Effects of Replacement of Fish Meal by Soybean Meal and Supplementation of Methionine in Fish Meal/Soybean Meal-based Diets on Growth Performance of the Southern Catfish Silurus meridionalis

Two experiments (Experiment I and 11) were conducted to evaluate the effects of dietary soybean meal (SBM) with or without supplementation of methionine on the growth performance of the southern catfish Silurus meridionalis. Fish were fed isonitrogenous (48% crude protein) and isoenergetic (20 KJ/g gross energy) diets for 8 wk in a recirculating rearing system. In Experiment I, six diets containing 0.0,11.6, 23.1, 34.7, 46.3, and 57.9% solvent‐extracted SBM as replacement of 0% (control), 13%, 26%, 39%, 52% and 65% fish meal (FM) protein were formulated to examine the effects of dietary SBM on growth performance. Each of the six diets was randomly fed to triplicate tanks, and each tank was stocked with 10 fish (average initial weight 23.78 ± 0.09 g). Fish fed the diets with 13%, 26%, and 39% protein from SBM had significantly higher or similar specific growth rate (SGR) compared with the control group. However, SGR in fish fed the diets with 52% and 65% protein from SBM was significantly lower than other groups (P < 0.05). These results showed that 39% of FM protein could be replaced by SBM protein in diets of the southern catfish without significantly reducing growth. In Experiment II, seven diets were formulated to examine the effects of supplemental methionine on the growth performance of this fish (initial weight of 19.73 ± 0.36 g) fed diets at the two SBM substitution level (SL) for replacing 39% or 52% FM protein. The control diet was the same as that (0% SL) in Experiment I. Three methionine levels (0.00%, 0.12%, or 0.26% at 39% SL, 0.00%, 0.21%, or 0.33% at 52% SL) were separately supplemented to represent two endogenous controls (no methionine supplementation), and to produce diets with the same methionine content as that found in either the body carcass of this fish or the control diet (0% SBM protein), respectively. The results showed that there were no significant differences in feeding rate, digestibility and SGR between fish fed the diets with and without supplementation of methionine at 39% SL. However, supplementation of methionine at 52% SL results in significantly higher SGR and feed efficiency (FE) than that of fish fed the diet without supplementation (P < 0.05). It is suggested that the endogenous methionine content in the diet at 39% SL could meet the requirement for the growth, but is insufficient at 52% SL. The results of the present study indicate that methionine is one of the limiting factors in SBM‐based diets to growth of the southern catfish, and supplementation of methionine into diets containing a high content of SBM could improve the growth performance of this fish.     

Nutritive Evaluation of Lysine- and Methionine-Supplemented Raw Vs Heat-Processed Soybean to Replace Fishmeal as a Dietary Protein Source for Grey Mullet,Mugil cephalus,and Milkfish,Chanos chanos

Two experiments were conducted to study the effect of methionine- and lysine-supplemented raw and hydrothermically processed full-fat soybean as a dietary protein source on growth performance, digestibility, and digestive enzyme activity in grey mullet, Mugil cephalus (mean BW 0.55 g), and milkfish, Chanos chanos (mean BW 3.83 g). Eight isocaloric (gross energy about 18.27 kj g^?1) and isonitrogenous (crude protein about 40%) diets (1–4 = raw soybean based; 5–8 = processed full-fat soybean based) were formulated. A fishmeal-based diet was used as the reference/control diet. Growth performance, nutrient retention, feed conversion ratio (FCR), and protein digestibility in fishes correlated well with the trypsin inhibitor activity levels of the diets. Carcass phosphorous levels were significantly (P < 0.05) higher in fish fed the fishmeal control diet. Irrespective of the fish species, significantly (P < 0.05) lower levels of total ammonia excretion and reactive phosphate production (mg kg^?1 BW d^?1) were recorded where the fish were fed processed full-fat soybean diets compared with the fish fed fishmeal or raw soybean diets. Among these diets, the best growth performance and the lowest levels of metabolic waste were obtained in fishes fed the methionine- and lysine-supplemented processed soybean-based diets containing no fishmeal.     

