6.0 CATFISH FARMING

Cat-fish cultures are very popular in the United States. Maximum gains of catfish are at 30°C but good results are also obtained when the temperature varies between 26°C to 34°C. Countries with tropical and sub-tropical climates have, in this respect, a great potential. Typical examples are Thailand and Philippines where catfish production is integrated with livestock generating manure as the only source of feed for fish.

Brown (1977) states that channel catfish (Ictalurus punctatus) can be raised in still waters, floating water raceways, tanks, troughs, pens or cages. These fish can utilize wet or dry feeds as meals, sinking pellets, floating pellets, blocks or crumbles. A general feed formulation guide is given below:

The ingredients and amounts to make a tonne of feed are given in table 14 below:

Table 14 : Ingredients and amount to make a tonne of feed for channel catfish

Source: Anon (no date)

Grizzel et al. (1975) describes methods of catfish farming in ponds, raceways cages, the requirements for quantity and quality of water as well as proper choice of catfish species, handling of eggs and fry and rearing of fingerlings. The biggest and single section of this particular programme describes the feeding of catfish and problems associated with production particularly in terms of BOD (biochemical Oxygen Demand) and COD (Chemical Oxygen Demand) levels and the degree of compatibility of the fish in relation to oxygen and other important parameters in order to obtain maximum output.

In a study of Texas A&M University (1977), the aspects of fish rearing in animal waste ponds were briefly reported. The conclusions relevant to the research programme are as follows: Rapid fish growth was achieved in ponds of 0.1 and 0.25 acres which received the wastes from one hog and 21 laying hens, respectively.

Sundraraj and Goswami (1969) have described the technique of hypophysation of catfish. The Indian catfish Heteropneustes fossilis are routinely spawned in 10 gallon (45.3) litre glass aquaria. They suggest to keep only one pair in each aquarium. Running water facilities, according to these authors, are not necessary for the Indian catfish since they have necessary respiratory structure.

Andrews (1978) reported that several by-products and sources of plant protein used as donors of amino acid to catfish have some effects on the output of catfish. The results of the experiment are shown in Tables 15 and 16.

Table 15 : Results from a study in which animal by-product and plant protein sources were substituted on an isonitrogenous basis for corngluten meal in Catfish Feeds

1. The basal diet contained the following ingredients (/kg diet) : menhaden meal 40g, soybean meal (50P), 200g yellow corn 250g, retinyl acetate, 3000 IU; riboflavin, 40mg; panthothenic acid, 55 mg; thiamin, 3 mg; niacin, 15 mg; vitamin B₁₂, 0.01 mg, dl-a-tocopheryl acetate, 25 mg; menadione sodium bisulfate, 4 mg; folacin, 0.5 mg; pyridoxine hydrochloride, 6 mg; biotin, 0.1 mg; ascorbic acid, 200 mg; etoxyquin, 100 mg; choline, 100 mg; Cu, 5mg; Fe, 100mg; Mn, 10mg; 1, 0.3mg, Zn 25 mg; and Co, 0.05 mg;

2. All diets were isonitrogenous at 26.5% protein and were formulated to contain 5% lipid, 1.5% calcium and 0.9% phosphorus. Levels were adjusted with animal fat calcium carbonate and dicalcium phosphate, respectively. Cellulose was used applement all diets to 100%;

3. Total sulfur amino acids (met + cys).

4. Values followed by the same letter are not significantly different (< 0.05).

Source : Andrew, 1978

Table 16 : Results from a study in which animal byproduct and plant protein sources were substituted on an isonitrogenous basis for soybean meal in catfish feeds

1. The basal diet was the same as the one used in experiment 1 (table 15, footnote 1) except it contained 200 g/kg of corngluten meal and no soybean meal.

3 Values followed by the same letter are not significantly different (P < 0.05).

Source: Andrew, 1978.

