CA2145632A1 - Treatment of grain with expander - Google Patents

Abstract

Processing grain is described. Whole or preprocessed grain is fed into an expander where it is pressed past a hydraulically adjustable resistor at a temperature and pressure that are gradually built up towards predetermined levels as the feed is pressed forwards towards a slot in the adjustable resistor. Processed grain, feed, feedstuffs and mixed feeds and the use of an expander for processing grain are also described.

Description

~ W O 94/07376 21 ~ 5 6 3 2 PC~r/N 093/00142 Treatment of corn with expander.

The present invention relates to a method for processing grain.

The invention is especi~llyint~ncled for processing grain so as to increase the proportion of undegraded protein in the grain wi~l,oul having any marked effect on the digestibility of the carbohydrates.

NO Patent Application No. 884302 relates to the conversion of ~ ted meat and offal to le~Lul~ed animal protein. This substance has a low hydrolysable collagen content. The amount of gelatine and/or hydrolysable collagen in the meal, or the material from which 15 the meal is produced, is re~ce~ The protein in the product is, in its entirety, composed of extracted animal protein. During the production process a heated wet mass of animal meal is formed which is subjecled to ~ , and the ~ u.c; and temperature which ~ulluund the mass are reduced once the textured animal protein20 product has a content of m~ hle g~laline that is less that 10% of the dry subsLances in the product. The fat content is less than 10% in the dried product. During the process the p-cs~u~ is reduced by extruding the mass from an area of relatively high pressure to an area of relatively low pl~ ule, through an extrusion nozzle. An extrusion-facilitating agent and/or a soîlellel are added during the process.

NO Patent Application No. 820396 describes a method for producing animal feed from ~gri~ ultllr~l products such as sugar beet or sugalld ne mass, citrus pulp, or the sub~ e obtained during the Ç4~ ;01t of ~gri~ultllr~l products such as ~ tillers' grains from ~0 r~ tillt~.rilos. These products or s-~b~ es are dehydldled by means of a p~ssing operation and/or an evaporation process. During the process the product or sllhst~n~-e is heated in water vapour at a ~ ,ssule of 0.1-0.8 mpa and at a te~..re ~ .e within the range of 100-210C. The product or s.lb~ e is then co~ A in a carrier vapour35 in that it is crushed mP~h~ni~lly and/or ~ubje,ted to a sudden fall in ~ Ule which leads to an e~r~nsi- n and bursting of solid p~icles. An even particle size of 0.5 and WO 94/07376 3~2, PCr/NO93/û0142--S mm is thereby achieved. The pa~ticles are dried in a heat exch~nger where the carrier vapour serves chiefly as a collLfil)uLoly drying agent. The substance is then separated from the carrier vapour and is cooled in a known way per se.

NO Patent Application No. 753,896 describes a method for producing an enh~n~ed feed .-for fish and ch~.llfich, This fish and ch~.llfich feed is produced on the basis of ~ruteh~aceous fish and meat substances mixed with starch-cont~ining substances. I'he mixture is thereafter extruded, at a telllp~.dlul~ within the range of 90-120C for a ' period of time lasting a maximum of 1-3 min~ltes and at a pressure of a maximum of 1.5 atm.

Patent Application No. 461769 describes a method for producing palatable and non-toxic 15 feeAst~lffc for~ "lc. Starch-cont ining sub~LcLllces from gr~in orsimilarare mixed with niLl~gellous sul ~Lcu~ces. The mixture is then processed in an extruder where the s~lbst~nre is heated to a lelll~ d~ of 120-175C and in addition is subjected to a pressure of from approx. 28 kg per cm2 to approx. 35 kg per cm2. The finished 20 product gives rise to increased protein .ylllhe~.is in the rumen and a protein ~ccimil~tion effect that is con.ci~ bly greater than can be achieved by using o"linclly meçh~nic~l mixtures of the nill~gen"us substance and the starch-co..l~ -g substance.

Patent Application No. 802316 relates to a method for producing a dry ready-to-eat grain product of high fibre content. It is produced by mixing grain dough in~ dienl~ with maize bran meal until the product has a fibre content of at least 1.5 % . The ingredients are boiled in a boiler/extruder under conditions of lempelc,lule and pl~s~.ule sufficient to cause the dough to expand on the Aicsol~n~ n of the boiler/eAll,Lder. The e~r~n~leA
30 dough struct~ te is then cut into se~ e pieces, wLere~on it is dried until it has a moisture level of appiox. 2-3 % .

The present invention thus relates to a method for pluces~;--g grain, çh~r~cteri7eci in that 35 whole or prep;ocessed grain is fed into an exr~n-ier where it is pressed past a hy~ lly adjustable resistor in that the pl~,s~ulc; and the ~ are g~radually ~ WO g4/07376 214 S 6 3 2 PCr/NO93/00142 increased to pre~ter nin~-d leveis as the feed is pressed forwards towards a slot in the adjustable resistor.

