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1.
A laboratory study was conducted to evaluate effects of dietary total protein and animal protein source and concentration on growth and feed efficiency of juvenile channel catfish Ictalurus punctutus and their response to Edwardsiellu ictuluri challenge. Eight diets evaluated were: three diets containing either 28, 32, or 36% crude protein with 6% menhaden fish meal and 6% meat and bonehlood meal and five diets containing 32% crude protein with either no animal protein, 68 or 12% menhaden fish meal, or 6% or 12% meat and bonehlood meal, respectively. Twenty channel catfish with an average weight of 6.6 g/fish were stocked into each of forty 110-L flow-through aquaria (five aquaridtreatment). Fish were fed to approximate satiation twice daily for 9 wk. Fish in each tank were then exposed to E. ictaluri . There were no differences in feed consumption, weight gain, feed efficiency, and survival before and after challenge among fish fed diets containing 28, 32, or 36% protein with 6% menhaden fish meal and 6% meat and bone/ blood meal. Fish fed a 32% all-plant protein diet had weight gain and feed efficiency similar to fish fed diets containing 12% menhaden fish meal, but had a higher weight gain than fish fed a 32% protein diet containing 6% meat and bonehlood meal. No significant differences were observed in survival after E. ictuluri challenge among fish fed diets containing the various levels of animal proteins. Results indicate that dietary protein levels varying from 28% to 36% do not appear to affect growth, feed efficiency. and E. icraluri resistance or susceptibility in fingerling channel cattish fed to satiation and raised from approximately 7 to 56 g under laboratory conditions. Data also demonstrate that a 32% all-plant protein diet can be fed to small fingerling channel catfish without adversely affecting growth, feed efficiency, or resistance to E. ictuluri .  相似文献   

2.
Abstract— A 2 × 5 factorial experiment was conducted using practical-type extruded feeds containing 20, 24, 28, 32, or 36% crude protein with or without animal protein. The animal protein supplement consisted of 4% menhaden fish meal and 4% meat, bone and blood meal. Channel catfish fingerlings (average size: 26.3 g/fish) were stocked into 50 0.04-ha ponds at a rate of 24,700 fishha. Five ponds were used for each dietary treatment. Fish were fed once daily to satiation for 202 d. There were no differences in feed conversion ratio (FCR), percentage fillet moisture, and survival among treatments. In fish fed diets containing no animal protein, feed consumption, weight gain, and percentage dressout were lower for fish fed the 20% protein diet than those fed diets containing 28% and 32% protein. Fish fed 28, 32, or 36% protein diets without animal protein did not differ in respect to percentage dressout and percentage visceral fat; fish fed the 36% protein diet had higher percentage fillet protein and a lower percentage fillet fat than fish fed other diets with the exception of fish fed the 28% protein diet. In fish fed diets containing animal protein, feed consumption, weight gain, percentage fillet protein and ash, and percentage dressout were lower and visceral fat was higher for fish fed the 20% protein diet than those fed other diets. Fish fed diets containing 24% protein and above with animal protein were not different in respect to weight gain and feed consumption, but fish fed the 24% protein diet had a higher percentage fillet fat than fish fed a 32% or 36% protein diet. Fish fed the 32% protein diet had a lower visceral fat. Considering animal protein vs non-animal protein with the data pooled across all diets without regard to dietary protein level, weight gain and FCR of fish fed diets containing animal protein were higher than those fed diets containing no animal protein. However, weight gain of fish fed diets containing 20, 28, or 32% protein with or without animal protein did not differ. Dressout percentage and fillet protein were higher and fillet fat was lower for fish fed diets containing no animal protein than those fed diets containing animal protein. Data from this study indicated that animal protein may not be a necessary dietary ingredient for fish fed 28% or 32% protein diets typically used for grow out of pond-raised channel catfish under satiation feeding conditions. Whether animal protein should be included in catfish diets containing less than 28% protein is unclear, since fish fed the 24% protein diet benefited from animal protein but those fed the 20% protein diet did not benefit from animal protein. Additional studies to provide more information on low-protein, all-plant diets are currently being conducted.  相似文献   

