to replace 50% and 100% anchovy meal. Each diet was randomly fed to four replicate groups of 25 and 30 shrimp per tank in clear (indoor) and green (outdoor) water trials, respectively. The results showed that growth performance and feed conversion ratio were not statistically different when salmon meal replaced anchovy meal in both trials. However, when hydrolysed salmon meal was used to replace 100% of the anchovy meal, growth performance of the shrimp significantly decreased. The four kinds of fish meal (anchovy, salmon by‐product meals and menhaden) were evaluated in an ingredient digestibility trial using the 70:30 replacement technique. In general, dry matter, energy, protein and individual amino acids digestibility of salmon meal were significantly higher than those of menhaden and anchovy meal. Results of this study demonstrated that salmon meals are a good protein sources which can replace anchovy meal. [ABSTRACT FROM AUTHOR]

Two 6‐week growth trials and a digestibility trial were conducted to evaluate the effects of brewer's yeast in practical shrimp feeds. In the first growth trial, graded levels (0, 60, 120, 180 and 240 g/kg) of a brewer's yeast (BY50) were used to replace fishmeal and soybean meal, referred to as Diet DBY0, DBY6, DBY12, DBY18, DBY24 and Diet LFM0, LFM6, LFM12, DBY18 and LFM24, respectively. The results showed that there were no significant differences in final biomass, survival, protein retention efficiency and feed conversion ratio; however, limited differences in final weight and weight gain were shown in the FM replacement series. There was no significant difference on the growth performance in the SBM replacement series. The second growth trial was conducted with Diet DBY0, DBY12, DBY18, DBY24, LFM0 and a low‐FM diet containing 20 g/kg of BY with 700g/kg (?) protein (Diet DBY70). Shrimp fed with Diet DBY0 exhibited significantly higher final mean weight and weight gain than those offered the Diet DBY24. Nutrient availability of BY50 and BY70 was similar to SBM and significantly higher than FM. Results indicated that 180–240 g/kg BY50 can be effectively used in shrimp diets as a replacement for FM, or up to 240 g/kg when replacing SBM. [ABSTRACT FROM AUTHOR]

A feeding trial was conducted to examine the effects of dietary supplementation of lysine and methionine on growth, nutrient utilization and carcass compositions in beluga, Huso huso. Four experimental soy protein based diets D0 (without lysine or methionine supplementation), D1 (lysine supplementation alone), D2 (methionine supplementation alone) and D3 (both lysine and methionine supplementation) were fed to triplicate groups. 240 fish with average weight of 144.6 ± 4.64 g were fed the experimental diets for 12wk. L-Lysine and DL-methionine were added to the diets containing 344 g kg-1 soybean meals at 22.02 and 12.94 g kg-1 of dry diet respectively. Significant higher weight gain, specific growth rate, protein efficiency ratio, condition factor, feed efficiency ratio, whole muscle protein and protein apparent digestibility were observed in fish fed soya protein-based diet supplemented with both lysine and methionine than that of fish of other dietary groups. There were no significant differences among fish fed diet supplemented with either methionine or lysine. Growth performances, feed utilization, carcass composition and apparent digestibility coefficients of protein, lipid and dry matter of fish fed control diet was significantly lower than those of fish fed diet supplemented both lysine and methionine and supplemented with either methionine or lysine. It can be concluded that beluga, fingerlings effectively utilize the supplemental amino acids (L-Lysine at 22.02 g kg-1 dry diet and DL-methionine at 12.94 g kg-1 dry diet) in the diets containing 344 g kg-1 soybean meals for better carcass proximate compositions, growth performance and feed efficiency and utilization.

Abstract In order to maximize the output, minimize the waste produced by the fish, and develop nutritionally adequate diets, the digestibility and nutritional value of feed ingredients were evaluated. The objective of this study was to determine apparent digestibility coefficients (ADCs) of dry matter, crude protein, gross energy, phosphorus, and amino acids in feed ingredients for mandarin fish, Siniperca chuatsi with initial average body weight of 31.27 ± 1.64 g. Nine experimental ingredients including white fish meal (WFM), meat and bone meal (MBM), maggot meal (MGM), soybean meal (SBM), fermented soybean meal (FSBM), peanut meal (PNM), corn gluten meal (CGM), cottonseed meal (CSM), and rapeseed meal (RSM) were added to reference diet containing 53% (WFM) at two levels of 15 and 30%. The ADCs of dry matter at the level of 30% were higher than those at the level of 15% in mandarin fish fed with the diet with WFM. In addition, the highest ADCs of dry matter (80.96%) was observed in fish fed with the diet with WFM at the content level of 30%, followed by lower ADC of the ingredients with FSBM, MGM, CGM, SBM, MBM, PNM, CSM, and RSM. However, the ADCs of dry matter in mandarin fish fed with the diet at the level of 15% were higher than those at the level of 30% in MBM, CGM and PNM. The results indicated that ADCs of the experimental ingredients were significantly affected by the ingredient type and the content level. The highest digestion of protein (88.90%) was also observed in WFM at the level of 30%, followed by FSBM (83.93%) and MGM (82.59%) at 30% content level, MGM and FSBM at 15% content level and CGM at 30% content level. Lipid ADCs of WFM, MBM, SBM, FSBM, CGM and CSM ranged from 83.96 to 93.25%, indicating that the lipid of these ingredients was efficiently digested by mandarin fish. The highest digestibility coefficient of energy (88.74%) was registered in WFM at 30% content level, followed by MGM at 30% content level, and the lowest digestibility coefficient of energy (49.24%) was recorded in RSM at 30% content level (P < 0.05). In addition, the apparent digestibility of phosphorus in animal feeds and plant feeds ranged from 35.75 to 63.91% and from 42.21 to 66.77%, respectively. Amino acids digestibility followed a similar pattern to those of ADCs of protein in the animal feeds. Amino acids digestibility in WFM and MGM were generally higher than those in MBM among all the plant feeds. The digestibility of amino acids in FSBM, SBM, and CGM were higher than those in RSM and CSM. In conclusion, these data provide more precise information concerning nutrient and energy utilization of Siniperca chuatsi and will allow ingredient substitutions in practical feed based on levels of available nutrients. Based on the current findings, we propose that FSBM, MGM, SBM, and CGM could be considered for incorporation into formulated diets for mandarin fish. Highlights • The ADCs of dry matter at the level of 30% were higher than WFM at the level of 15%. • The ADCs of the experiment ingredients were significantly affected by the ingredient type and the content level. • The highest digestion of protein (88.90%) was observed in WFM at the level of 30%. • The availability of amino acids in FSBM, SBM, and CGM were higher than those in RSM and CSM. • The high protein ADCs of WFM, MGM and FSBM indicates that they are potentially good protein sources for mandarin fish. [ABSTRACT FROM AUTHOR]

