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Determination of microbial protein in perennial ryegrass silage
Author(s) -
Driehuis F.,
Van Wikselaar P. G.
Publication year - 2001
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1046/j.1365-2494.2001.00251.x
Subject(s) - silage , dry matter , food science , perennial plant , lactobacillus plantarum , zoology , chemistry , composition (language) , biology , diaminopimelic acid , organic matter , bacteria , agronomy , lactic acid , ecology , linguistics , genetics , philosophy , 16s ribosomal rna
The microbial matter fraction was determined in perennial ryegrass silages of different dry‐matter (DM) contents, ensiled with or without Lactobacillus plantarum . 15 N‐Leucine and the bacterial cell wall constituent diaminopimelic acid (DAPA) were used as markers for microbial‐N. Perennial ryegrass crops with DM contents of 202, 280 or 366 g kg −1 fresh weight were ensiled in laboratory‐scale silos and stored for 3 to 4 months. At different times after ensiling, silages were analysed and microbial fractions were isolated. Microbial‐N concentration determined with 15 N‐leucine reached a maximum during the first week of ensilage. It remained unchanged thereafter, except in silage with a DM content of 280 g kg −1 in which it decreased ( P < 0·01) by 32% during storage. After 3 to 4 months ensilage, microbial‐N concentration varied from ≈0·3 to ≈1·7 g kg −1 DM. A negative relationship was observed between microbial‐N concentration and silage DM content. Inoculation resulted in an approximately twofold increase ( P < 0·001) in microbial‐N concentration. Microbial‐N concentrations determined with DAPA were 1·14–2·07 times higher than those determined with 15 N‐leucine. However, 19–35% of the DAPA in silage occurred in a soluble form, indicating that this fraction of DAPA was not associated with intact bacteria.