Note: Descriptions are shown in the official language in which they were submitted.
lO~G;~36
EXTRUSION PROCESSED STARCH-NPN RUMINANT FEED
AND METHOD OF PRODUC ING SAM:E
This invention relates to a re~cted, p~lat~ble, non-
toxic, processed food product for ruminant animals as well as
to a process for producing the product wherein the feed compo- -
sition contains modified, interacted energy and protein-produc-
ing constituents derived from a selected class of starch-bearing
materia.ls and a nonprotein nitrogenous (NPN) substance respec-
tively. More particularly, it is concerned with such products
which include a minor proportion of a lipid material such as
an anlmal fa.t which unexpectedly serves to greatly facilitate
cooking, processing and handling of the feed without a concomi-
tant decrease in other desirable feed properties such as the
microbial protein synthesis level thereof.
It is known that nonprotein nitrogenous substances
such as urea may be incorporated into feed for ruminants as
replacement for protein sources therein. Such added urea or
other NPN source ls first degraded by rumen microorganisms to
ammonia and the latter is then converted to microbial protein.
A maJor portion of such microbial or bacterial protein is then ;.
enzymatically degraded to amino acids in the small intestine
of the rumina.nt where, after being absorbed, they are available
for use by the animal. As will be readily apparent, NPN supple-
~entation of ruminant feed is extremely attractive from an eco-
nomic standpoint, since relatively inexpensive materials such
as urea can be fed in place of costlier natural protelns coming
from traditional sources such as cereal grains or the like.
In practlce, attempts at directly admixing raw urea
and ruminant feed to supplement the protein level of the latter
have met with a number of serious obstacles which have severely ~-
limited use of conventional NPN feeds. For example, palatability
(Dkt. #15499) ~ :
3.046~36
and toxicity problems inherent in the addition of urea to cereal
grains and other conventional feeds such as grasses, roughage
and vegetable starches have drastically limited the amount of
NPN that can be mixed with the normal feed ration. Generally,
no more than about 4~ by weight of urea can be directly added
to raw ruminant feed compositions without undesirable results,
because of toxic reactions, inefficient utilization of the urea,
segregation of the constituents, unpalatability of the feed, and
the tendency of the mixture to form a solid block by virtue of
the hydroscopic nature of urea.
0~ extremely successful response to the problems out-
lined above is disclosed in U. S. Patent No. 3,624,489. In par-
ticular, this patent discloses that the amount of NPN added to
ruminant feed can be greatly increased without attendant toxicity
or unpalatability by combining NPN and a starch-bearing material
such as corn and subjecting the admixture to high levels of heat,
agitation, pressure and shear in the presence of sufficient water
to assure gelatinization of the starch material. This process
i8 advantageously carried out in an extrusion cooker and has the
effect of producing a modified, reacted feed product which is
characterized by an increa~e in the level of derivable bacterial
protein along with a protein assimilability efficiency significant-
ly greater than could be obtained in any simple ungelatinized
mixture of the starch-bearing material and NPN source. Moreover,
the reacted and combined constituents of the feed products of
U. S. Patent No. 3,642,489 have been found to be hydrolyzable with-
ln the rumen of a ruminant anlmal at æufficiently similar rates
to substantially increase the conversion of ammonia from the NPN
constituent into microbial protein without significant resultant
toxicity. The latter is important since rapid ammonia release
in the rumen can lead to inefficient protein conversion, loss of
ammonia through the elimination processes of the animal, and an
--2--
,
336
increase in the chance of toxicity to the ruminant.
Although NPN-supplemented feed products produced ~-
in accordance with the methods of Patent No. 3,642,489 have
experienced significant commercial acceptance on a worldwide
basis, certain problems lnherent in the cooking, processing
and handling thereof have remained, especially when food sources
such as tuber starches, waxy starch materials or cereal starches
with low levels of fat are employed, or when the starch source-
urea ratios of the feed are on the order of 4 to 1 or greater.
In such cases, the tendency of the starch-NPN admixture during
extrusion cooking to surge and build up ad~acent the extrusion
die can make it difficult to control processing conditions for
maximum conversion of the raw, ungelatinized starch and raw urea
to a desirable starch-controlled-urea product exhibiting enhanced ~
levels of ammonia conversion when subjected to rumen micro- -
organisms. For example, a characteristic of tuber and waxy
starch-urea products is that they are plastic and adhesive and
if cut at the face of the extruder die ln the normal manner, the -
- cut products will not separate from one another but will have a
tendency to adhere to a previously cut segment or segments thus
forming a continuous length of hot, plastic, sticky material
that tends to foul the cutting knife and its working parts. As
can be appreciated, this condition often results in a failure
to adequately process the feed due to the inability to efficiently
handle the extruded material as it emerges from the cooker.
