Catfish Vitamin Nutrition
Edwin
H. Robinson
Fishery Biologist, Coordinator
Thad Cochran National Warmwater Aquaculture Center
Meng H. Li
Assistant Fishery Biologist
Daniel F. Oberle
Research Assistant II
For more information, write Edwin Robinson at:
Thad Cochran National Warmwater Aquaculture Center
Mississippi State University
P.O. Box 197
Stoneville, MS 38776-0197
This publication was edited and designed by Robert A. Hearn, publications editor in the Office of Agricultural Communications, a unit of the Division of Agriculture, Forestry and Veterinary Medicine at Mississippi State University. The cover was designed by Nikki Bane, student artist.
Fishery Biologist, Coordinator
Thad Cochran National Warmwater Aquaculture Center
Meng H. Li
Assistant Fishery Biologist
Daniel F. Oberle
Research Assistant II
For more information, write Edwin Robinson at:
Thad Cochran National Warmwater Aquaculture Center
Mississippi State University
P.O. Box 197
Stoneville, MS 38776-0197
This publication was edited and designed by Robert A. Hearn, publications editor in the Office of Agricultural Communications, a unit of the Division of Agriculture, Forestry and Veterinary Medicine at Mississippi State University. The cover was designed by Nikki Bane, student artist.
Contents
Introduction
Vitamins
-- a group of organic compounds that are highly diverse in chemical structure
and physiological function -- are required in the diet for normal growth,
health, and reproduction of fish and other animals. Some animals are able
to synthesize certain vitamins in the body in quantities sufficient to
meet metabolic needs; thus, those vitamins do not have to be provided
in the diet. The vitamin nutrition of channel catfish has been the subject
of numerous research reports, which has culminated in the development
of a vitamin premix that is used to provide supplemental vitamins in commercial
catfish feeds. The premix contains all essential vitamins in sufficient
quantities to ensure optimum fish growth and health and to compensate
for losses during feed manufacture and storage.
The composition of catfish vitamin premixes has been based on vitamin requirements determined with small, rapidly growing catfish raised under laboratory conditions. These values have been considered sufficient to meet the needs of pond-raised fish. However, vitamin requirements may be affected by several factors, including fish size, environmental conditions, and fish health. Vitamins inherent in feedstuffs used in commercial catfish feeds are usually not considered when formulating catfish feeds because their bioavailability is not known, but they may be a significant source of vitamins. Pond organisms such as zooplankton contain relatively high concentrations of vitamins, but their contribution to the vitamin nutrition of catfish is also unknown. Since several factors may influence the vitamin nutrition of pond-raised catfish, vitamin requirements determined under conditions that reflect those used in the commercial culture of catfish would allow fish nutritionists to formulate catfish feeds that more precisely meet the vitamin needs of the fish.
The information presented in this bulletin includes a brief summary of the vitamin nutrition of catfish. However, the emphasis of the bulletin is on practical vitamin nutrition of catfish based on data from vitamin studies conducted at Mississippi Agricultural and Forestry Experiment Station research facilities over the last several years. Recommendations are made concerning vitamin supplementation of commercial catfish feeds.
This
bulletin is intended to provide a brief overview of the vitamin nutrition
of catfish. It also presents technical data from studies conducted at
the Delta Branch Experiment Station in Stoneville that provide new information
on practical vitamin requirements of catfish. Recommendations are given
on vitamin supplementation of commercial catfish feeds. English units
are used to present technical data because the bulletin is intended to
be useful to practicing nutritionists and catfish producers, as well as
other scientists.
Vitamin Requirements and Deficiency Signs
Table
1 summarizes qualitative and quantitative vitamin
requirements for channel catfish and characteristic vitamin deficiency
signs, which can be induced in catfish fed purified diets deficient in
a particular vitamin and raised under controlled conditions in the laboratory.
Vitamin deficiencies rarely occur in wild fish populations because fish
growth in the wild is relatively slow and natural foods contain adequate
amounts of all vitamins to meet the needs of the fish. Vitamin deficiencies
are more likely to occur in cultured fish because manufactured feeds promote
fast fish growth. Therefore, the cultured fish's vitamin requirements
are higher. Nevertheless, frank signs of vitamin deficiency are uncommon
in cultured fish because commercial feeds contain a vitamin supplement
that is generally more than adequate to meet the fish's needs. Occasionally,
however, abnormalities similar to vitamin C or pantothenic acid deficiency
signs have been observed in cultured fish. These instances are so rare
and so isolated that it is difficult to attribute them to a generalized
deficiency in the diet.
