chapter---5555 estelar -...

ChapterChapterChapterChapter----5555

UP-SCALING OF CARP FEED

AND FEEDING

Estelar

Up-Scaling of Carp Feed and Feeding.......�

103

5.1 INTRODUCTION

Fish requires food to grow, reproduction and for good health. Fish

becomes healthy only by the appropriate proportion of nutrients in their diet.

Fish feed should be well balanced and should be formulated according to the

need of the cultured fish. Nutrients are classified as protein, carbohydrate, fats,

vitamins and minerals. Fish feed is main factor for fish production and it should

have various properties according to the target species (Santhana et al., 2000).

Aquaculture is feed based industry, over 60% of operational cost coming

only from feed sources with shifting from extensive to semi- intensive or

intensive farming, depending on farm animals on exogenous feed supply in

more and more pronounced as the standing crop of culture species exceeds, the

natural feeding capacity of the pond. The artificial feed balanced with protein,

lipid, carbohydrate, fatty acids, vitamins, minerals and containing optimum

protein/energy ration is the common practice for better yield.

The fish farmers are not very well aware about the suitable feed

ingredients and their proportion in the formulated feed diet. The general feed

ingredients being used by fish farmer including rice bran, rice polish, oil cake

and groundnut oil cakes and husk etc. A small number of fish farmers are using

minerals and vitamins in supplements available feed in the market. In balanced

fish feed, the animal protein plays an important role in production.

Keep in view, reducing the feed cost and ultimately production cost of

fish for better return, there is an urgent need of some non-conventional feed

ingredients in the diet of fish.

5.2 REQUIREMENTS OF DIFFERENT NUTRIENTS IN FISH DIET

Fish require the nutrients, as same as required by other animals. The main

nutrients are protein, carbohydrate, lipid, vitamin, and minerals. The demand of

these elements for the preparation and selection of artificial fish feeds.

Estelar


104

5.2.1 Protein

Protein is the basic nutrient for all living things. It constitutes the most

important dietary component among the various food nutrients, as it is essential

for maintaining life and promoting growth. Protein taken by fish is decomposed

into amino acids through enzyme in the digestive organs. The amino acids are

absorbed internally and synthesized into fish protein for growing mending

tissues and maintaining life activities. It is used as energy for fish activities

when fats and carbohydrate are not sufficient. The demand of fish for protein

content in their diet is generally 25-40%. It is higher than the demand of

terrestrial animals like chicken/pig/cattle, which is 12-17% (Joshi, et al., 2010).

Since fish is cold blooded animal without need of maintaining body

temperature, they require minimum energy comparatively. Different fish have

different feeding habits, so their requirement for protein contents in feed is also

different. Carnivorous fishes like rainbow trout and eel need higher protein

content while herbivorous fishes need comparatively lower protein content.

The nutritional value of food depends not only on the quantity of protein

but also on the amino acids profile. Amino acids are composed of carbon,

hydrogen, oxygen, nitrogen and sometimes sulfur. The researchers have proved

that several amino acids must be fully prepared into the feed and are necessary

for fish growth. These amino acids are termed essential amino acids while other

amino acids, which may not exists or may be just a little in feeds, are called not

essential amino acids because they are needed only in small quantity and can be

synthesized internally. These ten amino acids must be included in fish feed for

their satisfactory development and growth. Besides, the proportion between

different essential amino acids in protein must confirm the nutritional

requirement of fish, which is dependent on the composition of amino acids in

fish protein, so the proportion of all essential amino acids of fish may be

referred to the composition of fish body protein.

