The relative impacts of wilting, chopping, compaction and air infiltration on the conservation characteristics of ensiled grass

Abstract

The chemical composition of baled silage frequently differs from that of comparable conventional silage. The extents of wilting, chopping, compaction and air infiltration potentially contribute to these differences in conservation characteristics. An experiment was organized in a 3 (0, 24 or 48-h wilting to influence herbage dry-matter content) · 2 (unchopped or chopped) · 2 (with or without compaction) · 2 (with or without air infiltration) factorial arrangement of treatments, to elucidate the relative effects of these factors on the conservation characteristics of ensiled grass. Dry-matter content of herbage and infiltration of air had a greater effect on silage conservation characteristics than chopping and compaction. The main interactions were between wilting and air infiltration, wilting and compaction, and compaction and air infiltration. Air infiltration stimulated a secondary fermentation in the unwilted herbage, reflected in a large increase (P < 0AE001) in clostridial activity. As wilting progressed, air infiltration facilitated yeast respiration of watersoluble carbohydrates (WSC) and resulted in an increase (P < 0AE001) in in-silo fresh-weight losses. Compaction reduced (P < 0AE05) silage pore space and, as a result, the extent to which air could penetrate the silage mass. Compaction of the wilted herbage restricted respiration and was reflected in increased (P < 0AE05) concentrations of WSC and in a reduction (P < 0AE001) in fresh-weight loss. The rapid achievement and maintenance of adequately anaerobic conditions is the primary requirement for baled silage. This study showed that failure to achieve this will lead to progressively greater losses, especially with drier herbage.

Mycotoxin occurrence on baled and pit silages collected in Co. Meath

“…In agreement with similar comparisons of silages produced in Co. Meath (McEniry et al, 2007) and nationally (Keating and O'Kiely, 1997 a, b) Haigh and Parker (1985), and showed limited evidence of undesirable secondary fermentations. The baled and pit silage history and management practices recorded largely reflect those also observed in other regional or national surveys (McEniry et al, 2006;O' Brien et al, 2005).…”

The effect of supplementing highly wilted grass silage with maize silage, fodder beet or molasses on degradation of the diets and the efficiency of microbial protein synthesis in the rumen of sheep

“…Silage contained a relatively high amount of residual WSC. The value was similar to highly wilted GS as reported by McEniry et al (2007) (from 86 to 103 g kg -1 DM for variants with restricted air infiltration), but higher than in the highly wilted GS examined by Eriksson et al (2004a) (69 g kg -1 DM). The concentration of residual WSC in GS from this study was similar or higher than in silages prepared from perennial ryegrass varieties that were selected for elevated levels of WSC (Merry et al, 2003;, Yanez-Ruiz et al, 2006.…”

Detection, identification, and typing of Listeria species from baled silages fed to dairy cows

“…Among the various silage conservation methods, wrapped bales are commonly used in Europe to preserve the quality of forage from meadows (Wilkinson and Toivonen, 2003;McEniry et al, 2007) and are gaining popularity in the United States in the last decade (Han et al, 2006;Arriola et al, 2015). Baled silage is often made from herbage that is wilted more extensively and presented more limited fermentation than conventional bunker silo silage, as it reduces the number of bales per hectare, plastic consumption, and costs, and can be more convenient when fed to animals (Han et al, 2006;McEniry et al, 2007;Tabacco et al, 2013). Unfortunately, the increased DM content also tends to increase fungal growth in wrapped forages (O'Brien et al, 2008;Tabacco et al, 2013), thus increasing hygienic issues as well as the risk of mycotoxicosis (O'Brien et al, 2007) and Listeria contamination (Fenlon et al, 1989).…”