Vitamins and Disease Resistance
Vitamins
and other nutrients are essential for the proper function of the immune
system. There is certainly a lot of attention given to the role of vitamins
in the health of humans and other animals, and there have been conflicting
reports on the amount of various vitamins that must be ingested to elicit
the proposed response. Likewise, there has been considerable interest
among catfish researchers and catfish producers concerning the use of
megadose levels of certain vitamins to enhance disease resistance in catfish,
and there have been conflicting reports as to the value of this practice.
Early evidence indicated that high levels of vitamin C reduced mortality
from certain bacterial diseases of catfish. As a result, some catfish
producers fed a high-C feed, which contained about 2,000 parts per million
(ppm) of vitamin C, during late winter or early spring, hoping to enhance
immune function of the fish. Data from at least six MAFES-supported studies
over the last few years indicate that high levels of vitamin C in the
diet of catfish are not necessary to enhance disease resistance. Concentrations
of vitamin C as low as 25 ppm have been shown to be sufficient to enhance
survival of catfish during challenge with the bacterium Edwardsiella
ictaluri. Commercial catfish feeds are generally supplemented with
enough vitamin C to provide 80 to 100 ppm of the vitamin in the final
feed, which appears to be in excess of that needed for fish health and
normal growth. The effects of other vitamins on immune function of catfish
have been investigated. Although specific changes have been measured in
certain aspects of immunity at the molecular level, there has been no
conclusive evidence that increasing the concentrations of supplemental
vitamins improves the resistance of cultured catfish to infectious diseases.
Vitamins in Feeds
The
concentrations of vitamins found in feedstuffs commonly used in animal
feeds can be found in various feed ingredient tables, and this information
can be used to estimate vitamin concentrations in formulated feeds. However,
the actual concentration and the estimated value may vary considerably
since tabular values are averages and the concentration of vitamins in
a particular feed ingredient may vary from batch to batch. A comparison
of vitamin concentrations, which were calculated from tabular values or
determined analytically, is presented in Table 2.
The data are based on a catfish feed that had the following ingredient
composition: soybean meal (34%), cottonseed meal (10%), corn (25%), wheat
middlings (20%), menhaden fish meal (4%), meat and bone/blood meal (4%),
fish oil (1.5%), dicalcium phosphate (1%), and trace minerals. The data
show that there is significant variation between vitamin concentrations
calculated from tabular values and those determined by analysis (Table
2). In addition, the data show that the feed without supplemental
vitamins contains enough thiamin, pyridoxine, niacin, and choline to meet
dietary requirements. However, the bioavailability of these vitamins to
catfish is not known. Even so, indirect data indicate that vitamins inherent
in feed ingredients are utilized fairly effectively by catfish. The information
presented in Table 2 also shows that a catfish feed
supplemented with a standard vitamin premix meets or exceeds the dietary
vitamin requirements of catfish. In fact, many of the vitamins exceed
the dietary requirement by several times.
Natural Foods
Because
of the high level of nutrients introduced by feeding, commercial catfish
ponds are fertile and thus normally contain large numbers of organisms,
including phytoplankton, zooplankton, and invertebrates such as insects
and crustaceans. Many of these organisms are high in protein, vitamins,
and other essential nutrients (Table 3). The degree
to which natural food organisms contribute to the nutrition of intensively
grown catfish is still unclear. It appears that the contribution of natural
food organisms to the protein and energy requirements of catfish is somewhat
low, but these organisms may provide significant quantities of vitamins
and other nutrients that are required in trace amounts. Studies discussed
in other sections of this bulletin have shown that vitamin deficiencies
can be produced by feeding catfish purified diets devoid of various vitamins
in aquaria under controlled laboratory conditions. However, deficiencies
could not be produced in catfish raised in ponds and fed practical feeds
that lacked a supplement of a specific vitamin. Vitamin requirements were
met either from vitamins naturally occurring in feedstuffs, from natural
food organisms, from intestinal synthesis, or from a combination of these
sources.
Vitamin Requirement Studies
A
series of studies to examine practical vitamin requirements of channel
catfish has been conducted over the last few years at our research facility.
All experiments were conducted in 0.1-acre earthen ponds stocked at a
rate of 10,000 fish per acre and managed according to industry practices.
All fish were fed once daily to satiation for the duration of the experiment.
Fish size and duration of each experiment are given in tables for the
specific experiment. Experimental treatments for each study are summarized
in Table 4.
Experiment 1
In
experiment 1, we evaluated diets containing either a full vitamin supplement,
no vitamin supplement, or one-half vitamin supplement (Table
5). There were no differences in fish feed conversion, survival, and
hematocrit (percent red blood cells in a given volume of blood), regardless
of dietary treatment. There was an increase in feed consumption and weight
gain of fish fed the diet containing one-half the supplemental vitamins.
