Growth and Diet Utilization in Pacu Piaractus mesopotamicus Using Soybean

Replacement of Casein-Gelatin as Protein Source

Maria Esther Palacios1,3, Konrad Dabrowski,1 and C.C. Kohler 2

1 The Ohio State University, School of Natural Resources, Columbus, Ohio, USA2Southern Illinois University, Carbondale, Illinois, USA

3Universidad Nacional de San Marcos, Lima, Peru

Fish market in Iquitos, Peru

Fish is an Important Protein Source in the Peruvian Amazon

Utilization of Plant Proteins by Pacu

Camu-camu(Myrciaria dubia)

Aguaje(Mauritia flexuosa)

Maca(Lepidium meyenii)

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Maca

Aguaje

Camu-camu

Control

Weeks

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Growth Rate of Juvenile Pacu Fed Experimental Diets Supplemented (15%) With Different Plant Protein SourcesControl semipurified diet = Casein (40%), gelatin (8%), wheat meal 15%-based

Body Weights and Food Conversion in Rainbow Trout and Pacu Juveniles After 4 Weeks of Feeding

Histological Examination of digestive tract (intestine, liver, pancreas) (Ostaszewska et al. 2003)

Mean weight

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Rainbow trout

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Initial weight

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Dietary treatment

Control SBM SPC

Objectives

To develop a semipurified, casein-gelatin based diet that can be used in nutrient requirement study with Amazonian fish.

To examine the effects of practical diets containing soybean meal (SBM) and soy protein concentrate (SPC) on growth and feed utilization in pacu, Piaractus mesopotamicus.

Composition of Experimental Diets

Control SPC (50 % SBM (50 % protein replaced) protein replaced)

Casein 40 20 20Gelatin 8 4 4SPC - 32 -SBM - - 44Dextrin 21.25 13.05 1.05CPSP* 5 5 5

MajorIngredients

* Soluble fish protein concentrate (Suprapeche, France)

Cod liver oil 11%; lecithin 3%;vitamin mix 4%; mineral mix 3%;CMC 0.5%

Experimental Conditions

Fish : juvenile pacu, Piaractus mesopotamicus Weight : 0.34 g ± 0.02 (35 fish/tank) Design : 3 dietary treatments (3 rep.) Feeding : 4 – 8 % BW/day (3 times/day) Water temp.: 26 ± 0.27 oC Period : 8 weeks

Growth rate (every 2 weeks) Feed utilization

Feed Conversion Ratio (FCR)FCR = food consumption (g) / body weight gain (g)

Protein Efficiency Ratio (PER)PER= Weight gain (g) / protein intake (g)

Net Protein Utilization (NPU) NPU(%)=Protein gain (g) / protein intake (g) x 100

Diet and whole body composition

Parameters Examined

Pictures of Facility, Fish, and Analysis of Fish Samples

Results

Protein Lipid Ash

Control 63.39 11.2 4.69

SPC (50%CP) 55.52 13.9 6.78

SBM (50%CP) 57.48 16.6 7.61

Diets

Proximate Composition of Experimental Diets (% Dry Matter)

Experimental diets

Control SPC SBM

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Growth Performance of Pacu After 8 Weeks of Feeding

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Feed Conversion Ratio (FCR) for Pacu in the Course of the Study

Rainbow trout Pacu FCR FCR

Casein- gelatin (Control) 0.87 ± 0.02b 0.76 ± 0.01a

SPC (50%CP) 1.07 ± 0.04a 0.73 ± 0.01a

SBM (50%CP) 1.04 ± 0.01a 0.61 ± 0.03b

Dietary treatments

•FCR: food consumption (g) / body weight gain (g)

•Means annotated with the same letter are not significantly different (P > 0.05)

Feed Conversion Ratio (FCR) of Juvenile Pacu and Rainbow Trout Fed Four Experimental Diets for 8 Weeks

Protein Lipid Ash

Control 67.28 19.3 14.27

SPC (50%CP) 69.04 15.3 15.53

SBM (50%CP) 66.34 15.0 15.97

Diets

Whole Body Proximate Composition (%Dry Matter) of Juvenile Pacu Fed Three Experimental Diets for 8 Weeks

Rainbow trout Pacu PER NPU PER NPU

Casein- gelatin 1.95 ± 0.05a 26.9 ± 1.5a 2.23 ± 0.03b 27.7 ± 0.5c

(Control)

SPC (50%CP) 1.77 ± 0.07b 22.7 ± 1.1b 2.59 ± 0.04b 32.2 ± 0.6b

SBM (50%CP) 1.76 ± 0.02b 24.5 ± 0.5b 3.07 ± 0.27a 41.8 ± 3.5a

Diets

Utilization of a Semipurified, Casein-gelatin Based Diet and Diets With 50% Protein Replaced by Soybean Meal (SBM) or Soy Protein Concentrate (SPC). Eight Week Feeding Experiments at 14- 18C (Rainbow trout) or 26 C (Pacu, Piaractus mesopotamicus)

PER = Weight gain / protein intake NPU (%) = Protein gain / protein intake

Protein Efficiency Ratios in Cultured Fishes

A comparison of protein efficiency ratios in young fish when fed semipurified diets (C: casein, G: gelatin, WG: wheat gluten, % of diet) in five studies on different species. Rainbow trout (Lee et al., 2004, our laboratories), coho salmon (Luzzana et al., 1997), channel catfish (Buentello and Gatlin 2000), pacu 0.3 g initial weight (Palacios et al., 2004, diet contained also 10% casein hydrolysate), and pacu 4.3 g initial weight (Tesser et al., 2004). The highest PER values in a particular study are shown.

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(4.3 g)

Cohosalmon

Pacu(0.3 g)

40%C8%G

10%C9%G

22%WG

10%C2.5%G

36%C6%G

Pacu(4.3 g)

15%C

38%WG

30%C8%G

Conclusions

Soybean meal protein replacement in casein gelatin based diets has significant positive effect on growth of pacu.

Pacu better utilize high protein diets containing plant protein sources compared to other species, such as salmonids and channel catfish.

Funding for this research was provided by the

Aquaculture Collaborative

Research Support Program

The Aquaculture CRSP is funded in part by United States Agency for International Development (USAID) Grant No. LAG-G-00-96-90015-00 and by participating

institutions.