Estelar


105

Thirty per cent protein level is optimum for growth of carp fingerlings,

also observed by Renukardhya and Varghese (1986); Gangadhar et al. (1997);

Rangacharyulu et al. (2000); Paul and Mohanty (2002). The growth of rohu,

common carp fingerlings in the experiment with various dietary protein levels

differed significantly. Renukardhya and Varghese (1986) reported that a level

of 30% protein in the diet was optimum for the good growth of Cirrhinus

mrigala. The optimum dietary protein requirement for fingerlings of Catla

catla was 35%. Fish is accepted universally as a rich source of nutrition

(Naylor et al., 2000). Protein requirement decreases with increasing body

weight (Pandian, 1989). Pandian (1987) advocated that protein requirement of

fish is uniformly high, mostly in the range of 32 to 40%. Fish feeds daily 2-3%

of their body weight (Seenappa, 2000).

Protein is expensive and hence becoming a dearer commodity for biotic

organisms. The dietary proteins requirements for a particular species or a group

of spices are different. But, De Silva and Gunasekera (1989) observed that

differences in optimal protein requirement within a group are vary narrow.

Much work has been done on the nutritional requirements of various fish

species but studies on the role of microbial community especially of fermented

feeds are scanty (Pullin, 1987; Shrinivasan 1987, Ayyapan et al., 1990).

However, studies have shown quite significant impact of microbial

communities on the growth of fish (Malik, 1992; Kumar, 1994,; Sharma and

Kumar, 1998; Kumar and Sharma 1999). All feeds either pelleted or not, are

being prepared by mixing various ingredients. However, by due to poor water

stability most of the feed settle down to the bottom of fish pond causing

economical loss to the fish farmer. The fermented feed is more nutrient rich

compared to the non-fermented one and exhibits a more favorable impact on

the fish growth (Kishan, 2000).

Estelar


106

5.2.2 Carbohydrates

Carbohydrates are the cheapest and most abundant source of energy in

fish feed. This occurs in three basic forms i.e. Sugar, Starch and Fibre. Sugars

are highly soluble in mono and disaccharides such as glucose and sucrose.

These are usually found in low levels in food stuff. Carbohydrate remain in the

fish feed in the range of 15-45%. Carbohydrates are decomposed into

monosaccharide by digestion and utilized by fish body. In the organic body it is

decomposed through oxidization into carbon dioxide and water and releasing

energy. Generally, fish are diabetic and don’t use much carbohydrate of the diet

for their metabolism. Carbohydrate is conveyed into livers and mussels as

glycogen form preserved the time being and the remaining part may be

converted into fats, to be cumulated for life maintenance in case of shortage of

food or stoppage of food tacking. Cellulose is also a kind of carbohydrate,

which is major component of plant cell wall. Among the cultivable fishes, only

few species like Tilapia and milk fish can digest cellulose at a rather low

utilization rate. It is believed that Cyprinids have lacking the cellulolytic

enzyme. In consequence, they are unable to utilize cellulose.

5.2.3 Lipids

Lipids are an important nutrient in the diet as a source of energy, carriers

of vitamins, essentials fatty acids, sterol and phospholipids. Lipids also impart

necessary flavour and thus may increase feed palatability. Each g. of fat

delivers 9 kilocalories of applicable heat. Fats are decomposed in digestive

tracts into fatty acids and glycerol which can be absorbed. After absorption, the

body fats are synthesized from the excessive fatty acid and glycerol, strong in

subcutaneous tissues, muscles, spaces between connective tissues and the

abdominal cavity.

Estelar


107

5.2.4 Vitamins

Vitamins are organic compounds and required in traces in the functions

of most forms of life. Vitamin requirements are affected by the size, age,

growth rate, physiological conditions, health status, and nutrient composition of

the diet, feed, environmental conditions and also the availability of vitamins

from natural food and gut microbial contributions. A number of vitamins take

part in the process of metabolism. Vitamin B1 of body carbohydrate, vitamin B

6 of proteins, vitamin C synthesis of body protein of animals, and vitamin D,

for normal metabolism of calcium and phosphorous, promoting the formation

of skeleton. As such, it is difficult to determine the exact amount of various

vitamins required by fish. However, on the basis of the practical state fresh

feeds are added to make up the deficiency of vitamins.

