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Tilapia culture in closed systems with application of bacteria and enzymes in Area of Sexual Reversion.


This trial was carried out at Gabati S.A., fry producer from Taura, Ecuador.

PRODUCTS:    Oxynova in the water.
                           HYDROYEAST AQUACULTURE in the feed.

Summary:

The system has 16 tanks with  water volumen of 30 MT each. The water supplied from a reservoir, which in turn, is supplied from a deep well of fresh water.  Alevine density used was 12 alevines per liter, during 20 to 25 days. Enzymes and bacteria were applied to 6 tanks , leaving 4 tanks as control. The systems has a continuous biomass , which allows to obtain 18 harvests per year, as long as one can obtain a good monthly recollection of alevines ( tilapia)

The parameters to measure in this test are weight / growth rate, survibebability and parasite presence.

Introduction:

Due to lack of adecquate infrastructure in the faro, Duch as, pipe distribution , etc, in the farm, the test was in a closed system , applying bacteria in the Area of Reversion to improve the quality of water, and in the feed , to improve nutrients assimilation and digestibility ( balance intestinal  microflora). The water savings was of 75% to 80%. The following water parameters were measured: Temperatura, Oxigen Demand, pH. and Ammonia. 

Materials and Methods:

The system is componed of 16 tanks, with a volume of 30 Mt each, on concrete base. Each tank has a galvanized steel and covered with a geo-membrane in the internally. Additional, the tanks have a porpous hose for oxygen distribution and mesh filtres , according to the alevine sizes. Water is  applied  with a 2 in. PVC pipe.
 
The tanks are cleaned by syphons , 1 to 2 times per week

12 alevines per liter were placed with an average weight of 0.015 grams with a previous treatment of immersion bath in saline medium during 3 minutes, for elimination of parasites. The alevibnes were fed with a diedt of 45% protein, 20 daily rations , with an inicial  biomass of 30%.  Weight sampling was done once per week, to adjuts feeding. The Sexual Reversion Process was of 20 to 25 days.

Daily  measurements of parameters were made: Oxygen , Temperatura and pH. Ammonia was measured with Standard kit for resh water , very 3 to 5 days.
 
Alevines were classified using wiremesh classifiers.

Oxynova  application in water:

Reversion or Sexual induction:

According to the established protocol, for the preparation and activation of the product, the procedure was as follows:
 
3 tanks Oxynova daily application in water (A)
3 tanks Oxynova application every 2 days. (B).
4 tanks control – tanks  controls (C).

Application of  HYDROYEAST AQUACLUTURE,  0.5 grams per kg for feed, was done same as above.

In This trial, the 4 control tanks and the test tanks , were kept in close system for 7 days . On the following week, 50% to 80% of the water was reduced and acification treatments were made, due to ammonia increase. 

PICTURE OF SEXUAL REVERSION TANK #3

General Reservoir:

Capacity: 1.800 MT.  Of water

                                                                           
The weekly Oxynova applications were made to the water, with help of a substrate and nitrogen source, due to the absence of a pumping recirculation system. This water source is pumped directly to the whole tank system.

PICTURE OF THE Oxynova TREATED RESERVOIR



TREATMENT OF ALEVINE TANKS IN SEXUAL REVERSION MODULE WITH HYDROYEAT AQUACULTURE IN FEED.

 Results:

The results in growth are observed in TABLE 1. In the tanks with HYDROYEAST AND Oxynova AQUACULTTRE , alevines weighing 1 grams were obtained at an average of 22 days in the closed system. , with the exception of tanks 06-08-14. , where temperature problems were present (34  to 35 degrees C)  an ammonia (>0.2 kg/lt). And 40% to 50% of the population east lost as indicated in table 2. The control tanks needed an extra week of precess to reach the desired weight. In addition the control tanlks needed extra water water. All as indicated in table 3.  