These data suggest that, as in the case with other monogastric animals, the amino acid contents as well as protein levels have to be considered when dietary protein sources are intercharged in catfish feed formulations. Despite the relatively high levels of protein in catfish feed, the amino acid balance is critical and can be easily upset. Brown (1978) recommended cheap complete catfish feeds for various weight categories. The aspects of this experiment will be taken into account in PARC research programme. Conclusions are as follows: Better feed efficiency may be obtained from a well-balanced diet containing 24% protein than from a poorly balanced diet containing 36% protein. Fed free choice and balanced in amino acids and energy, 25–30% protein is adequate for larger fish; Fingerlings respond to higher protein levels of 30 to 36%. Studies with semipurified diets containing lipids at 10% resulted in rapid growth, sometimes exceding the growth obtained from a commercial diet used as a control. Channel catfish, he said, have been found to utilize polysaccharides (Starch, dextrin) for growth more readily than simple suoars and he suggested adding starches to aid the pelleting quality of rations. Data at Auburn indicates that digestibility of cooked starch is higher than raw starch and a little more than twice the energy is available from cooked corn as from raw corn.

The aspects of feed preparation for commercial production of catfish were described by Lovell (1971). He concluded that good fish feed for catfish provides extremaly good conversion into fish biomass. He stresses the vital role of feed preparation in the form of pellets having good water stability. The size of pellets is of great importance. This approach is a feedlot type feeding in which all feed is consumed otherwise un-utilized feed would be a great wastage and would affect also the water quality also. According to him, the pellet should remain intact in the water for at least 10 minutes.

Fig: 5. Channel catfish (Ictalurus punctatus)

Source: MidGalski & Fichter, 1977.

6.1 Nutritional requirement of catfish

The nutritional requirements of catfish are described in several studies. The protein, mineral and vitamin requirement of channel catfish was reported by Dupree (1971). Results of the author's findings are given in Tables 17 and 18.

Table 17: Results of the effect of protein and water temperature¹on the weight gain and food conversion of fingerling channel catfish

Source: Dupree, 1971

¹ In the first experiment, water temperature initially averaged approximately 88°F; and decreased to approximately 75°F at the conclusion. In the second experiment, water temperature was a constant 65°F;

² Protein supplemented with tryptophan in second experiment.

³ Total feed offered (dry weight) equaled 411 and 394 grams in experiments I & II respectively:

Table 18: Total weight gain of fish fed various diets over an eleven week period starting July 16, 1968, and ending October 1, 1968. Values in columns A, B and C reflect gain of fish living at the end of the experiment and gain of fish that died during the experiment

Source Dupree, 1971

Beaven (1977) reported that Heteropneustes fossilis is considered highly nutritious and is esteemed for its invigorating qualities and is much in request among the natives as a diet. It can breed in captivity;

Khan (1934) discussed in his paper that Rita rita is a carnivorous fish and feed mostly on insects, of their larvae and young fish. It takes live baits, live worms and raw meat. The breeding of Rita rita commences in June and lasts upto the end of July in the Punjab. During the breeding season, it migrates to colder water and moves in shoals. Karam-Chandani and Motwani (1955) were of the view that the breeding of Rita rita in the River Ganga commences from the beginning of March and lasts upto the end of August. This fish is esteemed as food by the natives. It is a very hardy fish.

Mystus seenghala occurs in all the rivers and flourishes in tanks as well. Menon and Chacko (1958) have reported it to be a piscivore as it feeds on eggs and fry of other fishes. It breeds during June and July. Its flesh is firm and sweet but decomposes rapidly if kept long without being salted. It makes excellent food and is very common in the market (Khan, 1934). Some biochemical constituents namely calcium, copper, iron, potassium (Viswanathan, et al; 1966) Cholesterol (Siddiqi, 1966) have been estimated for Mystus seenghala.

Wallago attu is a highly acceptable food fish among the natives because of the absence of tiny bones. It thrives well in tanks and takes a live fish as bait, worms or raw meat; Menon and Chacko (1958) have reported it to be a typical piscivore. It spawns during June and August (Ahmed, 1943) and migrates to shallow waters and breeds a little carlier than Cirrhina reba, Cirrhina mrigala, Labeo rohita, Catla catla etc; (Mookerjee, et al; 1944, 45). Some biochemical constituents namely calcium, iron, (Natrajan and Sreenivasan, (1961); Viswanathan et al. 1966); Copper, Potassium (Viswanathan, et al; 1966); Cholesterol (Siddiqi, 1966), Folic acid (Banerjee and Chatterjee 1963c); Vitamin C, Niacin (Saha, 1939, 1941) have been worked out for Wallago attu.