5.2.5 Minerals

Fish also have dietary requirements of minerals as like in higher

vertebrates, such as calcium, sodium, magnesium, potassium, chlorine, sulfur

and trace elements of iron, copper, zinc, cobalt, iodine, manganese, nickel,

fluorine etc. These are the important regulator of physiological process; need to

provide strength and rigidity to bone in fish and to maintain acid-base

equilibrium and osmotic relationship with the aquatic environment. Diet is the

main source of minerals, although some minerals are absorbed from the

environment. Non-availability of adequate qualities of minerals affects growth

and may cause irrecoverable deficiency disease. Minerals in the diet may

enhance the utilization of carbohydrate by fish; accelerate the growth of fish

tissues like skeleton and muscles. Improve their appetite and speed up the

growth of fish body.

Estelar


108

5.3 FEEDING HABIT OF THE TESTED FISH SPECIES

5.3.1 Silver carp

Silver carp is a pelagophil and planktophagus species. Larval stages

feeds on unicellular algae, fry and adult fish subsist on flagellate,

dinoflagellata, myxophycae, bacillariophycae, protozoa and rotifera

supplemented with decayed macrovegetation and detritus. When kept in ponds,

it thrives well on artificial feeds, such as bone meal, rice bran and flour (Hora

and Pillay, 1962). The post larvae feeds on zooplankton and, on reaching 1.5

cm in length, the fry begin to feed on phytoplankton. The fish shows certain

anatomical and morphological modifications correlated with its micro-

planktophagous feeding habit.

5.3.2 Grass carp

Grass carp, also known as ‘White Amur’ in Russia. According to

Nikol’skii (1956), grass carp of length greater then 30 mm is almost

exclusively a vegetarian. In the case of smaller fry, the diet may comprise

rotifers, crustaceans, unicellular algae and occasionally chironomid larvae.

Macrophytes material is first eaten at the size of 17 to 18 mm. and at this size

the importance of rotifers in the diet declines and that of chironomids increases.

In India, the fry of grass carp at 25 to 27 mm. size have been observed to accept

wolffia as feed. At 27 mm. length, macro vegetation forms the bulk of its diet,

and at the size of 30 mm upward, the fish, as stated above, is completely

herbivore. According to Hora and Pillay (1962), the fish at 25 mm. size can

readily take rice bran, bean meal and dried cow dung, oilcake, silkworm pupae,

kitchen refuse, soil and dung are often given as supplementary feed. Stroganov

(1967) stated that food ingestion of grass carp at low temperature (3-9 0C) is

irregular and may increase if the temperature rises by 3-4 0C. Feeding becomes

intensive at temperature above 16 0C, the fish consuming a wide range of

aquatic plants.

Estelar


109

5.3.3 Common carp

Cyprinus carpio is the world-wide most extensively cultivated species.

Although exotic to India, it is already being cultivated in the country singly as

well as along with Indian major carps. The fish is voraciously omnivorous;

efficiently converting the food ingested into flesh, grows very fast and is prone

to artificial feed. It is non-predatory, when cultured along with major carps; it

competes for food mostly with mrigal and kalbasu.

5.4 TYPES OF FISH FEED INGREDIENTS

5.4.1 Plant origin feed ingredients

Cereal Grains: Soybean, wheat, and maize are commonly used grain feeds.

Soybean, which is a nutritional food, contains at least 38% crude protein and is

rich in essential amino acids. Soybeans are usually ground up into “bean milk”

for feeding to fry. About 5-7 kg of soybeans can supply the milk required to

raise 10,000 fish from fry to fingerlings. Some bean milk particles are directly

consumed by the fry but most become fertilizer for the proliferation of

plankton. For grass carp brooders, wheat and rice sprouts are often supplied.

These grains are rich in vitamins, especially vitamin E, which is beneficial to

gonad development. For granulated feeds, wheat powder is often used as a

binder.

