Fingerling Channel Catfish Research Articles

Effects of dietary pantethine and lipid levels on growth and body composition of channel catfish, Ictalurus punctatus

The effects of various dietary lipid and pantethine levels on body composition of channel catfish were investigated using a 2 × 3 factorial design. Purified casein/gelatin diets containing two levels of lipid (5 and 10%) and three levels of pantethine (0, 250, and 1000 mg/kg) were fed to fingerling channel catfish initially weighing 3.3 g in 38-1 flow-through aquaria for 12 weeks to evaluate the effects of the experimental diets on growth rate and feed efficiency. Following the feeding trial, fish were analyzed for proximate composition of whole-body, liver and fillet samples as well as hepatosomatic index and intraperitoneal fat (IPF). Fatty acid analysis was also performed on fillet lipids. Factorial analysis of variance indicated that dietary lipid had significant ( P < 0.05) effects on growth, feed efficiency and body composition. The diets containing 10% lipid generally produced higher weight gain and feed efficiency values as well as higher IFF, whole-body and fillet lipid levels. In the liver, 10% dietary lipid significantly increased only the ash level. Fatty acid analysis of fillet samples revealed that both dietary lipid and pantethine had significant effects on composition. The 5% lipid diets generally produced increased levels of palmitic, stearic and oleic acids and the 10% lipid diets produced increases in myristic, linoleic, erucic and docosapentaenoic acids. Supplementation of pantethine had no effects on weight gain and feed efficiency but produced increased levels of oleic acid in fillet lipids. Based on results from this study, dietary lipid significantly influenced performance and lipid deposition of channel catfish, whereas effects of pantethine (at 250 and 1000 mg/kg diet) were negligible.

Dietary rutin has limited synergistic effects on vitamin C nutrition of fingerling channel catfish (Ictalurus punctatus)

A study was conducted to determine the possible synergistic effects between dietary rutin (a bioflavonoid) and vitamin C, and to evaluate their antioxidant effects in fingerling channel catfish. Purified casein/gelatin diets containing two levels of rutin (0 and 1000 mg/kg diet) and three levels of L-ascorbic acid (0, 1500 and 3000 mg/kg diet) in a factorial arrangement were fed to fingerling channel catfish for 16 weeks. Fish fed the diets without supplemental vitamin C showed deformed spinal columns, external hemorrhages and fin erosion after 10 to 12 weeks. Also these fish had significantly (p < 0.05) depressed body weight gain, feed efficiency, hematocrit, hepatosomatic index (% liver weight), as well as reduced liver, fillet and plasma vitamin concentrations after 16 weeks. Liver, fillet and plasma vitamin C concentrations were correlated with dietary vitamin C levels. Forced oxidation of fillet samples significantly (p < 0.05) increased 2-thiobarbituric acid (TBA) values of fillets from fish fed diets without vitamin C and rutin. However, results from the present study indicated only limited synergistic effects of dietary rutin on vitamin C nutrition of channel catfish.

Na-L-ascorbyl-2-monophosphate as a source of vitamin C for channel catfish

Channel catfish ( Ictalurus punctatus) fingerlings (1.5 g average initial weight) were fed semipurified diets supplemented with 0, 15, 30, 60 or 120 mg/kg (0, 0.08, 0.16, 0.32, and 0.64 mmol/kg) of ascorbic acid molar equivalent supplied by either Na-L-ascorbyl-2-monophosphate (AAP-Na) or Mg-L-ascorbyl-2-monophosphate (AAP-Mg). After 12 weeks, weight gain was significantly equal for all fish fed AAP-Na or AAP-Mg, although growth rate was less for fish fed the ascorbic acid-free diet (basal). There were no gross signs of vitamin C deficiency in any of the fish fed AAP-Na or AAP-Mg, while spinal deformities were found in 26% of the fish fed the basal diet. Bone collagen content was equal for all treatments with AAP-Na or AAP-Mg; however, there was reduced bone collagen content, a sensitive indicator of vitamin C deficiency, in fish fed the basal diet. Percentage recovery of ascorbic acid from commercially extruded catfish feeds supplemented with AAP-Na and AAP-Mg was 99 (±11.1) and 98 (±12.1), respectively. This study indicates that AAP-Na has equimolar activity to AAP-Mg as an ascorbic acid source for growth and collagen synthesis in channel catfish and that both compounds are highly stable against processing loss. Previous studies had shown that AAP-Mg has equal vitamin potency for channel catfish as L-ascorbic acid.