The following conclusions can be drawn: protein utilization was affected only by the protein source and water temperature. Krishnandhi and Shell (1966 found that animal protein (Casein) was superior to plant protein (soy) at 5 % and 30% of the purified diet and that the mixture of soy and casein was superior to casein alone;

According to Hastings and Dupree (1969) in the aquarium phase, growth increased linearly with the protein level from 10–40% of the dry diet but 5% dietary protein resulted in no increased gain;

Dupree and Halver (1970) completed the first phase of this programme by determining that arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine were indispensable in the diet;

According to Dupree (1971) the lysine requirement for channel catfish under experimental condition was between 1.25 and 1.75% of the dry diet;

Based on the weight gain and mortality data in the preliminary experiment by Dupree (1969) the requirement for vitamin E appears to be near 20 units/kg of dry feed; Dupree (1970) fed a series of 16 purified diets that contained 0–20,000 units of Vitamin A as the acetate or as beta carotene per kg of dry ingredients. Weight gain was linear with the quantity of vitamin A acetate upto 1,000 units.

The Auburn University study suggests that a deficiency of dietary calcium will be a problem only in low calcium waters coupled with low dietary phosphate. Lovell (1971) suggests that the phosphate (P) requirement for growth is near 0.6% of the dry weight.

The energy and lipid requirements of catfish were reported by Andrews (1971). Results reviewed in his paper indicate that environmental temperature influences the level of fat in catfish; It is evident that other factors such as dietary protein and energy will also influence body composition. Hastings (1967a) recommended 1,200 kcal of metabolisable energy per pound of ration but did not identify the unit (poultry, swine etc) which was used in calculating these values. Lovell (1971) investigated the significance of feed preparation for feeding catfish; There was, statistically, a high and significant difference between feed fed in pellet and meal form. Feed conversion for pellet feed was 1.6 whereas for meal form it was 3.3. Below are tabulated results of these experiments (tables 19 and 20).

Table 19: Weight gain and feed conversion for channel catfish fed Auburn No. 1 feed mixture in pelleted and meal forms

Source: Lovell, 1971.

Table 20 Average percentage weight gains for catfish rations containing various levels of fibre

Source: Lovell, 1971

Some aspects of warm quality fish and feeding were reported by Hastings (1970). Taking into account the necessary variable involving performance of the fish under the effects of feeding environments and other factors numerical evaluation of fish production is expressed in the following equation.

Wt = f (T + Sr + Wo + H + Fa + Fq + Fm + Ff + D + Wp + .....................) (1)

The formula that has proved suitable and which lends itself easily to modifications imposed by inventory or ingredient price is as follows:

Hastings (1973) studied ‘phase feeding for catfish’. Feed formulation and production of fish and cost data calculated on per acre basis have been shown in Tables 21, 22 and 23.

Table 21 : Dates at which various protein densities were fed

Table 22 : Formulation of feeds containing different levels of protein

* A sifted product from rice hulls, smaller the 177 microns.

Table 23 : Production and cost data calculated on per-acre basis

* Income (fish-feed) = proceeds from selling fish at $ 0.35/1b minus cost of feed at prices shown in table - 22.

Source: Hastings, 1973.

Conclusions have been derived as under: Continued evidence has shown increased catfish production with higher amounts of protein in the diet. More profit with phase feeding indicates that the protein level in feeds may be adjusted to fish growth as regulated by water temperature. Dabrowski (1976) described the method to calculate the optimal density of food for fish larvae. He suggested that the optimal density of plankton required for the growth and development of Coregonus lavaretus larvae is calculated on the basis of the volume of water searched, the probability of successful feeding responses and the result of experimental growth studies. The feeding optimum depends on water temperature and the time at which feeding begins. Results of the experiment have been given in the tables (24) and (25).

Table 24 : Results of the experiment on larvae Coregonus lavaretus fed with defined amounts of food

Source: Dabrowski, 1976

Table 25 : Calculation of the optimal density of plankton for Coregonus lavaretus larvae by the method of experimenta¹ growth

Source: Dabrowski, 1976.

