Submitted to: Poultry Science Association
Publication Type: Abstract Only
Publication Acceptance Date: 6/20/2002
Publication Date: 8/11/2002
Citation: Buhr, R.J., Berrang, M.E., Cason Jr, J.A. 2002. Recovery of bacteria from broiler carcass respiratory tracts before and after immersion scalding. [abstract] Poultry Science Association. 81(suppl.1):149.
Technical Abstract: We previously reported an increase in the numbers of total aerobic bacteria, coliforms, and E. coli recovered from broiler carcass respiratory tracts following commercial scalding. To determine if this increase during immersion scalding (presumed to be induced by changes in internal and external carcass pressures and temperatures) could be prevented, a plastic pull-tie was placed around the neck to occlude the trachea prior to scalding. Three carcasses were removed from the shackle line in sequence, one prescald and two postscald. The first carcass was removed from the shackle line within the bleed tunnel 30 s before the scalder. Also at this point a pull-tie was placed around the neck of a second carcass. After proceeding through a commercial triple-tank counter flow scalder with the pull-tie, the second carcass was removed from the shackle line, and then immediately a third carcass was removed (which did not receive a pull-tie). This sequence was repeated eight times on each of two days. All carcasses were bagged individually, packed on ice, and transported to the lab. For each carcass the skin and attached feathers covering the thoracic inlet were removed toward the head, and the exposed area sprayed with 70% ethanol. The trachea was cannulated, 60 mL of buffered saline gently introduced into the respiratory system, and the carcass inverted 30 times to facilitate rinsing the trachea, lungs, and air sacs. Rinse was collected and serial dilutions plated for the detection of total aerobic, coliform, and E. coli bacteria. Results are presented as log10 cfu/mL of rinse. The numbers of bacteria recovered from prescald untied carcasses were 3.2 total aerobic bacteria, 2.7 coliforms, and 2.6 E. coli. Rinses from carcasses sampled postscald (without the pull-tie) had increased bacteria numbers at 4.5 total aerobic bacteria, 4.5 coliforms, and 4.0 E. coli. Those carcasses that received a pull-tie prior to scalding and were sampled after scalding had the lowest number of bacteria at 3.0 total aerobic bacteria, 2.4 coliforms, and 1.7 E. coli. Results confirmed that these bacteria increased in numbers within the respiratory tract of the carcass during immersion scalding and the increase was prevented by occluding the trachea prior to the carcass entering the scalder.