Protein nutrition of farmed tilapia: searching for unconventional

sources

Abdel-Fattah M. El-Sayed

Oceanography Department, Faculty of Science,University of Alexandria, Alexandria, Egypt

Tilapia culture• Rank third in the world, in terms of

production, after carps and Salmonids.• One of the fastest growing farming

activities, annual growth rate of 13.4% during 1970�2002.

• Practiced in about 100 countries.• The production increased from 383,654 mt

in 1990 to 1,505,804 mt in 2002• 6% of total farmed finfish production in

2002.

• Nutrition: > 50% of operating costs. • Protein represents 50% of feed cost.• The selection of proper quantity and quality of

dietary protein is a must• Tilapia:

- herbivorous / omnivorous - low on the food chain- Produce high quality protein from low quality

food• The challenge• Develop commercial, cost effective tilapia feeds

using locally available, cheap and unconventionalresources.

Protein requirements

Extensively studiedResults are varying, sometimes contradictory !!

Why?• Indoor studies• Short- term (4-8 weeks)• Sometimes imbalanced diets (Casein vs

casein/gelatin)• Ignored cost/benefit analysis

35-40Casein/Gelatin45FM40FM/SBMBroodstock30FM45-26430FM6.1-16.530Casein3.5035Casein/Gelatin2.4Fingerlings40FM0.8040FM0.51

45% FM0.012FryO. niloticus

RequirementProteinsource

Weight (g)Species and life stage

Protein requirements

28-8.87O. mossambicus X O. hornorum

32-1.24O. niloticus X O. hornorum

28SBM2132FM0.6-1.120FM+CSM145-242O. niloticus X O. aureus

35-40Casein/Gelatin1.4-1.735Casein1.35-1.80T. zillii34Casein/albumen7.556Casein/albumen2.5036SBM or FM0.30-0.50O. aureus

30-35FM6-3040-50FMFryO. mossambicus

Require-ment

Proteinsource

Weight (g)Species and life stage

0.61.00 (0.28)0.43 (0.17)Tryptophan

3.21.6

3.75 (1.05) 1.792.50 (1.00)PhenylalanineTyrosine

1.32.1

2.68 (0.75)0.53

0.99 (0.40)1.33 (0.53)MethionineCystine

2.63.11 (0.87)2.01 (0.80)Isoleucine4.33.39 (0.95)3.40 (1.35)Leucine3.02.80 (0.78)2.20 (0.88)Valine3.33.75 (1.05)2.93 (1.17)Threonine1.51.72 (0.48)1.05 (0.42)Histidine4.14.20 (1.18)2.82 (1.13)3.80 (1.52)Arginine---5.12 (1.43)3.78 (1.51)4.05 (1.62)Lysine

O. niloticus4O. niloticus3O. mossambicus2

O. mossamicus1

RequirementAmino Acid

1Jackson and Capper (1982); 2Jauncey et al. (1983); 3Santiago and Lovell (1988); 4Fagbenro (2000).

Essential Amino acid requirements of tilapia

Major protein sources

Animal protein sources:– Fish meal– Fishery by-products– Terrestrial animal by-products

Plant protein sources:– Oilseed plants – Soybean Meal– Cottonseed meal/cake– Other oilseed by-products– Aquatic plants– Grain legumes

Single-cell proteins

– deficient in Cys, Lys and Met– gossypol

CSM

• deficient in Met, Lys, Cys• antinutrients:

– protease (trypsin) inhibitor – phytohaemagglutinin– anti-vitamins

SBM deficient in MetMBMdeficient in Lys and MetHFMdeficient in IsolBMdeficient in EAA (Lys)PBMfree amino acidsFish silage

Shortage in supply, increased prices, competition

Fish mealLimitationsIngredient

O. niloticus (10.8)200-20Chicken offal silageO. niloticus (0.1)1000-100Animal by-productsO. niloticus (0.01)660-100HFMO. niloticus (3.9)1010-50BM Red tilapia (9)<100100BM O. niloticus (20)<100100BM O. mossambicus (1)1000-100BM O. mossambicus (1)1000-100MBM + BM (2:3)O. niloticus (20), Red tilapia100100MBMO. niloticus (1.4)4010 -40 PBM+HFMHybrids (195)5050PBMO. niloticus (20), Red tilapia 100100Shrimp meal