Studies on the Maturation and Spawning of Milkfish Chanos chanos Forsskal in a Photoperiod-Controlled Room

Progress in propagation of milkfish has been impeded by the shortage of mature broodstock. This study was a first step toward revealing the environmental cues for the maturation of milkfish. Experiments were carried out during 1978-1985 in an indoor tank (5.2 × 4.8 × 13 m) under photoperiod control and in an outdoor tank (63 × 5.4 × 13 m). In two controlled, long-photoperiod regime experiments, 86 and 83% of the fish matured, the highest percentages yet reported. In these experiments, milkfish matured one month earlier than the normal spawning season, two months after the fish were exposed to the long daylight regime. Only 21% of the fish under a natural photoperiod regime in the outdoor tank matured. Results of the current study suggest that a change and increase in photoperiod are necessary for the onset of maturation.     

Texture and Flavor of Hybrid Striped Bass Fed Soybean Meal Diets

Baked fillets from hybrid striped bass (Morone saxatilis x M. chrysops) fed varying amounts of soybean meal and raised in ponds or tanks were evaluated for flavor and texture. Using a triangle test, panelists were able to discriminate between fillets from fish fed soybean meal in the diet as compared to fillets from fish fed only fish meal with respect to flavor and texture in most comparisons. In paired comparison tests, panelists described fillets from fish fed soybean meal as less dry or tough compared to fish-meal-fed fish. In addition, panelists were able to discriminate between fillets from fish raised in ponds compared to those raised in tanks, regardless of diet. However, in a limited test, panelists found no differences in the acceptability of fillets with respect to flavor and texture. Data showed that soybean meal in the diet of hybrid striped bass had a significant discernible effect on flavor and texture of fillets, but this effect was not important in acceptability of the fillets.     

Use of duckweed (Lemna sp.) grown in sugarmill effluent for milkfish, Chanos chanos Forskal, production

Abstract. Oxidation treatment of sugarmill waste using duckweed ( Lemna sp.) as part of the system, to reduce effluent nutrient concentrations and biological oxygen demand (BOD), was evaluated during a 6 month milling season in Negros Oriental, Philippines. Mean ammonia concentration in effluent water was reduced from 0·87 to 0·31 mg/l NH₃-N and orthophosphate from 0·93 to 0·51 mg/l P₂O₅, while mean BOD was reduced from 611 to 143mg/t BOD₅, after treatment. Seasonal mass fish kills in the adjoining bay no longer occurred during the 3 years following introduction of this treatment. The mean duckweed production (dry weight) was 8–8g/m²/day. Duckweed was harvested from a 1·9ha area of the system and transferred to an adjacent milkfish, Chanos chanos Forskal, farm. Its fertilization effect, in terms of lablab production ( lablab is the biological complex of bluegreen algae, diatoms, bacteria and various animals which forms a mat at the bottom or floats in patches), was evaluated in the milkfish ponds. This was compared with ponds fertilized with either inorganic fertilizers or cow manure, in the traditional way. Lablab growth was significantly increased using duckweed, with ash-free dry weight production averaging 32g/m²/day following fertilization with duckweed compared with 4g/m²/day using inorganic fertilizers. Milkfish net production averaged 320 kg/ha/90-day crop in inorganically fertilized ponds. 545kg/ha/90-day crop for cow manure and 820kg/ha/90-day crop in duckweed-fertilized ponds. The system is described and the benefits of this integrated waste treatment-fish production facility are discussed.     

低鱼粉日粮添加蛋氨酸对幼鲤生长的影响

以鱼粉10%的玉米大豆粕型幼鲤饲料为对照组(A),降低饲料鱼粉含量为5%后,分别添加不同水平的DL-蛋氨酸及其羟基类似物添加量分别为B:0.5%DL_蛋氨酸、C:0.514%蛋氨酸羟基类似物、D:0.564%蛋氨酸羟基类似物、E:0.614%蛋氮酸羟基类似物,比较研究用豆粕代替部分鱼粉,添加蛋氨酸及其羟基类似物对幼鲤的...     