3.
Two feeding trials were conducted with juvenile largemouth bass Micropterus salmoides to evaluate alternative plant and animal source proteins for their ability to replace fish meal in practical diets. The first trial was designed to identify the most promising candidates. The second trial was conducted to evaluate how much of the fish meal could be replaced by those candidates. In Study 1, feed‐trained largemouth bass (3.1 ± 0.7 g) were randomly stocked into 18114‐L glass aquaria at 25 fish per aquarium. Fish were fed one of six experimental diets, each containing approximately 38% crude protein and 10% crude lipid, to apparent satiation twice daily. The control diet (CTL) contained 30% fish meal and 34.5% soybean meal. Diets 2–6 each contained 15% fish meal and at least 34.5% soybean meal with the remainder of the protein made up of either meat and bone meal (MBM), soybean meal (SBM), poultry by‐product meal (PBM), a 50150 mixture of blood meal and corn gluten meal (BM/CG), or 50150 mixture of hydrolyzed feather meal and soybean meal (FMISBM). There were three replicate aquaria per dietary treatment. After 12 wk, there was no significant difference (P > 0.05) among treatments in survival which averaged 92% overall. Only fish fed the PBM or BM/CG diets had average individual weights and feed conversion efficiencies that were not significantly different (P > 0.05) from the control diet (CTL). In Study 2, the formulation of the control diet (CTL) remained the same. Based on their performance in the first trial, PBM and BM/CG were chosen to now replace 75 or 100% of the fish meal. Fish were stocked at an average weight of 6.9 ± 1.7 g. After 11 wk, fish fed diets containing the BM/CG mixture at both levels were significantly smaller (P 5 0.05) than fish fed other diets and at 100% replacement survival was reduced. Fish fed diets containing poultry meal as the primary protein source performed as well as those fed the control diet (CTL). It appears that PBM can completely replace fish meal in diets for juvenile largemouth bass without adverse effects on growth, feed efficiency, or body composition.  相似文献   

4.
Abstract— The main objective of this study was to determine the effect of different levels of krill meal (KM) as a feed attractant in juvenile Nile tilapia fed soybean (SBM) diets on growth performance, feed utilization, and body composition. Fish of an initial average weight 0.8 × 0.01g were stocked in 18 glass aquaria (80 L each) at a rate of 25 fish per aquarium. Fish meal (FM 20% of the diet) was used as the sole source of animal protein in the control (Diet 1). Diets 2 to 6 had (SBM) protein with various levels of krill meal (0.0,1.5,3.0,4.5, and 6.0%, diets 2-6 respectively). Test diets were fed to satiation to triplicate groups of Nile tilapia four times daily for 20 wk. Fish fed krill meal supplemented diets had significantly ( P < 0.05) better growth performance compared with fish fed the unsupplemented and FM control diets. The krill meal increased growth of Nile tilapia by 31.9% compared to control diets (average Anal wet weight, 14.15 × 0.95 g and 10.72 × 0.2 g, respectively). Moreover, weight gains were not significantly different for fish fed diets with different levels of krill meal. Feed utilization parameters such as feed intake, feed conversion ratio, protein efficiency ratio differed significantly for fish fed krill meal diets compared with control. Digestibility of nutrient and energy of diets increased with increasing levels of krii meal. The incorporation of krill meal in diets significantly affected the protein, fat, ash, and energy of whole body composition. These results suggest that supplementation of krill meal at 1.5% in the diets of Nile tilapia as attractant or stimulant may lead to increased feed intake, growth performance, and feed utilization. Soybean meal can completely replace fishmeal in diets for juvenile tilapia.  相似文献   

