The Fisheries Institute (IP-APTA), of the São Paulo State Department of Agriculture and Supply, developed a protocol that proved to be very effective in controlling infections by the bacterium Streptococcus agalactiae, one of the main diseases of fish farming. The addition of probiotic to the diet of tilapia in intensive cultivation, together with vaccination, increases the fish survival rate by approximately 98%.
IP researcher Leonardo Tachibana claims that S. agalactiae is one of the bacteria that has the highest prevalence in tilapia breeding in Brazil, causing high mortality rates. To combat the disease, the IP researchers combined feeding with vaccination, “in the experiment, we fed the animals probiotics, added to the feed, for 21 days, after which we vaccinated the fish and a revaccination two weeks later. After another 15 days, we carried out an intentional infection with S. agalactiae to see if tilapia developed the disease ”, explains the IP researcher, from the São Paulo Agency for Agribusiness Technology (APTA).
The researchers also report that the measures are promising and can enhance the control and prevention of diseases, “the fish fed with probiotics and vaccinated had a very good survival rate, close to 98%, whereas those that were only vaccinees had a shorter survival – although much higher than that of the control groups, without vaccination ”says Tachibana.
Still according to the researcher, the vaccine application is one of the main factors for the decrease in the use of antibiotics “when you start making applications, you start to depend less and less on antibiotics to treat the diseases that affect the fish – thus as with other types of livestock. Although they are the most efficient option when there is no vaccine available, it is known that long-term use of antibiotics is not sustainable, ”he says.