Growth and Body Composition of Nile Tilapia,Oreochromis niloticus,Fry Fed Organic Diets Containing Yeast Extract and Soybean Meal as Replacements for Fish Meal,with and without Supplemental Lysine and Methionine

Quantities of fish meal (FM) have remained level for the past several decades; however, demand has dramatically increased because of its inclusion in all animal production as a high‐quality protein source. Soybean meal (SBM) is the most widely used plant‐protein ingredient for replacing various proportions of FM in aquatic animal diets. However, use of SBM as the sole protein source has often resulted in reduced fish growth. There is a growing segment of consumers who desire organically grown seafood, and tilapia is one of the most‐cultured fish in the world. As tilapia have herbivorous/omnivorous feeding habits, tilapia fed organic diets may allow producers to enter this rapidly developing market. A feeding experiment was conducted to evaluate the combination of organic SBM and an organic yeast extract (YE) as complete replacements for FM in Nile tilapia, Oreochromis niloticus, fry diets. Nine diets were formulated to contain various percentages of organic YE (0, 15, 30, and 45%) in combination with organic SBM (84–34%) with and without amino acid (methionine and lysine) supplementation. At the conclusion of the study, fry fed a control diet containing 20% FM and fry fed a diet containing 45% YE/36%SBM with amino acid supplementation showed no significant differences (P > 0.05) in final weight, weight gain, and specific growth rate (SGR) compared to those fed all other diets. On the basis of these data, an organic diet which replaces FM with a combination of SBM and YE with added methionine and lysine is commercially feasible and further investigation into the increased use of these two ingredients as protein sources in aquaculture diets is warranted.     

Replacement of Fish Meal with Soybean Meal in the Production Diets of Juvenile Red Snapper, Lutjanus campechanus

The replacement of fish meal with soybean meal in fish diets has met with varying degrees of success. Quite often, poor responses to high soybean meal diets are either due to shifts in the nutrient profile or a reduced palatability of the diet when fish meal is removed. The present research was designed to evaluate the replacement of menhaden fish meal with solvent-extracted soybean meal in practical diets containing 10% poultry by-product meal and formulated to contain 40% protein, 8% lipid, and a total sulfur amino acid content of > 3.0% of the protein. The response of red snapper (mean initial weight 10.9 g) to diets containing graded levels of fish meal (30,20, 10, 0%) as well as the response to a low fish meal diet (10%) without poultry by-product meal were evaluated over a 6-wk growth period. Significant ( P ± 0.05) differences in final mean weight, percent weight gain, and feed conversion were observed. Final weights (percent gain) ranged from 30.9 g (185.5%) for fish offered diets with 30% fish meal to 12.6 g (16.3%) for fish offered diets with 0% fish meal. Corresponding feed conversion efficiencies ranged from 60.1% to 7.7%. No significant differences were observed for survival between treatment means. Although there was a clear reduction in performance as the fish meal was replaced with soybean meal, the use of 10% poultry by-product meal or 10% fish meal resulted in similar performance of the fish. This is a good indication that poultry by-product meal does not have palatability problems and could be used as a substitute. The present findings suggest that replacing fish meal with high levels of soybean meal appears to reduce the palatability of the diet. While the cost reducing benefit, with respect to the replacement of fish meal, has been shown with other species, before high levels of inclusion can be efficiently utilized further research is needed to address the palatability problems observed with red snapper.     

A preliminary study on the protein requirements of Chanos chanos (Forskal) fry in a controlled environment

Milkfish (Chanos chanos) fry with an average weight of 40 mg per fish were stocked in 60-l wooden-glass aquaria filled with 30 l of filtered sea water with a salinity of 32–34 p.p.t. and a temperature of 25–28°C. They were fed diets containing 20, 30, 40, 50 and 60% protein and 2740 kcal of digestible energy per kg at a daily rate of 10% of the biomass for a period of 30 days. Fish which were fed the diet containing 40% protein had the highest weight gain which was significantly higher (P < 0.05) than those of fish receiving the lower dietary levels of protein. Slightly lower weight gains were obtained when fish were fed diets containing 50 and 60% protein. Although feed conversion values were not statistically different (P < 0.05) among all treatments, the value for the 40% protein diet (1.96) was the best. The mean survival rates were low for all treatments but was highest for the 40% protein diet. No significant difference (P < 0.05) was found in the survival rates of fish receiving different treatments. Results show that a dietary level of 40% protein was required by milkfish fry for maximum growth, efficient feed conversion and high survival rate.     