5.
A factorial experiment was conducted to evaluate effect of dietary protein (28% or 32%), animal protein (0, 3, or 6%), and feeding rate (satiation or >90 kg/ha per d) on production characteristics, processing yield, and body composition of pond-raised channel catfish Ictalurus punctatus . Fingerling channel catfish (average weight: 55 g/fish) were stocked into 60, 0.04-ha ponds at a rate of 18,530 fish/ha. Five ponds were used for each dietary treatment. Fish were fed once daily to satiation or no more than 90 kg/ha per d for 147 d. Fish fed at a rate of >90 kg/ha per d consumed about 85% of the amount of feed consumed by fish fed to satiation. Dietary protein did not affect the total amount of feed fed, amount of feed consumed per fish, weight gain, feed conversion efficiency, or fillet protein. Animal protein had no effect on the total amount of feed fed, amount of feed consumed per fish, weight gain, or fillet protein and ash. Fish fed a diet containing 6% animal protein converted feed more efficiently than fish fed diets containing 0% and 3% animal protein. Fish fed to satiation daily consumed more feed, gained more weight, converted the feed less efficiently, and had a higher carcass yield, a higher level of visceral fat as compared to fish fed at a rate of >90 kg/ha per d. Feeding rate had no effect on fillet protein. Results from this study indicated that both a 28% and a 32% protein diet with or without animal protein provided the same growth rate of channel catfish raised in ponds from fingerlings to marketable size if feed is not restricted below a maximum rate of 90 kg/ha per d. Even though there were some interactions among the three factors evaluated, dietary protein levels of 28% to 32% and animal protein levels of 0% to 6% do not appear to markedly affect carcass yield and fillet proximate composition of pond-raised channel catfish.  相似文献   

6.
Three levels of dietary protein (26, 28, or 32%) and four levels of animal protein (0, 2, 4, or 6%) were evaluated in a factorial experiment for pond-raised channel caffish using practical-type extruded feeds. Meat, bone, and blood meal (65% protein) was used as the animal protein source. Channel catfish fingerlings (average weight: 69 glfish) were stocked into 48 0.04-ha ponds at a rate of 24,700 fishha. Four ponds were used for each dietary treatment. Fish were fed once daily to apparent satiation for 158 d. No differences were observed in weight gain, feed consumption, feed conversion ratio, survival, and hematocrits of channel catfish fed diets containing various levels of dietary protein and animal protein. Inclusion of animal protein in the diet did not affect fish dressout, percentage visceral fat, or fillet composition. Comparison of means pooled by dietary protein without regard to animal protein showed that fish fed diets containing 26% protein had a lower percentage dressout than fish fed higher protein diets (55.4% vs. 56.3%). Fish fed the 32% protein diet had lower visceral fat than those fed the 26% or 28% protein diet (2.9% vs. 3.6% or 3.4%). Fillet fat was lower for fish fed the 32% protein diet than for fish fed the 26% protein diet (5.8% vs. 7.1%). Fillet fat in fish fed the 28% protein diet (6.5%) was not different from fish fed either 26% or 32% dietary protein. No differences were detected in fillet protein, moisture, and ash concentrations among fish fed diets containing various concentrations of protein. There were no interactions between dietary protein and animal protein for any variables. Results from the present study indicate that animal protein can be eliminated from diets for grow out of channel catfish fed to apparent satiation using diets containing 26% to 32% crude protein.  相似文献   

7.
ABSTRACT

Animal protein, generally fish meal, has traditionally been used in the diet of channel catfish. However, our previous research indicates that animal protein is not needed for growing stocker-size catfish to food fish when the fish are stocked at densities typical of those used in commercial catfish culture. Whether this holds when fish are stocked at high densities is not known; thus, we conducted an experiment to evaluate the effect of feeding diets with and without fish meal to channel catfish stocked in earthen ponds at different densities. Two 32% protein-practical diets containing 0% or 6% menhaden fish meal were compared for pond-raised channel catfish, Ictalurus punctatus, stocked at densities of 14,820, 29,640, or 44,460 fish/ha. Fingerling channel catfish with average initial weight of 48 g/fish were stocked into 30 0.04-ha ponds. Five ponds were randomly allotted for each fish meal level?×?stocking density combination. Fish were fed once daily to satiation for two growing seasons. There was a significant interaction between stocking density and fish meal for net production; net production increased in fish fed a diet containing fish meal compared with those fed an all-plant diet at the highest stocking density, but not at the two lower stocking densities. Net production of fish fed diets with and without fish meal increased as stocking density increased. Viewing the main effect means, weight gain decreased and feed conversion ratio increased for fish stocked at the two highest densities, and survival was significantly lower at the highest stocking density. Visceral fat decreased in fish at the two highest stocking densities. Body composition data were largely unaffected by experimental treatment except for a reduction in percentage filet fat in fish at the highest stocking density, and fish that were fed diets containing fish meal had a lower percentage fillet protein and a higher percentage fillet fat. It appears that at stocking densities two to three times higher than generally used, animal protein (fish meal) may be beneficial in the diet of channel catfish. In regard to stocking densities, high stocking results in higher overall production, but the average fish size decreased as stocking density increased.  相似文献   

