Автор неизвестен - Krmulture in iran - страница 47

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(version16) and tested at P < 0.05.

Table 1 Ingredient and proximate composition of experimental diets

Ingredients (g kg-1 diet)

 

 

Dietary treatment

 

 

FO

CO

SO

LO

CSLO

Fish meal (defatted)

540

540

540

540

540

Soybean meal

100

100

100

100

100

Fish oil

143

-

-

-

-

Canola oil

-

143

-

-

-

Safflower oil

-

-

143

-

-

Linseed oil

-

-

-

143

-

Vegebale oil1

-

-

-

-

143

Blood meal

40

40

40

40

40

Wheat meal

70

70

70

70

70

Wheat starch

60

60

60

60

60

Vitamin premix2

15

15

15

15

15

Mineral premix3

10

10

10

10

10

L-methionine

10

10

10

10

10

L-lysine

2

2

2

2

2

Di-calcium phosphate

5

5

5

5

5

Calcium carbonate

5

5

5

5

5

Moisture

8.1

7.6

7.8

8.2

7.7

Crude protein

47.2

46.9

46.8

47.1

47

Crude lipid

14.9

14.9

15.1

15

15.1

Crude starch

11.9

12

11.8

11.9

12.1

Gross energy (kcal/g)4

4.55

4.54

4.54

4.56

4.57

1Blend vegetable oil: was formulated using canola oil (40%), linseed oil (30%) and safflower oil 230%).

2Vitamin mixture: (mg or IU/kg of diet) Vitamin A (as acetate) 1600000 IU; vitamin D3, 400000 IU; choline chloride.12000; niacin, 4000; riboflavin, 8000; pyridoxine, 4000; folic acid, 2000; vitamin B12, 8000; biotin, 1; inositol, 20000; vitamin C, 60000; vitamin H2, 2.4; vitamin B2,

8000; vitamin K3, 2000; vitamin E,40000.

3Mineral mixture (g/kg): zinc, 12.5 g; iron, 26 g; manganese, 15.8 g; copper, 4.2 g; cobalt, 0.48 g; selenium, 2 g; iodine, 1 g.

4Calculated on the basis of 5.64, 9.43, and 4.11 (kcal/g diet) for protein, fat, and carbohydrate,

respectively (NRC 1993).

Growth indices are shown in table 2. No significant differences were detected in growth indices of fish fed control diet (FO) and those fed on diet containing canola oil (CO) and blend vegetable oil (CSLO). But total replacement of fish oil with safflower oil (SO) and linseed oil (LO) resulted in decreased weight gain (WG), specific growth rate (SGR), and Daily growth rate (DGR). The food conversion ratio (FCR) in groups fed CO and CSLO did not show any significant differences compared to the control group (FO), whereas FCR was significantly higher in SO and LO treatments. Hepatosomatic index (HSI) in SO and LO groups showed no significant differences compared to the control fish (FO). Nevertheless, this parameter was significantly lower in CO group and significantly higher in CSLO group compared to control. Visceralsomatic index (VSI) in treatments SO and CSLO had no significant differences with control; however, VSI in CO and LO was significantly lower compared to control (P < 0.05). Condition factor (CF) was found in fish fed 100% fish oil replaced diets with vegetable oil (CO, SO. LO and CSLO), significantly higher compared to control fish (P < 0.05).

Recent studies on concentrated plant protein inclusion in rainbow trout diet showed that it can potentially replace whole dietary fish meal with either no reduction or just a slight reduction in growth (Kaushik et al. 1995), which is similar to our findings. There are several explanations for undesirable effects of higher levels of plant derived ingredients in salmonids diet such as higher carbohydrate content which is not generally well digested by salmonids (Singh and Nose 1967). However, it is not conceivable that carbohydrate could have noticeable effects on fish growth in this study, since all diets had balanced carbohydrate content.

Histomorphometrical study of duodenum revealed that mean diameter and length of folds, height of epithelium, mean distribution of goblet cells (except in safflower oil), in response to replacement of vegetal oils increased significantly (P<0.05).Whereas, thickness of submucosal layer and tunica muscularis significantly decreased (P<0.05). These data revealed a positive role of vegetable oils on absorbing features of duodenum.

Table 2 Growth indices of rainbow trout fed experimental diets for 60 days (n=9 fish/tank).

