Fingerling Channel Catfish Research Articles

Dietary Selenium Requirement of Fingerling Channel Catfish

Two experiments were conducted in aquaria to determine the minimum dietary selenium requirement of fingerling channel catfish (Ictalurus punctatus). Casein-gelatin diets containing graded levels of supplemental selenium (as Na2SeO3) ranging from 0 to 15 mg/kg were fed to catfish for 15 weeks in experiment 1 to broadly define their selenium requirement and toxicity levels. Although growth of catfish was affected by dietary selenium level, significant differences in weight gain were not easily discernible due to variability among the groups of fish. Weight gain data generally indicated that the basal diet containing 0.06 mg Se/kg diet caused growth depression, and a supplemental selenium level of 15 mg/kg also caused a reduced growth response, which indicated selenium toxicity. Selenium concentrations in edible muscle tissue increased almost linearly with increasing dietary selenium levels. Liver and plasma selenium-dependent glutathione peroxidase (Se GSH-Px) activities indicated the selenium requirement of fingerling channel catfish was between 0.1 and 0.5 mg Se/kg diet. In experiment 2, casein-gelatin diets containing incremental levels of supplemental selenium were fed to catfish for 14 weeks to more precisely determine their minimum dietary selenium requirement. Growth data and liver and plasma Se GSH-Px activities indicated that the minimum selenium requirement of fingerling channel catfish fed adequate vitamin E was 0.25 mg Se/kg dry diet. Based on these data, it appears that selenium supplementation of commercial catfish feeds is warranted.

EFFECT OF DIETARY LINOLEIC ACID LEVEL ON GROWTH, FOOD CONVERSION AND SURVIVAL OF CHANNEL CATFISH

ABSTRACTSemipurified diets containing 2.0 to 2.5% highly purified linoleic acid as the only dietary lipid produced similar growth responses in channel catfish fingerlings fed experimental diets for 14 weeks. Poorest growth was demonstrated by fish on a fat‐free diet and a diet which contained 4.0% linoleic acid, but growth on those diets was not significantly different (p > 0.05) from that obtained on diets containing 3.0 or 3.5% linoleic acid. Best food conversion (1.9 g of feed offered/g of weight gain) was associated with the diet containing 2.5% linoleic acid and poorest (2.6) occurred in fish which received 4.0% linoleic acid. Survival was highest (100%) in fish fed 2.0% linoleic acid and decreased linearly with increasing dietary linoleic acid level. The results of this study support the theory that poor growth of channel catfish on diets high in vegetable oils cannot be solely attributed to high levels of dietary linoleic acid.

Effects of feeding diets containing an imbalance of branched-chain amino acids on fingerling channel catfish

A series of studies was conducted to investigate the effects of feeding diets imbalanced with respect to branched-chain amino acids on channel catfish. Basal diets contained casein and gelatin supplemented with crystalline L-amino acids to correspond to the amino acid pattern found in 24% whole egg protein except for the branched-chain amino acids. Basal diets were formulated to be deficient in either leucine, isoleucine, or valine. Excess levels of either leucine, isoleucine, or valine were added to the appropriate basal diet. Growth and feed efficiency data demonstrate that excess leucine depressed growth of fish fed diets deficient in isoleucine or valine, but not in diets adequate in branched-chain amino acids. The deleterious effects of excess leucine could be reversed by supplementation with the deficient amino acid, but not by the other branched-chain amino acid. Growth was also depressed in fish fed excess isoleucine but not valine in leucine-deficient diets. Serum levels of isoleucine and valine suggest that leucine may control the tissue uptake of these amino acids in the channel catfish.

Dietary Pantothenic Acid Requirement of Fingerling Channel Catfish

Two experiments were conducted to reevaluate the dietary pantothenic acid requirement for fingerling channel catfish. Purified diets supplemented with calcium d-pantothenate were used in both experiments. The results indicate that the previously reported requirement value was underestimated. The minimum dietary calcium d-pantothenate level that produced maximum growth, feed efficiency and prevented the characteristic deficiency sign of gill lesions was 15 mg/kg of diet. The gill lesions were detected in 2 weeks in fish fed deficient diets. A reduction in the gill lesions was evident within 2 weeks after fish fed the deficient diet were converted to a diet containing 40 mg calcium d-pantothenate per kilogram of diet. In one experiment there appeared to be a high correlation between disease susceptibility and dietary calcium d-pantothenate level. Based on these observations and since the requirement may vary depending on fish size, age, water temperature, water ionic strength, fish density, oxygen availability, etc., we recommend a value of 30 mg calcium d-pantothenate per kilogram of diet be used in formulating catfish feeds.

