| dc.description.abstract | The research was conducted in order to study the effect of probiotics administration in controlling subclinical salmonellosis in chicken. The research was divided into 3 part trials. Part A: 100 broilers were divided into 5 groups. The first group (1A) was the control group (not given probiotic and antibiotic), the second group (2A) received feed containing zinc bacitracin, the third group (3A) received probiotic Bacillus apiarius, the fourth group (4A) received probiotic B. coagulans, and the fifth group (5A) received probiotic BM (contained 6 isolates of Bacilius sp). The probiotic were supplemented in drinking water (109 CFU/litre). Part B and C were the same pattern of trial as part A and challenged with Salmonella. Part B was oral infected (inoculated) with S. enteritidis and part C was infected with S. typhimurium (108 CFU) at 3 week old. The chickens were necropsied at 1, 2, 3 and 4 week post infection and further investigated for feed conversion rate (FCR); body weight; blood picture (total erythrocyte and leukocyte count, packed cell volume and haemoglobin concentration); gross and microscopical lesion of intestine, liver; bursa of Fabricius and cecal tonsil; phagocytosis and clearance of polymorphonuclear cell and reisolation of Salmonella. Administration of probiotics (B. apiarius, B. coagulans and BM) improved FCR; increased body weight; increased the intestinal villus surface area and successfully eliminated Salmonella from caecum. The study showed an improvement in the blood picture of the probiotic-administered groups. The probiotics administration decreased gross and microscopical lesion of intestine, liver, bursa of Fabricius and caecal tonsil due to Salmonella infection. The number of macrophage, plasma cell and lymphocyte on the small intestine and germinal center on cecal tonsil increased in the probiotic-administered groups. As well as enhanced the capacity and activity of phagocytosis and clearance of polymorphonuclear cell. The length and width of lymphoid folicle of bursa of Fabricius were increased in the probiotic-administered groups. Lower body weight and higher FCR were present in all infected groups (B, C) compared with uninfected group (A). This study showed that probiotics (B. apiarius, B. coagulans and BM) administration on broiler chicken can increase body performance and enhance health and immune system. This study affirms that probiotics administration can increase protection of chicken against Salmonella sp. a highly virulent enteric bacterial pathogen. | |