8.
Abstract. Semipurified diets containing either 25% or 30% crude protein (CP) from soy isolate (soy) or 30% CP from casein and gelatin (casein) were supplemented with either of two levels of L-lysine HCI (0 or 0·5% of diet) in a 3 × 2 factorial arrangement and fed to fingerling channel catfish, Ictalurus punctatus (Rafinesque), in aquaria for 8 weeks. Factorial analysis of variance indicated a significant ( P < 0·001) positive effect of lysine on weight gain, protein conversion efficiency (PCE) and feed efficiency. Fish fed the soy diet containing 25% CP showed increased weight gain of 24% with lysine supplementation while fish fed soy and casein diets containing 30% CP showed increases of 11 % and 3%, respectively. However, supplementing the 25% CP soy diet with 0–5% L-lysine HCI did not enhance growth performance to the level offish fed the unsupplemented 30% CP soy diet. Significant effects of dietary protein levels and sources on weight gain, PCE, feed efficiency, haematocrit, hepatosomatic index (HSI; % liver weight), intraperitoneal fat (IPF) ratio, dry matter of fillet and whole-body, as well as lipid and protein content of whole-body tissue, were also observed. Fish fed the casein diet containing 30% CP had the greatest weight gain, PCE, feed efficiency, haematocrit and whole-body protein values and lowest IPF ratio and whole-body lipid values compared with those of fish fed the soy diets. Supplemental lysine did not affect body condition indices or proximate composition of whole-body and fillet tissues of fish fed the different protein sources. Therefore, based on this study, dietary protein levels and sources significantly influenced performance characteristics of channel catfish and supplemental lysine was most beneficial at a reduced CP level.  相似文献   

9.
There are several estimates of the optimal dietary crude protein concentration for juvenile tilapia fed high quality animal proteins or mixtures of animal and plant derived feedstuffs. In the present study, the optimal dietary crude protein concentration for hybrid tilapia Oreochromis niloticus × O. aureus reared in glass aquaria was determined using diets free of fish meal. Further, initial weight of fish was approximately 21 g, which is the beginning of the growout phase of many commercial operations. The diets contained primarily corn co-products and soybean meal as the sources of amino acids, and were formulated to provide 24, 26, 28, 30, 32 or 34% crude protein. The diets were fed to quadruplicate groups of tilapia for 10 wk. Increasing concentrations of dietary crude protein resulted in proportional improvements in weight gain and feed efficiency up to 30% dietary crude protein. Fish fed 24% dietary crude protein exhibited significantly reduced weight gain compared to fish fed 28–34% dietary crude protein. Protein efficiency ratio (PER) of tilapia was unaffected by dietary crude protein concentration. However, fish fed 28% crude protein exhibited numerically higher PER (2.58) than fish fed other levels of crude protein. Muscle crude protein levels were lower in fish fed diets containing 24–28% crude protein than in fish fed 30% and higher concentrations. Quadratic regression analyses of weight gain and feed efficiency data indicated the optimal dietary crude protein concentration to be 29.65% and 28.33%, respectively, while broken line analyses indicated 27.5 and 27.3%, respectively. Based on weight gain, feed efficiency, PER, and proximate composition data, the authors recommend 28% dietary crude protein as the minimum for hybrid tilapia fed all-plant diets and reared in tanks.  相似文献   