Performance parameters

Dietary treatment

FO

CO

Initial body weight (g) Final body weight (g) Weight Gain (g/fish)

Feed intake (g/fish)

15.1±0.2a 69.9±2.3a 54.8±2.2a

55.4±7.8ab

15.2±0.1a 69.6±0.4a 54.4±0.2a

49.9±0.3a

FCR2

DGR3

SGR4

HIS5 VSI6 CF7

1.01±0.03

b

0.98±0.0

3b

2.87±0.0 1.16±0.0

I. 47±0.0

II. 2±0.2c 1.22±0.0

_2a

Values are means ±S.D. Values with the same superscripts within the same row are not significantly different (P < 0.05). 1See Table 1 for diet abbreviations. 2FCR, food conversion ratio; 3DGR, Daily growth rate; 4SGR, specific growth rate; 5HIS, Hepatosomatic index; 6VSI, Viscerosomatic index; 7CF, Condition factor.

2.88±0.07

a

1.17±0.02

a

1.51±0.02

bc

15.2±1.0a 1.08±0.03

b

SO

LO

CSLO

15.2±0.1a

15.4±0.2a

15.1±0.2a

58.2±0.5b

61.5±2.5b

68.2±2.2a

43.0±0.4b

46.1±2.3b

53.1±2.1a

38.8±3.8a

39.4±3.9bc

54.0±6.0a

b

d

bc

1.2±0.05a

1.2±0.01a

1.02±0.0

4b

2.45±0.0

2.55±0.07

2.83±0.0

1b

b

8a

1.02±0.0

1.05±0.02

1.14±0.0

1b

b

3a

1.57±0.0

1.50±0.03

1.75±0.0

7b

bc

6a

15.9±0.3a

13.7±0.9b

16.1±0.6a

1.20±0.0

1.17±0.02

1.20±0.0

3a

a

9a

Acknowledgements

This study was supported by Faculty of Veterinary Medicine and Artemia and Aquatic Animals Research Institute of Urmia University, Iran.

Caballero, M.J., Obach, A., Rosenlund, D. Montero, Gisvold, M., Izquierdo, M.S., 2002. Impact of different dietary lipid sources on growth, lipid digestibility, tissue fatty acid composition and histology of rainbow trout, Oncorhynchus mykiss. Aquaculture 214, 253-271.

Dosanjh, B.S., Higgs, D.A., Plotnikoff, M.D., McBride, J.R., Markert, J.R., Buckley, J.T., 1984. Efficacy of canola oil, pork lard and marine oil singly and in combination as supplemental dietary lipid sources for juvenile coho salmon (Oncorhynchus kisutch). Aquaculture 36, 333-345.

Greene, D.H.S., Selivonchick, D.P., 1990. Effects of dietary vegetable, animal and marine lipids on muscle lipid and hematology of rainbow trout (Oncorhynchus mykiss). Aquaculture 89, 165- 182.

Guillou, A., Soucy, P., Khalil, M., Adambounou, L., 1995. Effects of dietary vegetable and marine lipid on growth, muscle fatty acid composition and organoleptic quality of flesh of brook charr (Salvelinus fontinalis). Aquaculture 136, 351-362.

Hardy, R.W., Scott, T.M., Harrell, L.W., 1987. Replacement of herring oil with menhaden oil, soybean oil, or tallow in the diets of Atlantic salmon raised in marine net-pens. Aquaculture 65, 267-277.

Labbe, C., Loir, M., Kaushik, S., Maisse, G., 1993. The influence of both rearing temperature and dietary lipid origin on fatty acid composition of spermatozoan polar lipids in rainbow trout (Oncorhynchus mykiss). Effect on sperm cryopreservation tolerance. In: Kaushik, S.J., Luquet, P. (Eds.), Fish Nutrition in Practice. INRA, Paris, pp. 49- 59.

Olsen, R. E., Dragnes, B. T., Myklebust, R., Ring0, E.,2003. Effect of soybean oil and soybean lecithin on intestinal lipid composition and lipid droplet accumulation of rainbow trout, Oncorhynchus mykiss Walbaum, Fish Physiology and Biochemistry, 29: 181-192.

Singh, R.P. and Nose, T. 1967. Digestibility of carbohydrates in young rainbow trout. Bull. Freshwater Fish. Res. Lab 17, 21-25.

Thomassen, M.S., Rosjo, C., 1989. Different fats in feed for salmon: influence on sensory parameters, growthrate and fatty acids in muscle and heart. Aquaculture

79, 129- 135.

