effect of probiotic on morphology of digestive system and immune system in broiler chicks

an experiment was conducted under completely randomized design to study the effect of different levels of probiotic biomin imbo (0.0, 0.05, 0.1, 0.15 per cent) in starter, (0.0, 0.025, 0.05, 0.075 per cent) in grower and (0.0, 0.0125, 0.025, 0.0375 per cent) in finisher diets on morphology of digestive system and immuno system of broiler chicks for 49 days. 400 day old chicks (mixed male and female) were procured and divided in to four treatments and four replicates (25 chicks in each replicate). morphology of digestive system was studied through slaughtering of 2 chicks from each treatment at the end of experiment. microorganism colonies in the gut (small intestine) were counted. immune system was studied as production of different anti body through srbc injection in chicks. as result was revealed, probiotic had significantly effect on morphology of small intestine (villi, height  and the length of crypts cells) as compare to control groups (p<0.01). it was observed that, most differences owed to treatment 2,3 and 4 as compare to control group(p<0/01). in case of crypt cells (width and depth of cells), treatments 3, 2 and 4 had significant differences with control group (p<0.01).where as differences among themselves were not significant. probiotic also had significantly effects on levels of blood anti-body production in various treatments (p<0.01). incase of one week after injections of srbc, treatment 2 showed decreasing trend of producing anti-body, as compare to other experimental groups, and differences were significant (p<0.05). even though, after two weeks of post injections, the lowest levels of anti-body production were owed to treatment 3 and 4 as compare to other groups (p<0.05). the highest and the lowest levels of anti-body titrations against newcastle virus  after injection srbc were owed to treatment 4 and 3 respectively, as compare to other groups and differences between them were significant (p<0.05). the highest and the lowest levels of anti-body titrations of bronchitis along with influenza were belong to treatments 3 and 2 respectively as compare to other experimental groups (p<0.05). by this knowledge, it can be proposed to the poultry industries to use pobiotic (biomin imbo) safely at the rate of 1.0, 0.5 and 0.25 kg/ton in the broiler chicks rations when they are reared under ideal conditions.