Palatability of Sarafloxacin HCl-Medicated Feed to Channel Catfish

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 ...

Effect of Protein Level and Feeding Frequency on Growth and Body Composition of Cage-Reared Channel Catfish

Abstract Channel catfish (Ictalurus punctatus) fingerlings were stocked in eight 1.25-m3 floating cages at densities of 320 fish/m3 and fed to satiety once or twice daily for 105 d with diets containing either 34 or 38% protein. Experimental diets were formulated by a commercial feed mill with recommended levels of essential amino acids, vitamins, and minerals. Fish fed a diet containing 38% protein had significantly (P 0.05) were found when body composition was analyzed in relation to dietary protein level, feeding frequency, and their interaction. These data indicate that channel catfish reared in cages may require a diet with a hi...

Replacing Fish Meal with Seafood Processing Wastes in Channel Catfish Diets

Abstract Various seafood processing wastes were collected, analyzed, and evaluated for their use as primary protein sources in catfish diets. Finfish wastes (flounder racks and mixed finfish) were higher in crude protein content (60 versus 40%) than blue crab (Callinectes sapidus) wastes. Practical diets containing menhaden (Brevoortia spp.) fish meal or one of four seafood processing wastes (flounder racks, mixed finfish, blue crab, and blue crab without carapace) amounting to 10% of the diet were fed to fingerling channel catfish (Ictalurus punciatus) for 7 weeks under controlled, laboratory conditions. Weight gain and feed efficiency did not differ among treatments. Similar diets containing Atlantic herring (Clupea harengus) or blue crab meal were compared with a standard production diet containing fish meal in a 139-d field cage culture experiment. Caged channel catfish fed the control or Atlantic herring diets had greater daily gain and net production than those fed the crab diet.

Improvement of Cottonseed Meal Protein with Supplemental Lysine in Feeds for Channel Catfish

Two studies were conducted to evaluate cottonseed meal (CSM) with and without supplemental lysine as a substitute for soybean meal (SBM) in catfish feeds. One study was conducted in aquaria under controlled environmental conditions with fingerling channel catfish, and the other was conducted with fish raised in 6-m3 net pens suspended in a 1.6-ha earthen pond. In each study, solvent extracted CSM was substituted for SBM on a nitrogen basis. Supplemental lysine was added to the feeds in which CSM replaced 50 and 100% of the SBM because they were estimated to be deficient in available lysine. In the aquarium study, 0, 25, 50, and 100% of the SBM was replaced with CSM. The same feeds used in the aquarium study were used in the net pen study, except that the 25% substitution was not used. Fish raised in aquaria were fed 4% body weight divided into two equal daily feedings, and those raised in net pens were fed to station once daily. Data presented herein demonstrate that channel catfish can effectively utiliz...

Effect of Source and Dietary Concentration of Ascorbic Acid on Tissue Concentrations of Ascorbic Acid in Channel Catfish

AbstractSemipurified diets containing either no ascorbic acid or supplemental amounts of 11, 22, 44 and 132 mg/kg from Gascorbic acid (AA), L‐ascorbyl‐2‐monophosphate (AAP) or L‐ascorbyl‐2‐sulfate (AAS) were fed to channel catfish fingerlings (13 ± 2.1 g average initial weight) in aquaria. After a feeding period of 14 wk, weight gain was measured and ascorbic acid content of liver and anterior kidney of the fish was determined. Growth was normal for fish fed all dietary levels of AA and AAP, but lower in fish fed the control and diets supplemented with all levels of AAS; however, growth improved as the concentration of AAS increased. Liver and kidney ascorbic acid increased with level of dietary supplementation in fish fed AA and AAP but only traces or no detectable levels were found in the tissues of fish fed AAS or the controls. Liver and kidney levels of ascorbic acid were significantly higher in fish fed AAP than in fish fed corresponding levels of ascorbic acid from AA. Regression of liver ascorbic acid content on diet concentration indicated that the potency of AAP for maintaining liver storage of ascorbic acid at a minimum acceptable level is 1.74 times higher than that of AA on an ascorbic acid equivalent basis. These results demonstrate that AAP and AA have similar vitamin activity for growth in channel catfish, but AAP is markedly more effective for maintaining tissue levels of ascorbic acid, and that AAS has limited vitamin activity for growth and its contribution to the tissue ascorbic acid pool is negligible.