However, one would not expect fish fed one-half of a vitamin supplement
to gain more weight than fish fed a full supplement of vitamins. Fish
weight gain and feed conversion were typical of healthy catfish, regardless
of dietary treatment, and there were no gross indications of any dietary
vitamin deficiency. There were no marked differences in liver concentrations
of B-complex vitamins, regardless of diet, but liver vitamin C and vitamin
E concentrations were lower in fish fed no supplemental vitamins (Table
6). This study indicates that vitamins inherent in the diet were utilized,
and/or there was some contribution from natural food. In the case of B-complex
vitamins, there also may have been some intestinal synthesis. However,
it is likely that the largest contribution to the vitamin nutrition of
the fish came from dietary ingredients.
Experiment 2
Since
the results from experiment 1 were unexpected, we conducted a second experiment
to further investigate the need for supplemental vitamins in catfish.
In experiment 2, we compared diets that contained either a full vitamin
supplement, no vitamin supplement, one-half vitamin supplement, one-fourth
vitamin supplement, or a supplement with one-half the normal allotment
of B-complex vitamins (Table 7). There were no differences
in weight gain, feed consumption, feed conversion, survival, or hematocrit
of fish, regardless of dietary treatment. As in experiment 1, there were
no differences in the concentration of B-complex vitamins in the liver,
but vitamin C concentrations decreased as the vitamin supplement was reduced
(Table 8).
The results were again surprising, particularly in regard to vitamin C. There is essentially no vitamin C inherent in feed ingredients used in catfish feeds, and thus a deficiency was expected in fish fed a diet without any supplemental vitamin C. However, no gross efficiency signs were noted, and the fish appeared to be robust and healthy. It has been suggested that low concentrations of vitamin C in liver tissue is indicative of a vitamin C deficiency, but we do not feel that is the case since no overt signs of deficiency were observed. We have conducted other studies in which tissue vitamin C was very low, but deficiency signs were not apparent. Tissue storage of vitamin C reflects excess intake; thus, it is possible to meet dietary requirements for the vitamin without large amounts being deposited in various tissues. The implication from this study is that the fish met their vitamin C requirement from natural food organisms found in the pond, since this is the only available source of the vitamin. If this were the case, it would appear that enough vitamin C was ingested to cover metabolic needs. However, based on liver concentrations, there was little or no excess. Evidence from other studies we have conducted indicates that vitamin C requirement for catfish may be only 15 to 25 ppm, which is less than previously reported. Regardless of the contribution of natural foods to the vitamin C nutrition of catfish, vitamin C supplements are still needed. Variability in the abundance and type of natural food organisms from one pond to another would prevent producers from depending on natural food as the sole source of vitamin C.
Experiment 3
It
appeared that supplements of the B-complex vitamins can be eliminated
or at least reduced in catfish feeds. However, before such a recommendation
could be made, additional studies were conducted to investigate the removal
of single B-complex vitamins in diets of pond-raised catfish. Experiment
3 was conducted to evaluate diets containing either a full vitamin supplement,
no supplemental riboflavin, one-half the recommended level of supplemental
riboflavin, no supplemental niacin, or one-half the recommended level
of niacin (Table 9). There were no differences in
weight gain, feed consumption, and feed conversion in fish, regardless
of dietary treatment. Liver riboflavin concentrations were the same in
samples taken in October and February; fish were on full feed in October,
but they received little prepared feed in February. Liver niacin concentrations
were lower in fish fed no supplemental niacin, but the concentration of
niacin in the liver of these fish was still relatively high. There was
a decrease in niacin concentrations from October to February. These data
support our contention that supplemental riboflavin and niacin may not
be necessary in diets of pond-raised catfish.
Experiment 4
Experiment
4 was conducted to evaluate diets containing either a full vitamin supplement,
no supplemental thiamin, one-fourth the recommended amount of supplemental
thiamin, no pyridoxine, or one-fourth the recommended amount of pyridoxine
(Table 10). Weight gain, feed consumption, and
feed conversion were not different among fish on the various dietary treatments.
There were no differences in the concentration of thiamin in the livers
of fish sampled in October, regardless of diet. However, the February
liver samples showed a reduced level of thiamin, as compared to the samples
taken in October. In addition, February liver samples of fish fed less
than a full thiamin supplement had reduced levels of thiamin. Liver concentrations
of pyridoxine were not different among fish fed the various diets, but
concentrations increased dramatically in February samples, as compared
to the October samples. We are unable to explain the increase in liver
pyridoxine, since we would have expected it to decrease. The data from
this study indicate that supplemental thiamin and pyridoxine may not be
needed in feeds for pond-raised catfish.