Abstract: Four commercial solvent‐extracted oilseed meals/cakes, viz. soybean meal (SBM), groundnut oil cake (GNC), rapeseed meal (RSM) and sunflower oil cake (SFC), were fermented with fungus Aspergillus niger, and its effect on apparent digestibility coefficient (ADC) was studied in Penaeus vannamei. Reference diet and eight experimental diets containing 700 g/kg reference diet and 300 g/kg test ingredient with 5 g/kg chromic oxide were formulated. Each diet was randomly allotted to three tanks containing ten shrimps. Shrimps were adapted to the experimental diets for a week, and faeces were collected using Falcon tube from second week onwards. The ADC of all the ingredients significantly (p < .05) increased with fermentation and the increase being higher in SBM (78.46%–91.71%) for dry matter and in SFC (71.51%–87.02%) for protein. Analysis of variance showed that the ADC of both dry matter and protein significantly (p < .05) differed in treatments (p = <.001) and ingredients (p = <.001). The average ADC of ingredients was ranked as SBM > GNC > RSM > SFC. The most digestible essential amino acid (EAA) in fermented ingredients was methionine in SBM, arginine in GNC, valine in RSM and histidine in SFC. A better improvement in amino acid digestibility was observed in fermented SFC. Results indicated that P. vannamei efficiently digests fermented ingredients compared to unfermented ones. [ABSTRACT FROM AUTHOR]

Abstract: Three six‐week growth trials and a digestibility trial were conducted to evaluate a fish meal analogue (FMA) as a replacement for fish meal (FM) in shrimp feeds. Trials 1 and 2 evaluated and confirmed the potential of FMA supplementation (0, 48.5, 97, 145.5 and 194 g/kg) as a replacement for FM up to 200 g/kg without balancing for phosphorus (P) in practical diets for juvenile Pacific white shrimp L. vannamei. At the end of trial 1, shrimp offered diets containing 48.5 g/kg FMA exhibited significantly higher weight gain (WG) than those fed with the diet containing 145.5 g/kg FMA. At the end of trial 2, dietary FMA inclusion at 48.5 and 97 g/kg significantly improved WG and protein retention (PR), while reducing FCR and protein content of shrimp body compared to the diet containing 194 g/kg FMA. To determine whether P deficiency is the cause of reduced growth, the third trial was conducted utilizing equivalent diet but balanced for P. At the end of trial 3, shrimp fed diet containing 48.5 g/kg FMA+P showed significantly higher WG and PR than those fed diet containing 145.5 g/kg FMA+P. No decreasing trend of growth was detected in the diets containing FMA compared to the FM‐based diet. Apparent digestibility coefficients of dry matter, energy, protein and amino acids of FMA were determined using chromic oxide as an inert maker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility of FMA were significantly lower than those of soybean meal and FM which were run at the same time. Results of this work indicate that FMA can replace up to 200 g/kg FM in shrimp diets with supplemental inorganic P. Given the good growth across the range of inclusion without any indication of a growth depression, the low nutrient digestibility of FMA may be due to an atypical response or the product simply does not work with the testing technique. [ABSTRACT FROM AUTHOR]

A growth trial and a digestibility trial were conducted to evaluate seaweed Ulva sp. as a substitution for fish meal (FM) in commercial-type feed formulation for Pacific white shrimp, Litopenaeus vannamei. Towards this goal, the 6-week growth trial utilized increasing levels (0, 6.35, 12.7, 19.05, and 25.4%) of the first batch of Ulva meal (UM1) to replace up to 8% FM in a plant-based feed formulation. At the end of the growth trial, shrimp offered diets containing 12.7, 19.05, and 25.4% UM1 exhibited significantly reduced weight gain. Apparent net protein retention (ANPR) was significantly decreased, while feed conversion ratio (FCR) was significantly increased when shrimps were fed with diets containing 19.05 and 25.4% UM1. Crude lipid content of whole shrimp samples were significantly decreased when UM1 was supplemented in the diets. Apparent digestibility coefficients of dry matter, energy, protein, and amino acids of two batches of Ulva meal (UM1 and UM2) were determined using chromic oxide as an inert maker and the 70:30 replacement technique. Energy and protein digestibility of UM1 and UM2 were significantly lower than FM and soybean meal (SBM) which were run at the same time. As a result of relatively low protein availability, individual amino acids digestibility of UM1 and UM2 are also significantly lower than those of FM and SBM. Results of the present study indicate that UM1 can be included in the shrimp diet up to 6.35% to replace 2% fish meal without resulting in growth depression. The low nutrients availability and high mineral contents of Ulva meal may explain a portion of the observed reduction in shrimp growth. [ABSTRACT FROM AUTHOR]

