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Technical note: Relationship between in situ NDF degradability and enzymatic NDF hydrolysis in forages, nonforage fibrous feeds, and crop residues1

Authors :
Gianluca Giuberti
Francesco Masoero
Antonio Gallo
Sara Bruschi
Paola Fortunati
Source :
Journal of Animal Science. 95:4172-4180
Publication Year :
2017
Publisher :
Oxford University Press (OUP), 2017.

Abstract

The study was performed on forages ( = 8), nonforage fibrous feeds ( = 10), and crop residues ( = 2). Samples were characterized for in situ NDF degradability (NDFD) at 6, 12, 18, 24, 30, 36, 48, 72, 96, 120, and 240 h of ruminal incubation. Then, samples were characterized for enzymatic NDFD by adopting a multistep enzymatic method consisting of a preincubation (PreInc) phase followed by enzymatic incubation (EnzInc) steps. In the PreInc phase, samples were incubated in a NaOH solution for 0, 30, 60, or 90 min. Then, in the EnzInc phase, samples were first incubated in a buffered enzymatic solution containing hemicellulase, cellulase, and Viscozyme L enzymes. Then, samples were incubated in a xylanase-buffered enzymatic solution. These 2-step EnzInc lasted for a total of 16 (8 h for the first enzymatic step + 8 h for the second enzymatic step), 32 (16 + 16 h), or 48 h (24 + 24 h). The enzymatic NDFD coefficients were increased by increasing both PreInc and EnzInc incubation times, and no PreInc × EnzInc interaction was observed, except for ryegrass hay. On average, enzymatic NDFD increased ( 0.80, < 0.05) and low errors of prediction were measured when specific enzymatic conditions were performed to predict in situ NDFD at intermediate (from 24 to 48 h) ruminal incubation. Generally, worse regression performances were obtained when enzymatic NDFD were used to predict in situ NDFD evaluated after shorter or longer incubation times. The direct prediction of the rate of NDF degradation was not possible using enzymatic NDFD coefficients. Even if the proposed multistep enzymatic method appeared promising, further studies are required to improve enzymatic NDFD prediction ability within specific forage types or nonforage fibrous feeds.

Details

ISSN :
15253163 and 00218812
Volume :
95
Database :
OpenAIRE
Journal :
Journal of Animal Science
Accession number :
edsair.doi...........588db9f5753f0aeb94121310466bdd16
Full Text :
https://doi.org/10.2527/jas.2017.1630