New assessment based on the use of principal factor analysis to investigate corn silage quality from nutritional traits, fermentation end products and mycotoxins

Abstract

The main quality traits of corn silages differed throughout the entire silo face. Minimization of the area exposed to risk of air penetration represents the best strategy to preserve the nutritional value and safety of corn silages. PFA allowed a clusterization of original variables into 11 PCs, appearing able to discriminate well and poorly preserved corn silages.

Use of principal factor analysis to generate a corn silage fermentative quality index to rank well‐ or poorly preserved forages

“…Details about various parameters of interest (i.e. dimensions of bunkers, bags or piles and main characteristics of sealing system such as longitudinal and lateral presence of silage wrap plastic film, type of plastic film used to cover silage, presence and type of material placed on the top of plastic film, uniformity of material distribution on the top of plastic film, use of silage additives and mode of service) were described in a previous study as well as estimation of proportion of corn silage working face at risk of air penetration based on mass penetration resistance (PenR) measured as indicator of density of silage silo . Corn silage silos were clustered into four groups based on specific ensiling characteristics.…”

“…They were: presence of material placed on the top of plastic film (yes vs. no), silo storage type (piles or bags vs. bunkers), type of material placed on the top of ensiled mass (tyres or gravel bags vs. tile or sand) and, lastly, uniformity in the material distribution on top of ensiled mass (yes vs. no). Identified clusters were: piles and bags (cluster 1), bunkers uniformly covered with tyres, gravel bags, tile or sand (cluster 2), bunkers irregularly covered with tyres or gravel bags (cluster 3) and uncovered bunkers (cluster 4) …”

“…Mycotoxins produced by Fusarium spp., Penicillium roqueforti and Aspergillus fumigatus were simultaneously extracted from dried silage samples and quantified by HPLC–tandem mass spectrometry (HPLC‐MS/MS) as previously described by Gallo et al Ethanol and VFA were quantified by GC, whereas lactic acid determination was carried out by using HPLC equipment . The NH 3 ‐N was determined according to AOAC method 973.49.…”

“…Indeed, the exposure of ensiled corn silage to the risk of air penetration and aerobic deterioration causes DM and nutrient losses, heat‐damage of nutrients and the proliferation of undesirable microorganisms, such as mycotoxigenic fungi . Chemical determinations of main fermentation end‐products provide information about the rate and extent of either favourable or adverse fermentations and they are commonly used to obtain a summary of conditions affecting the silage making process or feed‐out face management of ensiled crops . To this end, fermentative quality indexes, such as Flieg–Zimmer's or Vanbelle and Bertin's scores (hence defined as Vanbelle), have been proposed to rank between well‐ and poorly preserved forages according to the relative amounts of lactic acid, acetic acid, butyric acid or ammonia nitrogen (NH 3 ‐N) that are in the silages.…”

Nutritive value of corn silage from intensive dairy farms in Brazil

“…In countries where the dairy industry is well established, the standards for corn silage production, as well as the nutritive value of silage, are already well described in the literature Khan et al, 2015;Gallo et al, 2016). Conversely, in hot environments, such as in Brazil, the quality of corn silage is influenced by production techniques (e.g., less resource availability), type of hybrid (e.g., predominance of flint corn), and climatic factors (e.g., proliferation of many pests and bacterial and fungal pathogens; Adesogan, 2009;Adesogan, 2010).…”