Use of Plant Proteins in Catfish Feeds: Replacement of Soybean Meal with Cottonseed Meal and Replacement of Fish Meal with Soybean Meal and Cottonseed Meal

Plant protein sources were evaluated in 32% protein grow-out feeds for channel catfish (initial weight: 180 g/fish) stocked at high densities (24,700 fish/ha) in 0.04 ha earthen ponds. Each of the eight practical-type feeds was assigned for five replicate ponds. The fish were fed to satiation once daily for 170 d. Specifically, cottonseed meal and cottonseed meal plus supplemental lysine were evaluated as replacements for soybean meal. Soybean meal, a combination of soybean meal and cottonseed meal, or a combination of soybean meal and cottonseed meal plus supplemental lysine were evaluated as a substitute for animal protein sources. Based on weight pin, feed conversion ratio, body composition, percentage visceral fat, and dressed yield, the data indicated that cottonseed meal plus lysine can be used as a total substitute for soybean meal in catfish feeds. However, it is not recommended that more than 30% cottonseed meal be used in catfish feeds until additional data are available on the effects of gossypol on reproduction in catfish. Also, data indicated that plant proteins can be used as a total replacement for animal protein without detrimental effects. Reduced weight gain was observed in fish fed a feed that contained 68% of the established available lysine requirement. However, fish fed feeds estimated to contain only 76 or 82% of the available lysine requirement did not show reduced weight gain. This suggests that lysine may be more highly available from cottonseed meal than previously estimated, or that natural food organisms in the pond contributed nutrients including lysine, or that fish were able to consume enough of the marginally deficient feeds to meet their requirement for lysine. This study was conducted with large catfish fed a 32% protein feed to satiation once daily. If smaller fish, a lower protein fed, or a restricted feeding regimen had been used, the results may have been different.     

Evaluation of Alternative Protein Sources to Replace Fish Meal in Practical Diets for Juvenile Tilapia,Oreochromis spp

Two feeding experiments were conducted to evaluate if methionine is limiting in practical grow‐out diets for tilapia, Oreochromis spp. Four diets containing 32% protein and 5% lipid were designed to compare the use of diets high in dehulled solvent‐extracted soybean meal (DSESM) and expeller pressed soybean meal (EPSM) compared with a diet containing 6% fish meal (FM). Tilapia (4.78 ± 0.07 g, mean ± SD) were randomly stocked into twelve 600‐L flow‐through tanks at 20 fish per tank. After 6 wk, there were no notable trends or statistically significant differences (P > 0.05) in final mean weight, survival rate, and feed conversion ratio (FCR) among the treatments. Because results of this study indicated that DSESM could totally replace FM in practical diets for juvenile tilapia, a second batch of diets were formulated using other protein sources. Typical levels of cottonseed meal (CSM), DSESM, and meat and bone meal (MBM) were used to evaluate whether methionine could be limiting. Two basal diet formulations were tested either without or with methionine supplement (0.06/100 g diet). The first diet contained 15% CSM, 27% DSESM, and 10% MBM and the second diet contained 15% CSM and 37% DSESM. These diets contained 28% protein and 5% lipid. Tilapia (3.90 ± 0.05 g) were randomly stocked into twelve 60‐L glass aquaria of a recirculation system at 18 fish per aquarium for 5 wk and then moved to the 600‐L flow‐through tanks for five more weeks. After 10 wk, there were no statistically significant differences (P > 0.05) in final mean weight, survival rate, and FCR among the four treatments. Results of the present study indicated that DSESM and EPSM could totally replace FM’s inclusion rate in commercial diets for juvenile tilapia. Furthermore, methionine did not appear to be limiting in practical diets using typical levels of CSM, DSESM, and MBM as primary protein sources.     

