The effect of sample grinding procedures after processing on gas production profiles and end‐product formation in expander processed barley and peas

Abstract

Grinding is a technological process widely applied in the feed manufacturing industry and is a prerequisite for obtaining representative samples for laboratory procedures (e.g. gas production analysis). When feeds are subjected to technological processes other than grinding (e.g. expander treatment), grinding afterwards may disturb the effect of processing, both in practice and when laboratory techniques are applied. Therefore, this study aimed to establish the possible effects of different grinding procedures and sample preparation on the degradative behaviour of expander processed barley and peas. Samples of expander processed barley and peas were subjected to six different sample preparation procedures (intact sample, dissolved sample, samples ground stepwise over 6 and 3 mm sieves, samples ground stepwise over 6, 3 and 1 mm sieves, samples ground over a 3 mm sieve and samples ground over a 1 mm sieve). The patterns of gas production in these samples were studied over a period of 72 h incubation using an automated in vitro gas production system. The particle size distribution determined by dry sieve analysis and the Coulter counter method changed due to the different grinding procedures. Grinding the samples of expander processed barley and peas changed the kinetics of gas production and led to a faster degradation, most pronounced after stepwise grinding. However, the formation of the fermentation end-product was not affected by the method of sample preparation. In expander processed barley, the difference in the degradation pattern due to the different grinding procedures was small.

Processing Technologies and Cell Wall Degrading Enzymes To Improve Nutritional Value of Dried Distillers Grain with Solubles for Animal Feed: an in Vitro Digestion Study

“…37 Possibly, protein−cell wall interactions that occur during autoclaving reduce NSP degradability. The effect of wet-milling on the maximum rate of fermentation in undigested residues of both maize (see Supporting Information, Figure S3) and DDGS (Figure 2) demonstrates the accelerating effect of decreased particle size on fermentation, 38 which could indicate higher fermentability in vivo.…”

In vitro gas production profiles and fermentation end‐products in processed barley, maize and milo

“…Processing may alter the physicochemical characteristics of a feed in two ways. Because processing often affects the particle size distribution,21–23 it may interfere with analytical procedures that involve filtration, such as NDF analysis. Changes in the contribution of DM to different fractions are also possible if processing either alters the solubility, thereby changing the size of the truly soluble fraction (SWF), or reduces the size of particles, thereby increasing the size of the ISWF.…”