Mycoplasma bovis infection is an economically important disease in dairy and feedlot cattle. The pathogen is a common bacterium found in mucous membranes in animal species, including respiratory, urogenital, and gastrointestinal tracts. M. bovis infection is a highly contagious disease with over 70% infection rate. The prevalence of M. bovis infection is wide
and highly reported among young calves. The mortality is usually reported in 2-6 weeks old calves while the peak clinical incidence is at the age of one month. In adult dairy cows, the organism takes a long period (months to years) to colonize the mammary gland. The aim of the present study was to measure interleukins 1 & 6 and lysozyme as parameters of the host
immune response to M. bovis in mice experimentally infected with the pathogen. The expirement was carried out on 20 albino mice (6-weeks-old) divided into two equal groups. The experimental group was interprotineally (I/P) inoculated with 1ml containing 1x 107 CFU of fresh prepared M. bovis while the control group received phosphate buffered saline (PBS). Animals were bled from the tail vein under the Laboratory Animal License by collecting approximately 30
µl of blood into clean capillary tubes at, 1st, 3rd and 7th day post infection. Serum samples were collected for measurements of lysozyme, IL-1 and IL-6 levels using ELISA kits. The study denoted general activation of immune response in the infected mice with markedly increased lysozyme, as well as interleukins 1 and 6. Strong immune response was detected at
the 7th day post infection as revealed by elevated Il-1 & 6 levels. From the obtained results, it could be concluded that the cell-mediated immunity seems to play an important role in an elimination of M. bovis from the host and M. bovis infection effectively stimulated the cellmediated immunity in mice