Effects of Replacing Fish Meal with Soybean Meal in Diets for Red Drum Sciaenops ocellatus and Potential for Palatability Enhancement

Two 8-wk feeding trials were conducted with juvenile red drum to determine the maximum levels of soybean meal that may replace fish meal in diets containing 38% crude protein, without reducing weight gain. In the first experiment, fish fed diets containing up to 90% of the protein from soybean meal gained as much weight as fish fed a diet with 100% of protein from fish meal, but fish fed the diet with 100% of its protein from soybean meal gained significantly (P < 0.05) less. Supplementation of glycine and fish solubles individually at 2% (as-fed basis) in diets containing 90% of their protein from soybean meal tended to increase weight gain of fish compared to those fed a similar diet without supplementation. Similar results were obtained in the second experiment, as fish fed diets containing 90% of their protein from soybean meal gained as much weight as fish fed a diet with 100% of its protein from fish meal. Fish fed diets with 95% and 100% of their protein from soybean meal gained significantly less weight than those fed the diet with all of its protein from fish meal. Supplementation of glycine at 2% in the diet containing 95% of its protein from soybean meal significantly improved weight gain of fish relative to those fed a similar unsupplemented diet. Supplementation of fish solubles at 5% of diet on a dry-matter basis provided a nonsignificant increase in weight gain compared to that of fish fed a similar unsupplemented diet. In both experiments there was greater observed consumption of the soybean-meal-based diets than diets with all of their protein from fish meal. A minimum of 10% of protein from fish meal appears necessary in practical diets containing most of their protein from soybean meal to prevent impaired growth and feed efficiency of red drum.     

不同大豆产品替代鱼粉饲养南美白对虾的试验

分别采用脱皮豆粕、大豆蛋白、发酵豆粕等大豆产品,等氮替代饲料中10%的鱼粉(对照组鱼粉35%,替代组鱼粉25%),饲养体重为0.06 g南美白对虾(Penaeus vannam eiBoone)一个月,结果表明,对照组(35%鱼粉)幼虾的增重率、成活率均最大,为1316%、97.5%;脱皮豆粕组幼虾的增重率为最低,仅783%;哈姆雷特大豆蛋白、比多福大豆蛋白、富肽蛋白(发酵豆粕)组幼虾增重率为1033%、983%、1050%,均显著高于脱皮豆粕组(P<0.05),但低于对照组(P<0.05);对虾体肌肉成分的分析显示,各组幼虾肌肉在水分、蛋白质含量方面没有显著差异。上述结果表明,大豆蛋白和发酵豆粕均为优于脱皮豆粕的鱼粉替代品。     

Growth Rate of Pacu,Piaractus mesopotamicus,Fingerlings Fed Diets Containing Co-Dried Fish Silage as Replacement of Fish Meal

Abstract

Fish meal has been the most common animal protein source used to feed fish, even though it is fairly expensive and seasonally available. The objective of this work was to investigate co-dried fish silage as an alternative animal protein source for diets of pacu, Piaractus mesopotamicus.The diets did not differ significantly (P >0.05) with respect to average weight gain, ration consumption, apparent feed conversion, protein efficiency and specific growth rates. However, apparent protein digestibility and protein productive values were significantly different (P <0.01). Diets containing fish silage, co-dried with agricultural by-products (soybean meal or broken rice), showed better results than the control diet, which contained fish meal as the only animal protein source. The results showed that alternative ingredients can be used effectively to replace fish meal in pacu diets. Co-dried silages are economically and environmentally advantageous, since they use residues generated in the farm.     