Abstract: Three growth trials and a digestibility trial were designed to evaluate the efficacy of a novel bacterial biomass (BB) in commercial‐type feed formulation for Pacific white shrimp, Litopenaeus vannamei. In trial 1, the basal diet was supplemented with 0, 60 and 120 g/kg BB to replace soybean meal (SBM). Significant improvement was observed in the survival when BB was incorporated in the diets. However, shrimp fed diets containing 120 g/kg BB exhibited significantly lower weight gain (WG) and higher feed conversion ratio (FCR). To confirm the results from trial 1 and explore the effects of BB supplementation at low levels, the basal diet was incorporated with 0, 10, 20, 40, 60 and 120 g/kg BB to replace SBM in trial 2. Significant reductions in WG, FCR, lipid content of whole body, protein retention efficiency and most amino acids retention efficiency were detected in shrimp fed with diet containing 120 g/kg BB. Trial 3 was designed to elucidate whether the digestible protein is the cause of reduced growth. No improvements in terms of growth performance and FCR were detected in the treatments balanced for digestible protein. Apparent digestibility coefficients of energy, protein and amino acid (AA) for BB were determined using chromic oxide as an inert marker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility coefficients of BB were significantly lower than those of fish meal (FM) and SBM that were given at the same time. Results of this study indicated that BB can be utilized up to 40 g/kg in shrimp feed without causing a decrease in growth. However, supplementations (≥60 g/kg) of BB can result in negative effects on growth response, FCR and protein as well as amino acids retention efficiency. At the lower levels of inclusion, shrimp performance was improved when BB was supplemented on a digestibility basis; however, at the higher level of inclusion, there was no improvement, indicating there may be other nutrients limiting. Based on enhanced survival in the treatment with BB supplementation in trial 1, further research regarding the immune effects of BB in practical shrimp feed will be necessary. [ABSTRACT FROM AUTHOR]

Abstract: The effect of replacing fish meal (FM) with meat and bone meal (MBM) in diets for juvenile Pseudobagrus ussuriensis was evaluated in a 90‐day feeding trial. Six isonitrogenous (crude protein, 430 g/kg) and isolipidic (crude lipid, 74 g/kg) diets were formulated to contain MBM to replace FM at 0 (S0), 200 (S20), 400 (S40), 600 (S60), 800 (S80) and 1000 g/kg (S100), respectively. The results showed that there was no significant difference in weight gain (WG) among fish fed S0, S20 and S40 diets. However, a significant reduction in WG occurred when 600, 800 and 1000 g/kg FM protein was replaced by MBM (p < .05). Similar trends were observed in specific growth rate and protein efficiency ratio. Apparent digestibility coefficients (ADC) of protein and dry matter of the diets S80 and S100 were significantly lower than those of the other diets. The ADC of phosphorus significantly reduced with the increase in dietary MBM level. Nitrogen and phosphorus excretion increased with the increasing dietary MBM level. Protease, lipase and amylase activities of the diets S80 and S100 were significantly lower than those of the other diets (p < .05). The results of this study showed that the optimum dietary MBM replacement level was 34.3% according to broken‐line model based on WG against dietary MBM replacement level. [ABSTRACT FROM AUTHOR]

Abstract: Seven isonitrogenous and isolipidic diets containing fish meal (FM) protein replaced by corn gluten meal (CGM) protein at 0% (the control, C0), 10% (C10), 20% (C20), 30% (C30), 40% (C40), 50% (C50) and 60% (C60) were fed to juvenile Pseudobagrus ussuriensis for 8‐weeks to evaluate the effects of FM protein replaced by CGM protein on growth, feed utilization, nitrogen (N) and phosphorus (P) excretion and IGF‐I gene expression of juvenile P. ussuriensis. The results showed that the replacement level up to 40% did not affect the weight gain, specific growth rate (SGR), feed intake and protein efficiency ratio, whereas these parameters were depressed by further replacement level. Apparent digestibility coefficients (ADC) of dry matter, crude protein significantly decreased, but ADC of phosphorus significantly increased with increasing dietary CGM levels (p < .05). Fish fed diets with FM protein replaced by CGM protein led to an increase in nitrogen excretion, but led to a reduction in phosphorus excretion. No significant differences were observed in alpha‐amylase and lipase activities of intestine (p > .05). The lowest pepsin activity was found in C60 group. Fish fed diet C40, C50 and C60 had significantly lower serum lysozyme activity compared with fish fed diet C0 (p < .05). The lowest plasma alkaline phosphatase activity and the highest plasma alanine aminotransferase and aspartate aminotransferase activities were observed in C60 group. Fish fed diet C60 had significantly lower hepatic IGF‐I gene expression compared with fish fed diet C10 (p < .05). Broken‐line model analysis based on SGR against the CGM substitution level indicated that the appropriate replacement level was 37.7%. [ABSTRACT FROM AUTHOR]