Oil Cakes: Oil cakes are by-products of oil plants, after oil pressing. Bean

cakes, peanut cakes, cotton seed cakes, mustard cake, and rapeseed cakes are

often used in fish farming. This type of feed is rich in crude protein (30-40%).

If cakes are used to fry feed, they must be broken into pieces, soaked, and

ground up into milk. About 150–200 kg of cake is needed to nurture 10,000

fingerlings with body length greater than 10 cm. Cotton seed cakes are

commonly used in carp culture in the USA and the USSR. This is not so

common in China. However, China is cotton-producing country and the use of

Estelar


110

cotton seed cake as a fish feed shows great potential. There is a little gossypol

in cotton seed cakes, which is detrimental to livestock, but harmless to fish.

Wheat bran: Wheat bran is a by-product of the rice and wheat processing

industry and is rich in vitamin B, apart from crude proteins, fats, and

carbohydrates, it is an important ingredient of compound feeds.

Green fodder: Green fodders include aquatic plants and terrestrial plants and

are mainly used as feed for grass carp and breams and, sometimes, for common

carp, crucian carp, and tilapia. The main aquatic plants used are Wolffia

arrhiza, Lemna minor, Vallisneria spiralis, Potamogeton malainus,

Potamogeton maackianus, Hydrilla verticillata, Eichhornia crassipes, Pistia

stratiotes, and Alternanthera philoxeroides. The main terrestrial plants used are

Echinochloa crusgalli, Pennisetum alopecuroides, Lolium perenne, Sorghum

sudanense, Pennisetum purpurlum of the grass family; Lactuca tenticulata of

the composite family; and various leaves and vines from melon and vegetable

crops. Water lettuce (Pistia stratiotes), water hyacinth (Eichhornia crassipes),

and alligator weed (Alternanthera philoxeroides) must be minced or fermented

before they are given to the fish. To ferment one of these aquatic plants, 100 kg

is mixed with 3-4 kg rice bran and 0.5 kg yeast; the container is then sealed and

stored for 2 days at 26 °C. Alligator weed sometimes contains saponin, which

is toxic to fish. If, it has been processed by adding, a little table salt (2-5 per

cent concentration), the toxicity is eliminated and the feed becomes palatable.

When these aquatic plants are mashed into a paste with a high-speed masher,

they are appropriate feeds for fry culture. Green fodders contain mostly water

and cellulose. However, they also contain the principal nutrients, i.e. fat,

protein and carbohydrate, and rich in vitamins. Green fodders are the principal

feed for grass carp and serves as supplemental feed for other cultivated fish.

Estelar

Fig

. 4

0:

Exp

erim

enta

l ta

nk

s fo

r fe

ed t

rial

Estelar


111

5.4.2 Animal origin feed ingredients

Animal feed have a higher nutritional value than the plant feed because

they give a more complete supply of nutrients and are rich in proteins and

essential amino acids. Among the cultivated fish species in China, most are

herbivorous or omnivorous; the only carnivorous species is black carp.

Common animal feed include fish meal, trash fish, silkworm pupae, fresh-water

shellfish (e.g. Viviparus quadratus and Corbicula fluminea), kitchen waste, and

earthworms. Viviparus quadratus lives in rivers and lakes with a high fecundity

and feeds on epiphytic algae. It has a meat rate of 22-25% and a food-

conversion ratio of 40 for black carp. Corbicula fluminea lives in the clay

bottom of rivers and lakes and is collected with Viviparus quadratus. It has a

meat rate of 13% and a food conversion ratio of 60 for black carp. Both species

are commonly fed to black carp. In most of cases supplementary feed of grow

out fish comprises only oil cakes of mustard/ground nut and rice/wheat bran at

1 : 1 ratio by weight (Tripathi, 1990). Medda et al. (1993) revealed that there is

very specific variation in the relative growth rate of two carp species Catla

catla and Labeo rohita is response to experimental feeding with amino acid and

vitamin enriched diets.

