USE OF L. FARCIMINIS AND L. RHAMNOSUS COMPLEX TO REDUCE THE HARMFUL EFFECT OF AMMONIA ON THE RESPIRATORY TRACT OF BROILER CHICKENS

Studies have shown that adding lactobacilli to drinking water or feed results in faster live weight gain and reduced NH3 excretion (Mahardhika et al., 2019; Pezzuolo et al., 2019). There is an in vitro study (Chen et al., 2018) describing the ability of L.rhamnosus to utilize NH3 nitrogen. Therefore, the aim of our study was to find out whether it is possible to reduce NH3 emissions and harmful effects on the respiratory tract of broiler chickens by adding a mixture of L.farciminis CNCM-I-3699 and L.rhamnosus CNCM-I-3698 (MixL) simultaneously to feed and litter. In a triplicate 35-day study, 780 (260 per replicate) newly hatched Ross 308 broiler chicks were housed in two identical biochambers with full microclimate control. The control group (Con, n=130) received basal diet ad libitum, and the probiotic (ProX, n=130) additionally received MixL. MixL was spread on the ProX bedding every week. Every day, the amount of NH3 was determined with electrochemical sensors (E2618-NH3-RP) in the incoming and outgoing air of each biochamber. Litter moisture was determined every 7 days. The titer of antibodies to IBV was determined in the blood of chickens at the end of the study (ELISE 25). The organs of the respiratory system were examined macroscopically (pathoanatomically) and microscopically (H&E). Comparison of the Con and ProX groups showed that the emission of NH3 differs statistically significantly at 1-3 weeks and becomes unsignificant at 4-5 weeks of bird life. The results for IBV in the first repetition were negative, but the second and third AV titers showed positive results in both groups. No macroscopic changes were detected in the lungs. Histological examination showed that the inflammatory picture with a more severe degree is observed more often in the Con group. In general, the probiotic group managed to reduce the harmful effects of NH3 more effectively.