Samples form lungs, trachea and air sacs were collected from 40 turkey poults suffering f rom respiratory signs for bacteriological examination for isolation and identification mycoplasma spp. The results revealed, 18 (45%) samples were positive (+ve) for mycoplasma spp. Antibiogram study of isolates revealed that pefloxacin and tiamulin was effective against mycoplasma. A total of 40, one-day old poults provide free from mycoplasma infection were divided into 4 equal groups. 1 st group healthy negative (-ve control) 2 nd , 3 rd & 4 th groups were artificially infected with Mycoplasma gallisepticum (MG), 2 nd group infected non treated (+ve control), 3 rd group infected treated with 5 mg pefloxacin / kg bwt in drinking water for 5 successive days and 4 th groups was infected treated with 25mg tiamulin/kg bwt in drinking water for 5 successive days, At 1 st and 10 th days post treatment 5 poults from each group were sacrificed for record lesion scores % and two blood samples were taken from each poults for hematobiochemical parameters study. Poults infected with Mycoplasma gallisepticum revealed loss of appetite, depression, sneezing, conjunctivitis, frothy exudation in eyes, air sacculitis 7 ( 70 % ), pericarditis 7 (70 % ), perihepatitis 8 (80 % ) & mortality rate 4 (40 ( % beside induces significant increase in WBCs, AST ALT, ALP uric acid, creatinine and significant decrease in weight gain. Phagocytic %, index, killing % IgA, IgG, IgM, T protein, albumin and globulin. Medication mycoplasma gallisepticum by tiamulin or pefloxacin revealed disappears of clinical signs, reduced mortality rate to10%, mild lesion scores re-isolation rate of Mycoplasma gallisepticum from poults treated with pefloxacin was (20%) and (10%) for tiamulin beside improve in hematobiochemical parameters and returned to nearly normal level at 10 th day post treatment. It could be concluded that pefloxacin and tiamulin was effective in treatment Mycoplasma gallisepticum in poults and ameliorate severity of its lesions besides improving adverse effect in hematobiochemical parameters.

A total 110 one-day-old chicks were used in this study to investigate antibacterial effects of organic acid (formic and propionic acid) either alone or together against Salmonella pullorum (Sal. pullorum). 10 chicks were slaughtered and examined bacteriologically to prove that chicks free from salmonella, the remender100 broiler chicks were divided into 5 groups (20 chicks/each), 1 st group healthy chicks (negative control), At 14 th day of age broilers in group 2 nd , 3 rd , 4 th and 5 th experimentally infected with Sal. pullorum, 2 nd group infected chicks (positive control), 3 rd group chicks received 0.1 ml formic acid /liter drinking water from 1 st to 35 th day of age and infected with Sal. pullorum, 4 th group chicks received 0.1 ml propionic acid/liter drinking water from 1 st to 35 th day of age and infected with Sal. pullorum. 5 th group received formic acid and propionic by same dose, period and route of infection with Sal. pullorum. At 1 st day post supplementation 5 chicks from each group were slaughtered and two blood samples were taken for estimation of hematobiochemical parameters. Cloacal swabs were collected for salmonella reisolation. Infected broilers showed clinical signs represented by anorexia, closed eyes diarrhea, dehydration, mortality rate 30% and reduction in body weight gain, RBCs, Hb, PCV%, MCHC, lymphocytes total protein, albumin , CAT and SOD beside significant increase in FCR, MCV, MCH, WBCs, heterophil, monocyte globulin, ALT, AST, ALP, uric acid ceatinine and MDA, associated with insignificant decrease in esinophil and basophil. Broilers received formic acid or propionic acid either alone or together for 35 days and infected with Sal. pullorum showed no clinical signs, insignificant decrease in RBCs, Hb, PCV%, MCHC, lymphocyte eosinophil, T. protein, albumin, A/G ratio, CAT, SOD and insignificant increase in weight gain, MCV, MCH,WBCs, heterophil, basophil, monocyte globulin, ALT AST, ALP, uric acid, creatinine and MDA, improved FCR, reduced mortality rate to 5% but both acids together induced zero mortality beside reduction in re-isolation of S al. pullorum. It could be concluded that, formic and propionic acid play an important role in control of salmonellosis in broiler and act as growth promoters beside improved hematobiochemical parameters so we recommend using formic acid and propionic acid allover fatting period.