7OO

First International Larviculture Conference in Iran

Wassef, E. A., Wahby, O. M., Sakr, E.M., 2007. Effect of dietary vegetable oils on health and liver histology of gilthead seabream (Sparus aurata) growers.

Aquaculture Research, 2007, 38, 852-861.

A Survey on zooplanktons of Steel lagoon at Astara as

food for fish larva

Sanaz Siavoshan1, Mohammad Reza Rahimibashar2, Habib Vahabzade3, Masoud Farrokhroz4

1 M.S.c, Reprodoction and Culture of fishes, Islamic Azad University of Lahijan (Siavoshan_ 65@yahoo.com)

2 Phd, Sea Biology, Islamic Azad University Of Lahijan

3 Phd, Fishery , Islamic Azad University Of Lahijan

4 , Phd , Fishery , Islamic Azad University Of Lahijan

Abstract

Reservoirs are among the most sensitive freshwater bodies and their ecological structure and hydrobiology are unique. Steel lagoon is one of these which is located in Guilan province, with an area of over 138 ha and its located in 48 ° 51' 1 ' ' E and 38 0 22' 17 ' ' N . This study aimed to identify, count and examine the temporal and spatial variation of zooplanktons during a sampling year (from January 2011 to December 2012) in 5 station and capability of culturing fish Larva at this lagoon. Sampling zooplanktons was done by P.V.C Pipe. The result showed that annual abundance at Steel lagoon is 328.5 ± 39.05 Ind.l-1. Considering the relatively high densities of zooplanktonic during the year that determined , Steel lagoon has culture potential for fish larva and plankton feeder fishes such as big head carp in a extensive culture method .

Keyword: Steel lagoon, Culture fish Larva, Zooplankton, Astara

Primary consumers or zooplanktons are in second level of food web in aquatic ecosystems and playing a very important role in food web associated with phytoplanktons. Understanding the relationships between environmental factors and the structure of zooplankton assemblages is a crucial challenge . It may help determine the origin of spatial and temporal variations in food availability for fish larva , and thus identify the habitats and water masses in which fish larva find the most suitable and abundant food ( Cushing , 1996 ; Fortier et al ., 1992 ) . In shallow waters , fish predation usually exerts a strong influence on the size structure but also on the taxonomic composition of the zooplankton (Jeppesen et al ., 1997 ; Zimmer et al ., 2001 ; Jakobsen et al., 2003 ) . In addition to predation , the zooplankton community structure also depends on food abundance and quality and , in turn , on competition for this food ( Benndorf and Horn , 1985 ; Vanni , 1987 ; Kerfoot et al 1988) and hydroperiod (e.g.,Girdner & Larson,1995 ; Mahoney,Mort & Taylor ,1990) . In most of fresh water resources such as lagoons , zooplanktons have most important fishery of May until July . As background of this study , the researches of Sabkara et al ., 2001 which examined the distribution and abundance of zooplankton in Anzali lagoon ( during 1997 to 2000 ) can be refered . Riazi ( 2002 ) has done the study about zooplankton in Gomishan lagoon . The study of spatial and temporal variation and abundance of zooplankton communities at Amirkolayeh lagoon in Lahijan took place by Mohammadzadeh et al., 2009 . The assessment of seasonal and inter-annual zooplankton dynamics in temporary pools with different hydroperiods took place by Tavernini , 2008 . Carassou et al., 2010 has studied the spatial and temporal distribution of zooplanktons and their relationship with environmental conditions at New Caledonia lagoon . Tatina et al., 2008 has studied the zooplanktons of Steel lagoon .

Regarding the management of lagoon and their applications , practical aspests of this ecosystem is considered , so , the current study is aimed to identify , examine the spatial and temporal variations , number of

zooplankton communities and finally , analyse and totaling the outcomes to assess the possibility and way of usage of this lagoon in order to culture fish larva .

Materials ang Methods

Stell laggon , which is one of the Natural protected area , is located on approximately 7 Km away from Astara . Its surface of area is 138 h and is on 38° 22' 45" and 38° 21' 41" N (Latitude) and 48° 51' 28" and 48° 50' 47" (Longitude).According to the classification of lagoons (IUCN -1990), Steel lagoon in Astara is one of the natural lagoons specially for watering and its water level is unstable or variable (from Henric Majnoonian).

Regarding to the fact that the Steel lagoon was closes , ecological changes , changes in type of bottom , existence of plant cover , outlet and inlet water and average depth of the lagoon , five sampling stations were determined to take samples (Map 1).

