Microbial contamination occurring on lamb carcasses processed in the United States

Lamb carcasses (n = 5,042) were sampled from six major lamb packing facilit ies in the United States over 3 days during each of two visits (fall or win ter, October through February; spring, March through June) in order to deve lop a microbiological baseline for the incidence (presence or absence) of S almonella spp. and for populations of Escherichia coli after 24 h of chilli ng following slaughter. Samples also were analyzed for aerobic plate counts (APC) and total coliform counts (TCC). Additionally, incidence (presence o r absence) of Campylobacter jejuni/coli on lamb carcasses (n = 2,226) was d etermined during the slaughtering process and in the cooler. All samples we re obtained by sponge-sampling the muscle-adipose tissue surface of the fla nk, breast, and leg of lamb carcasses (100 cm(2) per site; 300 cm(2) total) . Incidence of Salmonella spp. in samples collected from chilled carcasses was 1.5% for both seasons combined. with 1.9% and 1.2% of fall or winter an d spring samples being positive, respectively. Mean (log CFU/cm(2)) APC, TC C, and E. coli counts (ECC) on chilled lamb carcasses across both seasons w ere 4.42, 1.18, and 0.70, respectively. APC were lower (P < 0.05) in sample s collected in the spring versus fall or winter, while TCC were higher in s amples collected in the spring. There was no difference (P > 0.05) between ECC from samples collected in the spring versus winter. Only 7 out of 2,226 total samples (0.3%) tested positive for C. jejuni/coli, across all sampli ng sites. These results should be useful to the lamb industry and regulator y authorities as new regulatory requirements for meat inspection become eff ective.