An experiment was conducted by Singh et al. (1986) and found that

fortifications of conventional feed (rice bran, ground nut cake 1:1 ratio) with

little vitamin-mineral premix could increase the efficiency of the feeding more

than 100% for carp fingerlings. Yakupityage et al. (1990) examined the

efficiency of supplementary feeding of Nile tilapia, Silver carp and common

carp with rice bran in duck-fish integration system. Supplementary rice bran at

1% body weight per day significantly improved the growth of all species,

although higher percentage of feeding of rice barn has no influence on fish

yield. Asia accounts for over 80% of the world’s fish production (De Silva and

Davy, 1992). In the light of conflicting demand for land and water, fish culture

Estelar


112

practices need to be intensified to varying degrees, mostly through increasing

levels of supplemental feeding. The feed cost is one of the highest operational

costs (50-60%) in aquaculture. Through, a variety of feed ingredients of both

plant and animal origin are used in preparing artificial diet in intensive culture,

the quantity and quality of protein in the diet were seen to influence fish growth

.In fish much of the protein is converted into flesh during the growth. A variety

of ingredients of plant and animal origin has been screened for in corporation in

supplementary feed for carp and used either singly of in combination

(Lakshmanan et al., 1967). Chakrabarthy (1973) stated that animal protein

based fish diet is very effective for the fish production and given excellent

weight and length gain.

Nandeesha et al. (1991) stated that the growth attained by carps on

slaughter house waste based diet was always higher compared to that fed on

fish meal. Jadhav and Prasad Rao (1991) also reported that goat offal gives best

growth result in carps. Hassan et al. (1999) reported that growth of L. rohita

fingerlings was better with diet having slaughter house waste. Khan and Jafri

(1992) also found that growth of Rohu fingerlings was superior with goat-offal

based diet. Results indicated that conversion efficiency of slaughter house

waste mustard oil cake and rice bran was much higher than the conventional

fish feed consisting of rice bran and mustard oil cake.

5.5 SIGNIFICANCE OF NATURAL FEED AND SUPPLEMENTARY

FEEDING

It is widely accepted that, there are three basic feeding pathways by

which non- organic matter provides nutrition to fish i.e. direct feeding of fish

on the organic matter and feeding along autotrophic and heterotrophic

pathways which develop as a results of the fertilization of the pond by the

organic matter (Wohlfarh and Hulata, 1987). Among these, the heterotrophic

pathway has received considerable attention and it has been stated that, it is of

Estelar


113

greater importance in aquaculture than the autotrophic pathway (Schroeder

1977; Schroeder 1978; Wohlfarth and Schroeder 1979; Schroeder 1980).

The plankton community is an important component of aquatic eco-system

(Wetzel 1983). The studies of this complex community are wide ranging in their

application to the system as a whole including structure of the plankton (Rounick

and Winterbourn, 1983; Collier and Winterbourn, 1990), productivity (Elwood

and Nelson, 1972), herbivory and trophic status (Benke and Wallace, 1980; Hill

and Harvey, 1990). In natural communities, plankton contributes significantly to

primary production (Minshall, 1978; Cattaneo and Kalff, 1980) and represents

readily available food for many vertebrates (Lamberti and Moore, 1984),

including fish (Power et al., 1985). The abundance, productivity, structure of

plankton communities can be strongly influenced both by nutrient concentration

and herbivore. In addition to fertilizing the ponds for the proliferation of natural

food organisms, artificial feed must be used to meet the demands of various fish

species. Fish feed are the prime material base of aquaculture. Applying artificial

feeds in a fish pond can significantly raise the yield. Production of the Plankton

feeder fish is also enhanced by giving the supplementary feed to the growing fish

in addition to the available natural feed in the form of plankton. The feed is

directly consumed by the so-called feed eaters and, in turn, their excreta act as the

manure in the pond water. This multiplies the natural food organisms of the

plankton feeders. The present study was conducted to standardize the suitable feed

for the testes fish species i.e. silver carp, grass carp and common carp. Lubzens et

al. (1984) reported that adding rotifers to diet of carp larvae increase growth rate

and would allow either faster production of carp larvae from the hatchery, or the

use of larger larvae for stocking outdoor ponds. Sinha and Ramachandran (1985)

described that nursery should have plenty of fish food organism of smaller size

before the hatchlings are stocked. This is important since at that stage the yolk of

the hatching is observed and it starts feeding in nature. Keshavappa et al. (1990)