Sampling process took place monthly from Junuary 2010 and ended in December 2011. For sampling zooplankton, 30 Lit water collected by using a P.V.C pipe 1.5 m long and 5 Cm and then were filtered with a 40 u net mesh size. These samples were fixed with formalin to a final concentration of 4% . (APHA, 2005; WHO, 1999). In laboratory samples using Invert microscope (x 20) and reliable identification keys were identified and counted (Pontin , 1978 ; Krovichinsky & Smirnov, 1993 ; Ruttner-Kolisko, 1974) .

The spatial and temporal variability in the environmental conditions was described using an One-way Anova , Kruskal-Wallis and Tuky Tests.

Map 1 - Stell lagoon and latitude location Results

Based on studies, five groups of zooplanktons including: Rotifera, Cladosera , Copepoda , Protozoa and 35 genuses were knowledged. The annual average , maximum and minimum abundance of zooplankton was respectively 328.5 ± 39.05, 931.25 ± 87.16 and 87.4 ± 22 Ind.l-1. (Chart 1).

Chart 1 - The month average of zooplankton in Stell lagoon

Outcomes of One-way Anova Test showed that abundance of zooplankton in different months had a significant statistical difference . Kruskal-Wallis Test has showed the significant statistical difference during different months too . Examination of variations in zooplankton abundance in different stations showed that the maximum abundance was in station 3 with average 446.33 ± 100.44 Ind.l-1 and minimum in station 2 with average 20 ± 10.72 Ind.l-1 (Chart 2 ) . One-way Anova and Kruskal-Wallis Tests also showed that there is a significant statistical difference among different stations from the viewpoint of zooplankton abundance .

Discussion and Conclusion

Zooplanktons as consumers of phytoplanktons are one part of the important food web in aquatic ecosystems which constantly and actively found in different aquatic resourses and consumed by other members of food web , specially by nektons and their one of the significant parts in food resourses of fishes particularly in larva period and after that (Sabkara et al ., 2004) . In monthly assessment ( examination ) of zooplanktons at Steel lagoon , it was recognized that the increase in zooplankton abundance initially happened in April and then in June , which was because of increasing rate of predation and increase in water temperature , which led to increase in number of zooplanktons and this process continues in July and August , until in September there is a decrease in number of zooplanktons , which is because of begin raining and decrease in water temperature . As Mohammad Ov ( 1990 ) believed that the cause of decrease in zooplankton productions which begins to happen from second half of July , is because of decrease in consumption of zooplanktons by fishes larva , summer stagnation and decrease in water volume . During the fall and winter there is a decrease in number

of zooplanktons too, which is derived from the decrease in water temperature. Majority of zooplanktons at Steel lagoon are Rotatorias. Awaless (1991) believed that Rotatorias are the chief larva food of varieties of fishes. The importance of Rotatorias in feeding fishes larva from begin feeding time is mostly related to having a high rate of proteins and rich fat resources specially Omega 3 ( Lubzems , 1989 ) . So , we can say that regarding to the fact that Rotatorias are the major zooplanktons at steel lagoon and yearly abundance average of zooplanktons at Steel lagoon and yearly abundance average of zooplankton ( 328.5 Ind.l1 ) , theres a possibility to culture fishes larva in this lagoon . Station 2 has the least zooplankton abundance among all of the stations , and it can be derived from low water temperature and flowing water at this stations . The annual average abundance of zooplanktons at Steel lagoon was 328.5 Ind.l-1 , which is very low in compare with Anzali lagoon 920 Ind.l-1 ( Sabkara et al 2004 ) and it can be because of lower phytoplankton abundance at Steel lagoon and consequently feeding rate of zooplanktons and the number of them will decrease . While in compare with Gomishan lagoon 5.4 Ind.l-1 ( Riazi , 2002 ) and Amirkolayeh lagoon 35 Ind.l-1 ( Mohammadzadeh et al ., 2009 ) , it was more but there was a similarity in zooplankton abundance average in compare with New Caledonia lagoon 350 Ind.l-1 ( Carassou et al 2010 ) . zooplankton genuses identified at the lagoon was similar with the studies done by Tatina et al ., 2008 .

According to the assessments took place at Steel lagoon , we can say that zooplankton abundance is suitable for culturing warm water fishes larva . Finally , must say that , With out carefully study and assessment number and species of fishes we cant determined to ability rearing abundance of fishes larva living in lagoon . On the other hand , during sampling ( May and Ceptember ) observed severe mortality of fishes . Thus to determine the exactly density of fishes larva to culture at Steel lagoon needed for more examination at this lagoon .