Both whole and preprocessed grain can be processed according to the present invention.
The term preprocessed grain is used to mean, for example, grain that has been rolled, coarsely ground, gr~m~l~t~d or subjected to other methods that result in crushed grain.
It can be processed s~ ely or mixed in with the rest of the finich~d co~-ce~ .temixture. The mass is fed th~ rLer into a conditioning zone where steam is added and is mixed into the mass. The mass in then fed into an expander where it is processed at a ~ peldlul~ in the range of 80-190C, preferably 110-160C, and most preferably130-135C, and under a p~ssule in the range of 10-150 bar, preferably 30-40 bar.
5 The processed grain, feed, feel~lff and mixed feed also constitute a part of the invention.

The use of an expander for processing grain is also described. Various studies and 20 experimP!nt~ are des~;libed below. R~;re~;nce is l},e~ero~ made to the att~h~d figures where:

Fig. 1 is a schPm~ti~ illnstr~tion of the ~legral1~tion of protein over time measured in sacco.

Fig. 2 shows the reduction in protein ~legr~ ti~n as the rate of passage increases.

Fig. 3 shows how pl~,SS~llt; and te..~ e g~ 1ly build up during expansion.

Figs. 4-6 show the effect of pl~,s~ , and le~ on the ~egr~ hility of protein and dry matter in pre~ studies.

35 Fig. 7 illl.s~ s the co~ en~es of exr~nllPr processing for the raw m~eri~l costs.

WO 94/07376 PCr/NO93/00142~

2 1 ~ 4 - Fig. 8 shows the difference be~ween the raw material costs involved in expansion and those involved in non-exr~ncion The Nol~vegiall Governm~nt has introduced AAT (content of amino acids absorbed in the int~stin~) and PBV (protein balance in rumen) as measure for protein value in feeds for rllmin~ntc. This results in a more goal-oriented ~Itili7~tic)n of feed protein for inter dairy cattle. A b~l~n~ecl supply of AAT and PBV in relàtion to requirements. is central in this context. In the fe~l.~rrtable of 11 March 1992, the AAT content and o PBV contem of barley of normal quality have been put at 102 grams and -48 grams, respectively, per kilo of dry matter, and for oats at 67 grams and 1 gram"t;s~euLi~/ely, per kilo of dry matter. The ~egr~ l~bility of feed protein in the rumen (NGP) and the in~ostin~l digestibility of undegraded feed protein (FINP) for barley are set at 70% and 15 75% respectively, and for oats at 88% and 62% lGs~e~Li~/ely.

Calculations have shown, however, that it will often be desirable to have higher AAT
values and lower PBV values than found in grain of normal quality. A higher AAT
20 value in the grain will allow for the inrlllcion of more grain in the conræ~ ,.te mixtures.
At the same time the cost of the ulixLulc;S can be reduced somewhat. The amount of unprocessed oats used in cattle feed can, for example, be reduced by as much as 20%
in comparison to today's level. Grain with a low PBV value will, in combination with protein-rich roughage, give the basis for a good total utili7~tion of the protein in the ration.

A higher AAT value and a lower PBV value can be obtained either by increasing the plupo,Lion of digestible carbohydlaLes or by increasing the l.l~o,Lion of undegraded 30 feed protein. An increased proportion of digestible carbohyd.aL~;s by the gçl~tini~tion of starch is possible. Gel~tinice~l starch will, however, give rise to conceql~ences ~etriment~l to the state and function of the rumen in cattle in high lactation.
Gel~tinic~tirn is, moreover, an expensive solution in terms of the ~Prhni~ es used and 35 the work leLluil~;d.

~ W O 94/07376 PC~r/N 093/00142 In sacco is the best method we have today for e~c~mininE the degr~ hility of food in the rumen. This method is based on a standard procedure (Vik-Mo 1988). The principleof the method is to dete~rnin~ how great a ~-`ùpolLion of the feed disappears from nylon bags that remain in the rumen for dirr.,~;"~ periods of time.

The degradability of protein in the rumen is central in the evaluation of protein for nlmin~nt~.

' Generally the degradation of protein can be described on the basis of Fig. 1 (SAl-l~, 1986).

Easily soluble protein (NPN = non protein nitlugell) which con~tit~lt~s the greatest part I5 of fraction A in Fig. 1, will be converted quickly by the microbes in the rumen. and ammonia will be formed. A high content of NPN therefore also usually gives rise to a high level of (legr~ bility. The conversion of the pure protein that is degradable (fraction B) takes place in several stages. First b~ct~rioenzymes cause the extr7~cel~ r 20 breakdown of the protein into peptideslamino acids. Most of these peptides/amino acids are then absolbed by mic~ es and broken down further to ~mmoni~ inter alia. A
~lopu~lion of the peptideslamino acids will be incol~uldlt;d directly into the microbe body, or will pass out of the rumen unarr~ted and thereby be a source of bypass protein. The degradability of fraction B is deteTminP,d by several factors, but in principle the de~-~hility is lletermin~A by how quickly the degr~ tinn occurs (c = rate of ~egr~tion~ %Ihour) and how long the feed remains in the rumen (k = rate of passage, %Ihour). Both these factors are taken into account, in addition to the size of fraction A and f~ction B, when calcuI~ting the total degr~d~hility. The protein that is not broken down in the rumen or is broken down very slowly co~ e~ fraction D.

