High throughput accurate method for estimating in vitro dry matter digestibility of maize silage

P.-L Lopez-Marnet,M.-P Jacquemot,V Méchin,M Reymond,S Guillaume

doi:10.1186/s13007-021-00788-5

Abstract

BackgroundSince the introduction of studies on maize silage digestibility at the end of the nineteenth century, protocols to estimate dry matter digestibility have not stopped evolving. Since the early 1980s, the protocol developed by Aufrère became a benchmark in many laboratories to estimate in vitro dry matter digestibility. In order to increase its throughput, to facilitate its execution and to decipher the impact of the different parameters of the protocol we decided to test the combination of 7 parameters in 21 different protocols.ResultsWe thus tested the impact of (1) the presence or absence of pepsin in HCl solution, (2) the temperature of incubation during enzymatic hydrolysis, (3) the presence or absence of a gelatinization step, (4) washing/rinsing versus neutralization step, (5) the presence or absence of α-amyloglucosidase in enzymatic solution, (6) the duration of cellulase incubation, and (7) the concentration of the cellulase solution. The major result of our work highlighted that it was essential to carry out a gelatinization step to correctly estimate the in vitro dry matter digestibility of maize silage.ConclusionsThe proposed protocol in this paper is innovative, reliable, highthroughput and easy to implement in many laboratories to accurately quantity in vitro dry matter digestibility.

Highlights

Since the introduction of studies on maize silage digestibility at the end of the nineteenth century, protocols to estimate dry matter digestibility have not stopped evolving
Reference values of in vitro dry matter digestibility (IVDMD) IVDMD reference values were determined by LANO laboratory on a selection of 6 maize dry matter samples that cover a large range of variation for dry matter digestibility
IVDMD values obtained with protocol 1 varied from 67 to 77%DM which faithfully reflects the values obtained by the LANO laboratory

Summary

Introduction

Since the introduction of studies on maize silage digestibility at the end of the nineteenth century, protocols to estimate dry matter digestibility have not stopped evolving. Since the early 1980s, the protocol devel‐ oped by Aufrère became a benchmark in many laboratories to estimate in vitro dry matter digestibility. First introduction of study on maize silage digestibility appeared in France with the work of Auguste Goffart “Manuel de la culture et de ensilage des maïs” [1] for cow winter nutrition and milk production. During the middle of the twentieth century, the concept of digestibility was first introduced by comparing in vivo silage digestibility and in vitro dry matter digestibility (IVDMD) using rumen fluid [2, 3] (Table 1). Tilley and Terry [2] were the first to propose IVDMD quantification following a two step protocol.

Methods

Results

Discussion

Conclusion