Partial Replacement of Fish Meal by Fermented Soybean Meal in Diets for Black Sea Bream,Acanthopagrus schlegelii,Juveniles

The effect of fish meal (FM) substitution with fermented soybean meal (FSBM) in the diets of the carnivorous marine fish, black sea bream, Acanthopagrus schlegelii, was investigated. An 8‐wk feeding trial was conducted with black sea bream (11.82 ± 0.32 g; mean initial weight) in indoor flow‐through fiberglass tanks (25 fish per tank). Six isonitrogenous and isoenergetic diets were formulated, in which FM was replaced by FSBM at 0% (control diet), 10% (FSBM10), 20% (FSBM20), 30% (FSBM30), 40% (FSBM40), or 50% (FSBM50), respectively. Each diet was fed to triplicate groups of fish twice daily to apparent satiation. The results showed that there was no difference in survival of black sea bream during the feeding trial. Fish fed the FSBM10 or FSBM20 diet showed comparable growth performance compared with fish fed the control diet (P > 0.05), whereas more than 30% replacement of FM adversely affected weight gain and specific growth rate (P < 0.05). Feed intake was significantly lower for fish fed the FSBM50 diet compared with fish fed the control diet. Feed conversion ratio (FCR) tended to increase with increasing dietary FSBM with the poorest FCR observed for fish fed the FSBM50 diet. Protein efficiency ratio and protein productive values showed similar patterns. Apparent digestibility of nutrients significantly decreased with increasing dietary FSBM level. With the exception of protein content, no significant differences in whole body and dorsal muscle composition were observed in fish fed the various diets. Fish fed the FSBM50 diet had significantly lower intraperitoneal ratio than fish fed the control or FSBM10 diet. Hepatosomatic index and condition factor were unaffected by dietary treatments. This study showed that up to 20% of dietary FM protein could be replaced by FSBM protein in the diets of juvenile black sea bream.     

Use of Fermented Fisheries By-products and Soybean Curd Residues Mixture as a Fish Meal Replacer in Diets of Juvenile Olive Flounder, Paralichthys olivaceus

A 10‐wk feeding trial was conducted to evaluate the potential use of fermented fisheries by‐products and soybean curd residues mixture (FFSM) as a partial replacement for fish meal (FM) in the diet of juvenile olive flounder, Paralichthys olivaceus. Five experimental diets were formulated with FFSM replacing 0, 15, 30, 45, and 60% of the FM protein (FFSM₀, FFSM₁₅, FFSM₃₀, FFSM₄₅, and FFSM₆₀, respectively). Juvenile olive flounder averaging 5.99 ± 0.08 g (mean ± SD) were randomly distributed into aquaria at 15 fish/aquarium, with three replicate aquaria for each experimental diet. Weight gain (WG) of fish fed FFSM₀, FFSM₁₅, and FFSM₃₀ was significantly higher than that of fish fed FFSM₄₅ and FFSM₆₀ (P < 0.05). Also, WG of fish fed FFSM₄₅ was significantly higher than that of fish fed FFSM₆₀ (P < 0.05). There were no significant differences in WG among fish fed FFSM₀, FFSM₁₅, and FFSM₃₀ (P > 0.05). Specific growth rate (SGR) of fish fed FFSM₁₅ was significantly higher than that of fish fed FFSM₄₅ and FFSM₆₀ (P < 0.05). Also, SGR of fish fed FFSM₀, FFSM₁₅, FFSM₃₀, and FFSM₄₅ was significantly higher than that of fish fed FFSM₆₀ (P < 0.05). There were no significant differences in SGR among fish fed FFSM₀, FFSM₁₅, and FFSM₃₀ and among those fed FFSM₀, FFSM₃₀, and FFSM₄₅ (P > 0.05). Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed FFSM₆₀ were significantly lower than those of fish fed FFSM₀, FFSM₁₅, FFSM₃₀, and FFSM₄₅ (P < 0.05); however, there were no significant differences in FE and PER among fish fed FFSM₀, FFSM₁₅, FFSM₃₀, and FFSM₄₅. Hepatosomatic index of fish fed FFSM₀, FFSM₁₅, and FFSM₃₀ was significantly higher than that of fish fed FFSM₆₀ (P < 0.05); however, there were no significant differences among fish fed FFSM₀, FFSM₁₅, FFSM₃₀, and FFSM₄₅ and among those fed FFSM₄₅ and FFSM₆₀. No significant differences were observed in condition factor and survival rate among all dietary groups tested. The whole‐body proximate composition averaged 75.0 (% dry matter basis [DM]), 8.66 (% DM), 16.38 (% DM), and 76.1%, for crude protein, crude lipid, ash, and moisture, respectively. Based on growth performance, the FFSM could replace up to 30% FM protein by the ANOVA test; however, broken‐line model analysis indicated 28.7% as an optimum replacement level in juvenile olive flounder diets.     