L-Ascorbyl-2-Monophosphate has Equal Antiscorbutic Activity as L-Ascorbic Acid but L-Ascorbyl-2-Sulfate is Inferior to L-Ascorbic Acid for Channel Catfish

Channel catfish (Ictalurus punctatus) fingerlings (13 g average initial weight) were fed semipurified diets supplemented with 0, 0.06, 0.12, 0.24 and 0.72 mmol/kg (0, 11, 22, 44 or 132 mg/kg) of ascorbic acid molar equivalent supplied by either L-ascorbic acid, L-ascorbyl-2-monophosphate (Mg salt) (AAP), or L-ascorbyl-2-sulfate (K salt) (AAS). After 14 wk, weight gains were equal for all fish fed diets containing L-ascorbic acid or AAP; however, growth rates were less for fish fed AAS at all dietary levels and for fish fed the ascorbic acid-free diet (control). There were no gross signs of vitamin C deficiency in any of the fish fed L-ascorbic acid or AAP, whereas spinal deformities were found in the controls and in fish fed all but the highest concentration of AAS. The percentage of spinal deformities decreased as dietary levels of AAS increased. Reduced bone collagen content and histopathology in liver and gill tissues also indicated ascorbic acid deficiency in the controls and in fish fed all but the highest concentration of AAS. Limited histopathology was found in fish fed the lowest level of L-ascorbic acid but not in those fed the lowest level of AAP. Regression analysis of weight gain data showed that the vitamin activity of ascorbic acid from AAS was only 5.2% of that from L-ascorbic acid for growth. This study indicates that AAP has equimolar activity to L-ascorbic acid as a vitamin C source for channel catfish and that AAS has vitamin activity for this species but at a much lower level than the other compounds.

Overwintering Paddlefish in Monoculture and in Polyculture with Channel Catfish and Rainbow Trout

Paddlefish, "Polydon spathula," overwintered in monoculture and in polyculture with fingerling channel catfish, "Ictalurus punctatus," or with rainbow trout, "Oncorhynchus mykiss," were examined for growth and compatibility in nine 0.04-ha ponds. Paddlefish in polyculture had significantly greater (P ≤ 0.05) individual weight gains than those in monoculture. Feed in polyculture treatments probably served as a fertilizer, promoting zooplankton production for paddlefish consumption and growth. Paddlefish in polyculture with fingerling channel catfish had significantly greater (P < 0.05) individual weight gains than paddlefish polycultured with rainbow trout, although there was less feed input with channel catfish than with rainbow trout. Bloody and frayed fins on paddlefish stocked with rainbow trout suggested fin nipping by rainbow trout which may have interfered with paddlefish feeding and growth. Paddlefish overwintered in polyculture with fingerling channel catfish demonstrated increased weight gains and good species compatibility.

Recovery of Channel Catfish from Abdominal Surgery

Abstract Surgical incisions, performed with anesthesia in a septic environment, were made in the lateral–ventral abdominal wall of 244 fingerling channel catfish (Ictalurus punetatus; mean weight, 39.8 g ± 1.2 SE), and survival was monitored for 27 d. The incisions allowed gross observation of developing gonads to determine gender. After fish recovered from anesthesia in aerated water (about 30 min after they were first netted), they were dosed with NaCl (5.9 g/L) and nitrofurazone (211 mg/L). Thereafter, the fish were treated twice daily for 10 d with salt and nitrofurazone in a flow-through water system. They resumed feeding 6 d after surgery. Twenty-seven days after surgery, survival averaged 95.5% and all incisions were healed. Small channel catfish do not have to be killed or allowed to die after invasive procedures. Nevertheless, continued research is needed on noninvasive procedures to obtain biological information without surgery-related mortality.

Growth and Bone Development in Channel Catfish Fed 17‐α‐Methyltestosterone in Production Ponds

AbstractEffects of feeding 17‐α‐methyltestosterone (MT) to channel catfish (Icralurus punctatus) grown to harvestable size in earthen ponds were examined. Channel catfish fingerlings (mean weight, 14.4 g), stocked in 0.04 ha ponds (7,410 fish/ha) were fed diets containing MT at concentrations of 0, 2.5, and 10 mg/kg for 123 days. Weight gain by fish fed the control diet (0 MT) was higher (P &lt; 0.05) than that of fish fed the treated diets. Increasing the dietary concentration of MT reduced weight gain further (P &lt; 0.05). Both male and female fish fed MT had enlarged and thickened heads, and their skins were dark. Their dorsal and pectoral spines were short and the tips, which are normally very sharp, were soft and blunt. Weight of the rib bones per unit of length decreased (P &lt; 0.05) as MT was added to the diet. Breaking strength of the ribs (force required to break the bone at its midpoint) measured by an Instron shear press, was less (P &lt; 0.05) for fish fed MT than for control fish. The ratio of calcium to phosphorus in bones was lower (P &lt; 0.05) in fish fed MT. These results indicate that feeding MT at these doses (2.5 mg/kg or above) to channel catfish suppresses growth rate and reduces size and strength of bones.

