Medico-legal technique dating the age of cutaneous wounds in pigs.

A Canadian-Italian Swine Cluster 2 and AgriInnovation project.

The welfare of farm animals is improving, and many acts (travel management) and environment (group gestation) are to be modified. Pig industry stakeholders are also looking for tools and measurement methods to identify where improvements need to be made. Finding a method for identifying whether cutaneous lesions found on pig carcasses have been achieved at the slaughterhouse or during transport or on the farm is one element that will help monitor the management of animal welfare.

Human as animals, we do not all have the same facility to make us bruises or to heal, so we must find a more effective measurement method than to compare the color of the lesions (hematomas) with the naked eye with a color scale. Each evaluator has a different vision and a different sensitivity to hues (imagine to discuss the difference of tone of the painting of your walls with a designer). It is understood that using a device that can always measure the light properties of lesions uniformly (the color is related to electromagnetic waves) is more reliable than a human eye. An Italo-Quebec team then used a technique based on the physical properties of light: spectrophotometry directly measured on healthy skin compared to that of skin with a lesion.

First, the Italo-Quebec team showed the age of the skin lesions samples that the eye evaluation cannot differentiate while spectrophotometry can. Indeed, spectrometry makes it possible to differentiate induced lesions in less than 7 hours before bleeding (at the slaughterhouse or during transport) or in more than 25 hours before the slaughter of the animal (on the farm).

In a second step, the researchers compared the spectrophotometric analyzes with the biological reality of the healing of the tissues of the skin, ie with biological measures of inflammation of the skin with the genetic expression of inflammatory markers and histological observations (observation by microscopy of skin cells). This method of biological diagnosis is too long and expensive to be used routinely in slaughterhouse but allows to validate the spectrophotometric data in relation to the biological reality. The validation confirms that the spectrophotometry reflects well the biological state in relation to the age of the lesions 25h and more before the bleeding or in the 7h preceding this one.

This work was completed by Marika Vitali (doctoral student, Department of Veterinary Medical Sciences, University of Bologna), Sabine Conte and Luigi Faucitano, all three experts in animal welfare (postdoctoral fellow and researcher at Agriculture and Agri-Food Canada, respectively) and, with the support of CRIPA researchers: Martin Lessard, immunologist (Agriculture and Agri-Food Canada), Dr. Marie-Odile Benoit-Biancamano, veterinary pathologist (U. of Montreal), Frédéric Guay, expert in pork management (U. Laval ) and their colleagues from the University of Bologna, Dr. Luca Sardi and Dre. Giovanna Martelli (Veterinary Specialist in Animal Welfare, Graduate ECAWBM).

This study unveils the validation of a forensic technique based on the porcine model that could be used in human forensics.

Affiliation of the authors:

Marika Vitali ad Dre. Giovanna Martelli, Dr. Luca Sardi, Department of veterinary medical sciences (DIMEVET), University of Bologna, Italia.

Researchers: Luigi Faucitano and Martin Lessard*, Postdoc : Sabine Conte from Agriculture and Agri-Food Canada Center of research and developpment of Sherbrooke (AAC)

Frédéric Guay* University Laval

Marie-Odile Benoit-Biancamano* Faculty of veterinary medicine, University of Montreal

Cécile Crost Coordinator of the CRIPA (Swine and poultry infectious diseases research center).

*researchers member of the CRIPA

Source: Use of the spectrophotometric color method for the determination of the age of skin lesions on the pig carcass and its relationship with gene expression and histological and histochemical parameters. M. Vitali, S. Conte, M. Lessard, K. Deschêne, M.O. Benoit-Biancamano, C. Celeste, G. Martelli, L. Sardi, F. Guay, and L. Faucitano. J. Anim. Sci. 2017.95:3873–3884.