How to improve the hygienic quality of forages for horse feeding.

BACKGROUND: Improving the hygienic quality of forages for horse nutrition seems to be a reasonable target for decreasing the prevalence of pulmonary diseases. The aim of the experiment was to study the effects of different agricultural practices on the main aero-allergens contained in forages, including breathable dust, fungi, mycotoxins and pollens. RESULTS: Results showed that the late harvest of hay, a second crop or a haylage production provides a good alternative to increase hygienic quality by reducing fungi contamination and breathable dust content. Barn drying of hay, while having no effect on breathable dust, similarly reduced fungi contamination. In contrast, when hay was harvested at a lower dry mass content (750 g DM kg⁻¹ versus 850 g DM kg⁻¹), both breathable dust and fungi contaminations were increased, which could at least be reversed by adding propionic acid just before baling. Zearalenone was detected in different hays, and even in one case, in breathable dust. CONCLUSION: Overall, our data suggest that different approaches can be used to increase forage hygienic quality for horse feeding and thus reduce their exposure to factors involved in equine pulmonary disease.

[Factors influencing the elimination of the migration of inhaled mineral particles (author's transl)]. / Facteurs influençant l'épuration et la migration des particules minérales inhalées.

The reaction of the body to inhaled mineral dust brings into play physiological and pathological mechanisms in which immunological processes may be involved. An analysis is made of phagocytosis by alveolar macrophages, of the transport of dust to the lymphatic system, of dust aggravation in lymphoid tissues on lymph glands and of the resulting lesions. The part played by dust in immunological disturbances is put forward in the cases of tubercular infections, experimental arthritis and tumors.