Based on experiment and field data, Hoagman (1974) suggests that the minimum food for Coregonus clupeaformis larvae is 10–20 cop ponds daily. According to the data, Coregonus lavaretus larvae consume on an average 80–90 individuals of plankton at 13.5°C for the first 16 days of life. A real feeding optimum can be obtained by dividing the time into even short periods. According to Andrews (1979), total absorption rate and digestible energy values were best at 90% of free intake of food but absorption rate of protein was not effected by feed restriction. Murai and Andrews (1979) described Panthothenic acid requirement for channel catfish fingerlings. Fingerlings require about 10 mg/kg of panthothenic acid for maximum growth, feed efficiency and prevention of gross signs of deficiency. Signs of deficiency were anorexia, loss of body weight, clubbed gills, anaemia and eroded skin, lower jaw, fins and barbels and a high death rate. None had fused gill filaments, which had been reported in deprived salmonids. Andrews and Murai (1979) reported that for maximum growth, the catfish require pyridoxine, about 3 mg/kg diet, though 2.2 mg/kg prevented all other signs of deficiency.

Reddy and Katre (1979) state that air-breathing catfish Heteropneustes fossilis juveniles were given either no feed or from 1 to 12.73% of initial body weight daily for 30 days of live Tubifex tubifex worms. The 12.73% was the maximum that could be eaten by fish of 4.015± 0.340 g under laboratory conditions. By geometric derivation the amount required was: for maintenance, 12; for optimum, 40; and for maximum intake, 130 mg/g body weight daily. Specific dynamic action increased from 14 mg/g daily at optimum to 70 mg/g daily at maximum rate of feeding.

Murray and Andrews (1979) have reported the effect of dietary salt on growth of channel catfish. They concluded that the 0.06% sodium and 0.17% chloride already present in basal diet was sufficient for good growth and feed efficiency. Most came from menhaden meal 10% of diet. Thus diets with less fish meal or less salt in the water may need salt supplements. Absence of growth depression indicated that the catfish renal system was able to excrete salt up to that from 2% supplemented salt in diet.

Hepher (1979) suggests that a limited number of complementary diets of increasing nutritional value might be prepared, and given to cover nutritional requirements in excess. Usual practice in Israel is to give cereal grains alone upto a stocking rate of carp about 800 kg/ha, then to add increasing proportions of protein-rich pelleted diet.

Lovell (1979) has described factors affecting voluntary food consumption by Channel catfish. According to him, feeding catfish pond twice daily would increase intake and growth at minimum temperature of 26°C or over: As water cooled, a change should be made to one feed a day, then as water reached 20°C, a change to a feed on alternate days would be more productive.

Grusevich (1979) has reported the nutrition of channel catfish in their first year. According to him, stomach contents of three channel catfish (Icralurus punctatus) with natural and artificial feeding indicated that in a fish 5.5 to 8.5 cm long, the main feed items were Daphnia magna up to 65% (not stated whether by number, weight or volume) and artificial feed upto 98.3% and in fish 8.5 to 13.5 cm long, Chironomidea 31.9 to 89.2%, Hydrophilidae, Ephemeroptera, Hemiptera and odonata.

Arunachalam (1979) reported the effect of feeding on surfacing activity and food utilization in the catfish Heteropneustes fossilis. He concluded that when the diet was increased from 20 to 26.3 mg/g daily, conversion efficiency of catfish decreased from 43.2 to 33.2%. Vahl (1979) presents the hypothesis that only 2 factors are necessary to design a feeding method for maximum growth of fish in aquaculture. These factors are maximum voluntary feed intake in one meal and emptying rate of the stomach.

Murai and Andrews (1975) reported that supplemental panthothenic acid markedly improves growth rate, survival and feed conversion and prevents a loss of appetite, clubbed gills and sluggishness. According to these researchers, diets fed to cat-fish fry (Ictalurus Punctatus) should contain at least 250 mg of panthothenic acid/kg of diet.

Andrews and page (1975) noted the effect of frequency of feeding on culture of catfish. Optimum growth and food efficiency were obtained from groups fed to satiation 2 times/day. Gains in weight were substantially reduced in groups fed only 1 time/day and were not enhanced by feeding 4 times/day. The fact that food efficiencies were similar in fish fed 1, 2, 4 times/day indicated that fed intake and not utilization was the growth limiting factor.