In practice, the l1eg~ hility is c~lcul~t~l on the ba~is of two equations given by 0RSKOV & McDONALD (1979). The n~ce~.y i~u~lllaliûn with regard to fraction A and fraction B can be found by means of the in sacco method. A special programme in the St~ti~ti~l Analysing System (SAS) c~lcuI~te~ A, B and c from equ~tion 1. The W O 94/07376 3 2 PC~r/N 093~0142 solutions to A, B and c are later inserted in equation 2 which gives us the effective protein degr~ tion (~PD) in the feed.

Equation 1 p = A + B(l -(e~Ct)) Equation 2 EPD = A + (B*c / c+k) -where: p = s~lbst~n~e washed out over time t A = substance which is degraded imm~Ai~t~ly B = subst~nce which can~e degraded over a length of time o c = the degradability rate of fraction B, %/hour k = rate of passage of feed through the rumen, %/hour (according to the AAT-system, 8%/hour is standard.

i5 The q~l~ntiti~s that are described in comle;Lion with Figure 1 will vary especially between fee~c~h~-ffs but also within the same fee~s~h~-ff. This in turn will have a great effect on the protein value in the feed. The value of the effective protein deg~tion is thus a total picture of what really hd~)enS in the rumen. Today, it is this method that 20 tells us most about how the protein in a fee~lchlff reacts in the rumen and what protein value the fee~lshlff has when given to ~u~ nl~.

The effective protein c~egr~ tinn will depend upon the rate at which the feed passes through the rumen. Figure 2 shows how the degradability is reduced when the rate of passage is increased for control in products 2, 3 and 4.

The rate of passage will vary according to a lu-~bel of conditions, inter alia the feed and the feeding conditions. This in turn may be of co.~ .enre for how the protein reaches ~ the intçstinç. A high feed intake and a high ~ro~ollion of concçntr~te will increase the rate of passage, whilst low digestibility will reduce it.

The ~1e~tion rate may be related to a number of ci~nifi~nt sources of error. Firstly, the rlegr~ tion rate in a feed mixhure will be an average value for several fee-~sh~ffc.
A second i",~o,k~,~ point is that not all the protein which leaves the nylon bag need ~ W O g4/07376 214 S 6 3 2 PC~r/N 093/00142 necec.c~r~y be ~egr~ble in the rumen.

An expander is used during the processing of the grain. There are several kinds of expanders on the market today. ~ighest p,~ s~u-t;; and le",pe,~lure are reached with the expander produced by A. Kahl Nachf, Hamburg, Germany. It is this expander that has been used in the e~ ;...entc and studies.

The expander is in principle constructed like a simple extruder, and the feed is pressed ' past a hydraulicaLly adjustable resistor. The hydraulicaLly adjustable resistor aLlows for a relatively good control of the actual steps involved in the processing. By adjusting the resistor the ~l~s~ule can be made to rise to 80-100 bar. At the same time the te"l~,alure in the feed can rise to 150-190C. However, for practical reasons it will ~s seldom be relevant to use procescin~ conditions over 100 bar and 1~0C. The expansion is a mech~nir~l process in which the desired effect is achieved by means of pressure and friction.

zo ~es~u,~ and Lelllp.,~ are gr~ lly ,ncl~ascd as the feed is pressed fo,~anls towards a slot in the adjustable resistor. The close relation b~ween pl~iS~iUl~ and lell"~e.alure is outLined sch~m~t~ y in Figure 3. The figure also shows that the intense processing lasts for a very short period of tirne. After passing the resistor the pl~sallle falls instantly. At the same time there is a a certain degree of e~cp~ncion in the feed. Ihe fall in ~ ule also leads to the evaporation of moisture and a rapid faLI in temperature in the feed.

The e~pAI~-ler kills the ge....;...lion capacity of the grain and has an effect on the 30 ~egr~rl~bility of the protein and dry matter in feed for rllmin~nt~ This is of great p~`.ti~`~l, c."~ e and rin~n~i~l co,~ nre for the production and use of conce,.l . l~s.

35 The expander can be used inter alia for the production of feed for l~llllh~Anlc~ poultry, pigs and fish.

W O 94/07376 PC~r/N 093/00142 ~
2~4~6~2 An expander placed in the production line prior to the pellet press will produce better pellets and increase the capacity of the pellet press considerably (approx. 20-40%).
Energy con~ Lion during pelleting will normally decrease somewhat. The heat treatment will kill a number of bact~ri~ such as, for example, Salmonella, and thus improve the hygienic quality of the feed. E2P~ ction in the activity of the natural inhibitors in the feed, such as gluco~inol~tçs, will probably also take place. The expander also makes it possible to incrç~ç the mixing in of liquid feedstuffs such as ~at and molasses as they can be added directly in the ~ n~lel.

A large number of studies and ~ e. ;...~ntc have been carried out. The first studies were meant to show whether there were grounds for ~ lming that there is any real effect of pressure and t~l-,pelalul~; on the ~çgr~ tion of protein and dry matter in the rumen.

The samples were tested for the degr~hility of protein and dry matter, and each sample was tested in two cows. Table 1 ~ rlosçs data relating to the samples and the results for effective protein ~çgr~ tion (EPD) and effective degr~ ti()n of dry matter (EDD) in the rumen.