胶原蛋白部分替代鱼粉饲养异育银鲫的试验

进行了两个试验以评价水产饲料中胶原蛋白替代鱼粉的效果。生长试验是在基础饲料(对照组,含鱼粉12%)中分别以2%、4%胶原蛋白等重量替代鱼粉饲养平均体重6.5g的异育银鲫(共315尾)35d,各组鱼体增重率分别为71.3%,70.9%,71.9%,各组间没有显著差异(P>0.05);消化试验是采用平均体重110g的异育银鲫,按套算法测定了异育银鲫对胶原蛋白的蛋白质消化率为97.3%。研究结果表明,胶原蛋白具有很高的消化吸收率,可部分替代鱼粉而对异育银鲫的增重无影响。     

Partial Replacement of Fish Meal with Corn Gluten Meal in Diets for Japanese Flounder Paralichthys olivaceus

Abstract.— Feeding experiments were conducted to evaluate corn gluten meal (CGM) as an alternative protein source for fish meal in the diet of Japanese flounder Paralichthys olivaceus . A diet containing 75% white fish meal as a sole protein source was the control, and 20, 40, and 60% of fish meal protein was replaced with CGM protein in the experimental feeds. Juvenile fish of about 8 g initial body weight were fed each diet to apparent satiation twice a day. 6 d per week for 8 wk at 20 C. Survival rates of fish ranged from 98 to 100% and were not significantly different ( P > 0.05) among treatments. Final body weight, weight gain, feed efficiency and protein efficiency ratio of fish fed the diets containing CGM up to 40% substitution levels were not statistically different from those of fish fed the control diet. All production parameters for fish fed the diet replacing 60% of fish meal protein were significantly lower than the control ( P ≤ 0.05). Supplements of crystalline amino acids to the CGM diet improved the nutritive value of the diet. Since substitution up to 40% did not adversely affect hematological and hematochemical parameters as well as whole body composition of the cultured fish, it is suggested that up to 40% of fish meal protein can be replaced with CGM in the diet of juvenile Japanese flounder.     

Winter Feeding and Growth of Channel Catfish Fed Diets Containing Varying Percentages of Distillers Grains with Solubles as a Total Replacement of Fish Meal

Channel catfish, Ictalurus punctatus, with an average initial weight of 515g, were fed four experimental pelleted diets (1-4) with increasing percentages (0, 35, 55, or 90%) of distillers grains with solubles (DGS) during the winter. A fifth diet was formulated identical to diet 4 except that 0.6% supplemental lysine was added to meet the published requirement. Yield, individual weight, individual length, survival, and weight gain of fish were not significantly different (P > 0.05) among treatments. Average individual fish weight at harvest was 542 g and represented a weight gain of 5.4%. Percentage moisture, protein, and fat of waste, (skin, head, and viscera) were not significantly different (P . 0.05) among treatments. Percentage protein of the dressed carcass of fish fed diet 4 (90%) DGS without lysine) was significantly lower (P < 0.05) than in fish fed diet 3 (55% DGS), and percentage fat was significantly lower (P < 0.05) than in fish fed diet 5 (90% DGS + 0.6% lysine). These data indicate that DGS is a suitable diet ingredient and can be used at levels up to 90% inclusion in winter diets for channel catfish without addition of supplemental amino acids. Use of DGS in diets may be economical, especially if prices of fish meal and soybean meal increase dramatically or if DGS is locally available.