Partial substitution of soybean meal with animal protein sources in diets for channel catfish

Nine-week laboratory feeding experiments were conducted to evaluate partial substitution of animal protein sources into a 32% protein soybean-meal-corn basal diet for channel catfish ( Ictalurus punctatus) fingerlings. In the first experiment, substitution of 5, 10, 20, and 40% menhaden fish meal into the basal diet resulted in increases in weight, protein, and fat gains as fish mean was increased to 20% ( P < 0.05), and an increase in fat gain as fish meal was increased to 40% ( P < 0.05). In the second experiment, the basal diet was supplemented with 5 and 10% fish meal or isonitrogenous amounts of protein from meat and bone meal (5.6 and 11.3%), blood meal (3.4 and 6.8%), and a 60:40 combination of meat and bone and blood meals (5 and 10%). Weight, protein, and fat gains were improved ( P < 0.10) when the lower level of each animal protein, except blood meal, was substituted into the basal diet. Increasing the dietary level of each animal protein, except blood meal, improved gains over those from diets containing the lower level of the animal protein ( P < 0.10). Fish meal improved gains more than isonitrogenous levels of the other animal proteins at both dietary levels ( P < 0.10). Estimated amino-acid contents of the diets indicate that the increase in growth produced by including fish meal may be explained on the basis of increasing dietary levels of the most limiting amino acids; however, the increase in growth effected by including the other animal protein sources in the diet cannot be explained on that basis. Food consumption during the first 3 days of experiment indicated that inclusion of fish meal, meat and bone meal, or the meat and bone-meal-blood-meal combination improved diet palatability.

Growth Response of Fingerling Channel Catfish to Sheltered Feeding

Abstract A fish excluder that provided a sheltered feeding area for small fingerling channel catfish (Ictalurus punctatus) in a multiple-cohort production system was tested. Small fingerlings (mean weight, 12.7 g) were stocked in ponds with larger submarketable fish (286 g). Fingerlings in the ponds with excluders showed a 64% increase in weight gain over fish in the control group.

Winter Polyculture of Rainbow Trout and Fingerling Channel Catfish

Abstract The feasibility of rearing rainbow trout (Oncorhynchus mykiss) with overwintering fingerling channel catfish (Ictalurus punctatus) at one of two densities was examined. Individual weight gain, net production, and feed conversion were better for rainbow trout in monoculture than in either polyculture treatment. There was a significant difference in growth but not in survival of channel catfish polycultured at low and high densities with rainbow trout.

Genotype-environment interactions for growth of blue, channel and hybrid catfish in ponds and cages at varying densities

Channel catfish, Ictalurus punctatus; blue catfish, I. furcatus; and hybrid channel ♀×blue♂ catfish fry were grown in ponds at densities of 7410/ha–2 245 000/ha. Channel catfish fingerlings and hybrid fingerlings were grown in ponds at densities of 7410/ha–22 230/ha, or 7410/ha with the addition of 1000 or 2000 kg/ha of co-stocked larger fish and in cages at 275/m 3. Genotype-environment interactions for growth rate occurred ( P<0.05) between hybrid catfish and channel catfish fry and between blue catfish and channel catfish fry stocked at varying densities. Channel catfish fry grew faster ( P<0.05) than hybrid fry at low densities, but hybrid catfish fry grew faster than channel catfish fry at higher densities. The relative growth advantage of channel catfish fry over blue catfish fry increased with density. The increased growth rate of hybrid catfish fry compared to channel catfish fry at high densities was observed in both communal and separate experiments. Hybrid catfish fingerlings grew faster to market-size than channel catfish fingerlings at all densities in ponds. Their relative advantage to channel catfish increased with density and the addition of larger competing fish in the ponds. The hybrid was also superior to channel catfish in both communal and separate high density experiments when grown from fingerlings to marketsize. Genotype-environment interactions occurred for growth rates in cages or ponds. Hybrid catfish grew faster ( P<0.01) than channel catfish in ponds, but slower ( P<0.01) than channel catfish in cages.