~ W O 94/07376 214 5 6 3 2 PC~r/N 093/00142 Table 1: Values for effective protein ~eEr~ ti~n (EPD) and effective dry matter degradation of (EDD) in the rumen Product Code Pressure (bar) Temp. (C) EPD,~i ETD,%
, .
2 200Control 80.3 71.6 2 125Open exp. 120 61.9 74.5 2 90 5 113-160 86.2 69.2 2 105 30 150-160 86.5 73.5 3 300Control 82.5 77.5 3 40Open exp. 140 72.2 72.2 3 18 40 130 73.3 71.9 3 35 100 165 69.2 71.9 4 400Control 68.4 72.7 4 163Open exp. 40 69.2 71.1 4 135 80-100 112-125 69.7 73.9 4 155 110 125-140 64.5 70.7 The values for EPD and ~1 ~D are an average for two cows. In gçnPr~l, there was little variation between cows.

The results after the procçs~in~ are, as expected, not as marked for feed A for dairy cows (product 4) as for products 2 and 3. This is because feed A for dairy cows is composed of seve~al fee~st ~ . Neve.ll.clcss, it can be seen that the highest pressure and te~.pæ~ have given rise to the lowest protein (leg~rl~tinn. Figures 4-6 give the results from Table 1 in the form of bar rli~gr~ms.

In sacco e,~yt;,llllents These ~ ;---çntc were carried out in order to dete~nine the effect of the expander on protein degradability (NGP) and the clegraf~hility of dry matter (NGT).

W O 94/07376 PC~r/N 093/~0142 ~
214~632 The following six raw m~t~ were sP~P~tecl ground barley, rolled barley, ground oats, rolled oats, extracted soybean meal and extr~ t~ r~pesfxd meal. In addition, four simple conce-t~te llPi~ulGs were made of these raw m~tt-n~ (mixed feed 1), with ground and rolled grain of both low protein content (17% crude protein) and highprotein content (35 % crude protein).

A total of ten samples were processed in the expan~ at three different levels ofpres~urG and lGlllpelalu~G as shown in Table 2. -~`

A sample was taken at each processing level to be used in the in sacco determination of the NGP and the NGT.

s A total of 35 samples were tested using the in sacco method. Three cows per sample were used as parallels for the individual raw m~teT i~l~ and the mixed feeds 2, whilst two cow were used for mixed feeds 1.

20 The results were as follows:

Te~ )e~ lG and pressure Table 2 shows an overview of the ~ e~ , and pressure reached at the dirr~Glll levels of processing which have been coll~ ed.

~ W O 94/07376 214 5 6 3 2 PC~r/N 093/00142 Table 2: An overview of tel~peldlule and pressure at dirrel~nt levels of tre~tment for the dirr~ l products , Process.. Mild Medium Intense -. Temp. Press. Temp. Press. Temp. Press.
C bar C bar C bar Feedstuffs Ground barley 128 23 155 60 160 120 l3 Rolled barley 135 24 156 60 168 100 Ground oats 131 35 158 50 169 100 Rolled oats 130 45 - - 145 100 Soybean meal 129 44 155 80 173 lO0 Rapeseed meal 132 40 155 50 190 100 Mixtures (1):
Low prot., rld. 128 30 158 60 165 90 Low prot., grd. 130 33 155 51 163 94 High prot., rld. 130 25 155 45 176 100 High prot., grd. 128 32 157 50 172 100 20 The Lellll)e.dLul~ and ~ , were l--e~sul~d during the passage of the feed through the adjustable resistor in the exr~n~ier. During mild ~,rocecsi.~ an attempt was made to keep the Le.l.p~ ldlWC; at approx. 130C. It can be seen that this telll~lalule was reached at dirre;lc;nl ~I~S~ulc;S. A Lel..peldLu.~: of 155C was desirable during the medium level 25 of processing. With soybean meal, however, the l,.cs~u.c; had to be increased.

During intense processing, no limits were made on the production process. The aim here was primarily the highest ~ e~ ~ possible within the capacity of the equipment.
For most of the fee l~..rr~, a limit was reached bt;lween 160 and 180C and at a pl~eS~ule of 100 bar. When processing rolled oats, the lelllpeldL~ did not Ase beyond 145C, even at high pressure. In the case of r~peseed meal, the ~elllp~ldlule reached 190C.
.

Degradability of protein (NGP) 35 Table 3 shows a total overview of protein legr~ hility (NGP) iul the in sacco ent.

W O 94/07376 PC~r/N 093/00142 ~
2145~32 Table 3: Degradability of protein (NGP), rate of passage 8 %/hour Protein de~radation. %
Process.......... Unprocessed Mild Medium Intense Feedstuffs:
Ground barley 71.7 57.1 54.4 54.5 Rolled barley 67.4 52.7 48.5 48.5 Ground oats 89.0 67.2 59.6 . 46.5 Rolled oats 87.2 77.6 ~ 69.7 Soybean meal 62.4 52.4 45.3 ~- 48.5 ~pesee~ meal 63.8 63.2 59.9 55.9 Mixtures (1):
Low prot., rld. 67.3 51.6 Low prot., grd. 67.5 48.8 High prot., rld. 63.3 54.5 High prot., grd. 61.6 58.1 Mixtures (2):
High prot., grd. 59.9 49.8 Low prot., grd. 66.3 47.4 1) Mixtures which have been l,rocessed as a mixture in an expander.
20 2) Mixtures Co~ g fee~ ff~ that have been l"ocessed sep~ ely in an expander and later mixed m~nll~lly to form a mixture.