Awaless, A., 1991 , Mass culture and nutritional quality of the freshwater rotifer for Gudgoen . European Aquaculture Society , Special Publication . Gent , Belgium . ? p.

Benndorf, J., Horn, W.,1985. Theoretical considerations on the relative importance of food limitation and predation in structuring zooplankton communities. Archiv fu r Hydrobiologie Beiheft, Ergebnisse der Limnologie 21, pp. 383-396

Carassou , L., Le Borgne, R., Rolland , E., Ponton , D., 2010 , Spatial and temporal distribution of zooplankton related to the environmental conditions in the coral reef lagoon of New Caledonia, Southwest Pacific , Journal of Marine Pollution Bulletin , pp. 367 - 374

Cushing, D.H., 1996 , Towards a science of recruitment in fish populations. In: Kinne, O. (Ed.), Excellence in Ecology. Ecology Institute of Oldendorf-Luhe, Germany, 175 p.

Fortier , L., Levasseur , M.E., Drolet , R., Therriault , J.C., 1992 , Export production and the distribution of fish larvae and their prey in a coastal jet region . Marine Ecology Progress Series 85 , pp. 203 - 218

Girdner, S.F., Larson, G.L., 1995 , Effects of hydrology on zooplankton communities in high-mountain pools, Mount Rainier National Park, USA. Journal of Plankton Research, 17, pp. 1731-175

Jakobsen, T.S., Hansen, P.B., Jeppesen, E., Gr0nkja2r, P., S0ndergaard, M., 2003. Impact of three-spined stickleback Gasterosteus aculeatus on zooplankton and chl a in shallow, eutrophic, brackish lakes. Journal of Marine Ecology Progress

Series 262, pp. 277-284

Jeppesen, E., Jensen, J.P., S0ndegaard, M., Lauridsen, T., Pedersen, L.J., Jensen, L., 1997. Top-down control in freshwater lakes: the role of nutrient state, submerged macrophytes and water depth. Hydrobiologia 342/343, pp. 151-164

Kerfoot, W.C., Levitan, C., DeMott, W.R., 1988. Daphnia-phytoplankton interactions: density-dependent shifts in resource quality. Ecology 69, pp. 1806-1825

Krovchinsky , N., Smirnov , N., 1993 , Introduction of Cladocera , The Institution of Water and Environmental Mamagment . London , UK. 129 p.

Lubzens , E., 1989 , Possible use of Rotifer resting eggs and preserved live Rotifers in aquaculture and mariculture , 218 p.

Mahoney, D.L., Mort, M.A., Taylor, B.E., 1990 , Species richness of Calanoid Copepods, Cladocerans and other Branchiopods in Carolina bay temporary pools, American Midland Naturalist, 123, pp. 244-258

Majnoonian . H , 1999 , lagoons : Classification and protection of lagoons , Environmental protection agency , 176 p

Mohammadzadeh . M , Nezami . Sh , Keivan . A , Khara . H , 2009 , Study of diversity and density of zooplanktons and their spatial and temporal variation in Lahijan Amirkolayeh lagoon , Journal of Biological Sciences of Lahijan , N : 2 , pp. 61 -

69

Mohammad Ov . R.A , 1990 , zooplanktons aquatic resource of Nakhjavan , ? , 38 p

Pontin , R.M., 1978 , A key to the fresh water planktonic and semiplanktonic Rotifera of the British Isles . Titus Wilson and Son Ltd. 178 p.

Rizai . B , 2002 , Survay of lagoon zooplankton Gomishan , Journal of Ecology , N : 29, pp. 36 - 44

Ruttner-Kolisko , A., 1974 , Plankton Rotifers , biology and taxonomy , Austrian Academy of Science , 146 p.

Sabkara . J , Makaremi . M , 2004 , Distribution and abundance of planktons and their role in Anzali lagoon during 1997 to 2000 , Journal of Iranian Fisheries , N : 3 ,

pp. 87 - 113

Standard Methods for the Examination of Water and Wastewater , 2005 , American Public Halth Association , ? p.

Vanni, M.J., 1987. Effects of food availability and fish predation on a zooplankton community. Ecological Monographs 57, pp. 61-88

WHO, 1999. Toxic Cyanobacteria in water. E & FN Spon . 416 p.