Abstract: This experiment investigated intestinal enteropathy and digestive function of rainbow trout challenged with soybean meal‐based diet (SBM) at optimal or suboptimal environments created by normal or reduced water flow, respectively. Oxygen level remained above 7 mg L‐1 for optimal environment and between 4 and 5 mg L‐1 for suboptimal environment. Triplicate groups of fish (mean body weight 74 g) were fed fishmeal‐based diet (FM) or SBM at optimal environment in period 1 (28 days). In period 2 (42 days), fish were subjected to a change from FM to SBM or remained on the same diet as used in period 1. The fish were also exposed to change from optimal to suboptimal environment or remained under optimal conditions. The fish subjected to change from FM to SBM, regardless of their environment, showed similar degree of enteropathy from day 14. Lipid and starch digestibility was lower in SBM‐fed fish at suboptimal environment compared to fish fed the same diet at optimal environment. Crude protein digestibility, however, was highest in SBM‐fed fish at suboptimal environment throughout period 2. In conclusion, in SBM‐fed rainbow trout, exposure to suboptimal environment did not change the degree of enteropathy; however, lipid and starch digestibility were further reduced. [ABSTRACT FROM AUTHOR]

Growth and digestibility trials were conducted to evaluate the use of flash dried yeast ( FDY) as a supplement in practical shrimp feeds. The six-week growth trial evaluated the effects of FDY supplementation (0, 10, 20, 40 and 60 g kg-1) in the plant-based practical diet on the performances and proximate compositions of juvenile Pacific white shrimp, Litopenaeus vannamei. Final biomass, final mean weight, per cent weight gain ( WG), feed conversion ( FCR) and protein retention efficiency ( PRE) of Pacific white shrimp were not significantly influenced when FDY was added up to 40 g kg-1 of the diet. However, 60 g kg-1 FDY supplementation significantly reduced growth, feed utilization and protein retention. Supplementation of FDY in the practical diets of Pacific white shrimp did not affect protein, moisture, lipid, crude fibre, and ash content of whole shrimp body. Apparent digestibility coefficients of energy, protein, and amino acid ( AA) for FDY were determined using chromic oxide as an inert marker and the 70:30 replacement technique. The energy and protein digestibility of FDY were 38.20% and 53.47%, respectively, which were significantly lower than fishmeal ( FM) and soybean meal ( SBM) that were run at the same time. Most amino acid digestibility of FDY was lowest among the three ingredients tested. Results of this work indicated that energy, protein and amino acid digestibility of FDY are lower compared to SBM and FM, and high levels supplementation (≥60 g kg-1) of FDY can cause negative effects to the growth response of Pacific white shrimp. Based on these results, further research regarding the effects of the low level inclusion of FDY in practical diets on immune responses of Pacific white shrimp is warranted. [ABSTRACT FROM AUTHOR]

The ability of frogs to digest dietary nutrients changes with growth, with the animals becoming more or less demanding. The objective of this study was to determine the apparent digestibility coefficients of protein, energy and ether extract of 14 ingredients used in bullfrog diets (spray-dried blood meal, hydrolysed feather meal, poultry by-product meal, red blood cell concentrate, tilapia by-product meal, sardine fishmeal, salmon fishmeal, meat and bone meal, corn gluten meal, soybean meal, corn, wheat bran, soy protein concentrate and soybean oil). A total of 2,325 bullfrogs ( Lithobates catesbeianus) in different phases of development were used: early phase (mean weight of 30-50 g), growth phase (80-110 g) and finishing phase (150-200 g). Faeces were collected using the method of dissection. Marked differences in digestibility of the ingredients were observed between the different phases of frog development. Among the ingredients studied, salmon fishmeal and corn gluten meal showed good utilization of the protein (78.9% and 86.7%, respectively) and energy fraction (89.4% and 83.3%, respectively). The salmon fishmeal, poultry by-product meal, sardine fishmeal, soy protein concentrate, wheat bran and soybean oil exhibited good ether extract utilization (81.2%-92.8%), recommending their use in bullfrog diets. [ABSTRACT FROM AUTHOR]

A ten-week feeding trial was conducted to evaluate the effect of replacing fishmeal with two differently processed cottonseed meals (CSM), namely XC and SC, separately in turbot (5.28 ± 0.02 g). Nine isonitrogenous and isoenergetic diets were formulated without fishmeal replacement (FM), 150 g/kg (XC15, SC15), 250 g/kg (XC25, SC25), 350 g/kg (XC35, SC35) and 450 g/kg (XC45, SC45) of fishmeal replaced by CSM. Fishmeal was successfully replaced by XC in turbot diets without growth reduction at 350 g/kg, but not by SC even at 150 g/kg. The apparent digestibility coefficients of SC-included diets were significantly lower than XC-included diets at same replacement level. The activities of aspartate aminotransferase and superoxide dismutase were significantly affected in XC45 and SC45 group. The XC45 and SC-included diets caused shortened distal intestine villi height and structural damage of liver compared with FM diet. This study indicated that different processing methods could affect the nutritional value of CSM and effect as a protein source for turbot. CSM with high quality could be an important alternative dietary protein source for juvenile turbot. [ABSTRACT FROM AUTHOR]

