Cilj istraživanja bio je ispitati utjecaj dodatka komercijalnog (Probios®) i pokusnog (kultura Lactobacillus acidophilus izolirana iz acidofilnog mlijeka, inaktivirani pekarski kvasac, vitamin C i laktoza) probiotskog preparata putem vode za piće na imunosni odgovor protiv gumborske bolesti kod tovnih pilića. Istraživanja su provedena na 105 jednodnevnih pilića provenijence Cobb 500 podijeljenih u tri skupine (dvije pokusne i jedna kontrolna skupina). Probiotski tretman obje pokusne skupine pilića bio je prva tri dana života i trodnevno pri vakciniranju pilića protiv njukaslske i gumborske bolesti te infektivnog brohitisa (dan prije, na dan i dan nakon vakciniranja). Tijekom pokusa pilići su vakcinirani prema programu imunoprofilakse koji je načinjen u skladu s titrom kongenitalnih protutijela. Kontrolom imunosnog odgovora protiv gumborske bolesti kod pilića u dobi od 28 i 42 dana utvrđene su veće, odnosno značajno (p<0,05) veće srednje vrijednosti titra protutijela kod pilića pokusne P2 odnosno P1 skupine u usporedbi s vrijednostima kontrolne K skupine. Istovremeno, statistička značajnost razlika srednjih vrijednosti titra protutijela između pokusnih skupina nije utvrđena.The aim of the study was to examine the effect of commercial (Probios ®) and experimental (the culture of Lactobacillus acidophilus isolated from acidophilus milk, inactivated bakers’ yeast, vitamin C and lactose) probiotic preparations through drinking water on the immune response against Gumboro disease in broiler chickens. Research was conducted on 105/day old Cobb 500 chicks divided into three groups (two experimental and one control group). Probiotic treatments of experimental groups of chickens were the first three days of life and three days during the vaccination of chickens against Newcastle disease, Gumboro disease and Infectious bronchitis (the day before, on the day of and the day after vaccination). During the experiment chickens were vaccinated under the program of immunoprophylaxis, made in accordance with congenital antibody titres. By controlling the immune response against Gumboro disease in chickens at the age of 28 and 42 days higher and significantly (p <0.05) higher mean antibody titers were found in experimental P2 and P1 groups compared with control K group, respectively. In the same time, statistically significant differences in mean values of antibody titers between the experimental groups were not determined