It can be seen from this table that the protein degra~hility is reduced for all feedstuffs that have been p~cessed in an P~p~n~Pr. This applies ecreci~lly to the grain products (barley and oats) and the ll~ib~lules with a low protein content (a lot of barley and oats).
In these products the NGP is reduced by 15-20 %-units. The reduction for ground oats is a total of 33.5 %-units. There is also a ~ub~u.Lial reduction (10-15 %-units) in the case of soybean meal and the protein-rich ~ , Co..~ g rolled grain. The reduction 30 in ~legr~ hility is smaller for ~ ~s~ meal and the protein-rich mixture cont~inin~
ground grain.

It can be seen from Table 3 that in general there has been little to be gained in terms of 35 reduced (legr~ hility by raising the ~e~ c~ above 130C and the pressure over 40 bar. During the intense pr~ces~ing there was, in several cases, a tendency towards a ~ W O 94/07376 214 5 6 3 2 PC~r/N 093/00142 neut~lizing effect. However, oats, and to some extent rapeseed meal, are the exception.

Experiments with processed barley Table 4 shows the in sacco iegr~bility of protein in the rumen, and the digestibility of dry matter, protein and nnde~ ed protein in the intestine measured by using mobile nylon bags in unprocessed and FK-pl~cçc~e~ barley (the term F~ procescing is used to mean the e7cr~n~ion of feed in a Kahl expander). The content of AAT and PBV are c~lcul~ted on the basis of 41 % digestibility of fibre and 92 % digestibility of nitrogen-free l3 extracts (NFE). All studies and c~ ti-ns have been carried out in accordance with Nordic glli~lelines in the AAT/PBV system in the Department of Animal Science (IHF) at the Norwegian Agricult~ University. The conditions during procecsing are approx.
130C and 30 bar for all processed samples in Table 4.

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t2 E , ~ d ~ ~ :., 2 ~ '~ r ~ ~ ~r_ rA ~ ~ ~ 00 E~ 3 ~ ~ ~ ~ c z ~ ~ ~ ~ m W O 94/07376 21~ 5 6 3 2 PC~r/N 093/00142 The protein values in unprocessed barley in Table 4 are very similar to the values in the new fee~tl~ff table. The ~K processing of barley has reduced the NGP by 18 %-units from 68 % in unprocessed barley to 50 % in processed barley. The total digestibility of dry matter and protein measured by using a mobile nylon bag is virtually unaffected by the ~ùcesshlg. The estim~ted digestibility of the undegraded protein (FINP) has been increased by 7 %-units, from 79æ in u,~pl~cessed barley to 86% in processed barley.
The AAT value in barley is increased by 18 grams per kilo of dry matter from 104 in unprocessed barley to 122 in processed barley. At the same time the PBV value has ' been reduced from -43 grams per kilo of dry matter in unprocessed barley to -66 grams per kilo of dry matter in processed barley.

When c~lc~ ting the AAT and PBV, it is ~s~med that the processing does not have any particular effect on the content of digestible carbohydrates. Results from digestibility tests on sheep fed with processed concellLldte mixtures give no indication of an increase in the digestibility of carbohydld~es due to the procecsing.

20 The experiments show a clear effect on the NGP and the estim~t~l protein value when barley is p~cessed at about 130C and 30 bar. The processing conrlition.~ at 125-130C
and 30 bar seem to be a lower critical limit for ob~i~ g the AAT and PBV values in barley as given here. Gentler ~uces~ g by means of an çxr~nrler, and even normalpelleting, gives some reduction in NGP, but the effect is nonetheless small in comparison with the aforçm~ntioned FK ,ul~cessu~g at 130C. There seems to be little to be gained from processing at tempeldlulbs above 130C in terms of a further increase in the protein value.

30 Pelleting FK-processed barley does not cause a further reduction in the NGP. The effect on the NGP is the.-,fulc; due to urc;s~ul~ and Ir~ t; tre~tm~lt given in the e~dllder and not the pellPting.

~5 W O 94/07376 PC~r/N 093/00142 ~

Results of the expander ~ e-iments Table 5 shows the effect of processing on the NGP and AAT values in barley and oats, and also the NGP in mixtures. Six portions of barley and five portions of oats were tested. The in sacco degr~ tion of protein and dry matter has been determined for all portions, whilst the AAT value has been c~lcul~ted for fi~ portions of barley and two of oats. In the case of mixtures, the variation in protein content makes it difficult to compare the AAT value. The NGP in six ~ s with a large quantity of barley and 13 oats has nevertheless been included.

Table 5: The effect of expander p.~,cessil1g on the degradability of protein in the rumen (NGP) and content of amino acids absorbed in the intestinP (AAT).
ArhhmPtic mean and range of variation.

Ullvr~cessed E~r~n-led N Mean Variation N Mean Variation NGP. %:
Barley 6 68 66-72 6 48 43-53 Oats 5 88 85-91 5 67 61-72 Mixture 6 72 65-77 6 62 49-75 AAT. ~/kg:
Barley 5 93 91-95 5 112110-113 Oats 2 59 59-59 2 81 75-87 The exr~n~Pr tests show the following:

- Based on the average of six portions, the NGP is reduced by 20 %-units in barley that has been e~rr~n~e~

- Based on the average of five polliolls, the AAT is increased by 19 grams per kilo in barley.

