title: New assessment based on the use of principal factor analysis to investigate corn silage quality from nutritional traits, fermentation end products and mycotoxins.
abstract: BACKGROUND
  A survey on 68 dairy farms was carried out to evaluate the ensiling procedures adopted to store corn silage. Samples from core, lateral and apical zones of the feed-out face of silos were analysed. A principal factor analysis (PFA) was carried out on the entire database (196 silage samples and 36 variables) and 11 principal factor components (PCs) were retained and interpreted.
  
  
  RESULTS
  Ensiling procedures influenced the area exposed to risk of air penetration. Cores had higher dry matter, starch and lactic acid content or lower pH, fibre, propionate and butyrate concentrations than peripheral samples (P < 0.05). The highest (P < 0.05) mycophenolic acid and roquefortina C concentrations were detected in lateral samples. Chemical and digestibility variables loaded on two PCs; four PCs were characterized by end-products associated with clostridia, heterolactic, homolactic and aerobic fermentations; two PCs were associated with mycotoxins, whereas three PCs explained ensiling procedures.
  
  
  CONCLUSIONS
  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.
authors: Feed and Food Science and Nutrition Institute, Faculty of Agricultural, Food and Environmental Sciences, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy.
authors: Antonio
authors: A
authors: Gallo
authors: Feed and Food Science and Nutrition Institute, Faculty of Agricultural, Food and Environmental Sciences, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy.
authors: Terenzio
authors: T
authors: Bertuzzi
authors: Feed and Food Science and Nutrition Institute, Faculty of Agricultural, Food and Environmental Sciences, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy.
authors: Gianluca
authors: G
authors: Giuberti
authors: Feed and Food Science and Nutrition Institute, Faculty of Agricultural, Food and Environmental Sciences, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy.
authors: Maurizio
authors: M
authors: Moschini
authors: Feed and Food Science and Nutrition Institute, Faculty of Agricultural, Food and Environmental Sciences, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy.
authors: Sara
authors: S
authors: Bruschi
authors: Carla
authors: C
authors: Cerioli
authors: Feed and Food Science and Nutrition Institute, Faculty of Agricultural, Food and Environmental Sciences, Università Cattolica del Sacro Cuore, 29122, Piacenza, Italy.
authors: Francesco
authors: F
authors: Masoero
mesh_terms: D005285:Fermentation; D005504:Food Analysis / Q000379:methods*; D009183:Mycotoxins / Q000737:chemistry*; D009753:Nutritive Value; D025341:Principal Component Analysis / Q000379:methods*; D012820:Silage / Q000032:analysis*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D009183:Mycotoxins
keywords: corn silage; fermentation end-products; mycotoxin; principal factor analysis