Dietary organic acids used as growth promoters anti-microbials
Disease is a major limiting factor to aquaculture expansion and productivity. Of particular concern to tilapia aquaculture are bacterial diseases caused by the Streptococcal groups, such as Streptococcus agalactiae, which can cause widespread mortalities, particularly in warm water and high intensive culture systems in various countrieS. Antibiotics such as oxytetracycline (OTC) are still being used as the most common treatment and/or prophylactic against bacterial diseases, including Streptococcus, in many sectors of the aquaculture industry. However, as the global trend in antibiotic use becomes more restricted and unpopular in the aquaculture industry, it will become increasingly important to identify suitable prophylactic and growth-promoting alternatives and among these, interest in organic acids is growing.
The intensification of tilapia culture systems has led to this hardy fish being susceptible to various bacterial diseases causing economic losses to tilapia farmers.
Organic acids are organic compounds considered as “Generally Regarded as Safe.” Various factors may influence the efficacy of organic acids, including the species, age, diet composition, type and concentrations of organic acids as well as the culture conditionS. Several studies have reported the beneficial effect of organic acids in improving nutrient utilization, which has been largely attributed to the acidifying effects of the diets, thus making nutrients, particularly minerals, more available.
In previous studies, red hybrid tilapia, Oreochromis sp., fed dietary organic acids blends (OAB) showed a slight, but not significant, improvement in growth performance and phosphorus (P) utilization, as well as significantly improving their resistance to S. agalactiae infections. However, it was unclear whether tilapia growth performance can be further improved by higher dietary inclusion levels of organic acids in a dose-dependent manner. It is also currently not known whether the gains in growth, feed efficiency, and antimicrobial effects observed in tilapia fed organic acids-added diets are as efficacious as antibiotics commonly used in the aquaculture industry for such purposes.
Fig. 1: Oxytetracycline residue in tissues of red hybrid tilapia sp. after 20 weeks oral medication.
– See more at: http://advocate.gaalliance.org/dietary-organic-acids-used-as-growth-promoters-anti-microbials/#sthash.ggeDzExZ.dpuf