Four groups of 36 days old chicks were infected experimentally with mycoplasma gallisepticun suspension while a control group was injected with nutrient broth and another control group was left uninfected Thtee of the infected groups were treated with either Tylosin Spiramycin or lincomycin.
Parameters of airsacculitis score, and weight gain food conversion were used to evaluate the treatment.
Also, the residues of tylosin in blood plasm nd muscles and the level of spiramycin in blood plasma was estimated by a microbiological assay.
The results showed significant differences between infected and non-infected groups with all parameters used Treatment with tylosin and apramycin improved weight gain and increased food consumption but did not reduce airsacculitis score. Tylosin level in plasma was 75 μg/ml at termination of treatment and 0.16 μg/ml after 3 days, While measurable level was seen after 7 days. With spiramycin the corresponding levele were 0.43, 0.20, and 0.18 μg/ml respectively. The level of tylosin in guacles was 0.14 μg/mg
EFFECT OF THREE ANTIBIOTICS ON BYPERIMENTAL INFECTION OF BROILERS WITH MYCOPLASMA GALLISEPTICUM