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Ruminal degradation of cell wall associated nitrogenous compounds of several 15 N‐labelled feeds
Author(s) -
Vanegas Jorge L,
Arroyo José M,
González Javier
Publication year - 2016
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7590
Subject(s) - chemistry , straw , zoology , dry matter , sunflower , contamination , agronomy , biology , inorganic chemistry , ecology
BACKGROUND Ruminal in situ effective degradability ( ED ) of dry matter ( DM ), neutral ( NDF ) and acid ( ADF ) detergent fibres, total‐N and NDF ( NDIN ) and ADF ( ADIN ) bound‐N in sunflower seed ( SS ), wheat grain ( WG ) and wheat straw ( WS ) were measured in three ruminally cannulated sheep, correcting microbial N‐contamination using the 15 N dilution technique modified to consider the 15 N supply to adherent bacteria. RESULTS The lack of correction for N‐contamination under‐evaluated ED estimates in 1.52% (total‐N), 28.0% ( NDIN ) and 33.3% ( ADIN ) in SS and in 1.02% (total‐N) and 4.43% ( NDIN ) in WG . In the remaining cases, this contamination prevented establishing apparent degradation kinetics and, therefore, errors were not measured. Microbial corrected ED estimates in SS were higher in total‐N (0.917) than in NDIN (0.559) and ADIN (0.520), which showed similar values. This behaviour was also shown in WS (0.670, 0.386 and 0.426, respectively), whereas decreasing values were shown from total‐N (0.917) to NDIN (0.830) and ADIN (0.482) in WG . CONCLUSION Results confirm that NDF and ADF procedures failed to remove large fractions of particle adherent microorganisms, under‐evaluating the ED of NDIN and ADIN . Degradation of NDIN represented a significant part of the degraded N, whereas ADIN contribution was only negligible in WG . © 2015 Society of Chemical Industry