Stomach contents of channel catfish (I. Punctatus), ranging in length from 47–440 mm collected from farm ponds of Auburn University (Alabama, USA), were examined by Devaraj (1976). He reported that supplemental feed was second in importance among other food items consumed by fish of all size groups. Other food items present in the stomachs in varying quantities were algae, mollusks, microcrustaceans, coleopterans, trichopterans, fish remains and detritus, indicating the Omnivorous feeding habit of channel catfish.

Stickney and Andrews (1971) noted the combined effect of dietary lipids and environmental temperature on growth, metabolism and body composition of channel catfish (I. Punctatus). The lipid level in fish carcasses increased with temperature: upto 30°C for all dietary supplements. At the optimum temperature for growth (30°C), fish fed beef tallow contained less lipid than those fed the other supplements. The fatty acid composition of the diets was reflected in both liver and carcass lipid.

Stickney (1971) carried out experiments in aquarium to test the effect of photoperiod on growth of channel catfish fingerlings.

More rapid growth was noted with a 12 hr photoperiod, although differences among the groups were not statistically significant. Feed conversion ratios were slightly improved at 12 hour photoperiod. Results indicated that controlled photo-period has little effect on the production of catfish.

Andrews, Lee and Murai (1972) reported the temperature requirements for channel catfish from fingerling to marketable size. The optimum temperature in terms of growth and food conversion was between 28°C and 30°C.

Anderson and Lewis (1974) stated that within the temperature ranges (80°F-60°F), the transferring of fish to cold water and returning them to warm water without tempering is a satisfactory means of handling channel catfish in hot weather.

Lovel and Lie (1978) observed that channel catfish fingerlings fed semipurified diets in flowing - water aquariums for 16 WK required a dietary source of vitamin D for normal growth and bone mineralization.

6.2 Double cropping

Brown (1976) in his brief note described the potential of double cropping for fish farmers. His conclusions were as follows: 'By double cropping, or rotating with rainbow trout, crawfish freshwater shrimp, siler silver or bighead carp, buffaloe, white amur or tilapia, catfish producers can get more income from their raceways, ponds or cages. According to him, actual rearing days are 132 for rainbow trout and 206 for channel catfish. “By double croping, we increased our returns by 93%”, Brown said.

In the same paper, he also refers to the possibility of shrimp culture. The conclusion which is significant for this particular programme is as follows: Shrimps were grown for 111 days in the raceways below the catfish, showing a 40.9% increase in growth in less than one month.

Shrimp, it was said, may have to be full some supplement as a backup to whatever they find in the effluent. A 2.5 Feed conversion was attained using a commercial trout feed. Some complications, however, may be experienced in growing crawfish, since they are predators of fish eggs and are in competition with fish for feed.

Busch and Koon (1975) suggest that the catfish pond may need aeration in late summer. In these tests, a paddle wheel and pump circular bio-filter unit was used with the following results: Combinations of cloudy days and warm weather in late summer may result in low oxygen levels in fed catfish ponds. When oxygen levels drop below 3 ppm, catfish usually will not feed well. Oxygen levels below 1 ppm can result in fish kills. The paddlewheel has its ancestory in riverboat propulsion and finds its present days use in the treatment of domestic sewage and livestock wastes. Reduced in size, it is now showing promise as an energy saver when used to maintain oxygen levels in catfish ponds.

Processing of channel catfish was reported by Melton, Wilson and Hord (1976). The conclusion of this research group was as follows. Fish muscle is considered to be tender when slaughtered, further softening may result in an over-tender or mushy texture. Muscle pH was not significantly changed by slaughter treatment or chill time. It did increase slightly during the chill period in all treatment groups. Thio-barbituric acid (TBA) values increase in meat as oxidative rancidity develops. Fish suffocated in ice had significantly higher TBA values at 8 and 12 hours chilling than either the electrocuted or beheaded groups. TBA values increased significantly during the chill period in fish of all three slaughter groups.

Mississippi researchers proposed the catfish lebelling law. The proposed measure says that catfish offered for retail sale must be labelled as farm-raised, river or lake, imported or ocean catfish.