PICTURE OF ALEVINES IN TANK NO. 12 WITH Oxynova  AQUACULTURE TREATMENT IN THE WATER AND WITH HYDROYEAST AQUACULTURE TREATMENT IN THE FEED



TABLE 1

 

WEIGHT (GR)

DAYS

 

1 WEEK

2 WEEK

3 WEEK

4 WEEK

5 WEEK

PROCESS

A

 

 

 

 

 

 

Oxynova/DAY 

 

 

 

 

 

 

TQ 06

0.016

0.050

0.13

 

 

21

TQ  08

0.013

0.023

0.05

0.12

 

25

TQ  12

0.015

0.045

0.11

 

 

22

B
Oxynova/DAY EVERY 2 DAYS

 

 

 

 

 

 

TQ 09

0.013

0.05

0.09

0.133

 

22

TQ 04

0.015

0.04

0.06

0.10

 

22

TQ 14

0.02

0.09

0.11

 

 

21

C

 

 

 

 

 

 

TQ 01

0.013

0.032

0.058

0.090

0.17

26

TQ 03

0.016

0.020

0.05

0.068

0.16

30

TQ 05

0.017

0.023

0.05

0.065

0.13

28

TQ 10

0.015

0.025

0.06

0.090

0.14

28


TABLE 2

 

DAYS

BIOMASS

BIOMASS

SUPERV.

 

PROCESS

INITIAL(KG)

FINAL(KG)

%

 

 

 

 

 

A

 

 

 

 

TQ 06

21

5.1

25.60

57.0%

TQ 08

25

4.58

22.80

53.0%

TQ 12

22

5.5

30.75

80.0%

B

 

 

 

 

TQ 09

22

2.974

23.04

80.0%

TQ 04

22

5.3

24.6

93.0%

TQ 14

21

5.3

27.0

51.0%

C

 

 

 

 

TQ 01

26

4.67

31.34

52.7%

TQ 03

30

5.8

28.2

48.0%

TQ 05

28

6.0

29.3

65.0%

TQ 10

28

5.3

29.0

70.0%




TABLE 3

 

DAYS

TREATMENTS

 

PROCESS

1 WEEK

2 WEEK

3 WEEK

4 WEEK

5 WEEK

 

 

 

 

 

 

 

A

 

 

 

 

 

 

TQ 6

21

 

 

 

 

 

TQ 8

25

 

 

 

 

 

TQ 12

22

 

 

 

 

 

B

 

 

 

 

 

 

TQ 09

22

 

 

 

 

 

TQ 04

22

 

 

H202

H202

 

TQ 14

21

 

 

H202

 

 

C

 

 

 

 

 

 

TQ 01

26

 

H202

 

H202

 

TQ 03

30

 

H202

H202

H202

 

TQ 05

28

 

H202

H202

 

H202

TQ 10

28

 

H202

H202

 

 

Discussion:

Water Quality

In winter season , ambient temperatura rises approximately betwen 30 to 32 degress C, in the Reversion Area. It is covered with plastic to keep temperature constant. Even without the plastic cover the temperature rises in the water in the tanks. Ph, Ammonia were controlled and measured by doing water changes and acidifying the medium to maintain a pH between 7-7.5. 

In the summer season , we do not have these handling inconvenientes, and these parameters have lesser risks

PICTURE OF PLASTIC COVER IN TANK AREA OF SEXUAL REVERSION




PICTURE OF TANK # 8 SEXUAL  REVERSION - ALEVINES TREATED WITH  WITH Oxynova  IN THE WATER AND THE FEED WITH HYDROYEAST AQUACULTURE



Conclusions

1) The continuos use of  Oxynova compared with the alternate use ( every 2 days) of Oxynova, showed the same statistical results in weight gain .

 2)With the use of both, Oxynova AQUACULTURE and HYDROYEAST AQUACULTURE , better survivalbilty was obtained, compared to the control by  an average of 11%.  

3) Good grwoth was obtained in 22 days, with regular feed at 45% protein in 20 rations, although, conversion needs improvement.

4) In the groups treated with  Oxynova  e HYDROEYAST AQUACULTURE,  50%  reached their desired trasference weights at the third week , and the other 50% at the fourth week.  100% of  the control groups reached their desired weights at the fith week.


Prepared by:
Biologist. Ana K. fuentes P.
GUAYAQUIL, FEBRERO/2007

Trial carried out and supervised by
CORBERCORP CIA. LTD.
Mr. Antonio Cordero and his team of biologists
Distributor of Aquaculture Products from AGRANCO CORP. USA in Guayaquil, Ecuador