Coelomic Distention in Channel Catfish Fingerlings

Coelomic Distention in Channel Catfish Fingerlings

Genetic and environmental control of fingerling size in channel catfish

The 360 channel catfish fingerlings used in this study were from three full-sib families (120/family) hatched in the summer of 1980. Forty fish (20 ♀ and 20 ♂) per size-class (large, medium, and small) were visually selected from each full-sib family. Half the fish in each size-class within each family were fed a commercial high protein diet (37.5%) and the other half a commercial low protein diet (32.0%). Catfish from the large, medium, and small size-classes fed the high protein diet for 20 weeks gained 86, 46, and 63% more weight than their full-sibs fed the low protein diet, respectively. The small size-class fingerlings fed the low protein diet for 20 weeks weighed only 24% as much as the large size-class fingerlings fed the high protein diet. Results indicated that economic management of catfish fingerlings should include visual sorting of the fingerlings and feeding according to their size and sex. The smaller fingerlings should be eliminated by selection from within-family due to their high mortality and low growth rate. Continuation of the study for an extra 10 weeks with only the high protein diet fed to all six groups indicated the strongest compensatory growth was for the small size-class catfish previously on the low protein diet. This study demonstrates that catfish size is not strictly genetically controlled and can be altered by protein intake.

Dietary Zinc Requirement of Fingerling Channel Catfish

Two experiments were conducted in order to establish the essentiality of zinc for fingerling channel catfish (Ictalurus punctatus) and to determine their dietary zinc requirement. Purified egg white diets with and without supplemental zinc were fed to channel catfish fingerlings for 12 weeks in the essentiality experiment. Catfish fed the basal diet containing 1.0–1.5 mg Zn/kg diet developed deficiency signs such as anorexia and suppressed growth. After week 8 of this experiment, two groups of fish fed the basal diet were converted to the zinc-supplemented diet, which contained 28 mg Zn/kg diet. Deficiency signs in these fish were alleviated after consumption of the zinc-supplemented diet. In the requirement experiment, graded levels of a zinc premix were added to egg white diets and fed to fingerling channel catfish for 14 weeks. Serum alkaline phosphatase, serum zinc, bone zinc and bone calcium data indicated that the minimum zinc requirement of fingerling channel catfish was 20 mg Zn/kg dry diet.

POLYCULTURE OF THE PRAWN, Macrobrachium rosenbergii, WITH FINGERLING AND ADULT CATFISH, Ictalurus punctatus, AND CHINESE CARPS, Hypophthalmichthys molitrix AND Ctenopharyngodon idella, IN EARTHEN PONDS IN SOUTH LOUISIANA

ABSTRACTA study was conducted to determine the feasibility of growing the giant prawn (Macrobrachium rosenbergii) in polyculture with channel catfish (Ictalurus punctatus) fingerlings and adults. Nursed juvenile prawns, 0.5‐1 g, were stocked in 18 0.04 ha ponds at 2,500/ha. Eight ponds were stocked with 0.05 g catfish fry at 100,000/ha or 200,000/ha; eight ponds received 13 g catfish fingerlings at 3,700 or 7,400/ha. Two ponds received prawns only as a control. Prawn survival from all ponds averaged 96%, and in no case was survival less than 84%. Prawn survival was not affected by the size or stocking density of catfish. Prawn yields averaged 170 kg/ha after a 107‐day grow‐out period. Overall, males averaged 87±25.3 g and females 55±13.9 g at harvest. Prawn yields and male weight at harvest were independent of catfish stocking size and stocking density. Harvest weight of individual female prawns was affected by catfish treatment. Prawn morphotypic profile was independent of catfish stocking treatment. Average adult catfish survival and yield were 52% and 1,305 kg/ha at the high stocking density, and 51% and 735 kg/ha at the low stocking density. Fingerling catfish survival and yield in fry‐stocked ponds averaged 41% and 963 kg/ha at the high density and 50% and 603 kg/ha at the low stocking densities. Poor catfish performance was not believed to be related to the presence of prawns.

