The potential of a plant extract to provide fluorescent chlorophyll derivatives to act as markers of faecal contamination on carcasses

Cleanliness in the abattoir is of the utmost importance and strategies are carried out on farm to ensure that the animals arrive at the abattoir with limited faecal matter clinging to the hide. Currently carcasses are checked by ‘eye’ and trimmed to remove contaminated areas. Small areas of faecal contamination may not be visible to the eye and may harbour millions of pathogenic bacteria. Spectroscopic imaging is a rapidly evolving research area, with the potential to provide real-time solutions for the detection of faecal contamination on carcasses (Ashby et al. 2007). Chlorophyll is ubiquitous in green plants and thus grazing diets. During digestion in the gut, chlorophyll is only partially degraded to coloured and fluorescent intermediates: the phaeophytin, chlorophyllide, phaeophorbide and pyrophaeophorbide derivatives of chlorophylls a and b (Lee et al. 2009). This study assessed the potential of a chlorophyll containing feed (PX - an extract from lucerne; Medicago sativa) to provide fluorescent markers in the faeces which could then be used for on-line detection in the abattoir.