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TRIAL RESULTS USING ENZYMES & BACTERIAL CULTURES
(A Two-step application of bacteria formula and PT4W Enzyme)
PRODUCTION SITE
Lagonglong, Misamis Oriental, Philippines
SITE DESCRIPTION
The farm is small size shrimp farm primarily used for research. Total area is approximately 5 hectares, with a total production area of 3.8 hectares composed of 5 ponds.
Ponds were developed in the early “90’s”. These ponds initially produced well, using Taiwanese shrimp farming methods; production declined as the soil became unproductive, and were then laid fallow for 2 years, and eventually taken over 1997. Since then, production was consistently above national averages using semi-intensive densities.
| ABW on harvests: |
33g per animal |
| Average survival over 3 years: |
81%, with consistent use of bacteria and pro-biotics |
| Normal cycle duration |
150 days |
PROCEDURE
We chose two equal-size ponds (3,000 m2/3100 m2) for the trials. Both are already beyond mid-cycle of culture, at the 125 days, but average body weights from samples reflected on 13 grams. Many factors may have contributed to this; a radical change in pond salinity due to heavy change in the feed formulation due to lack of supply of the usual brand of feed. Both occurrences resulted in a prolonged lack of appetite and hence the application of the two-step procedure described in the product information sheet.
Control Ponds: Up to this time, the other three ponds were considered as control ponds. All exhibited the same conditions as the trial ponds.
Two batches of one and one-half kilos of GLB Bacteria was mixed with 10 gallons each of isotonic water and aerated for 3 hours to activate the bacteria in the formula. Into this activated formula, we added one and one-half liters each of PT4W enzyme. This brew was then broadcasted around the two ponds (one 10-gallon bucket per pond). Strong aeration was maintained over the next 24 hours, and Dissolved Oxygen levels were monitored during this time. The procedure was repeated every 15 days.
OBSERVATIONS
Nothing on the surface gave any indication as to what was happening on the pond bottom. Appetite was strong and consistent as when before, shrimp guts were full during inspection of samples collected daily. Feeding was adjusted based on demand. However, feed adjustments were done almost every two days due to rapid increases in average body weight.
 Pond water remained stable throughout the cycle. No water exchanges were necessary, only water additions to compensate for evaporation. Algae density remained constant bright green in color, with no instances of die-off.
Animals in both test ponds and control ponds appeared very healthy, with no signs of deformities or undesirable algal growths on shells. However, growth rates were quite dissimilar. Where shrimp in the test ponds exhibited rapid weight gain, the shrimp in the control pond exhibited slow gains. Shrimp samples from both ponds showed clear bodies, smooth and shiny carapace, very active and mobile.
One week after the application, it had become quite evident that the shrimp in these test ponds were responding to a better procedure. It was then decided that all control ponds should receive the same treatment, so that the benefits can be extended to all. Management decided that it would stand to gain time and additional profit if all ponds were given the sample application.
At the final harvest, qualities of stock in all ponds were mostly classified as top grade. However, due to perhaps earlier problems some of the numbers were inconsistent:
| ABW 18g-up |
85.4% of harvest |
| Undersize 12-17g |
11.8% |
| Stunted Shrimp (about 5-8 g) |
2.8% |
| ABW Total |
32.8 grams |
| fry density at seeding |
28 animals per m2 |
| % Survival at harvest |
89.4% |
| Feed Conversion Ratio |
2.7 |
| Days of Culture |
160 |
Pond bottom in all ponds were odorless after harvest. Black muck was only concentrated at the center, to a total of one half inch thick. Estimated turn-around and preparation time for next cycle would be 18 days maximum.
CONCLUSIONS
Inconsistent weight distribution in harvested stock may have been the result of inconsistent quality of fry, heavy rainfall as well as change in feed brand at mid-cycle.
Better results would have been obtained if the PT4W enzyme were added from inception of the  culture cycle, to be applied well ahead of fry seeding. This allows the bacteria and the enzyme to have a head start in preparing the pond environment for the shrimp stock, so that conditions promoting fry survivability are already enhanced even at the start.
Preliminary results show that upwards of 15% of total feed costs over the course of the cycle can be saved with consistent use of this two-step procedure, due to rapid weight gain in the last 60 days of culture. This rapid weight gain will also result in earlier harvest or bigger animals and will likewise hasten turn-around times, resulting in more cycles per calendar year.
Consistent application of bacteria has shown that survival rates of 90% can be attained on a regular basis. (Figures based on P. monodon culture).
GLB bacteria and PT4W enzymes can be used as a tandem pond-rehabilitating agent. Already it can help shortcut the pond preparation process thus save on preparation costs while ensuring that pond bottom is even better prepared than the manual methods normally used. In addition, we believe that the very deteriorated ponds can also be reconditioned with this method, possibly by using higher doses than those used for simple pond preparation.
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