10.
Three feeding experiments were conducted to evaluate growth and body composition in blue caffish Ictalurus furcatus or channel caffish I. punctatus when fed diets containing 22% protein with or without supplemented methionine and/or lysine. All experiments were conducted in 110‐L aquaria that were part of a recirculating system. In Experiment 1,15 juvenile blue catfish (2.7 g) were randomly stocked into aquaria and fed one of three diets containing different (22%, 27%, and 32%) percentages of protein. Fish were fed twice daily to excess for 10 wk. In Experiment 2, juvenile blue catfish (5.4 g) were randomly stocked into aquaria and fed one of six diets containing either 22% (diet 1) or 32% (diet 2) protein. The diet containing 22% protein (diet 1) had either 0.3% crystalline L‐methionine (diet 3), 0.4% crystalline L‐lysine (diet 4), or 0.3% L‐methionine + 0.4% L‐lysine (diet 5) added. A sixth diet was formulated to contain 32% protein and 0.2% crystalline L‐methionine. Fish were fed in excess for 12 wk. In Experiment 3, juvenile channel caffish (10.3 g) were stocked and fed diets 14 from Experiment 2, twice daily in excess for 8 wk. In Experiment 1, after 10 wk, final individual weight, weight gain (%), and specific growth rate (SGR) of blue catfish fed diets containing three protein levels were not significantly different (P > 0.05) and averaged 12.9 g, 378%, and 2.2%/d, respectively. Fish fed the diet containing 27% protein had higher (P < 0.05) whole‐body protein (65.4%) compared to fish fed diets containing either 22% or 32% protein. In Experiment 2, final weight, weight gain (%) and SGR of blue catfish were not significantly (P > 0.05) different among diets and averaged 24.7 g, 355%, and 1.8%/d, respectively. Percentage whole‐body protein and lipid were not significantly (P > 0.05) different between fish fed diets containing 22% or 32% protein. In Experiment 3, channel caffish fed a diet containing 32% protein had significantly (P > 0.05) higher final individual weight, weight gain (%), and SGR compared to fish fed diets containing 22% protein, with and without supplemental methionine or lysine. Results indicate that blue catfish may be able to utilize a diet with 22% protein, and that addition of crystalline methionine and/or lysine did not improve growth. However, channel catfish grown in aquaria did not appear to have similar growth when fed a diet containing 22% protein compared to fish fed 32% protein, even when supplemental methionine or lysine was added. Further research on blue catfish and the use of a low‐protein diet (22% protein) needs to be conducted in ponds.  相似文献   

11.
Abstract

This study evaluated the effects of dietary protein concentration (26, 28, and 32%) and an all-plant protein diet (28% protein) on growth, feed efficiency, processing yield, and body composition of channel catfish, Ictalurus punctatus raised from advanced fingerlings to large marketable size (about 800 to 900 g/fish) for two growing seasons. Fingerling channel catfish (average weight = 56 g/fish) were stocked into twenty 0.04-ha ponds at a density of 18,525 fish/ha. Fish were fed once daily to satiation during the two growing seasons and fed according to recommended winter feeding schedules during the winter. There were no differences in diet consumption, weight gain, feed conversion ratio, survival, processing yields (carcass, shank fillet, and nugget), or fillet composition (moisture, protein, fat, and ash) among fish fed the various diets. These results indicate that a 26% protein diet containing plant and animal proteins or a 28% all-plant protein diet is adequate for channel catfish raised in ponds from advanced fingerlings to large marketable size without adversely affecting weight gain, feed efficiency, processing yield, or body composition. Large marketable-size channel catfish appear to use diets less efficiently but give higher processing yields compared to small marketable-size fish.  相似文献   

12.
Frass is the by‐product of the larval meal industry and includes larval waste, exoskeleton sheds and residual feed ingredients. Experimental frass was derived from the larvae of black solder flies fed distillers' dried grains with solubles and had a protein and fat content of 216 and 60 g/kg, respectively. A 10‐week study was conducted to evaluate the effect of dietary levels of frass on growth, feed utilization, and body proximate and mineral composition of channel catfish, Ictalurus punctatus. Five diets containing 0, 50, 100, 200 and 300 g frass per kg diet were fed to channel catfish (5.24 ± 0.04 g) in quadruplicate aquaria to apparent satiation twice daily. Final weight gain was significantly increased in fish fed diets containing frass at levels from 100 to 300 g/kg. Fish fed diets without frass, and with 300 g/kg frass, showed the lowest and highest feed intake, respectively. Feed and protein efficiencies, however, were significantly lower in fish fed frass at levels of 200 g/kg and higher compared to the control diet. Survival, whole‐body composition and mineral content were not affected by frass. In summary, black soldier fly larval frass has potential as a protein source or just an ingredient for enhancing palatability of catfish diets.  相似文献   