Experiment 5
Experiment
5 was conducted to evaluate diets containing either a full vitamin supplement,
no supplemental pantothenic acid, one-eighth the recommended level of
supplemental pantothenic acid, or one-fourth the recommended level of
supplemental pantothenic acid (Table 11). There
were no differences in weight gain, feed consumption, feed conversion,
and survival of fish fed the various diets. Liver concentrations of the
vitamin were similar for fish on each treatment, and there were no differences
in liver concentrations measured in October or in February. These data
indicate that supplemental pantothenic acid may not be needed in feeds
for pond-raised catfish.
Experiment 6
To
verify data from the previous experiments, experiment 6 was conducted
to evaluate diets containing either a full vitamin supplement, no supplemental
pantothenic acid, no supplemental pyridoxine, no supplemental thiamin,
no riboflavin, or no niacin (Table 12). An additional
diet included a choline supplement. Choline was deleted from some catfish
premixes several years ago, and it was not part of the control vitamin
premix used for our studies.
There were no differences in weight gain, feed conversion, survival, or blood test results of fish, regardless of dietary treatment. There were no consistent differences in liver concentrations of the various vitamins of samples taken in October or February (Table 13). Liver pantothenic acid and thiamin concentrations were lower in fish fed diets containing no supplemental pantothenic acid or no supplemental thiamin, as compared to fish fed a full vitamin supplement. Liver concentrations of choline were somewhat higher in fish fed a choline supplement, but they were very high in fish fed a diet without the supplement. Liver vitamin concentrations of the other vitamins were not remarkably different among fish fed diets with and without a specific vitamin. These findings support data from the other studies that indicate certain of the B-complex vitamins are not needed in feeds for pond-raised catfish.
Stress Response Experiment
The
effects of acute confinement of fish from the above experiments were evaluated
by the Department of Biology at the University of Memphis. Fish were confined
for 6 hours, and blood samples were taken after 1 and 6 hours of confinement
and 12 hours after release. Plasma chloride and osmotic pressure were
stable throughout the confinement. Cortisol concentrations were elevated
1 and 6 hours after confinement, but returned to preconfinement concentrations
12 hours after release. The lack of supplemental vitamins in the feed
did not impair the ability of the fish to mount or maintain cortisol secretion.
These data indicate that sufficient concentrations of vitamins were available
to fish fed diets without a vitamin supplement or containing a reduced
allotment of vitamins to overcome the effects of acute stress.
Vitamin Stability Studies
Floating
catfish feeds are manufactured by extrusion, which involves high pressure,
high temperature, and high moisture conditions that are conducive to the
destruction of vitamins. Losses of vitamin C, which is particularly sensitive
to oxidation during feed manufacture, may be as high as 50% unless a stabilized
product is used. To ensure that adequate vitamin C is retained in a floating
catfish feed, either a stabilized form is used or excess ascorbic acid
is added to compensate for losses during feed manufacture. Generally,
it is more economical to over-fortify with an unstablized form of the
vitamin. However, if feeds are to be stored for several weeks, a stable
form of vitamin C is usually warranted.
Most vitamin stability research has focused on vitamin C. However, some of the B-complex vitamins are added at levels several times their dietary requirement to compensate for anticipated losses during feed manufacture. We conducted a study to evaluate the stability of B-complex vitamins during manufacture of extruded catfish feeds. Riboflavin, pantothenic acid, and niacin had retention values of 100%, 100%, and 96.3%, respectively. Thiamin mononitrate and pyridoxine hydrochloride were relatively stable, having retention values of 65% and 70%, respectively. Results of this study indicate that large excesses of these vitamins are not necessary to ensure that adequate levels remain after feed processing.
Conclusions and Recommendations
Studies
conducted at our research facility indicate that supplementation of commercial
channel catfish production diets with B-complex vitamins and vitamin C
can be substantially reduced without affecting fish performance. Certain
vitamins could possibly be eliminated altogether. Studies conducted on
vitamin requirements at the Mississippi State University Department of
Biochemistry and at the Texas A&M University Department of Wildlife and
Fisheries Sciences indicate that the riboflavin, niacin, and vitamin E
requirements for channel catfish are lower than previously reported. These
data further indicate that the level of these vitamins in commercial catfish
feeds can be reduced. Vitamin concentrations proposed herein for catfish
feeds are still relatively conservative, even though some recommendations
are considerably lower than previously recommended (Table
14). A reduction in the amount of supplemental vitamin E, thiamin,
riboflavin, pyridoxine, and pantothenic acid is recommended, along with
the deletion of supplemental choline and niacin. The new recommendations
allow for losses during feed manufacture and include a margin of safety.