- Based on the ~verage of five por~ions, the NGP is reduced by 21 %-units in oats W O 94/07376 PC~r/N 093/00142 21~S632 that have been e~r~n l~

- Based on the average of two portions, the AAT is increased by 22 grams per kilo in oats.

, - Based on the average of six portions, the NGP is reduced on expansion by 10 %-units in mixtures. When there is 15% protein in the mixture, this concti7h~7~es approx. 11 grams AAT per kilo.

- St~ming barley causes a great reduction both in NGP and DDG

The digestibility of raw m~teri~71c and IlPL~u~s is described below.
7s Digestibility tests with sheep. mixtures (El) Table 6 discloses the digestibility of dry matter, protein, n,llugel~-free extracts (NFE), fibre and fat in unprocessed and exr~nrled con~e~ , tes.

W O 94/07376 PC~r/N 093/00142 ~

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Wo 94tO7376 214 5 6 3 2 PCr/NO93/00142 The digestibiIity tests show the following:

- Expansion does not have a system~tic effect on the digestibility of dry matter and protein.

- Expansion causes a small tendency towards increased digestibility of NFE.

- The digestibility of fibres and fat is reduced by approx. 15 %-units and approx. 3 13 %-units, l~;~e;Li~ely, by expansion.

Table 7 shows the digestibility of dry matter, protein, nitrogen-free extracts (NFE), fibre ~5 and fat in a mixture cont~ining Soy-Pass and a mixture cont~ining e~cr~ndecl barley and oats.

WO 94/07376 PCr/NO93/00142 ~

z~5F~2 20 Table 7: The digestibility of dry matter, protein, nitrogen-free extracts (NFE), fibre and fat in a mixture cont~ininE Soy-Pass and a mixture conr~ining expanded barley and oats.

N Dry matter Protein NFE Fibre Fat M 183. D79:
Soy-Pass 3 81.3 82.7 86.0 47.8 99.1 Ei~r~n~ 3 83.6 86.7 86.4 67.6 95.3 These digestibility tests show the following:

- A tendency towards greater digestibility of dry matter, protein and in particular fibre in a Co~ e mixture co.. l~;.. ;ng barley and oats in comparison with a mixture cont~ining Soy-Pass.

- No dir~.~nce in the ~iigestihility of NFli.

- A t~ndell~;y towards lower ~ estihility of fat in the exr~n~Pd mixture.

Tntestin~l rli~e5tibility of barley. oats and n~ ul~s (El) Table 8 shows the intPstin~ pstihility of dry matter, protein and lln~Pgr~riPd protein (UDP) measured by using a mobile nylon bag, and the in sacco d~Pgr~d~bility of protein (NGP) for barley, oats and mixtures.

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WO 94/07376 ~ PCr/NO93/00142 2~4$~32 22 The i,~ digestibility tests show the following:
1 ~'' ..
- The degradability of protein in barley, oats and mixtures is on average reduced by 15, 22 and 11 %-units respectively by exp~ncion.

- The digestibility of dry matter measured by means of a mobile nylon bag shows, at the same time, a tendency tOwalds an increase of 1, 3 and 3 %-units respectivelyon expansion.

- The digestibility of total protein measured by means of a mobile nylon bag shows no or only a slight tendency to increase on exp~ncion.

- Due to a reduction in the degr~hility in the rumen and small or no change in the total digestibility of protein, the digestibility of ..~.1P~.~.ded protein increases subst~n~i~lly in all kinds of fee~l~lllrr~ The increase is especially great for oats.

- The increase in digestibility of INP in barley, oats and mixtures is 9, 27 and 6 %-units, respectively.

Expansion versus steam boiling In Table 9 a co".l~ . ;con is made b~weell barley that has been e~p~n~e(l and barley that has been steam boiled (the SLR method) to ~ e the effect on the in sacco degr~d~hility of protein in the rumen and the i~ Sl;~ digestibility of dry matter, total 30 protein and llntl~ d proteiri measured by means of a mobile nylon bag.

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WO 94/07376 PCr/NO93/00142 ~, 21~5~32 The results show the following:

- Steam boiling reduces the NGP in comp~ricQn with expansion.

- There is no difference bc;Lween the two processing methods in terrns of the digestibility of dry matter.
.~ .
- There is a tendency towards a reduction in the-digestibility of protein on steam boiling (ie, the ~lupo~tion of indigestible protein increases).

- Due to the low NGP in steam-boiled barley, steam boilng has virtually no effect on the digestibility of the INP, although the plupûllion of in~igestihle protein has 15 increased a little.

- The values of the NGP and the total digestible protein in steam-boiled barley are the lowest that have been measured for barley hitherto.

De~radability in raw materials versus degradability in a ulixLul~ of raw materials In order to see the relation bc;~w~n the ~egra~l~bility of protein in raw m~t~ri~lc versus the degradability in a Illi~Lul~ of raw m~tl~ri~lc, one must take into account how great a plu~oliion of the protein in the llli~ Lulc; or-~in~tes from the individual raw material and multiply this by the relevant NGP. If protein from barley co..c~ s 50 % of the protein in a mixture, a reduction of, for example, the NGP in the barley of 20 %-units will reduce the NGP in the Illib~Ul~C by 10 %-units.