Estelar


114

made comparative study on the survival and growth of common carp from spawn

to fry when fed on soybean flour and conventional feed mixture of rice bran and

groundnut oilcake in fertilized and unfertilized cistern. In fertilized cistern, they

reported an average survival of 60.36% and growth of 6.48 mg. in soybean flour

fed cistern, whereas 31.23% survival and 4.74 mg. gain in weight in cistern fed

with conventional feed. In another experiment, where spawn were stocked in

unfertilized cistern, they reported an average survival of 69.76% and growth of

2.35 mg. with soybean flour and an average survival of 33.53% and growth

increment of 1.95 mg. with conventional feed. Shirgur (1991) explained that

rearing of carp spawn to fry needs continuous provision of suitable zooplankton

organism of desired quality and quantity in the nursery ponds for feeding and

growth. Intensive studies have shown that optimized rearing of carp fry (up to 20

mm. sizes) from spawn stage was possible with in a short cycle of 11 days by

adopting phased fertilization technique. Ovie et al. (1993) stated that the absence

of the natural fish food organism in a hatchery system, where induced breeding of

fish is practiced, requires that these organisms be harnessed in mixed or pure

culture from the wild and intensively cultured in enclosure to ensure their ready

availability to the young fish larvae and fry.

5.6 TYPES OF FEED

The natural food of fish is classified under three groups, i.e. 1-Main

food or the natural food which the fish prefers under favorable conditions and

on which it thrives best. 2-Occasional food or the natural food that is well

liked and consumed as and when available. 3- Emergency food which is

ingested when the preferred food items are not available and on which the fish

is just able to survive. Certain microscopic planktonic crustacean group and

rotifers from the ‘main food’ of spawn and fry (15-20mm. size range) of the

Indian major carps and majority of other cultivable species, with phytoplankton

forming the ‘emergency food’ (Alikunhi, 1952). Spawn and fry with a small

Estelar


115

and short straight intestine appear to digest rotifers and cladocerans fairly

rapidly and thrive well on zooplankton. Phytoplanktonic algae are not so easily

digested and, at least, some algal forms (euglena, phacus, eudorina, oscillaroria,

microcystis, filamentous green algae, etc.) remain undigested being ejected

intact along with faecal matter. The food and feeding habits of the fungerlings

of Indian major carps differ markedly from those of their hatchlings and fry.

Nikol’skii (1963) divided food of fishes into four categories according to the

relationship between the fishes and their food. These categories are: (1) basic

food, which the fish usually consumes, comprising the main part of the gut

content; (2) secondary food, which frequently found in the guts of fishes, but in

small amounts; (3) incidental food which only rarely enters the gut; and (4)

obligatory food which the fish consumes in the absence of basic food.

5.7 FORMULATED FEEDS

Formulated feeds are composed of several materials in various

proportions. In fish farming; formulated feeds have the following advantages.

1. The ingredients of formulated feeds can complement one another and raise

the food utilization rate.

2. Proteins can supplement one another improving the essential amino acid

conformation of the feed and raising the protein utilization rate.

3. Food sources can be broadened by mixing feeds disliked by the fish with

other preferred feeds.

4. By adding a binding agent to produce pelleted feeds, the solution of

nutrients in water is diminished and wastage is reduced.

5. Drugs may be mixed into the feeds (indicated feeds) to control fish diseases.

6. Formulated feeds are convenient to transport and preserve; they are suited to

automatic feeding, which can lead toward the mechanization of fish farming.