Zimmer,K.D., Hanson,M.A., Butler, M.G., Duffy, W.G., 2001. Size distribution of aquatic invertebrates in two prairie wetlands, with and without fish, with implications for community production. Freshwater Biology 46, pp. 1373-1386

Effects of different soybean levels supplemented with lysine and methionine in the diets on the growth and survival of juvenile Beluga (Husohuso)

Somayeh Soltanzadeh*, Hossein Oraji, Khosrow JaniKhalili, Ahmad Nosrati

Fisheries Department, Faculty of Natural Resources, Sari Agricultural Sciences and

Natural Resources University, Sari, Iran

* Corresponding author. Fax: +98 9198419989.

E-mail address: soltanzadeh.somayeh@yahoo.com (S. Soltanzadeh)

Abstract

This study was conducted to assess the effects of different soybean levels supplemented with lysine and methionine in the diets on the growth performance, survival rate of juvenile beluga sturgeon (Husohuso). Beluga juveniles (68.5+0.50 g) were randomly allocated into 18 oval tanks (350 L) at a density of 8 fish per tank and triplicate groups. It were fed six isonitrogenic and isoenergetic diets as Control diet (0% soybean meal and 0% lysine and methionine supplemented) and SBM1 diet ( 12% soybean meal and 0.2% and methionine supplemented), SBM2 (24% soybean meal and 0.4% and methionine supplemented), SBM3 (36% soybean meal and 0.6% and methionine supplemented), SBM4 (48% soybean meal and 0.8% and methionine supplemented) and SBM5 (60% soybean meal and 1% and methionine supplemented). After 7 weeks of feeding on the experimental diets, growth factors (final weight, weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)), survival rate were measured. The results indicate that adding soybean levels supplemented with lysine and methionine in the diets decrease final weight, weight gain, SGR and increase FCR compared to the control(P<0.05). Although no significant differences (P>0.05) were observed between

Control, SBM1 and SBM2 treatments in weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR). Results showed that soybean meal could be incorporated up to 24% in diets of juvenile Beluga which corresponds to a reduction of 13% fish meal in the control diet without compromising growth.

Keywords: Husohuso, Soybean meal, Lysine, Methionine, Growth

Introduction

Beluga (H. huso) is one of the most frequently captive-bred species of sturgeon. This species is suitable for aquaculture because of fast growth, reproduction capacity and tolerance to unfavorable rearing conditions (Vlasenko1994). Beluga(H. huso) is generally known as a carnivorous species, and fishmeal has been a prominent protein source used in most feed formulations for this species (Mohseni et al., 2006). one of the main challenges in fish production industry is to improve feed formulation with in order tomaximize nutrient retention, feed conversion ratio, nutrient digestibility, and dietary nutrient balance and minimize fish mortality through the development of health-promoting diets. Although unpredictable supply of fishmeal, attention has been given to the possibility of increasing the inclusion of vegetable protein sources in diets for carnivorous fish.Soybean meal (SBM) is considered a alternative protein source because of its availability, content relative to fishmeal. The amino acid profile of vegetable proteins used in fish feed differs significantly from marine proteins like fish meal; the most prominent differences relate to their content of lysine and methionine. A better understanding of amino acid interaction and intestinal adaptations concerning their absorption is major importance for the fish farming industry regarding feed design and optimisations, particularly when feeds are supplemented with specific crystalline amino acids to optimise their amino acid profile (Berge etal., 2004).

Materials and methods 1. Diets

six iso nitrogenous and iso energetic experimental diets were formulated, as SBM1 as Control diet (0% soybean meal and 0% lysine and methionine supplemented ) and SBM1 diet ( 12% soybean meal and 0.2% and methionine supplemented), SBM2 (24% soybean meal and 0.4% and methionine supplemented), SBM3 (36% soybean meal and 0.6% and methionine supplemented), SBM4 (48% soybean meal and 0.8% and methionine supplemented) and SBM5 SBM5 (60% soybean meal and 1% and methionine supplemented) (Table 1). Fish and soybean oil (1:1) were added gross energy constant in all treatment. Also Pellets (2 mm) were prepared, air-dried to about 19 g kg-1 moisture and sealed in vacuum-packed bags and frozen (-20 °C) until to use.

Table 1: Dietary formulations and proximate composition of the experimental diets (% of dry matter).

Ingredients(%)

Control

SBM1

SBM2

SBM3

SBM4

SBM5

Kilka fish meal

46

39

33

26

17.4

6.5

Soybean meal

0

12

24

36

48

60

Wheat bran

10

10

10

10

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