In Table 10 the NGP in a processed and u~lucessed llP~L.Il~, with a high and lowprotein content lcslJe~;Li~ely, is cal~ulated. Furthermore, the calculated values are compared with values found in in sacco tests.

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W O 94/07376 PC~r/N 093/00142 ~
~14~32 - This shows that the ~leg~d~hility of protein in the mixture, calculated on the basis of the NGP in the raw m~teri~lc, is on average 3 to 5 %-units higher than measured values for NGP.
s The consequences of expandin~ conce.~,.tes for cattle ~ `
The potential for saving on the costs of raw m~teri~lc~y e~r~n~ling concentrates for cattle under these conditions is between NOK 50 million and NOK 100 million per ' annum based on today's prices, ~epenr~ing upon the availablity and need for altemative protein-rich raw m~tP.ri~lc. This is equivalent to 4-8% of the total costs for raw materials in production IllibLLul~;s for dairy cattle.

~5 Mixed feed for dairy cattle in the AAT systems The introduction of the AAT system will give rise to new conce~ ,tes for cattle.Hitherto, it has been ~nticir~t~d that it will be ~-torçc~ ~ . y to have four to five mixed feeds for dairy cattle in the AAT system.

- Coarsely ground grain mixtures - Production IIPL~lUl~;;S
* 90 grams AAT per feed unit miL~ (FEm), low PBV value ("Cowfeed" low PBV) * 90 grams AAT per FEm, high PBV value ("Cowfeed", high PBV).
* 95-105 grams AAT per FEm, high AAT value ("Cowfeed", high miL~cers).

AAT col-ce ~ s The need for AAT in milk production is approx. 90 grarns AAT per FEm (85 grams AAT per kilo at 94 FEm per 100 kg) when the cow is fed with energy according to the norm. It is therefore natural that in the production of mixed feeds for dairy cattle one aims to meet this need "Covfeed", low PBV and "Cowfeed", high PBV). Varying PBV
values in the concP~-t~ es will make it possible to utilize the protein in the total ration in the best way possible.

WO 94/07376 21 ~ 5 6 ~ 2 PCr/NO93/00142 In cases of high yield and low energy relative to the norm, the need for AAT per FEm increases. Ideally this must be topped up with a protein conce~ dte. In everydayfeeding there are relatively strong desires to be able to use just one con~e.,l,~le mixture.
This mixture should cater as much as possible to the high yield cows in the herd. What AAT level this mixture should have is iifficult to determine now, but from 95 to 105 grams AAT per FEm covers the range of variation.

It is difficult to say how great the qu~ntiti~S of feed for dairy cattle within Ihe relevant ' AAT levels will be. The total sales of feed for dairy cattle in 1990 amounted to approx.
580,000 tonnes. If it is assumed that the ~ lw~ with 90 grams AAT per FEm coversthe volume of feed A for dairy cattle and 10%-feed for dairy cattle, and the mixture cont~ining 95-105 grams AAT per FEm covers the volume for 15 %-feed for dairy cattle, 15 we will get the following figures for estim~t~d quantity:

Production mixture 90 grams AAT per FEm: approx. 406,000 tonnes Production mixture 95-105 grams AAT per FEm: " 116,000 tonnes Today, coarse grain for l~ and 10%-feed for dairy cattle contain too little AAT
per FEm for them to be ,~;co.. en~ed alone for dairy cattle. Similarly, the AATcontent in feed A will normally be on the low side. The 15 %-feed for dairy cattle will normally provide a high enough AAT supply, but at the same time the high crude protein content will give a high PBV value and a relatively high price.

When introfin~ing the AAT system, it is of great i~ ce to find ways of increasing the AAT content in con~ es. In this context, exr~n~ion would seem to be of great 30 interest.

WO 94/07376 PCr/NO93/00142 _~
21~5~32 Examples of optimi7~tion The additional costs involved in expansion processing are set at NOK 4 per 100 kilos for barley and oats. Otherwise the price of raw materials is as given in today's price list.
Table ll shows examples of op~ tion of consentr~te mixtures with and without expanded barley and oats. It is ~csllmed that the exr~ncion process increases the AAT
content from 90 to 110 grams AAT per kilo of barley. For ats, it is ~ccllmed that AAT
is raised from 63 to 82 grams per kilo by the l.,ocessih~g. Apart from the expansion and subsequent increase in the AAT value in barley and~oats, the conditions in the ' calculations are equal. The op~ icns have been made in format.

By using expanded barley and oats, the crude protein content in the concentrate mixtures can be reduced con.cid-Pr~bly, without any reduction of the AAT value (Table 11). The PBV content is Cimlllt~np~ously reduced subst~nti~lly through the reduction of the crude protein content. When using ~ e~l barley and oats, there is no need for herring meal or soybean meal in the mixture at 85 and 90 grams AAT per kilo. At l00 grams per kilo, 3 % herring meal is included. Without a supply of exr~n~l-P~l barley and oats, 20 there will however be a need for 3 % herring meal at 85 grams AAT per kilo. At 90 and 100 grams AAT per kilo there will also be a need for 6.6% and 17.7% soybean meal, ~spec~ively. At the same time it can be seen from the table that the grain content, as the total of barley, oats and bran, ~h~l~ses on the use of exr~n~ied barley and oats.