Interactions of Freshwater Prawns, Channel Catfish Fingerlings, and Crayfish in Earthen Ponds

Abstract Prawns (Macrobrachium rosenbergii) were cultured in 0.04-ha ponds alone at densities of 25,000 and 50,000/ha, and at 25,000/ha with channel catfish fry (Ictalurus punctatus) at 150,000/ha. Catfish were also cultured alone at the same density. Mean survival was poor (prawns, 14-22%; catfish, 14-18%) and production was low (prawns, 90-270 kg/ha; catfish, 640 - 770kg/ha) after 140 days for prawns and 110 days for catfish. Survival and production values were lowest for prawns in the polyculture ponds (P < 0.05). Resident crayfish (Procambarus clarkii and P. acutus acutus) were harvested from all ponds (490 - 550 kg/ha).

Vitamin C and Disease Resistance in Channel Catfish (Ictalurus punctatus)

Channel catfish (Ictalurus punctatus) fingerlings were fed semipurified diets containing 0–150 mg/kg of vitamin C for 14 wk and subsequently at two temperature regimes infected with the pathogenic bacterium Edwardsiella tarda. Mortality rates were determined 96 h after infection. A supplemental vitamin C level of 30 mg/kg of diet was sufficient for normal growth and for prevention of deficiency signs such as lordosis, scoliosis, and a reduction in bone collagen formation. However, increased resistance against infection was provided when the level of supplemental vitamin C was increased to the highest dietary level, 150 mg/kg, at a water temperature of 23 °C. At 33 °C, increasing the supplemental level of vitamin C had significantly less effect on resistance against infection. The difference in response at the two temperatures indicates that the vitamin C requirement for resistance to infection is possibly higher when channel catfish are infected at lower temperatures, where the natural resistance is reduced, than when infected at a temperature near optimum for the natural resistance mechanisms of the fish.Key words: vitamin C, channel catfish, disease resistance, Edwardsiella tarda, infection

Magnesium Requirement of Fingerling Channel Catfish and Signs of Magnesium Deficiency

Purified casein diets with and without supplemental magnesium were fed to fingerling channel catfish (Ictalurus punctatus) in order to establish the essentiality of this mineral. Fish fed the basal diet containing 0.004% magnesium developed deficiency signs such as poor growth, anorexia, sluggishness, muscle flaccidity and high mortality. After 3 weeks, two groups of fish fed the basal diet were converted to the supplemental diet containing 0.057% magnesium. Deficiency signs in these fish were alleviated almost immediately. In a second experiment, graded levels of magnesium sulfate were added to casein-based diets and fed to channel catfish fingerlings to determine their dietary requirement for magnesium. Results indicated that a minimum magnesium level of 0.04% of the dry diet was required to maintain normal growth, serum and bone magnesium levels in channel catfish fingerlings.channel catfish magnesium requirement magnesium deficiency

Dietary Phosphorus Requirement of Channel Catfish

Two experiments were conducted to reevaluate the dietary phosphorus requirement of fingerling channel catfish. Basal diets containing either casein with supplemental inorganic phosphorus and 0.5% total calcium or egg albumin with supplemental inorganic phosphorus and 0.75% total calcium yielded similar requirement data. Eleven-week growth, feed efficiency, serum phosphorus, bone ash, bone calcium and bone phosphorus data indicate that 0.33% apparent available dietary phosphorus is adequate for maximum growth and bone mineralization. Based on these data and previous findings, we would suggest a value of 0.4% apparent available phosphorus be used in formulating catfish feeds. The apparent availability of phosphorus from soybean meal, as determined by the chromic oxide indicator method, was 29% for channel catfish.channel catfish phosphorus requirement available phosphorus soybean meal

