Set-up of a multivariate approach based on serum biomarkers as an alternative strategy for the screening evaluation of the potential abuse of growth promoters in veal calves

Abstract

A chemometric class modelling strategy (unequal dispersed classes – UNEQ) was applied for the first time as a possible screening method to monitor the abuse of growth promoters in veal calves. Five serum biomarkers, known to reflect the exposure to classes of compounds illegally used as growth promoters, were determined from 50 untreated animals in order to design a model of controls, representing veal calves reared under good, safe and highly standardised breeding conditions. The class modelling was applied to 421 commercially bred veal calves to separate them into ‘compliant’ and ‘non-compliant’ with respect to the modelled controls. Part of the non-compliant animals underwent further histological and chemical examinations to confirm the presence of either alterations in target tissues or traces of illegal substances commonly administered for growth-promoting purposes. Overall, the congruence between the histological or chemical methods and the UNEQ non-compliant outcomes was approximately 58%, likely underestimated due to the blindness nature of this examination. Further research is needed to confirm the validity of the UNEQ model in terms of sensitivity in recognising untreated animals as compliant to the controls, and specificity in revealing deviations from ideal breeding conditions, for example due to the abuse of growth promoters.

Keywords:

• serum biomarkers
• veal calves
• illegal treatments
• growth promoters
• multivariate analysis

Acknowledgements

The authors wish to thank Mrs Immacolata Carfora for technical assistance and Dr Paolo Oliveri (Department of Pharmacy, University of Genoa, Italy) for contributing to the development of the in-house Matlab routines for data analysis.

Additional information

Funding

This work was financially supported by the Regione Piemonte – Progetti di ricerca sanitaria finalizzata: ‘Biomarcatori sierici ed epatici di trattamenti illeciti: creazione di un database in vitelli a carne bianca allevati in condizioni controllate’ and ‘Validazione di biomarcatori proteici per la messa in evidenza di trattamenti con promotori di crescita illeciti nel bovino’.