Hormones and growth promoters in animal breeding : from physiological end-points to risk assessment considerations

Abstract

During the last fifty years, considerable progress in breeding performances of domestic species has been obtained due to a better knowledge obtained in physiology and in particular nutrition, growth, reproduction and lactation. This progress has been united with that of genetic progress accomplished in the different animal species in a context of an improved control of sanitary conditions of herds and a more accurate control of the existing breeding systems. The use of hormonal substances to better control reproduction functions and growth has become decisive within this progress. However, a profound tendency that restrains their use to certain critical moments in the life of an animal has appeared in Europe these last fifteen years, obliging researchers to search for alternatives via a better control of food, genetics and breeding systems, in order to guarantee to consumers a better, a priori, quality of animal products. Physiological functions that offer possibilities of exogenous hormonal control, usable hormonal substances and animal speculations are presented. A clarification of the toxicological risks that these substances present, the control and traceability of their use and the current regulations are given. Finally, the research that will allow making progress around the question of hormone use in breeding in a context of a remodelled society is evoked.