Sandifer (1975) has undertaken tests with the Malaysian marine prawn and he concluded that five freshwater ponds were stocked with about 25,000 laboratory grown prawns. Harvesting showed that 60–70% had not only survived but had shown substantial gain. Prawns, he said, cannot be put into a pond and allowed to just grow. It is necessary to have a complete system of tanks, circulating water systems of tanks, special diets and methods of catching.

Meyers (1974) emphasises commercial exploitation of aquatic animals including the genus of the fresh water shrimp. His conclusions relating to the requirements of this programme are as follows. Usually the hatchery or developmental phase does not pose difficult problems as the biology of the animal is concerned. Workers have found that production can be improved by reducing the overall length of the production cycle. Pond production estimates vary from 1–2,000 lb/acre to projections as high as 3,000 – 4,000 lb/acre. The prawn is omnivorous eating both plant and animal material locating food mainly by smell and touch.

Huner (1977) reported the problems and potential of fresh water aquaculture industry. His conclusions are as follows. Market potential was at least one million pounds of whole crawfish per four-months spring season. Peeled tail meat sold best in restaurants. Amborski postulated use of craw fish as living media for growth of viruses, for the study of antibacterial mechanisms since the hemolymph has natural antibiotic properties and would be available in large quantities from the tonnages of crawfish processed each year.

In a special report Emerson (1975) described a five year catfish farmer shakeout ends. She goes into the problems associated with prices, contract, growing, exports and future potential.

The potential of commercial crawfish aquaculture in Kenya was identified by Luisiana Scientists (1975). They made the following conclusions: Based on a single annual reproductive cycle, the yield of 500 – 600 lb/acre is not uncommon. Under proper pond management conditions, yields of 800 – 1,000 lb/acre are not considered unrealistic. Red swamp crawfish Procambarus charkii is an aggressive, omnivorous feeder which under favourable conditions can reach marketable size in 60 – 90 days.

Hawaii Firm (1975) described the aspects of catfish, prawn raising and marketing using giant Malaysian prawns and channel catfish. The results and findings of the particular programme were as follows. The catfish production ranges from 8,000–10,000 lb/acre a year. Fingerlings must still be imported from the mainland due to lack of success in channel catfish breeding. Ultimate plans call for a production of 500,000 lb catfish a year. The Laie farm coordinates agriculture with pond culture. Water for the ponds is supplied through artisian wells and the pond runoff is used to irrigate surrounding crops in a type of water recycling system. Since the ponds have to be periodically flushed to maintain water quality, significant amounts of nutrient-rich waste-water valuable for crop production become available in this way.

Mississippi scientists (1975) found that catfish, like Pavlov's dogs can be conditioned to associate a sound noise with food. In many commercial farms in Thailand this principle is being used when feeding catfish, Muller (1980). The Mississippi scientists concluded that catfish can be called by beating on a bucket or using a specific tractor equipped with a feed blower to accustom fish to a familier sound at feeding time. Goss and Ruane (1975) reported about the factors to be considered in designing the high density catfish raceway system to ensure that a safe, efficient, reliable system is constructed. These include (i) gross facility location and structure, (ii) water quality and supply, (iii) specific raceway structure and (iv) waste-water treatment. Variables which must be factored into the design of each major system component are reviewed. As apposed to typical pond culture, high density receway culture of catfish offers the advantages of less land area requirement, easier detection and control of detection and control of disease, elimination of trash and scavenger species, ease in handling and harvesting of fish, reduction in food losses and elimination of off-flavor problems.

The development of the catfish industry over the past decade was described by Brown (1977). The Table 26 shows the commercial potential of catfish production.

Table- 26 GROWTH OF COMMERCIAL CATFISH PRODUCTION

Source: Brown, 1977

The following conclusions are made. The total processed catfish sold in the United States is about 40–41 million pounds, including farm-raised, imports and the wide type. It also appears that the total production of catfish in 1975 was 97 million pounds, or approximately 4% of the total human food fish landed in the U.S. that year. The fact that commercially produced catfish has reached a mark of 2.6% of the total human fish-food produced in the United States in 1975, is evidence of the progress made by the industry in 10 years.