Unidirectional fluxes of na+, cl−1 and water in fingerling channel catfish, ictalurus punctatus

Abstract 1. 1. The influx of Na+ and Cl−(as 22Na+ and 36Cl−1) was measured in fingerling channel catfish (Ictalurus punctatus) and was found to be equivalent in a 7–8 g fish to about 20 and 40%, respectively, each day of their total body Na or Cl. In the smallest fish (l g), the rate of flux was 3–4 times as great as in larger (15g) ones. 2. 2. Unidirectional flux of water (as efflux of 3H-water) was very rapid, equivalent to about 3 times the total body water each hour. 3. 3. Drinking was relatively small equivalent to about 2.5% of the body weight each day (6% at pH 5) and so contributed little to the above fluxes, which presumably mainly occurred across the gills and possibly the skin. 4. 4. Influx of Na+ was reduced when the Ca2+ concentration was increased from 0.1 to 3 mM. Changes of pH between 8.3 and 5 and the presence of 0.01 mM A13+ such as may result from “acid rain” did not change Na influx. 5. 5. Efflux of Na+ was increased when the pH was decreased from 7.3 to 5, but neither Ca2+ (3 mM) nor Al3+ (0.01 mM at a pH of 5) had a significant effect. 6. 6. The unidirectional flux of water was reduced by 0.01 mM Al3+ at pH 5, but it was unchanged by a pH of 5 alone or 3 mM Ca2+.

Palatability of Diets Containing Sulfadimethoxine, Ormetoprim, and Romet 30 to Channel Catfish Fingerlings

Abstract Palatability studies with the two components of Romet, sulfadimethoxine and ormetoprim, indicate that ormetoprim is the primary component that causes reduced consumption of feed containing Romet by fingerling channel catfish (Ictalurus punctatus). When ormetoprim was added to purified diets at levels equivalent to 0.01, 0.05, 0.10, 0.25, and 0.50% Romet, depressed feed intake in 0.10 and 0.25% treatments resulted in consumption of about one-half of the recommended dosage (50 mg Romet/kg body weight). When Romet 30 was added to a practical catfish feed at four different levels (0.100, 0.125, 0.167, and 0.250%), feed intake decreased as the Romet content increased. The feed intake at each dosage resulted in the consumption of approximately 22 mg Romet/kg body weight per day. Based on the findings of this study, our recommendation is that the level of Romet in medicated feed for catfish be 8.3 g/kg feed and that the feed be fed at a rate of 1.0% of body weight!d.

Evaluation of L-ascorbyl-2-polyphosphate (AsPP) as a dietary ascorbic acid source for channel catfish

Channel catfish ( Ictalurus punctatus) fingerlings were fed purified diets containing 0 or 100 mg/kg of ascorbic acid equivalent supplied either by ethylcellulose-coated ascorbic acid, ascorbate-2-sulfate, or L-ascorbyl-2-polyphosphate (AsPP). Fish fed the ascorbate-free diet exhibited external signs of scurvy at 11 weeks. Carcass ascorbate concentrations, histopathology of gill tissue, and radiographs evaluated at the end of the experimental period confirmed that fish fed the ascorbate-free diet were scorbutic. Signs of ascorbate deficiency were not observed in fish fed other diets. Weight gain and carcass ascorbate concentration were highest in fish fed AsPP. Improvement in weight gain and increased tissue concentration of ascorbate in fish fed AsPP is not readily explained, but may related to the resistance of AsPP to oxidation; thus providing a higher concentration of ascorbic acid at absorption sites. The data from the present study demonstrate the efficacy of AsPP in promoting growth and preventing scurvy in catfish.

Effect of supplemental phytate and/or tricalcium phosphate on weight gain, feed efficiency and zinc content in vertebrae of channel catfish

A 12-week feeding experiment was conducted with fingerling channel catfish ( Ictalurus punctatus) to determine the effect of supplemental phytate and/or tricalcium phosphate on weight gain, feed efficiency and zinc content in vertebrae. Catfish fed a diet containing 2.2% phytic acid had significantly reduced weight gain and feed efficiency (653 vs 853 and 0.90 vs 1.02, respectively) compared to fish fed a diet containing 1.1% phytic acid. Zinc content in vertebrae was significantly reduced from 132.7 to 59.1 μg/g as the level of supplemental phytic acid was increased from 0 to 2.2% in fish fed diets containing 50 mg zinc/kg diet. Vertebral zinc content was not reduced when phytic acid was supplemented to diets containing 150 mg zinc/kg diet. There was no effect of supplemental tricalcium phosphate on weight gain or zinc content in vertebrae.