To gain more information on the practical vitamin requirements of catfish,
we have initiated a 3-year study to investigate the elimination of supplemental
vitamins in feeds for catfish raised in large ponds under a multiple batch,
topping system.
Acknowledgments
The
authors appreciate the support of the Mississippi Agricultural and Forestry
Experiment Station and the Delta Research and Extension Center for funding
this bulletin. Special thanks go to H. Randall Robinette, Craig S. Tucker,
and William R. Wolters, who provided critical reviews of the manuscript.
| Table 1. Vitamin deficiency signs and minimum dietary levels required to prevent signs of deficiency in catfish. 1 | |||
|---|---|---|---|
| Vitamin | Deficiency signs2 | Units | Requirement3 |
| Fat-soluble | |||
| Vitamin A | Exophthalmia, edema, acities | IU/lb | 450-900 |
| Vitamin D | Low bone ash | IU/lb | 110-220 |
| Vitamin E | Skin depigmentation, exudative diathesis muscle dystrophy, erythrocyte hemolysis, splenic and pancreatic hemosiderosis | IU/lb | 23 |
| Vitamin K | Skin hemorrhage, prolonged clotting time | ppm | R |
| Water-soluble | |||
| Thiamin | Dark skin color, neurological disorders | ppm | 1 |
| Riboflavin | Short-body dwarfism | ppm | 9 |
| Pyridoxine | Greenish blue coloration, tetany, nervous disorders | ppm | 3 |
| Pantothenic acid | Clubbed gills, anemia, eroded skin, low jaw, fins, and barbels | ppm | 15 |
| Niacin | Anemia, lesions of skin and fins, exophthalmia | ppm | 14 |
| Biotin | Anemia, skin depigmentation, reduced liver pyruvate carboxylase activity | R | |
| Folic acid4 | Reduced red blood cells | ppm | 1.5 |
| B12 | Reduced red blood cells | ppm | R |
| Choline5 | Hemorrhagic kidney and intestine, fatty liver | ppm | 400 |
| Inositol | None demonstrated | NR | |
| Ascorbic acid | Reduced red blood cells, scoliosis, lordosis, increased susceptibility to bacterial infections, reduced bone collagen formation, internal and external hemorrhage | ppm | 60 |
| 1Adapted
from Robinson, E. H. 1989. Channel catfish nutrition. Reviews in
Aquatic Sciences 1:365-391. 2Anorexia, reduced weight gain, and increased mortality are common vitamin deficiency signs. Thus, these signs are not included in the table. 3R and NR refer to "required" and "not required," respectively. 4From National Research Council. 1993. Nutrient Requirement of Fish. National Academy Press, Washington, DC. 5Determined using diets marginal in methionine and based on liver lipid concentration. |
|||
| Table 2. Calculated value1 and analysis value of selected vitamins in channel catfish feed with or without supplemental vitamins. | |||||
|---|---|---|---|---|---|
| Vitamin | Without supplemental vitamins | With supplemental vitamins | |||
| Calculated | Analysis | Calculated | Analysis | ||
| Thiamin (ppm) | 6.0 | 4.9 | 17.0 | 12.4 | |
| Riboflavin (ppm) | 2.3 | 4.9 | 15.4 | 19.8 | |
| Pyridoxine (ppm) | 5.2 | 4.8 | 16.2 | 23.5 | |
| Vitamin B12 (ppb) | 8.4 | 20.4 | 19.4 | 34.0 | |
| Folic acid (ppm) | 0.78 | 1.7 | 3.0 | 4.8 | |
| Niacin (ppm) | 31.1 | 70.4 | 119.1 | 163.8 | |
| Pantothenic acid (ppm) | 10.1 | 6.7 | 45.3 | 25.7 | |
| Vitamin C (ppm) | 0 | 0 | 162.5 | 96.5 | |
| Choline (ppm) | 1,760 | 2,072 | 1,760 | 2,072 | |
| Vitamin A (IU/lb) | N/A2 | <200 | 4,400 | 1,090 | |
| Vitamin D3 (IU/lb) | N/A | 123 | 2,200 | 1,002 | |
| Vitamin E (ppm) | 20.0 | 14.7 | 85.9 | 80.8 | |
| Vitamin K (ppm) | N/A | <11 | 4.4 | <11 | |
| 1Calculated
using values from vitamin concentrations given in feed ingredient
