Bushfire exposure is associated with increased pH and dark-cutting in beef longissimus thoracis at grading

To investigate if bushfire exposure is associated with increased loin pH, this study analysed temporal and geospatial data on fire incidence in South-Eastern Australia together with beef carcase quality and production records for fire affected animals (n = 451,299). Two outcomes were modelled: 1) loin pH at time of grading, and 2) the incidence of "high pH" defects (pH > 5.70). For both models, decreasing "time since closest fire" and "distance of property from closest fire" were associated with increasing loin pH and increased incidence of high pH carcases(p < 0.05 for all); interactions for "distance from the closest fire" with feed type (grain vs grass) and "days of fire exposure" with HGP (hormonal growth promotant) treatment (yes vs no) (p < 0.05 for both) indicate high pH outcomes were exacerbated in grass-fed and HGP treated cattle. It is concluded that exposure to bushfire is associated with increasing pH but the extent and magnitude of these increases are modulated by production factors.