A growth trial and a digestibility trial were conducted to evaluate the efficacy of phytase supplemented to practical shrimp feeds. The 5 weeks growth trial evaluated the effects of phytase supplementation in replete phosphorus (P) diets on the performances and compositions of juvenile Pacific white shrimp , Litopenaeus vannamei. No significant differences were observed in final biomass, final mean weight, weight gain, feed conversion ratio ( FCR), protein retention and survival across all the treatments. Shrimp reared on the P deficient diet had significantly higher P retention and lower whole body P levels as compared to shrimp fed the other diets. Copper content in the whole shrimp body was significantly increased in the treatment supplemented with 1,000 IU kg−1 feed phytase. The digestibility trial was conducted to study the combined effects of phytase supplementation levels and diet type (plant-based versus fishmeal-based) on apparent digestibility coefficients of Pacific white shrimp, Litopenaeus vannamei. There were no effects of diet type so the data was combined. Phytase incorporation at both 500 and 2,000 IU kg−1 significantly improved protein digestibility, whereas P digestibility was enhanced when 2,000 IU kg−1 phytase was supplemented to the diet. Apparent digestibility coefficients of alanine, arginine, aspartic acid, cysteine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tyrosine and valine were significantly increased when fed diets contained 500 and 2,000 IU kg−1 phytase supplementation. Results of this work demonstrate that under the conditions of the study growth was not enhanced by phytase supplementation in P replete diets. However, nutrient retention for Cu and digestibility of P, protein and a number of amino acids were enhanced. [ABSTRACT FROM AUTHOR]

A study was conducted to determine apparent digestibility coefficients ( ADCs) of dry matter ( DM), crude protein ( CP), lipid, gross energy, phosphorus and amino acids ( AAs) from Peruvian fish meal ( PFM), native fish meal ( NFM), meat bone meal ( MBM), dried daphnia meal ( DDM), soybean meal ( SBM), full-fat soybean ( FSBM), cottonseed meals ( CSM), rapeseed meal ( RSM) and corn gluten meal ( CGM) for Pseudobagrus ussuriensis (7.8 ± 0.06 g). Test diets were formulated to contain a 70:30 mixture of reference diet to test ingredient with chromic oxide (5 g kg-1) serving as the inert marker. ADCs of DM ranged from 49.94% ( CGM) to 87.11% ( PFM), the highest ADCs of DM were observed in PFM and the lowest was found in CGM. ADCs of CP in the test ingredients ranged from 74.92% ( CGM) to 93.41% ( SBM). ADCs of crude lipid ranged from 51.80% ( CGM) to 94.07% ( PFM) for fish. ADCs of energy ranged from 56.42% ( CGM) to 90.09% ( PFM). ADCs of phosphorus ranged from 21.81% ( CSM) to 65.70% ( PFM). AA availability for the test ingredients followed a similar pattern to ADCs of CP, in which values for PFM, NFM and MBM were generally higher ( p < .05) than those of other protein ingredients. Among all plant meals, the AA availability values in SBM were higher ( p < .05) than those in CGM, CSM and RSM. The availability of most AAs in CGM was the lowest ( p < .05) among all tested ingredients. In conclusion, PFM and NFM are good sources of available protein and AAs. When fishmeal supply is limited, MBM and DDM are substitutes for fishmeal reduction in P. ussuriensis diets; at the same time, SBM and FSBM are also very acceptable protein feedstuffs. However, CSM, RSM and CGM could not be used at high levels in P. ussuriensis diets because of their inferior digestibilities. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to evaluate the effects of replacing fish meal with soybean meal ( SBM) on growth, feed utilization, and nitrogen (N) and phosphorus (P) excretion of juvenile Pseudobagrus ussuriensis (initial average weight 0.50 ± 0.00 g). Seven isonitrogenous and isolipidic diets were formulated to contain SBM to replace fish meal protein at 0% (S0), 10% (S10), 20% (S20), 30% (S30), 40% (S40), 50% (S50) and 60% (S60) respectively. To investigate the effects of supplementation with crystalline amino acid to balance diet S60, one diet was formulated to add 0.30% methionine ( SM60). The results showed that there was no significant difference in weight gain among fish fed S0, S10, S20, S30 and S40 diets, however, a significant reduction in this variable occurred when 50% and 60% of fish meal protein was replaced by SBM ( P < 0.05). Apparent digestibility coefficients of dry matter, crude protein and phosphorus of diets were affected by dietary SBM levels. N and P excretion indicate that fish meal replacement by SBM led to an increase in N excretion, but led to a reduction in P excretion. No differences were detected in growth, feed utilization and N and P excretion between fish feed diets S60 and SM60. The results of this study show that 40% of fish meal protein could be replaced by SBM in diets of juvenile P. ussuriensis without having a significant negative effect on growth or feed efficiency, but that higher dietary SBM levels reduce fish performance. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the effects of using soybean meal supplemented with or without methionine (M) and graded levels of phytase (P) to replace high-level (60%) fish meal in the diets for juvenile Chinese sucker. Seven experimental diets (about 430 g kg−1 crude protein on dry matter basis) were formulated from practical ingredients. The control diet ( FM) was formulated to contain 400 g kg−1 white fish meal ( FM), whereas in the other six diets (diets 2-7), soybean meal ( SBM) was used to replace 60% fish meal with or without methionine (3 g kg −1) and 0,500, 1000, 1500 and 2000 U kg−1 phytase (designated as SBM, SM, SMP500, SMP1000, SMP1500 and SMP2000, respectively). Results from the feeding trial indicated that SBM without any methionine or phytase supplement replacing about 60% FM significantly affected the growth of fish ( P < 0.05). Weight gain of fish fed diet SM was significantly higher than the fish fed diet SBM, but still much lower than fish fed the control diet ( P < 0.05). SBM with methionine and phytase supplement significantly improved the growth of fish and apparent digestibility coefficients of phosphorus compared with the groups which fed diet SBM and diet SM ( P < 0.05). Weight gain of fish fed SMP1000, SMP1500 and SMP2000 had no significant difference than fish fed control diet. Furthermore, fish fed SMP1500 showed optimum weight gain and ADC of phosphorus between these three groups. This suggested that soybean meal with 3 g kg−1 methionine and 1500 U kg−1 phytase supplement could successfully replace 60% fish meal in the diet for juvenile Chinese sucker without affecting growth and enhanced the apparent digestibility coefficient of phosphorus. [ABSTRACT FROM AUTHOR]