It will also be recognized that any attempted solu-
tion to the problems alluded to above must not appreciably af-
fect the amount of bacterial protein which can be synthesized
by the ruminant from the feed product. In addition, any ex-
pedient employed for solving such problems must not adverselyeffect the breakdown rate of the NPN substance and carbohydrate
material or otherwise render the feed product toxic or unpalatable
~0'~336
to ruminants such as cattle, sheep and goats.
It is therefore the most important object of the
present invention to provide a cooked, gelatinized, palatable,
nontoxic, starch-NPN ruminant feed product and method of pro-
ducing same which is characterized by an unexpected ease of
cooking, processing and handling through the addition of a
minor amount of a lipid material incorporated into the feed
constituents prior to extrusion cooking thereof; the resultant
feed is thereby capable of being efficiently cut, dried, crushed,
stored and fed, and the feed has been found to release ammonia
when sub~ected to rumen bacterial attack in a manner essen-
tially equivalent to that of standard reacted starch-NPN feeds
which are free of added lipid, such that the palatability, toxicity
and ammonia release characteristics of the feeds hereof is not
adversely affected.
Another important object of the invention is to pro-
vide a starch-NPN feed product and method wherein the feed con-
tains an amount of lipid suvh as an animal or vegetable fat which
serves to synergistically maintain the microbial protein synthesis
level of the feed when the latter is sub~ected to rumen micro-
organisms at a level approximately equal to or even better than
the protein synthesis levels of otherwlse identical products
free of added lipid, even though the e~tent of starch damage
and gelatinization within the feed is lessened by virtue of the
lipid addition; thus, the feed products hereof are eminently
suited to serve as high protein ruminant feed notwithstanding the
fact that they are much easier to cook and process than many
prior feeds utilizing starch-bearing sources known to present
processing difficulties.
Another ob~ect of the invention is to provide a re-
acted starch-NPN ruminant feed product which includes an amount
of added fat from about 0.25 to 10~ by weight based upon the
- -
336
starch-bearing ma.terial, in order to control the tendency of
some starch-bearing materials (such as tuber starch materials,
low fat cereal starch materials and waxy starch materials) to
build up ad~acent the extruder die and emerge therefrom as a
hot, plastic, adhesive mass which is difficult to cut and dry
or otherwise further process.
A still further object of the invention is to provide
a high protein equivalent starch-NPN ruminant feed product and
method wherein lipid addition permits extrusion cooking of the -
feed constituents in the presence of greater quantities of
moisture than heretofore practical with feeds of high protein
equivalent values, so that the resultant feed products exhibit
unexpectedly high levels of microbial protein synthesis while
nevertheless retaining desira.ble handling characteristics.
- The feed products of the present invention are ad- ` -
vantageously processed in an expansion cooker such as a cooking
machine of the extruder type. For purposes of example, the
followlng discussion will center around commercial scale ex-
truders of the type sold by the Wenger Manufacturing Company.
Premixed sta.rch-bearing material, water, a NPN substance and
lipid material are admixed and introduced into the elongated
extrusion chamber of the cooker is provided with a primary ex-
trusion head and an extruder cone terminating in an apertured
extruæion die. An auger conveyor of variable pitch iB situated
within the extruder so that the feed constituent6 are conveyed
along the length of the extruder while being subjected to high
presæure, shea.r and compressive force.s. Heat is conventionally
supplied by way of steam jackets surrounding at least the extru-
sion head and cone sections of the cooker. In addition, many
such extruders are provided wi~h preconditioners including a
hopper for introducing the feed constituents into the unit and
an elongated zone provided with a central auger, discontinuous
10~36
conveyor flights or paddles for moving the material toward the
communicating inlet of the primary extruder section. A further
description of an exemplary extrusion cooker suited for use in
the methods of the present invention can be found in the dis-
closure of U. S. Patent No. 3,642,289. It is to be understood
however, that other types of extrusion cookers, such as those
sold by the Anderson, I.B.E.C., Company can also serve the pur-
poses of the present invention.
Feed constituents added to an extruder of the type
described are continuously moved through the machine while be-
ing sub~ected to agitation, heat, high compression and shear so
that at least a portion of the starch-bearing food material is
disrupted and allowed to intermingle and react with the NPN
source to provide the reacted ruminant feed compositions hereof.
At the extrusion end of the cooker the pressure on the product
is suddenly reduced to atmospheric so that an expanded and gelati-
nized feed product results.