13.
Two experiments were conducted in earthen ponds to evaluate the effect of dietary protein concentration and feeding rate on weight gain, feed efficiency, and body composition of channel catfish. In Experiment 1, two dietary protein concentrations (28% or 32%) and four feeding rates (≤ 90. ≤ 112, ≤ 135 kg/ha per d, or satiation) were used in a factorial arrangement. Channel catfish Ictalurus punctatus fingerlings (average size: 27 g/fish) were stocked into 0.04-ha ponds at a rate of 24,700 fish/ha. Fish were fed once daily at the predetermined maximum feeding rates for 282 d (two growing seasons). In Experiment 2, three dietary protein concentrations (24, 28, or 32%) and two feeding rates (≤ 135 kg/ha per d or satiation) were used. Channel catfish (average size: 373 g/fish) were stocked into 0.04-ha ponds at a rate of 17,300 fish/ha. Fish were fed once daily for 155 d. In both experiments, five ponds were used for each dietary treatment. Results from Experiment 1 showed no differences in total feed fed, feed consumption per fish, weight gain, feed conversion ratio (FCR), or survival between fish fed diets containing 28% and 32% protein diets. As maximum feeding rate increased, total feed fed, feed consumption per fish, and weight gain increased. There were no differences in total feed fed, feed consumption per fish, or weight gain between fish fed at ≤ 135 kg/ha per d and those fed to satiation. Fish fed the 28% protein diet had a lower percentage carcass dressout and higher percentage visceral fat than fish fed the 32% protein diet. Dietary protein concentrations of 28% or 32% had no effect on fillet protein, fat, moisture, and ash. Feeding rate did not affect FCR, survival, percentage carcass dressout, or fillet composition, except fillet fat. As feeding rate increased, percentage visceral fat increased. Fish fed at ≤ 90 kg/ha per d had a lower percentage fillet fat than fish fed at higher feeding rates. In Experiment 2, dietary protein concentration or maximum feeding rate did not affect total feed fed, feed consumption per fish, weight gain, FCR, or survival of channel catfish. Feeding rate had no effect on percentage carcass dressout and visceral fat, or fillet composition. This was due to the similar feed consumption by the fish fed at the two feeding rates. Fish fed the 24% protein diet had lower carcass dressout, higher visceral fat and fillet fat than those fed the 28% or 32% protein diet. Results from the present study indicate that both 28% and 32% protein diets provide satisfactory fish production, dressed yield, and body composition characteristics for pond-raised channel catfish fed a maximum rate of 90 kg/ha per d or ahove.  相似文献   

14.
Corn germ meal (CGM) is a by‐product of corn milling. On the basis of its nutrient composition and digestibility values, it appears to be a suitable ingredient for use in channel catfish, Ictalurus punctatus, diets. A study was conducted to examine the use of various levels of CGM in diets for pond‐raised channel catfish. Four 28% protein diets containing 0, 15, 25, and 35% CGM were evaluated. Fingerling channel catfish (mean initial weight: 71 g/fish) were stocked into 24, 0.04‐ha ponds at a rate of 14,826 fish/ha. Fish were fed once daily to apparent satiation for a 167‐d growing season. No significant differences were observed in total amount of diet fed, diet consumption per fish, net yield, weight gain, feed conversion ratio, survival, fillet yield, and fillet protein, fat, and moisture concentrations among fish fed diets containing various levels of CGM. Carcass yield decreased linearly as dietary CGM levels increased. Depending on prices, CGM can be used interchangeably with corn gluten feed in channel catfish diets as replacements for corn, wheat middlings, and soybean meal to reduce feed cost.  相似文献   