Twelve ingredients obtained from new, non-genetically modified soybean cultivars as well as commercially available sources of soybean meal (SBM) were evaluated in practical feed formulations for the Pacific white shrimp, Litopenaeus vannamei , using both digestibility and growth trials. Apparent digestibility coefficients for energy (ADE) and protein (ADP) were determined using chromic oxide as inert marker and the 70:30 replacement technique. Digestibility coefficients for ADE and ADP ranged from 76.6 to 91.3% and 93.6 to 99.8%, respectively. In general, two distinct groups of high and moderate digestibility values were observed. A separate 8-week growth trial was conducted to evaluate selected SBMs using six replicate tanks per dietary treatment (10 shrimp per tank, initial weight 0.52 ± 0.04 g). An SBM-based reference diet was formulated using commercial SBM (45.3), which was then completely replaced on iso-nitrogenous basis with other experimental SBMs. Significant differences ( P ≤ 0.05) were observed in growth performance but not survival. In general, trends in digestibility values were similar to those of the growth trial. Ingredients (I)-16, I-17, I-18, and I-19 demonstrate relatively higher values in terms of digestibility as well as supporting good growth. Results indicate that genetic selection of soybean for nutritional characteristics of the meal has the potential to increase the nutritional values of SBM for shrimp feeds. Statement of relevance This study provides useful and important information of 12 varieties soybean meal in shrimp to support the aquaculture feed industry development. [ABSTRACT FROM AUTHOR]

This study was designed to evaluate the efficacy of eight sources (designated A-H) of soybean meal ( SBM) which included six new non-genetically modified soya varieties in practical feed formulation for Pacific white shrimp, Litopenaeus vannamei, using both growth and digestibility trials. A soybean meal-based reference diet was formulated using conventional soybean meal (527 g kg−1 diet), which was then replaced on an isonitrogenous basis with various other experimental soybean meals. In a 6-week growth trial, shrimp in four replicate tanks per dietary treatment (10 shrimp per tank, initial weight 0.52 ± 0.04 g) were cultured in a recirculating system. There were no significant differences with respects to per cent weight gain and survival across all dietary treatments; however, final weights and feed conversion ratio ( FCR) were lower in shrimp offered diet 3. Apparent digestibility coefficients for the eight (A-H) different soybean meals were determined in L. vannamei for dry matter ( ADMD), gross energy ( ADE) and crude protein ( ADP) using 10 g kg−1 chromic oxide as inert marker with 70 : 30 replacement techniques. Coefficients ranged from 71.3% to 88.3%, from 76.6% to 91.3% and from 93.6% to 99.8%, for ADMD, ADE and ADP, respectively. Improved digestibility values were observed in soybean C which was characterized by crude protein (471 g kg−1), crude fat (97 g kg−1), low cooking temperature (180 °C), higher nitrogen solubility index (689 g kg−1) and protein dispersibility index (619 g kg−1). This indicates that new lines of soybean meal can be used to improve digestibility coefficients in shrimp feeds. [ABSTRACT FROM AUTHOR]

Apparent digestibility coefficients of dry matter, crude protein, lipid and energy, and amino acids availability in white fish meal, brown fish meal, meat meal, fermented soybean meal, soybean meal and rapeseed meal were determined for loach ( Misgurnus anguillicaudatus) (12.05 ± 0.21 g), using a reference diet with 5 g kg−1 chromic oxide and test diets that contained 700 g kg−1 reference diet, by weight, and 300 g kg−1 of the test feed ingredients. The juvenile loach was held in 300-l tanks at a density of 30 fish per tank. White fish meal, brown fish meal, meat meal and fermented soybean meal had highest apparent digestibility coefficients ( ADCs) of dry matter, crude protein and gross energy among ingredients tested, ranged from 50.4% to 60.9% for dry matter, from 64.6% to 88.4% for crude protein and from 57.9% to 79.0% for gross energy. The apparent digestibility coefficients of dry matter ranged from 61.0% to 66.9% for animal products and 50.4% to 60.7% for plant products. For crude protein, apparent digestibility coefficients of protein exceeding 80% were observed for white fish meal, brown fish meal, meat meal and fermented soybean meal, and the apparent digestibility coefficients of protein in rapeseed meal were the lowest among all the treatments. Lipids from both animal and plant feedstuffs were poorly digested by loach, ranging from 64.0% to 77.6%. The apparent digestibility coefficients of energy were similar to those of dry matter and protein, and the highest and lowest ADCs of energy were found in WFM and RM, respectively. The loach used dietary phosphorus from the animal feedstuffs more efficiently than from plant feedstuffs (soybean meal and rapeseed meal), with ADC-values ranging from 42.3% to 53.1% and from 25.1% to 32.7%, respectively. For the animal products, the availabilities of amino acids in white fish meal and brown fish meal were higher than that in meat meal, expect for Met, Asp, Pro, Gly, and Cys. Among all the plant products, the availabilities of amino acids in fermented soybean meal were higher than in soybean meal and rapeseed meal, and thus had a greater potential to be used as a dietary replacement of fish meal in loach diets. [ABSTRACT FROM AUTHOR]