Estelar


116

5.8 RESULTS AND DISCUSSION

Feeding is a very important part for the successful carp farming in

uplands. Two types of feeding practices are used: (1) machine feeding, which is

used for well-equipped and well managed farm, and (2) hand feeding, which

needs frequent supervision of the ponds, and is used on fish farms with fewer

facilities, in case of polyculture of carp, generally wet feed in the form of feed

balls is used for daily feeding at the rate of 3% of total biomass by placing in

feeding trays or in feeding bags. For the present experiment formulated diet

were prepared by locally available feed ingredients. A separate experimentation

was conducted for evaluating the diet in field conditions. Experiment was

conducted in three FRP tanks (size 1x1x0.7mt.) in outdoor condition at Krishi

Vigyan Kendra, Lohaghat, during the month of May-June, 2008 (60 days).

Three different test diets (Table 17) were formulated with locally available feed

ingredients like Rice bran, Mustered Oil cake, Madua flour and Soybean cake

with their proximate composition (Table 18). All the tested diets having

different feed ingredients composition were analyzed for their proximate

composition (Table 19). Data on the proximate composition reflected that there

was not any significant difference in the level of nutritive elements of all diets.

Protein level in the all diets was found in the range of 27.4-30% with almost

similar level of other elements.

Table 19 shows that data on growth performance revealed that feed D3

having 30% protein and 7.9% lipid is best among the all 3 tested diets having

the feed ingredients- rice bran, Mustard oil cake, Madua flour (Ragi), Soybean

cake and mineral and vitamin mixture. In the feeding trial of 2 months with the

diet D3, net weight was gained 55.78 gm with 95% survival and 3.1 FCR

(Table 20).

Estelar


117

Table 17: Composition of different test diets.

Diet Ingredients Ratio Qty. in 1 kg.

D1 Rice bran 49 490gm

Mustard oil cake 49 490gm

Mineral mixture 2 20gm



Madua flour 20 200gm




Madua flour 20 200gm

Soybean cake 10 100gm


Table 18: Proximate composition of major feed ingredients

All the values are per 100g. Feed

ingredients Protein (g.) Fat (g.) Fiber (g.)

Rice bran 13.5 16.2 4.3

Ragi (Madua) 7.3 1.3 3.6

Mustard 20.0 39.7 1.8

Soya been 43.2 19.5 3.7

Estelar


118

Table 19: Proximate composition of tested carp diets

Carp feed D1 D2 D3

Moisture 3.97 4.24 4.12

Crude protein 27.4 29.2 30.0

Crude lipid 7.5 7.4 7.9

Crude fiber 2.41 2.40 2.42

Total ash 20.66 21.44 20.14

NFE 38.06 35.32 35.42

Table 20: Growth, Survival and FCR of experimental diets.

Carp feed D1 D2 D3

Av. Initial weight (g) 3.2 3.05 3.11

Av. Final weight (g) 27.45 35.19 58.89

Av. Net wt. gain (g) 24.25 32.14 55.78

Av. Initial length (mm) 59.58 59.58 59.78

Av. Final length (mm) 124.46 143.4 159.08

Survival (%) 90 85 95

FCR 3.8 3.2 3.1

Estelar

Soybean Rice bran

Madua (Ragi) Mustard

Fig. 41: Fish feed ingredients

Estelar


119

The value of Specific Growth Rate is used to compare growth on a daily

basis. Higher growth and specific growth rate (3.46) indicates that the D3 is

superior over the other tested diets. Several scientists have also applied SGR as

growth index in different nutritional studies Dinesh (2004) and Pandey (2005).

