title: Effects of four short-chain fatty acids or salts on the dynamics of nitrogen transformations and intrinsic protease activity of alfalfa silage.
abstract: BACKGROUND
  Short-chain fatty salts have been widely used as food and forage preservatives because of their antimicrobial properties. This study evaluated the effects of four chemical compounds with antimicrobial properties on nitrogen transformations and intrinsic protease activity of alfalfa silage.
  
  
  RESULTS
  Potassium diformate (PD) and formic acid (FA) rapidly reduced silage pH. Silages treated with sodium diacetate (SD) and calcium propionate (CAP) had higher final peptide N concentrations than other silage. The free amino acid N contents in PD and FA treated silages were lower than other silages at all intervals of ensilage. The ammonia N concentrations in FA and PD silages were the lowest, followed by SD and CAP silages. As ensiling progressed, the aminopeptidase activity was completely lost by day 5 for FA and PD silages and inactive by day 7 for SD silage, while it remained active after day 7 for control and CAP silage. The carboxypeptidase activities in FA and PD silages were already reduced below 50% by day 1 of ensiling.
  
  
  CONCLUSIONS
  Potassium diformate was as effective as formic acid in depressing the proteolysis, while sodium diacetate and calcium propionate were inferior to formic acid in protecting alfalfa proteins from being hydrolysed. © 2016 Society of Chemical Industry.
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Wei gang 1, Nanjing, 210095, China.
authors.forename: XianJun
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Wei gang 1, Nanjing, 210095, China.|College of Animal Science, Anhui Science and Technology University, Feng yang, 233100, China.
authors.forename: AiYou
authors.initials: A
authors.lastname: Wen
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Wei gang 1, 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, Wei gang 1, Nanjing, 210095, China.
authors.forename: ZhiHao
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Institute of Ensiling and Processing of Grass, Nanjing Agricultural University, Wei gang 1, Nanjing, 210095, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shao
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001711:Biotransformation; D005232:Fatty Acids, Volatile / Q000494:pharmacology*; D005285:Fermentation; D005519:Food Preservation / Q000379:methods*; D005520:Food Preservatives / Q000494:pharmacology*; D005561:Formates / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D000455:Medicago sativa / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism / Q000382:microbiology; D009584:Nitrogen / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D011422:Propionates; D059748:Proteolysis; D012820:Silage / Q000032:analysis* / Q000382:microbiology
chemical_list: D005232:Fatty Acids, Volatile; D005520:Food Preservatives; D005561:Formates; D010940:Plant Proteins; D011422:Propionates; C030544:formic acid; C514136:calcium propionate; D010447:Peptide Hydrolases; D009584:Nitrogen
keywords: alfalfa silage; chemical additive; protease activity; proteolysis