A 63-day feeding trial was conducted to evaluate the effect of Clostridium autoethanogenum protein (CAP) on the growth, digestibility, postprandial free amino acid concentrations in serum, and gene expression related to protein metabolism in obscure pufferfish (Takifugu obscurus). The basal diet with 420 g/kg of fishmeal was used as the control diet (CAP0), and then 20 % (CAP20), 40 % (CAP40) and 80 % (CAP80) dietary fishmeal were replaced by CAP. Compared with diet CAP0, the growth and feed utilization was not affected in fish fed diet CAP20, but was significantly reduced in fish fed diets CAP40 and CAP80 (P < 0.05). The apparent digestibility coefficients (ADCs) of dry matter and protein in the CAP80 group were significantly lower (P < 0.05) than those of the other three groups, and the ADC of lipid was significantly decreased (P < 0.05) in the CAP40 and CAP80 groups. Fish fed diets CAP40 and CAP80 had lower taurine content in muscle compared to those fed diets CAP0 and CAP20 (P < 0.05). Higher free essential amino acid concentrations in serum were observed in fish fed diet CAP80 compared to the other diets at 2 h after refeeding (P < 0.05). Fish fed diets CAP40 and CAP80 showed lower hardness and gumminess in muscle than those fed the other diets (P < 0.05). The expression of peptide transporter1 (PepT1) in intestine and target of rapamycin (TOR) in muscle were significantly up-regulated in the CAP40 groups compared to the control (CAP0) (P < 0.05). However, relative expressions of 4F2 heavy chain (4F2hC), L-type amino acid transporter 2 (y+LAT2) and T-type amino acid transporter1(TAT1) in intestine were not significantly affected by graded levels of CAP (P > 0.05). The inclusion of CAP did not significantly affect the expression of ribosomal protein S6 kinase 1 (S6K1), eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) and 4E-BP2 (P > 0.05) in muscle and liver. In summary, in a basal diet containing 420 g/kg fishmeal, 20 % fishmeal in diets could be successfully substituted by CAP, while high-level CAP decreased the growth, feed utilization and digestibility in juvenile obscure pufferfish. The main reasons for the inhibition of growth performance were probably that excessive CAP caused dietary taurine deficiency and the imbalance of amino acid absorption. • CAP can partially substitute fishmeal without negative effects on growth and feed utilization in obscure pufferfish. • Fishmeal replacement by CAP significantly up-regulated the expressions of TOR and PepT1 at transcriptional level. • Excessive CAP may cause dietary taurine deficiency and the imbalance of amino acid absorption. [ABSTRACT FROM AUTHOR]

Abstract: Seven isoproteic (370g/kg) and isolipidic (90g/kg) diets containing seven various carbohydrate sources (wheat starch, sucrose, potato starch, maize starch, dextrin, maltose and glucose) at the same quantities (200g/kg) were fed to triplicate groups of Penaeus monodon (1.92±0.01g mean initial wet weight) for 74 days. All shrimp fed glucose and maltose-containing diets died within the first two weeks. After a 74-day feeding trial, the highest (P<0.05) weight gain (WG, %) and biomass gain (BG, g) were obtained with shrimp fed wheat starch or sucrose-containing diet; whereas, the lowest (P<0.05) WG and BG were observed for shrimp fed a dextrin-containing diet. The survival of shrimp fed wheat starch, sucrose, potato starch and maize starch-containing diets was higher (P<0.05) than shrimp fed a dextrin-containing diet, but no difference (P>0.05) was found among shrimp fed wheat starch, sucrose, potato starch and maize starch-containing diets. The highest and lowest protein contents of whole body and muscle were obtained from shrimp fed wheat starch and dextrin-containing diets, respectively. Diets containing dextrin or maize starch had inferior values of apparent digestibility coefficients (ADCs) of protein, dry matter and energy (P<0.05) compared to the three other diets, while dextrin or potato starch-containing diet gave the worst response in terms of ADC of carbohydrate (P<0.05). The highest 6-phosphogluconate dehydrogenase (6PGDH) and hexokinase (HK) activities were observed in shrimp fed a wheat starch-containing diet. Hepatopancreas amylase activity of shrimp fed a wheat starch and sucrose-containing diet was higher (P<0.05) than that of shrimp fed other diets. In conclusion, shrimp fed the wheat starch or sucrose-containing diet had the best growth performance. The activities of hepatopancreas enzymes involved in carbohydrate uptake (HK) and NADPH generation (6PGDH) increased preferentially as dietary carbohydrates became more suitable to support the shrimp''s rapid growth. All these data suggest that wheat starch and sucrose are the more suitable source of dietary carbohydrate and have the same nutritional value in P. monodon feed. [Copyright &y& Elsevier]

The effect of replacing fish meal with soybean meal (SBM) pretreated with phytase on feeds of juvenile rainbow trout was evaluated in a 90-day feeding trial. The rainbow trout (initial body weight, 4.01 ± 0.02 g) were fed five isonitrogenous (crude protein, 44.97%) and isolipidic (crude lipid, 13.42%) feeds. Diets were formulated to contain phytase-pretreated SBM replacing 0, 20, 40, 60 and 80% of fish meal protein, respectively. The results showed that there was no significant difference in weight gain (WG) among fish fed S0, S20, S40 and S60 diets; however, a significant reduction of this variable occurred when 80% of fish meal protein was replaced by phytase-treated SBM ( P < 0.05). Similarly, specific growth rate and protein efficiency ratio had a similar trend with WG. Apparent digestibility coefficient (ADC) of protein and lipid in the S80 diet was significantly lower than that of the other diets, and the ADC of phosphorus significantly increased with the increase of dietary phytase-treated SBM level. No significant differences among treatments were detected for moisture, protein, lipid and ash content in whole body and muscle samples. Nitrogen and phosphorus excretion indicated that fish meal replacement by phytase-treated SBM led to an increase in nitrogen excretion, but led to a reduction in total phosphorus excretion. The results of the present study show that 60% of fish meal could be replaced by phytase-treated SBM in diets of juvenile rainbow trout without compromising weight gain or feed efficiency. A quadratic equation according to regression analysis of weight gain against dietary phytase-treated SBM level indicated that the optimal level of dietary phytase-treated SBM replacement for maximum growth was 26.90%. [ABSTRACT FROM AUTHOR]

