Campylobacter is one of the most commonly reported bacterial causes of human foodborne infections in the United States. Recent evidence has demonstrated that Campylobacter is present in poultry semen and may contribute to the vertical transmission between the breeder hen and offspring. As Campylobacter is considered sensitive to oxygen and cold temperature, the objective of this study was to determine if aeration and storage temperature could reduce or eliminate Campylobacter in poultry semen. In 4 separate trials, pooled semen samples were collected from roosters or toms, diluted with a commercial poultry semen extender, and inoculated with an average of 10(7) cells/mL of a wild-type C. jejuni or C. coli semen isolate. Pooled ejaculates were then divided into 3 aeration treatments: Control (no aeration), air, or oxygen (gently bubbled for 20 min with atmospheric air or oxygen, respectively). Immediately after aeration, pooled semen samples were further divided to 3 test storage temperatures: 4, 23, or 42 degrees C. At 0, 2, 6, and 24 h of storage, samples were enumerated for Campylobacter. Aeration of the semen alone, or aeration with reduced temperatures (4 or 23 degrees C), did not reduce the amount of Campylobacter compared with the controls. Campylobacter concentrations were, however, reduced when stored at 42 degrees C for 24 h. This effect is associated with reduced sperm viability and is therefore not a practical treatment of reducing Campylobacter in semen. It appears alternative methods will be needed to eliminate Campylobacter from poultry semen.