Probiotic: How to harness the power of beneficial microbes.

Updated: Jun 21, 2021

Probiotics act as a live microbial feed supplement which beneficially improves microbial balance of the host animals as well as the environment. Probiotic can benefit the animal through intestinal microbial processes. In the aquaculture process, the bacteria strains in the water or soil can be change by eliminating the bad bacteria and adding good bacteria inside the water. Adding probiotics to control the pathogen in the shrimp farming industry is very common practice nowadays. However, the effectiveness can only be confirmed by the timing, dosage, administration, species and strain.


This probiotic works by three factors which are immunomodulation, competitive exclusion and bioremediation. The first action is to enhance the immune function inside the shrimp, so it is important for the shrimp body system to fight against pathogens. Second, probiotics can modify and stabilize the species composition inside the water, especially when you have a bacterial infection. Bioremediation helps in the improvement of water quality in which probiotics control the concentration of total ammonium nitrogen (TAN), phosphorus or sulphide.


Generally in aquaculture, the probiotic will be applied through water or feed additives. When applied to water, the probiotics containing certain bacteria strains will multiply and outgrow the pathogens inside the system when dosed. If applied through feed, a binder such as egg or oil is needed to coat the probiotic on the feed. Continuous supply of probiotic inside the feed or schedule of two week of feed and then skip for one week is suggested for the feed additive method.


The floc consist of microbial community which acts as the probiotic where the probiotic perform competitive exclusion. The UV filter which is use in RAS is not applicable in biofloc because all bacteria whether they are good or bad are in the same community. Bacteria in biofloc can be either heterotrophic or autotrophic both helping in treating ammonia. In RAS, probiotics can be used in two ways which are either included in the feed or to seed your K1 media so that the bacteria will grow fast. The k1 media is used to remove ammonia so the bacteria attached to this k1 is also categorized as probiotic.


Here in RAS Aquaculture, the biofloc system culturing the shrimp consists of bacteria which are either heterotrophic or autotrophic both helps to treat ammonia in the system. Probiotics helps good bacteria strains inside the system in the uptake of nutrients.




Figure 1 and 2. Probiotic in shrimp culture is important to increase beneficial bacteria in the biofloc system to combat pathogens and improve immune response.



In RAS which cultures the mud crab, probiotic is either included in the feed or to seed with K1 media for faster growth of bacteria. The K1 media is a biofilter which is used to remove ammonia so the bacteria attached to this K1 is categorized as probiotic. Generally, the probiotic will be applied through water or feed additives. Probiotics will multiply and outgrow the pathogen inside when dosed through water. While through feed application, a binder such as egg or oil is needed to coat the probiotic on the feed. A continuous supply of probiotic or schedule of two week feed and skip for a week is suggested for the feed additive method.




Figure 3 and 4. Probiotic is added to K1 media which consist of microbes as biofilter to remove ammonia from the RAS system.


Our company has constructed a model to justify the worthiness of this supplement to the business. The benefit over cost ratio (BCR) range during the investment in probiotic products is between 1 to 1.7. The BCR modelling includes the feed cost, probiotic cost and FCR reduction. Usually, the investment in probiotics if the BCR value is greater than 1. The highest cost benefit can go high up to 4.1 when there is high feed cost with lower probiotic cost. The lower probiotic cost can only be made if the probiotic was made by ourselves. If the BCR is lower than 1 it might have because of high probiotic and feed cost which make it not worth it to invest. However, a few factors need to be considered in this BCR which are the value of FCR, issues on diseases and issues on water quality.



 

In the biofloc system, probiotics are usually used as the bacteria starter. The addition of probiotics to the biofloc can further enhance the system, by improving growth, digestion, metabolism, disease-resistance and water quality, as well as reducing the vibrio load. The combination of probiotics and biofloc has high potential for increasing the sustainability of shrimp farming.



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