Abstract: Building a reliable database on apparent digestibility of protein sources is critical for accurate feed formulation and reduction of aquaculture wastes. Apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein, crude lipid, gross energy, phosphorus and amino acids for white fish meal (WFM), brown fish meal (native) (BFM), fermented soybean meal (FSBM), extruded soybean meal (ESBM), soybean meal (SBM), cottonseed meal (CM) and rapeseed meal (RM) were determined for Chinese sucker (Myxocyprinus asiaticus) (18.05±0.27g) using a reference diet (RF) and test diets (70% RF diet plus 30% of tested feedstuff) containing 0.5% chromic oxide as an inert marker. WFM had the highest apparent digestibility coefficient for DM (74.5%). For plant products, the ADCs of DM ranged from 54.3 to 71.6%. Protein digestion by Chinese sucker of WFM, BFM, FSBM and ESBM was significantly higher than CM and RM, ranging from 72.8 to 92.3% for plant products, and 90.3 to 91.2% for animal feedstuffs. Lipids from both animal and plant feedstuffs were highly digested by Chinese sucker, ranging from 89.8 to 94.9%. The highest digestibility coefficient of energy was registered for WFM, followed by BFM; and the lowest digestibility coefficient of energy was recorded for CM (P <0.05). The Chinese sucker did utilize dietary phosphorus from the animal feedstuffs (FSBM and ESBM) more efficiently than from plant feedstuffs (SBM, CM and RM), with values ranging from 58.8 to 61.4% and 25.8–56.0%, respectively. Amino acid availability reflected protein digestibility, except for ESBM, for which the availability of some amino acids was lower, possibly because of protein denaturation during processing. Based on the current findings, FSBM and ESBM could be considered as good potential substitutes for FM in diets for Chinese sucker. [Copyright &y& Elsevier]

Apparent digestibility coefficients of dry matter (DM), crude protein, crude lipid, gross energy, phosphorus and amino acids in Peruvian fish meal (FM), fermented soybean meal, extruded soybean meal, soybean meal, peanut meal, wheat gluten meal, corn gluten meal, shrimp byproduct meal, meat and bone meal (MBM), poultry meat meal and plasma protein meal (PPM) were determined for white shrimp ( Litopenaeus vannamei). A reference diet (RF) and test diets (consisting of 70% RF diet and 30% of the feedstuff) were used with 0.5% chromic oxide as an external indicator. A total of 1440 shrimp (initial mean body weight 1.05 ± 0.01 g) were randomly stocked into thirty-six 500-L fibreglass tanks with 40 shrimp per tank and three tanks per diet. Faeces were collected from triplicate groups of shrimp by a faecal collection vessel attached to the shrimp-rearing tank. The shrimp were fed to apparent satiation four times a day and the feeding experiment lasted for 6 weeks. Statistics indicate that apparent DM digestibilities for white shrimp ( L. vannamei) were the highest for FM, ranged 52.83–71.23% for other animal products and 69.98–77.10% for plant products. The protein and lipid from plant and animal sources were well digested by white shrimp. Apparent protein and lipid digestibility were in the range 87.89–93.18% and 91.57–95.28%, respectively, in plant products, and 75.00–92.34% and 83.72–92.79%, respectively, for animal products. The white shrimp demonstrated a high capacity to utilize phosphorus in the ingredients. The apparent phosphorus digestibility ranges of animal feedstuffs and plant feedstuffs were 58.90–71.61% and 75.77–82.30% respectively. Amino acid availability reflected protein digestibility, except that in MBM, for which the availability of some amino acid was lower, possibly due to protein damage during processing. Digestibility information could promote the use of ingredient substitution in least-cost formulated diets for white shrimp. [ABSTRACT FROM AUTHOR]

Apparent digestibility coefficients (ADCs) of dry matter (ADCd), crude protein (ADCp), energy (ADCe) and amino acids in selected feedstuffs were determined for juvenile Siberian sturgeon (8.38 ± 0.20 g). The tested feedstuffs were fishmeal (FM), meat and bone meal (MBM), poultry by-product meal, hydrolysed feather meal, fermented feather meal solvent-extracted cottonseed meal and soybean meal. ADCs were determined using a reference diet and test diets at 7 : 3 ratios with 5 g kg−1 chromic oxide (Cr2O3) as an inert marker. Fish were reared in a recirculating system and fed to apparent satiation five times daily. Cr2O3 in diets and faeces samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and acid-digestion colorimetry (AC) methods, respectively. The results showed that ICP-AES method was more accurate for Cr2O3 determination than AC method, and the results determined by ICP-AES method were used in this study. ADCd and ADCp of seven tested ingredients were lowest for MBM (59.1 and 84.5%) and highest for FM (79.9 and 94.5%); ADCe of tested ingredients were from 71.8% for SECM to 93.2% for FM. ADCs of amino acid in test ingredients followed similar trend to the ADCp. The ADCs of individual amino acids varied from 61.6% (histidine in MBM) to 98.8% (valine in FM). [ABSTRACT FROM AUTHOR]