Negative PBV values of -30 to -40 grams per kilo of con~e~ te are large. If one is to l~collll.lPn~l e,~ nd~ col-~e~ te with such low PBV values, one must be certain that the crude protein content in the roughage ration is s..fficiPntly high. If the roughage contains too little protein, it is clear at the same time that there are ch~apel ways of 30 incr_asing the PBV in the ration than using herring meal and soybean meal. The use of urea may be one ~lt-prn~tive. The addition of fish silage to the con~ te may be another ~ltPrn~tive.

35 By using expansion, the cost of raw m~teri~l~ can be reduced by NOK 15.8 per 100 kilos, at 85 grams AAT per kilo (Table ll). At 90 grams AAT per kilo, the ~ WO 94/07376 21 4 5 6 3 2 PCr/NO93/00142 corresponding figures are NOK 25.2 and NOK 35.6, respectively, per l00 kilos of conce~t~te. The significance of expansion processing is thus greatest at a high level of AAT.
. .

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~1~ WO 94/07376 21 4 5 6 3 2 PCr/NO93/00142 Expansion versus special quality protein-rich raw materials Figure 7 shows the cignifi~nce of exp~ncion in comparison with an alternative method for raising the AAT level in con~entr~tP. mixtures. The alternative method is the use of special quality herring meal (compressed meal cake) and special quality soybean meal (Soy-Pass). In the calculations the price of coml,lcssed cake is set at a price equivalent to that of low l~ e.~lulc (LT) herring meal. We have added NOK 25 per 100 kiIos to the price of Soy-Pass in relation to oldinal y extracted soy~e~l meal.

The use of special quality raw m~tPri~lc reduces the costs of raw materials with an increasing AAT level relative to ordinary raw m~tPri~lc. The lowest raw material price is still found when using exr~n~lP~ raw m~tPri~lc, but the dirr~-.lces in favour of the 5 expander are now conci~Pr~hly reduced. With AAT values above 9.5 % ~AT per kilo, the combination of expansion and special quality protein-rich fee~ ffs give the lowest raw material costs.

20 The financial consequences of e~l,an~ioll Figure 8 shows the dirr~,lc.~ce in raw m~tPri~l costs in Nol~egian kroner per 100 kilos between expansion and non-expansion with an increasing AAT level. The major mixed feed for dairy cattle is c;~l~e~ed, as mentioned, to be around 90 grams AAT per FEm (8.5 % AAT per kilo in Fig. 7). The reduction in the raw m~ten~l costs is then NOK
9 and NOK 16 per 100 kilos of co.~re.~ e respectively, with the lowest figure when special quality ylo~in~eQus raw m~tPri~lc are supplied. With a total volume of 406,000 tonnes, the potential saving in raw m~tPri~l costs is NOK 35 million and NOK 65 ~ million l~e.;li~/ely (3-6% of the raw m~ten~l costs).

Corresponding c~lc~ tions for 100 grams AAT per FEm with a volume of 116,000 tonnes gives a l~oL~ Lial saving of raw m~te.ri~l costs of NOK 15 million and NOK 35 35 million (6-12% of the raw m~tP,ri~l costs).

W O 94/07376 3 2 PC~r/N 093/00142 This shows that the potential saving in raw m~teri~l costs by e~r~n~ling concentrates for cattle under these conditions is between NOK 50 million and NOK 100 million per annum, opelaLillg with today's prices, ~iep~on~ing upon the availablity of and need for alternative protein-rich raw materials. This is the equivalent of 4-8 % of the total raw material costs in production mixtures for dairy cattle.

Claims

Claims 1.
A method for processing grain for protection of protein against degradation in the rumen, c h a r a c t e r i z e d i n that whole or preprocessed grain is fed into an expander where the temperature and pressure are gradually built up when the grain is mechanically pressed forwards towards an adjustable resistor in the outlet of the expander, wherein A. the temperature measured on the passage of the grain past the adjustable resistor shall be between 80 and 190°C and preferably between 110 and 160°C, B. the pressure against the adjustable resistor shall be between 10 and 150 bar, and preferably between 30 and 40 bar.

2.
A method according to Claim 1, c h a r a c t e r i z e d i n that feed, feedstuffs or mixtures of feedstuffs and whole or preprocessed grain are processed.

3.
A method according to Claim 1 or 2, c h a r a c t e r i z e d i n that an expander is used which provieds a basis for the processing of grain according to the above mentioned Claims 1 and 2.

4.
Processed grain, c h a r a c t e r i z e d i n that it is produced by the method according to Claims 1 to 3.

5.
Processed feed, c h a r a c t e r i z e d i n that it is produced by the method according to Claims 1 to 3.

6.
Processed feedstuff, c h a r a c t e r i z e d i n that it is produced by the method according to Claims 1 to 3.

7.
Processed mixed feed, c h a r a c t e r i z e d i n that it is produced by the method according to Claims 1 to 3.

8.
The use of an expander for processing grain.