title: Effects of sodium diacetate on the fermentation profile, chemical composition and aerobic stability of alfalfa silage.
abstract: OBJECTIVE
  The objective of this study was to evaluate the effect of sodium diacetate (SDA) on fermentation profile, chemical composition and aerobic stability of alfalfa (Medicago sativaL.) silage.
  
  
  METHODS
  Fresh alfalfa was ensiled with various concentrations of SDA (0, 3, 5, 7, and 9 g/kg of fresh forage). After 60 days of the ensiling, the samples were collected to examine the fermentative quality, chemical composition and aerobic stability.
  
  
  RESULTS
  The application of SDA significantly (p<0.05) decreased silage pH with the lowest value in silage with 7 g/kg of SDA. The proliferations of enterobacteria, yeasts, molds and clostridia were inhibited by SDA, resulted in lower ethanol, propionic and butyric acid concentrations and dry matter loss in SDA treated silages than control. The increasing SDA linearly decreased free amino acid N (p<0.001), ammonia N (p = 0.018) and non-protein N (p<0.001), while linearly increased water soluble carbohydrate (p<0.001) and peptide N (p<0.001). It is speculated that SDA accelerated the shift from homofermentative to heterofermentative lactic acid bacteria during the silage fermentation, indicated by lower lactic acid production in SDA-9 than SDA-7 silages after 60 days of ensiling. Alfalfa silages treated with SDA at 7 g/kg had highest Flieg's point and remained stable more than 9 d during aerobic exposure under humid and hot conditions in southern China.
  
  
  CONCLUSIONS
  SDA may be used as an additive for alfalfa silages at a level of 7 g/kg.
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: XianJun
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Nanjing 210095, China.|College of Animal Science, Anhui Science and Technology University, Fengyang 233100, China.
authors.forename: AiYou
authors.initials: A
authors.lastname: Wen
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Seare T
authors.initials: ST
authors.lastname: Desta
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shao
keywords: Alfalfa; Fermentation Quality; Silage; Sodium Diacetate