COMMUNAL STOCKING AND MULTIPLE REARING TECHNIQUE FOR CATFISH GENETICS RESEARCH

ABSTRACTThe correlation between gain in communal ponds and separate ponds for different strains, crossbreds, species, and hybrids of catfish in six experiments was 0.89 to 0.97 and averaged 0.93. The mean correlation between replicate communal ponds was 0.91. These high correlations were obtained within several experiments in which various genetic crosses, ages of fish, and stocking rates were involved. Rank of gain in communal ponds was the same as rank of gain in separate ponds. This allows the use of communal ponds for catfish genetics research.Three major variables determined the effect of initial weight on final weight. They were: the mean initial weight, the magnitude of the initial difference, and the harvest weight. These different conditions caused final differences of 2.6–16.7 g per g of initial difference.Multiple rearing is a technique where feeding is adjusted to ensure that fish are of similar sizes for the initiation of genetics experiments in communal or separate ponds. If compensatory gain exists in stunted channel catfish, the multiple rearing technique would not be valid for catfish genetics experiments. No growth differences (P &gt; 0.05) were exhibited between stunted and normal fish after 26 days. Compensatory gain was not exhibited by channel catfish fingerlings; therefore the multiple rearing technique is valid for genetics experiments involving fingerling catfish.

Effects of Diet on Lipogenic Enzyme Activities in Channel Catfish Hepatic and Adipose TissueAdipose Tissue

Three isonitrogenous, isoenergetic diets were formulated with varying levels of carbohydrate (CHO) and lipid to determine the effect of energy source on lipogenic enzyme activities in fingerling channel catfish. Diets A, B, and C contained, expressed as a percentage of total energy, 0% CHO and 49% lipid, 16% CHO and 33% lipid, and 46% CHO and 3% lipid, respectively. Duplicate groups of 60 fish weighing 435 ± 5 g/group were fed 3% of their wet weight per day. Fish fed the high lipid (A) diet grew as well as fish fed the high-CHO (C) diet. Fish fed diet B, however, had a significantly greater growth rate. Fish were sampled and composite samples of liver and mesenteric adipose tissue were assayed for the following enzymes: fatty acid synthetase, malic enzyme, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and NADP-isocitrate dehydrogenase. In both hepatic and adipose tissue, all lipogenic enzymes assayed were stimulated by the high-CHO diet. All lipogenic enzymes were depressed by the high lipid diet only in hepatic tissue. Enzyme activities were much lower in adipose tissue relative to hepatic tissue. The marked stimulation of the hepatic lipogenic enzyme activities by dietary CHO may explain why catfish can utilize higher levels of dietary CHO than certain solmonid fishes.lipogenic enzymes channel catfish

Effects of casein coating on utilization of dietary amino acids by fingerling carp and channel catfish.

A six week feeding study was carried out to elucidate the effects of casein coating on the utilization of crystalline amino acids (AAs) which had been supplemented to diets for carp and channel catfish fingerlings. The experimental diets were formulated to have similar essential amino acid (EAA) profiles, twtal AA contents, and other compositions to those of the control diet (25% casein and 10% gelatin). Both carp and catfish responded to the pH adjustment AA diet to a certain extent; coating the whole AA mixture with casein or the addition of 7.65% casein (total amount used to coat the mixture) to the AA mixture with pH adjustment improved growth and feed efficiency (FE) significantly in carp and almot four-fold in catfish. Addition of individually coated EAAs to gelatin instead of the uncoated EEAs improved growth and FE about four-fold in carp and almost three-fold in catfish. Also, addition of 2.5% casein (total amount used to coat the AAs) to gelatin with the uncoated EAAs improved growth and FE about three-fold in carp, but this treatment showed no significant effect in catfish. None of these treatment groups showed a performance comparable to that of the control groups. However, data from this study suggest that, in both species, utilization of an AA mixture could be improved by adding a certain amount of casein as well as couating the mixture with casein. Efficiency in utilization of EAAs supplemented to gelatin can be enhanced further by coating them individually with casein rather than by simply akking 2.5% casein.

Arginine Requirement and Apparent Absence of a Lysine-Arginine Antagonist in Fingerling Channel Catfish

A series of growth studies, utilizing casein-gelatin based diets supplemented with crystalline amino acids, were conducted to determine the arginine requirement for fingerling channel catfish (Ictalurus punctatus) and to evaluate the effects of excessive levels of dietary lysine and arginine. Weight gain and feed efficiency data indicate the arginine requirement to be 1.03 ± 0.07% and 1.00 ± 0.06% of the dry diet, respectively. Based on growth this corresponds to 4.29% of the dietary protein. There was no evidence of an arginine-lysine antagonism when excess lysine was fed in diets adequate or marginal in arginine. Similarly, growth and feed efficiency data suggest the lack of an antagonism when excess arginine is added to diets marginal in lysine. Apparently channel catfish are not as sensitive to disproportionate lysine and arginine levels as are other animals.arginine lysine-arginine channel catfish