Animal sources:recommendedtested

Species (weight, g)levels (%)levels (%)Source (specification)

Protein sources tested and recommended for tilapia

T. zillii (1.5)800-100CSM

Hybrids (195)5050CSM

O. mossambicus (12)500-100CSM

O. niloticus (20)100100CSM +/- lys

Hybrids (169)1000-100SBM + DCP+oil

Hybrids (84)1000-100SBM + EAA+ DCP+oil

O. niloticus (3.2)1000-100Soy protein concentrate

Hybrids (4.47)670-100SBM +/- Met

O. mossambicus (50)750-100SBM

O. aureus (0.3-0.5)1000-100SBM +/- Met

O. niloticus (0.8)7575SBM +/-Met

Oilseed plants

T. rendalli (0.93)200-50Sunflower meal

T. guineensis (N.A.)100100Macadamia press cake

O. niloticus (7.5-12)500-100Macadamia press cake

O. mossambicus (8.4)5020-50Palm kernel cake

O. niloticus (2.5)600-100Palm kernel cake

T. guineensis (52)100100Defatted cocoa cake

O. mossambicus (31)25-500-50Copra meal

O. mossambicus (0.3 -13 )15-7515-75Rapeseed meal

O. mossambicus (30)250-100Groundnut cake

T. zillii (2.4)250-75Sesameseed meal

O. niloticus (N.A)4020-40Yeast

O. niloticus ( )300-100Duckweed (Spirodela)

O. niloticus (14.5)500-50Duckweed (Lemna)

O. niloticus (0.4)500-75Duckweed (Wolffia)

Tilapia sp (not given)50-1000-100Duckweed

O. niloticus (7-14.5)20-3020-40Ceratopyhllumdemersum

O. niloticus (14.5)2525-50Potamogeton

O. niloticus (7)20-3020-40Eleocharis ochrostachys

O. niloticus (1), T. zillii (1)200-100Hydrodictyon

O. niloticus (4-40)<250-100Azolla pinnata

O. mossambicus (0.3)400-100Spirulina

Aquatic plants

O. niloticus (5)40-8020-80Toasted lima bean+ Met

O. aureus (9-50)13- 300-39Coffee pulpO. niloticus (...)1010-20Cocoa husksT. busumana (1.5)1000-100Pito brewery wasteTilapia (0.4)35-4916-49Corn distillers' grainsO. niloticus (30)100100Corn gluten + SBMO. niloticus (0.16)20-300-50Cowpea LPCO. mossambicus (0.3)3515-55Alfalfa LPCO. mossambicus (0.4-0.9)250-35Jack bean mealO. niloticus (2.92)25-3713-50Green gram legume O. niloticus (13.8-15.4)<10020-100Cassava leaf mealO.aureus (43-50)150-50LLM

O. mossambicus (50)O. mossambicus

<25100

0-500-100

Leucaena leaf meal (LLM)

Grain legumes

Carbon source (rice bran, wheat bran, wood, Grass cuttings, etc.) C:N ratio = 15:1

AerationAerobic

decomposition

Nitrogen fixation (Azotobacter)

Bacterial growth (Microbial mat)

Intensive Tilapia ponds

•Reduce dietary protein•Improve fish growth• Reduce water exchange•Reduce ammonia•Reduce cost

Production of natural food in tilapia fish ponds. After El-Sayed, 1999.

The use of unconventional protein sources

1- Amino acid vs mineral supplementation?