15.
Abstract.– Juvenile channel catfish Ictalurus punctatus (initial weight: 6.8 g/fish) were fed four practical diets containing 0, 250, 500, and 750 units of microbial phytase/kg and a diet containing 1% feed grade dicalcium phosphate (but no microbial phytase) under laboratory conditions for 12 wk. Fish fed the diets containing 250 units of microbial phytase/kg and above consumed more feed, gained more weight, and had a lower feed conversion ratio (FCR) in comparison to fish fed the basal diet containing no microbial phytase. Fish fed the diet containing dicalcium phosphate had intermediate weight gain and feed conversion ratio as compared to fish fed the basal diet and diets containing microbial phytase. Bone ash and phosphorus concentrations were lower for fish fed the basal diet than for fish fed other diets. No differences in weight gain, feed consumption, FCR, bone ash and bone phosphorus were observed among fish fed the diets containing various levels of microbial phytase. Fish fed the diet containing dicalcium phosphate had a lower bone phosphorus concentration than fish fed diets containing microbial phytase. Fecal phosphorus concentrations were lower for fish fed the diets containing microbial phytase than for fish fed the basal diet and the diet containing dicalcium phosphate. Results from the present study indicated that addition of 250 units of microbial phytase/kg to practical diets can effectively improve bioavailability of phytate phosphorus to channel catfish and may possibly eliminate the use of an inorganic phosphorus supplement in channel catfish diets. However, these data must be verified in trials conducted in ponds, prior to recommending removal of supplemental phosphorus from channel catfish diets.  相似文献   

16.
Abstract.— This study was conducted to evaluate corn gluten feed as an alternative feedstuff in the diet of pond-raised channel catfish Ictalurus punctatus . Three 32%-protein diets containing 0%, 25%, or 50% corn gluten feed were tested. Channel catfish fingerlings (average weight: 57 g/fish) were stocked into 15 0.04-ha ponds at a rate of 18,530 fish/ha. Five ponds were used for each dietary treatment. Fish were fed to satiation once daily for a 147-d growing period. No differences were observed in feed consumption, weight gain, feed conversion ratio, survival, or fillet protein concentration among fish fed the test diets. Fish fed diets containing 25% and 50% corn gluten feed exhibited a lower level of visceral fat and a higher carcass yield than fish fed the control diet without corn gluten feed. The diet containing 50% corn gluten feed resulted in a lower level of fillet fat and a higher level of moisture than the control diet. There were no visible differences in the coloration of skin or fillet of channel catfish fed diets with and without corn gluten feed. Results from this study indicated that channel catfish can efficiently utilize corn gluten feed at levels up to 50%n without adverse effect on feed palatability, weight gain, or feed efficiency. Corn gluten feed may be beneficial in reducing fattiness of channel catfish and improving carcass yield by reducing the digestible energy to protein ratio of the diet.  相似文献   

17.
Abstract Canola meal was used in channel catfish Ictalurus punctatus diets at levels of 0, 15.4, 30.8, 46.2 and 61.6%, by progressively replacing (on an equal nitrogen basis) 0, 25, 50, 75, or 100% of solvent-extracted soybean meal in the control diet. The feeds were formulated to contain approximately 29% crude protein and 2,650 kcal of digestible energy/kg on an air-dry basis. Each diet was fed to juvenile channel catfish to satiation twice daily for 10 wk. Fish fed the diets containing the two lowest levels of canola meal (15.4 and 30.8%) had similar weight gains, feed intakes, feed utilization efficiencies, and percent survivals relative to the group fed the control diet. Weight gains and feed intakes declined significantly as the dietary levels of canola meal were increased to 46.2% or higher, probably because of reductions in diet palatability and some impairment of feed utilization due to the presence of increased levels of antinutritional factors, particularly glucosinolates. Whole body percentages for moisture and crude protein were unaffected by the dietary treatments. Body ash contents, however, were lowest for fish fed the control diets but were essentially the same for fish fed the other diets. Fish fed the diet containing 30.8% canola meal had lowest body fat content but this effect may not have been diet related. Values for red blood cell concentration, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were not affected by dietary canola meal level, but hematocrit was higher (although not always significant) for fish fed the control diet. The results of this study suggest that canola meal can comprise about 31% of the diet of channel catfish by replacing half of the amount of soybean meal used in the control diet without adversely affecting growth or any other aspect of performance.  相似文献   