Effects of dietary copper on channel catfish

Purified diets with 0, 2, 4, 8, 16 and 32 mg supplemental copper/kg were fed for 16 weeks to channel catfish fingerlings. No signs of deficiency were noted in groups fed a diet without supplemental copper which contained 1.5 mg copper/kg of diet. Reduced growth and feed conversion were noted in fish fed 16 and 32 mg copper/kg. The copper levels in liver were significantly higher in fish fed 32 copper/kg than those fed the unsupplemented diet. Slight anemia was noted in fish fed 32 mg copper/kg. Plasma, erythrocyte and muscle copper levels were not affected by diets containing up to 32 mg copper/kg.

Total Aromatic Amino Acid Requirement, Phenylalanine Requirement and Tyrosine Replacement Value for Fingerling Channel Catfish

A series of experiments was conducted to determine the aromatic amino acid requirement, the tyrosine replacement value for phenylalanine and the phenylalanine requirement under conditions of adequate tyrosine for fingerling channel catfish. Effects of excessive dietary levels of tyrosine were also investigated. The studies were conducted utilizing casein and gelatinbased diets supplemented with crystalline L-amino acids to correspond to the pattern of 24% whole egg protein. Based on 8-week growth studies, the total dietary aromatic amino acid requirement for fingerling channel catfish was approximately 1.20 +/- 0.06% (50% of the dietary protein) of which about 50% could be supplied by tyrosine. The phenylalanine requirement per se, based on growth and feed efficiency, was determined to be 0.47 +/- 0.02% and 0.49 +/- 0.02%, respectively. High dietary levels of tyrosine (up to 10%) did not adversely affect performance of fingerling channel catfish. It appears that neither serum-free phenylalanine nor serum-free tyrosine can be used to accurately predict dietary aromatic amino acid adequacy for the fingerling channel catfish.

Leucine, Isoleucine, Valine and Histidine Requirements of Fingerling Channel Catfish

Growth studies were conducted with fingerling channel catfish to determine the minimal requirements for the amino acids leucine, isoleucine, valine and histidine. The experimental diets were formulated from purified ingredients to contain 24% crude protein and 275 kcal/100 g diet. Casein and gelatin served as protein sources and were supplemented with crystalline L-amino acids to provide the amino acid pattern found in 24% crude protein from whole egg powder. Based on dry diet the catfish required 0.84 +/- 0.04% leucine, 0.62 +/- 0.04% isoleucine, 0.71 +/- 0.03% valine and 0.37 +/- 0.01% histidine. These values correspond to 3.50% leucine, 2.58% isoleucine 2.96% valine and 1.54% histidine when expressed as a percentage of dietary protein. Quantitation of serum free amino acid levels revealed a marked increase in valine and isoleucine in leucine-deficient fish. In addition, increases in dietary isoleucine or valine resulted in changes in the serum levels of isoleucine, valine and leucine. These data indicate an apparent interaction among these amino acids in the catfish comparable to that previously observed in other species. Dietary histidine caused no increase in serum free histidine levels until the dietary requirement was reached. Muscle carnosine could not be detected in the catfish.

Effects of dietary cholecalciferol and ergocalciferol on catfish

In separate feeding trials, channel catfish fingerlings were fed 0, 1000, 4000, 8000, 20,000, 50,000, and 0, 500, 1000, 2000, 4000, 8000 I.U./kg diet of cholecalciferol and ergocalciferol for 28 weeks. The supplemental requirement for maximal growth was between 1000 and 4000 I.U. of supplemental cholecalciferol/kg diet. At supplemental levels of 1000 I.U./kg diet or less, the growth responses to ergocalciferol were equal to those obtained from equivalent levels of cholecalciferol. However, at higher supplemental levels of ergocalciferol, the weight gains were significantly less than those obtained from 2000 to 20,000 I.U./kg of cholecalciferol. Weight gains were significantly reduced when 50,000 I.U./kg of cholecalciferol were fed. Vertebrae bone ash values were not affected by dietary vitamin D levels. Reduced weight gains and feed efficiency were the only signs of vitamin D deficiency or hypervitaminosis D.