An evaluation of the hygienic quality in single‐species hays and commercial forages used in equine nutrition

Abstract

Pulmonary diseases such as recurrent airway obstruction have become a major concern in the horse industry. Airborne dust, including aeroallergens from forages, is suspected to be the main factor in its aetiology. Hypothesizing that grassland flora could affect hay hygienic quality, and therefore have implications for the respiratory health of horses, we compared five single-species hays (Trifolium repens, Lolium perenne, Alopecurus geniculatus, Poa trivialis and Holcus lanatus). Multi-species hay from Normandy, and different commercial forages (single-species haylage, multispecies haylage, Crau hay and hay from Swiss mixing), chosen to represent current horse forages, were also investigated. Dust, moulds, pollens and endotoxins were different among forage types, while mycotoxins were not detected in any of the forage types. Holcus lanatus hay was the dustiest among the single-species hays but also the least contaminated by moulds. A particular mould profile was associated with each plant species. The four commercial forages appeared to have a better hygienic quality than the multi-species hay. Among commercial forages, the single-species haylage was the least dusty but also the most contaminated by moulds. Overall the results suggest that the hygienic quality of equine forages could be improved by an appropriate choice of grassland species.

The haybiome: Characterising the viable bacterial community profile of four different hays for horses following different pre-feeding regimens

“…This is likely due to the multispecies composition of the meadow hay compared to the monoculture of the ryegrass. This would support the findings of Seguin et al [3] and Moore-Colyer [14] when comparing hygiene of single and multispecies hays.…”

“…Conserved forages are commonly fed to horses' at times where fresh forage is unavailable [1]. Hay is the predominant forage source fed to horses' in the UK [2], however the hygienic quality of hay is inherently variable and has been linked to sward composition grassland management, conservation techniques and environmental conditions, all of which can play a role in the quality of the forage [3,4]. When feeding, horses' inhale aeroallergens from forage which can exacerbate respiratory diseases.…”

Investigating the Link between Particulate Exposure and Airway Inflammation in the Horse

“…Use of Trifolium repens (white clover) and Lolium perenne (winter ryegrass) have been shown to minimize release of respirable particulates and mold colony forming units when harvested appropriately. 89 Late harvest, second cutting hay baled at 85% dry matter, 90,91 and haylage [89][90][91] provide the lowest potential for respirable particulate and fun-gal release. Choice of concentrate can also impact particulate matter exposure.…”

“…Hay composition and preparation significantly affect particulate and mold contamination. Use of Trifolium repens (white clover) and Lolium perenne (winter ryegrass) have been shown to minimize release of respirable particulates and mold colony forming units when harvested appropriately . Late harvest, second cutting hay baled at 85% dry matter, and haylage provide the lowest potential for respirable particulate and fungal release.…”

Fungal and chemical diversity in hay and wrapped haylage for equine feed

“…Although mycotoxins in fermented maize (silage) for cattle have been studied extensively (Alonso et al 2013;Storm et al 2014), less is known about the fungal diversity and fungal metabolites in hay and haylage for equines (Müller et al 2007;Liesener et al, 2010;Séguin et al 2010;2012;Müller, 2018;Schenk et al 2018). Maize ears are prone to Aspergillus and Fusarium infection in the field (Shotwell et al 1980;Young and Miller 1985), which can be carried over in the silage, whereas grasses in the field may be colonized by other fungal genera.…”