tables (National Research Council, 1993, Nutrient Requirements of
Fish, National Academy Press, Washington DC; Feedstuff Reference
Issue, 1997, The Miller Publishing Co., Minnetonka, MN). 2N/A = not available. |
|||||
| Table 3. Composition of zooplankton collected during the summer from channel catfish ponds in the Mississippi Delta. 1 | |
|---|---|
| Proximate nutrients (%) | |
| Dry matter | 7.7 |
| Crude protein | 72.5 |
| Crude fat | 6.2 |
| Crude fiber | 10.7 |
| Nitrogen-free extract | 8.1 |
| Ash | 2.6 |
| Vitamins | |
| Vitamin D (IU/lb) | 111 |
| Vitamin E (ppm) | 115 |
| Thiamin (ppm) | 3.4 |
| Riboflavin (ppm) | 100 |
| Pyridoxine (ppm) | 2.5 |
| B12 (ppm) | 2.2 |
| Folic acid (ppm) | 1.2 |
| Niacin (ppm) | 141 |
| Pantothenic acid (ppm) | 20 |
| Biotin (ppm) | 1.5 |
| Inositol (ppm) | 1,565 |
| Ascorbic acid (ppm) | 164 |
| 1Dry matter basis. | |
| Table 4. Dietary treatments for each experiment. 1 | ||||||
|---|---|---|---|---|---|---|
| Diet | Experiment 1 | Experiment 2 | Experiment 3 | Experiment 4 | Experiment 5 | Experiment 6 |
| 1 | Control2 | Control | Control | Control | Control | Control |
| 2 | No vitamin mix | No vitamin mix | No riboflavin | No thiamin | No pantothenic acid | No pantothenic acid |
| 3 | ½ vitamin mix | ½ vitamin mix | 6.6 ppm riboflavin | 2.2 ppm thiamin | 4.4 ppm pantothenic acid | No pyridoxine |
| 4 | ½ B-vitamins | No niacin | No pyridoxine | 8.8 ppm pantothenic acid | No thiamin | |
| 5 | ¼ vitamin mix | 44 ppm niacin | 2.3 ppm pyridoxine | No riboflavin | ||
| 6 | No niacin | |||||
| 1Vitamin
concentrations refer to supplemental vitamin concentrations. 2Control diet was composed of 34.1% soybean meal, 10% cottonseed meal, 25.3% corn screenings, 20% wheat middlings, 4% menhaden fish meal, 4% meat and bone/blood meal, 1% dicalcium phosphate, 1.5% catfish offal oil, 0.025% trace mineral mix, and the following supplemental vitamins: thiamin (11 ppm), riboflavin (13.2 ppm), pyridoxine (11 ppm), pantothenic acid (35 ppm), niacin (88 ppm), folic acid (2.2 ppm), B12 (0.01 ppm), ascorbic acid (100 ppm, in final product), A (2,000 IU/lb), D3 (1,000 IU/lb), E (66 ppm), and K (4.4 ppm). (Robinson, E. H. 1991. A practical guide to nutrition, feeds, and feeding of catfish. MAFES Bulletin 979, Mississippi Agricultural and Forestry Experiment Station.) |
||||||
|
and survival of pond-raised channel catfish fed the experimental diets in experiment 1.1 |
||||||
| Diet no. | Supplemental vitamin |
Weight gain |
Feed comsumption |
FCR | Survival | Hematocrit2 |
|---|---|---|---|---|---|---|
| lb/fish | lb/fish | % | % | |||
| 1 | Control | 0.69 b | 0.87 b | 1.27 | 92.7 | 27.3 |
| 2 | No vitamin mix | 0.63 b | 0.84 b | 1.33 | 93.8 | 26.2 |
| 3 | ½ vitamin mix | 0.80 a | 1.01 a | 1.27 | 94.3 | 27.7 |
| SEM3 | 0.03 | 0.03 | 0.02 | 1.7 | 0.9 | |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). Average initial weight
of fish was 72 pounds per 1,000 fish. The fish were fed once daily
to satiation from late April to early October. 2Percent red blood cells in a given volume of blood. 3SEM = standard error for mean. |
||||||
|
|
|||||
| Diet no. | Supplemental vitamin |
|
|||
| Thiamin | Riboflavin | Pyridoxine | Niacin | ||
| 1 | Control | 0.78 | 7.4 b | 3.8 | 51.1 ab |
| 2 | No vitamin mix | 0.69 | 7.6 ab | 3.9 | 49.0 b |
| 3 | ½ vitamin mix | 0.71 | 7.9 a | 3.7 | 56.8 a |
| SEM2 | 0.16 | 0.15 | 0.18 | 2.1 | |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). 2SEM = standard error for mean. |
