The objective of the presented study was to determine microbial contamination of calf muscle tissues in relation to slaughtering process of calves during a slaughter day. In order to determine the total aerobic bacteria count, and the presence of bacteria from the Enterobacteriaceae family and enterococci, 32 carcasses were examined (eight each slaughter day), while 40 carcasses (10 each slaughter day) were examined for the detection of Salmonella organisms. Microbiological evaluation of each bacterial group was performed according to the Polish Norms. In most cases, no significant differences were reported between the total aerobic counts on calf carcass surfaces as determined at each slaughter cycle. The daily log mean values were lower by 1 up to 1.5 log, respectively, than the maximal bacteria count (M). Bacteria from the Enterobacteriaceae family were isolated from 59.4% of the evaluated samples. However, contamination with these bacteria was insignificant - 1.7 x 10 cfu/cm2. Enterococci were isolated from all investigated samples and contamination ranged from 1.1 x 10 cfu/cm2 up to 4.1 x 102 cfu/cm2. Salmonella strains were not found in any of the evaluated samples. The order of the slaughtering calves during a slaughter day and the day of the week when the examination was performed did not have any influence on total microbial contamination of carcasses. Thus, sanitary conditions in the examined abattoir were satisfactory and slaughter process was conducted at a high quality level