18.
Two experiments were conducted to evaluate the palatability of sarafloxacin HCl to channel catfish, Ictalurus punctatus. Fingerling channel catfish were raised in 110-1 glass aquaria supplied with flowing well water at a rate of 1 l/min. Fish were fed to satiation once daily either a purified or a practical diet formulated to contain 0, 500, 1,000, 2,000, or 4,000 mg active sarafloxin HCl/kg of diet. Feed consumption was quantified daily for 5 days. All fish were weighed at the beginning and at the end of each experiment. There was a significant decrease in feed consumption of fish fed purified diets with increasing levels of sarafloxacin HCl. However, feed consumption was adequate to provide the proposed dosage regardless of drug concentration. Fingerling channel catfish readily consumed practical diets containing sarafloxacin HCl; feed consumption and weight gain of fish fed medicated and non-medicated practical diets did not differ. There were no apparent palatability problems that would negate use of sarafloxacin HCl in commercial channel catfish feeds.  相似文献   

19.
Three oilseed protein concentrates (soybean, canola, and sunflower) were evaluated to determine their potential, when supplemented with deficient essential amino acids, to partially or completely replace fish meal in diets fed to rainbow trout Oncorhynchus mykiss . Triplicate aquaria of juvenile trout (average weight of 12 g) were fed the experimental diets for 10 wk, at which time the average weight of the fish was approximately sixfold higher than the initial weight. Average fish weight gains on diets in which the protein component was 100% fish meal; 75% fish meal, 25% soybean protein concentrate; 50% fish meal, 50% soybean protein concentrate; and 75% fish meal, 25% sunflowerseed protein concentrate were not significantly different ( P < 0.05). The average weight of fish fed a commercial feed was significantly lower than that of fish fed the 100% fish meal diet, but not significantly different from fish fed the three other formulations mentioned above. Fish fed diets containing 50% fish meal, 50% canola protein concentrate; and 25% fish meal, 75% sunflowerseed protein concentrate had significantly lower average final weights than those of fish fed the other diets. Feed conversion ratio patterns among the dietary treatment groups reflected those of weight gain. Fish survival exceeded 95% on all diets. Apparent protein digestibility coefficients ranged from 79.5% (75% soybean protein concentrate, 25% canola protein concentrate) to 90.6% (100% soybean protein concentrate). The results of this study demonstrated that certain oilseed protein concentrates have good potential as protein sources in rainbow trout feeds when properly supplemented with essential amino acids.  相似文献   

20.
A feeding trial was conducted in aquaria with juvenile hybrid tilapia (Oreochromis niloticus×Oreochromis aureus) to evaluate the use of different protein sources in combination with distillers dried grains with solubles (DDGS). Twelve 110‐L glass aquaria were stocked with 28 juvenile (2.7±0.5‐g) hybrid tilapia per aquarium. Three replicate aquaria were randomly assigned to each of the four dietary treatments. Diets were isonitrogenous and isocaloric. The control diet contained 12% fish meal and 41% soybean meal as the primary protein sources (Diet 1). Each experimental diet contained 30% DDGS by weight, in combination with 8% fish meal and 34% soybean meal (Diet 2), 26% meat and bone meal (MBM), and 16% soybean meal (Diet 3), or 46% soybean meal alone (Diet 4). Fish were fed to apparent satiation twice a day for 10 weeks. There were no significant differences (P>0.05) in average weight gain, specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER) among tilapia fed Diets 1, 2, and 3. Fish fed Diet 4 had significantly lower (P<0.05) average weight gain, SGR, and PER than fish fed Diets 1 and 3. Relative cost per unit weight gain for Diets 1, 2, and 3 were statistically similar (P>0.05), while cost per unit weight gain for Diet 4 was significantly higher (P<0.05) than other diets. Diet 3 represented approximately a 20% cost savings compared with the control diet, with no reduction in growth. This study indicates that diets without fish meal containing 30% DDGS in combination with MBM and soybean meal provide good growth in tilapia. A diet without animal protein did not support acceptable growth.  相似文献   

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