Several scientists have calculated ponderal index or condition factor of

different fishes i.e. 0.73 to 0.95 in Tor putitora (Pathani and Das, 1980),

1.03-1.31 in Salmo trutta fario (Kumar et al., 1979) and 1.20-1.34) in

Salvelinus namayeush (Oosten and Eshneryer, 1956). Kumar et al., (1979)

concluded that the value of condition factor as about one is considered to be of

its average weight. The values of K in present study were recorded in the range

of 1.6 to 2.2 showed that the fishes of experimental unit are more robust (Table

21). The value of the AE for different 3 diets were in the range of 76.34-78.24

with highest for the diet D3, and the value of the PER for different 3 diets were

in the range of 24-29 with highest for the diet D3 (Table 22).

Table-21: Specific growth rate and condition factors of experimental diets

Test diets S.G.R. C.F.

D1 2.53 1.6

D2 3.41 2.2

D3 3.46 2.1

Table-22: Assimilation efficiency and Protein efficiency ratio of

experimental diets

Test diets A.E P.E.R

D1 76.34 24

D2 77.82 27

D3 78.24 29

Estelar


120

Table 23: Plankton composition and distribution pattern in trial ponds

Months

Species Feb Mar Apr May Jun Jul Aug Sep Oct Nov

Phytoplankton

(A) Chlorophyceae

Pediastrum spp. + + + + + +

Chlamydmonas sp. + + + + + + + + + +

Scenedesmus spp. + + + + + +

Chlorella spp. + + + + + + +

Pendorina + + + + + +

(B) Bacillariophyceae

Navicula spp. + + + + + + + + + +

Tabelaria. + + + + + + + + + +

Pinnularia sp. + + + +

(C) Cynophyceae

Microcistis sp. + + + +

Anabaena sp. + + + + + + + +

oscillatoria. + + +

Zooplankton

(A) Rotifera

Brachionus spp. + + + + + + + +

Keratella spp. + + + +

(B) Cladocera

Daphnia spp. + + + + + + + + +

(C) Copepoda

Cyclops spp. + + + + + + +

Microcyclopes sp. + + + + + +

Estelar


121

5.8.1 Plankton recorded

The natural food of the carps, plankton were analyzed and identified as

11 phytoplankton and 5 species of zooplankton were recorded. Out of 11

species, 5 species belongs to Chlorophyceae, 3 species belongs to

Bacillariophyceae and 3 species were belongs to Cynophyceae. Zooplankton

species were recorded as 2 species of Rotifera, 1 species from Cladocera and 2

species of Copepoda. Abundance of the natural food in the form of Plankton in

the trial ponds is the key factor for optimum growth of the fish.

The most common phytoplankton species comprised as Chlorella vulgaris,

Scendesmus species, Chlamydomonas sp., Pediastrum and Pendorina

(Chlorophyceae grou) Naviculla, Pinnularia sp. and Tabellaria,(Bacillariophyceae

group) and Microcistis sp, Oscilatoria and Anabaena sp. (Cynophyceae group).

Brachionus, Keratella, Daphnia, Cyclops and Microcyclopes sp. were the common

zooplankton in the experimental ponds during the study period (Table 23).

Species composition was not significantly different in different

experimental Ponds at the same location. But, the seasonal abundance and

count of the different species was significantly different. Under the group

Chlorophyceae, Chlamydomonas sp. and Chlorella sp. was dominant round the

year. In Bacillariophyceae group, Navicula spp. and Tabelaria, and in

Cynophyceae group, Anabaena sp. was the dominant species. Brachionus spp.

and Daphnia spp. were dominant zooplankton in the all ponds. Two peaks of

the plankton population were observed during the period of September to

November, and March to May. The total plankton volume varied from 1.6-3.2

ml/50 lit. in different experimental ponds. Maximum value was observed

during March to April in all ponds. Similar fluctuation pattern was observed in

total phytoplankton count. Total density was varied from 210-3700 nos./ltr.

Estelar


122

Total density of zooplankton was observed as 230-3200 nos./lit with peak

during September to November and March to May. Highest density was

observed in the month of April with appearance of algal bloom.

Estelar

chapter---5555 estelar -...

Documents