|||||
Table 6. Continued
|
|
|||||
| Diet no. | Supplemental vitamin |
|
|||
| Pantothenic acid |
Folic acid |
Ascorbate | Alpha- tocopherol |
||
| 1 | Control | 12.8 | 0.79 | 84.5 a | 112.6 a |
| 2 | No vitamin mix | 16.1 | 0.58 | 11.8 c | 13.3 c |
| 3 | ½ vitamin mix | 14.9 | 0.55 | 59.3 b | 72.4 b | SEM2 | 1.7 | 0.10 | 5.1 | 8.4 |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). 2SEM = standard error for mean. |
|||||
|
Table 7. Mean weight gain, feed consumption, feed conversion ratio (FCR), and survival of pond-raised channel catfish fed the experimental diets in experiment 2.1 |
||||||
|---|---|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Weight gain |
Feed consumption |
FCR | Survival | Hematocrit |
| lb/fish | lb/fish | % | % | |||
| 1 | Control | 0.98 | 1.66 | 1.65 | 98.8 | 29.9 |
| 2 | No vitamin mix | 0.98 | 1.50 | 1.52 | 98.5 | 25.2 |
| 3 | ½ vitamin mix | 1.03 | 1.77 | 1.71 | 96.7 | 31.7 |
| 4 | ½ B-vitamins | 0.96 | 1.87 | 1.95 | 95.5 | 30.2 |
| 5 | ¼ vitamin mix | 1.08 | 1.92 | 1.78 | 96.2 | 30.8 |
| SEM2 | 0.06 | 0.15 | 0.14 | 1.8 | 3.3 | |
| 1Means
within a column were not different (P> 0.05, least significant
difference test). Average initial weight of fish was 261 pounds
per 1,000 fish. The fish were fed once daily to satiation from late
April to early October. 2SEM = standard error for mean. |
||||||
| Table 8. Mean liver vitamin concentrations of pond-raised channel catfish fed the experimental diets in experiment 2. 1 | ||||
|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Liver vitamin (ppm) | ||
| Riboflavin | Pyridoxine | Niacin | ||
| 1 | Control | 5.9 | 4.6 | 56.9 |
| 2 | No vitamin mix | 4.4 | 3.6 | 54.7 |
| 3 | ½ vitamin mix | 6.1 | 4.5 | 63.8 |
| 4 | ½ B-vitamins | 4.5 | 4.1 | 58.5 |
| 5 | ¼ vitamin mix | 5.2 | 4.0 | 64.2 |
| SEM2 | 0.51 | 0.39 | 8.1 | |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). 2SEM = standard error for mean. |
||||
Table 8. Continued.
| Table 8. Mean liver vitamin concentrations of pond-raised channel catfish fed the experimental diets in experiment 2. 1 | |||||
|---|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Liver vitamin (ppm) | |||
| Pantothenic acid | Folic acid | B12 | Ascorbate | ||
| 1 | Control | 12.8 | 0.59 | 0.13 | 28.9 b |
| 2 | No vitamin mix | 10.6 | 0.70 | 0.12 | 5.5 c |
| 3 | ½ vitamin mix | 14.7 | 0.40 | 0.14 | 34.5 b |
| 4 | ½ B-vitamins | 12.2 | 0.71 | 0.14 | 52.8 a |
| 5 | ¼ vitamin mix | 11.4 | 0.64 | 0.13 | 13.1 c |
| SEM2 | 1.3 | 0.21 | 0.011 | 3.2 | |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). 2SEM = standard error for mean. |
|||||
| Table 9. Mean weight gain, feed consumption, feed conversion ratio (FCR), survival, and liver vitamin concentration of pond-raised channel catfish fed the experimental diets in experiment 3.1 | |||||
|---|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Weight gain |
Feed consumption |
FCR | Survival |
| lb/fish | lb/fish | % | |||
| 1 | Control | 0.72 | 1.07 | 1.56 | 73.0 |
| 2 | No riboflavin | 0.69 | 1.02 | 1.56 | 68.7 |
| 3 | 6.6 ppm riboflavin | 0.74 | 1.06 | 1.49 | 73.7 |
| 4 | No niacin | 0.66 | 0.97 | 1.53 | 73.2 |
| 5 | 44 ppm niacin | 0.68 | 1.02 | 1.57 | 73.1 |
| SEM2 | 0.03 | 0.05 | 0.04 | 3.7 | |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). Average initial weight
of fish was 73 pounds per 1,000 fish. The fish were fed once daily
to satiation from late May to early October and fed according to
winter feeding recommendations from early October to mid-February.
