The 11th Asia Pacific Poultry Conference (APPC 2018) took place on 25-27 March in Bangkok. The use of probiotics in animal feed has been significantly increasing all around the globe.
"Due to their effects on the microbial population in the gut, probiotics are able to promote a favorable microflora improving health by helping prevent diseases caused by pathogenic bacteria present in the gastrointestinal tract" said Dr. Veerle Hautekiet of Huvepharma, who was one of the speakers at the conference that attracted 1200 participants.
"The better health of the animal is supported by the increase in healthy microbial population related to improved animal performance, reflecting a more efficient digestion and improved immunity."
The micro-organisms found in the gastrointestinal tract of naturally reared neonatal animals and birds are generally originating from the adult (mother) and are supposed to provide the neonatal protection from enteric pathogens. "Due to intense livestock production, this natural colonization of the gut is not very pronounced, making animals more susceptible to intestinal pathogen challenge. Probiotics have a supportive effect in this case as they could mimic the natural colonization in neonates.
"However, they are also able to colonize the adult animal and in this way prevent pathogenic organisms from colonizing the intestinal mucosa." Hautekiet explained. The probiotic microbes adhere to the intestinal epithelium competing with pathogenic bacteria for adhesion sites in the intestinal epithelium - a mechanism widely known as competitive exclusion.
"Research has also shown that some probiotics produce antimicrobial substances that might inhibit the growth of pathogenic bacteria in the intestine. Some of these antibacterial substances are antibiotics."
Probiotics have complex effects on the immune system supporting antigen response. Research regarding immune stimulatory effects of probiotics demonstrated that probiotics can stimulate the intestinal T-cells, increase cytokine concentrations and serum immunoglobulins under challenge conditions. "It is a well-recognized fact that most probiotics have positive effects on poultry productivity. This has amongst others contributed to the improvement of nutrient digestion and absorption inflicted by probiotics. Probiotics are capable of positively influencing the enzyme activity in the intestine, for example by increasing the amount of amylase, cellulose and proteases."
Modes of action
The several modes of action of probiotics on poultry gut health are very complex. Nevertheless, the beneficial effects on gut flora, which go hand in hand with improved animal performance, were shown in numerous research trials. "The observed effects on gut health strongly depends on which probiotic strains are used. The reason being that even closely related probiotic micro-organisms seem to have different modes of action, leading to the necessity that probiotics be studied on a case-by-case basis," concluded Hautekiet.