1. Is EAA supplementation necessary??2. Can certain minerals meet the deficient EAA??

1. Sesame meal + Lys or Zinc or both2. SBM + Met or Phosphorus3. CSM + Lys

34444Vit & min mix

22222Fish oil

31111SB oil

2114.51514.515α-cell

0303000Zn SO4 (mg/g)

00.500.50L-Lys

025252525Sesame meal

3427272727Dextrin

118888Gelatin

2418181818Casein

5 (cont.)4321

Test dietsIngredients

Growth of T. zillii fed sesame seed based-diets

5

10

15

20

25

30

35

0 1 2 3 4 5 6 7

Time (weeks)

fish

wt (

g)

diet 1diet 2 (lys)diet 3 (zinc)diet 4 (lys+zinc)diet 5 (control)

112c21Corticated CSM + Lys

106c20Corticated CSM

144b20Decorticated CSM + Lys

138b19Decorticated CSM

198a21FM

FWIWProtein source

Growth of Nile tilapia fed CSM +/- Lysine supplementation

Growth of Nile tilapia fed cottonseed-based diets

020406080

100120140160180200

0 30 60 90 120 130Time (days)

Wei

ght (

g/fis

h) FMDCDC+ LysCCCC + Lys

1. High quality protein diet may not be cost effective

2. Low quality protein diet may lead to poor growth, but more profitable.

3. Cost/benefit analyses of the feed is necessary

4. Consumer target

Cost / benefit analyses

5.60c0.62bc112c21CC + Lys

5.32c0.66b106c20CC

4.59b0.76b144b20DC + Lys

4.50b0.77b138b19DC

3.23a1.07a198a21FM

Profit indexIncidence cost

FWIWProtein source

Performance of Nile tilapia fed CSM-based diets

Growth rates and profit index of Nile tilapia fed CSM-based diet

0

1

2

3

4

5

6

FM DC DC+Lys CC CC+Lys

ADG PI

30.429.630.030.830.931.6Crude protein15.010.07.07.04.05.0Α-Cell2.02.0Phosphorus2.02.02.02.02.02.0Vit & min. mix3.01.02.51.52.02.0SB oil3.01.02.51.52.01.0Sardine oil10.010.010.010.010.010.0Starch30.029.036.046.030.045.0Wheat bran

47.0Poultry by- product 20.040.0Meat & bone M15.030.0Blood meal

50.0Shrimp meal35.0FM

654321Ingredient

Animal protein based-diets fed to Nile tilapia for 150 days.

Growth of Nile tilapia fed different animal protein sources

0

50

100

150

200

250

300

0 30 60 90 120 150

Time (days)

Wei

ght (

g/fis

h)

FMSMBMMBMPBMBM+MBM

Performance of Nile tilapia fed all-animal protein sources

1.9c4.1c220bc13BM+MBM

2.3b3.5b248ac12PBM

2.2b3.6b240ac13MBM

2.0b4.0c199b12BM

2.3b3.4b258a12SM

1.7a4.8a273a13FM

Profit index

Incidence cost

FWIWProtein

Improving protein qualityPhytase supplementation• Many plant protein sources contain high levels of phytic

acid. • phytic acid binds with divalent minerals forming water-

insoluble salts. • The inclusion of bacterial phytase:

1. reduces phytic acid activity2. improves the utilization of plant protein sources.3. reduces the effect of antinutritional factors.4. protects amino acids from degradation.5. decreases leaching of water soluble components.

Protein digestibility• Problems:• interchangeable and inconsistent use of

terminology.• use of ME and DE values interchangeably• use varying energy values for the same

ingredient under the same terminology. • Use of energy values reported for other

fish species

86-89Sunflower SC9391 (57)9391 (56)90.9SBM

79 (72.5)Groundnut meal

90CSM 9790.7Corn gluten

8156Copra meal63 (30)63 (30)62 (42)Brewers grains

91.1Silkworm pupa 74 (59)87Shrimp meal

74 (59)Poultry offal 92.2MBM

85 (83)Fish silage90 (86)94Anchovy

87 (80Sardine9286 (80)72 (58)92.2Fish meal:

Digestibility of some protein sources by tilapia

Conclusions

• Studies should be long enough!!, 2-3 months?• Applied in the field, if possible• Use GE, if DE is not available• Supplementation of certain minerals may meet

the requirement of deficient EAA • EAA supplementation may not be necessary• More work needed (case by case..)• Supplementing plant proteins with Phytase may

be necessary

Thank you