2SEM = standard error for mean. |
|||||
Table 9. Continued.
| Table 9. Mean weight gain, feed consumption, feed conversion ratio (FCR), survival, and liver vitamin concentration of pond-raised channel catfish fed the experimental diets in experiment 3.1 | |||||
|---|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Liver riboflavin | Liver niacin | ||
| Oct. | Feb. | Oct. | Feb. | ||
| ppm | ppm | ppm | ppm | ||
| 1 | Control | 2.53 | 2.70 | 123.3 a | 71.2 b |
| 2 | No riboflavin | 2.62 | 3.21 | ||
| 3 | 6.6 ppm riboflavin | 1.93 | 3.33 | ||
| 4 | No niacin | 109.5 b | 75.5 ab | ||
| 5 | 44 ppm niacin | 129.2 a | 83.0 a | ||
| SEM2 | 0.42 | 0.37 | 3.5 | 3.2 | |
| 1Means
within a column followed by same letters were not different (P>
0.05, least significant difference test). Average initial weight
of fish was 73 pounds per 1,000 fish. The fish were fed once daily
to satiation from late May to early October and fed according to
winter feeding recommendations from early October to mid-February.
2SEM = standard error for mean. |
|||||
Table 10. Continued.
| Table
10. Mean weight gain, feed consumption, feed conversion ratio (FCR),
survival, and liver vitamin concentration of pond-raised channel
catfish fed the experimental diets in experiment 4. 1 |
|||||
|---|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Liver thiamin | Liver pyridoxine | ||
| Oct. | Feb. | Oct. | Feb. | ||
| ppm | ppm | ppm | ppm | ||
| 1 | Control | 5.51 | 3.40 a | 4.3 | 12.88 |
| 2 | No thiamin | 4.82 | 1.87 b | ||
| 3 | 2.2 ppm thiamin | 3.90 | 2.11 b | ||
| 4 | No pyridoxine | 4.2 | 13.25 | ||
| 5 | 2.3 ppm pyridoxine | 3.3 | 13.05 | ||
| SEM2 | 2.33 | 0.28 | 0.3 | 0.83 | |
| 1Means
within a column followed by same letter were not different (P>
0.05, least significant difference test). Average initial weight
of fish was 60 pounds per 1,000 fish. The fish were fed once daily
to satiation from mid-May to early October and fed according to
winter feeding recommendations from early October to mid-February.
2SEM = standard error for mean. |
|||||
| Table
11. Mean weight gain, feed consumption, feed conversion ratio (FCR),
survival, and liver vitamin concentration of pond-raised channel
catfish fed the experimental diets in experiment 5.1 |
||||
|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Weight gain |
Feed consumption |
FCR |
| lb/fish | lb/fish | |||
| 1 | Control | 0.62 | 1.18 | 1.90 |
| 2 | No pantothenic acid | 0.62 | 1.24 | 2.01 |
| 3 | 4.4 ppm pantothenic acid | 0.62 | 1.24 | 2.01 |
| 4 | 8.8 ppm pantothenic acid | 0.61 | 1.16 | 1.88 |
| SEM2 | 0.03 | 0.06 | 0.05 | |
| 1Means
within a column were not different (P> 0.05, least significant
difference test). Average initial weight of fish was 40 pounds per
1,000 fish. The fish were fed once daily to satiation from mid-May
to early October and fed according to winter feeding recommendations
from early October to mid-February. 2SEM = standard error for mean. |
||||
Table 11. Continued.
| Table 11. Mean weight gain, feed consumption, feed conversion ratio (FCR), survival, and liver vitamin concentration of pond-raised channel catfish fed the experimental diets in experiment 5. 1 | ||||
|---|---|---|---|---|
| Diet no. | Supplemental vitamin |
Survival | Liver pantothenic acid | |
| October | February | |||
| % | ppm | ppm | ||
| 1 | Control | 87.4 | 35.89 | 26.56 |
| 2 | No pantothenic acid | 89.3 | 32.29 | 28.44 |
| 3 | 4.4 ppm pantothenic acid | 88.5 | 28.47 | 27.66 |
| 4 | 8.8 ppm pantothenic acid | 91.5 | 28.12 | 31.24 |
| SEM2 | 1.2 | 6.16 | 2.94 | |
| 1Means
within a column were not different (P> 0.05, least significant
difference test). Average initial weight of fish was 40 pounds per
1,000 fish. The fish were fed once daily to satiation from mid-May
to early October and fed according to winter feeding recommendations
from early October to mid-February. 2SEM = standard error for mean. |
||||