In general, the method of the present invention involves
admlxlng a predetermlned quantlty of an edlble, ungelatinized -
starch-bearing food material with sufficient water to perm~t
gelatlnlzation thereof and a nonprotein nitrogenous substance
characterlzed by the property of being hydrolyzable to ammonia
by ruminant microorganisms. Finally, a minor proportion of a
lipid materlal sufficient to facilitate cooking and subsequent
handling of the feed product is added to the initial admixture
and the latter is thoroughly mixed. The second step of the method
invol~es contlnuously movlng the mixture ~nto and through a treat-
ment zone (e.g., an extrusion cooker) while agitating the admix-
ture and sub~ecting the same to a source of heat and high pres-
sure compression and shear forces for a period of time sufficientto disrupt and gelatinize at least a portion of the food material
and thereby permit reaction thereof with the NPN source. ;
-6-
: ~
la4~336
Lipid addition has been found to make the cooked,
reacted end product much easier to handle, cut and further pro-
cess as needed. In addition, it has unexpectedly been found
that such lipid addition serves to synergistically maintain the
microbial protein synthesis level of the feed at levels approxi-
mately equal to or in some cases greater than the levels of
otherwise identical feeds free of added lipid. As can be ap-
preciated, addition of a lipid (such 8S an animal fat for example)
would predictably have the effect of drastically lowering both
the extent of starch disruption and gelatinization, and concomi-
tantly the bacterial protein level of the resultant feed, since
the fat should provide a "lubrication" of sorts causing the un-
reacted admixture to pass through the extruder without sufficient
starch disruption and gelatinization. This should in turn re- -
sult in lowered protein synthesis when the feed is subjected to
rumen microorganism~, since the extent of such synthesis is in
general directly related to the degree of starch gelatinization
To the contrary however, actual test results have
demonstrated that the predlcted results do not obtain, but rather
the resultant feed in general maintains the desirable high levels
of derivable microbial protein needed for economically feasible
products. Although not completely understood, it is believed
that lipid addition in some manner synergistically acts on the
other feed constituents to yield the results alluded to above.
Moreover, lipid addition in some instances permits extrusion
cooking of the feed constituents in the presence of greater
quantitles of water than has heretofore been feasible, and
thls is likewise believed beneficial in maximizing the level
of protein synthesis derivable from the feed. For example,
while it has heretofore not been practical to process a starch-
NPN ruminant feeds of economically attractive protein equiva-
lents in the presence of moisture levels greater than about 30
~046336
by weight, addition of a minor amount of a lipid to the feed
constituents permits a total water fraction (derived from added
water and the native moisture present in the feed constituents)
during extrusion cooking to be at a level of from about 4 to
50~ by weight, more preferably at a level of from about 10 to
35~ by weight, and most preferably from about 15 to 25~ by weight.
Starch-bearing materials particularly adapted for use
in the present invention may be selected from the group consist-
ing of corn, sorghum, millet, cassava (tapioca), potatoes, yams,
rice, corn starch, potato starch, wheat starch, arrowroot,
turnips, rutabagas and mixtures thereof. Although carbohydrate
starch-bearing materials other than those listed above can be
processed with additional lipid in accordance with the invention,
many of such other products contain sufficient natural lipid or
otherwise can be handled by known means. In addition, it will
be clear that certain samples of the listed materials may need
greater or lesser quantities of added lipid depending principally
upon the indivldual characteristics and makeup of the samples.
The ~tarch-bearing materials are preferably in comminuted form
(e.g., grain ~hould be ground in order to give an average par-
ticle size of about 450 microns or less) so that water and/or
steam blended with the mixture in the preconditioning or ex-
truder zone of the extrusion cooker ls brought into intimate
contact with the starch-bearing material to facilitate gelatini-
zation thereof.
A wide variety of NPN substances can also be employed
in the present invention, with the preferred sources including
urea, uric acid, biuret, ethylene urea, ammonium phosphate, am-
monium bicarbonate, ammonium carbamate, ammonium citrate, am-
monium formate, ammonium acetate, ammonium propionate, ammoniumlactate, ammonium succinate, ammonium fumarate, ammonium malate,
diammonium phosphate, propionamide, butyramide, formamide, aceta-
--8--
336
mide, isobutane diurea, dicyanodiamide, creatinine and creatlne.Urea is the most preferred NPN source however, because of its
relatively low cost and high nitrogen content.
Similarly, a wide variety of lipid materials can be
utilized to good effect in the invention, but preferred lipids
are taken from the group consisting of animal fats, animal greases,
vegetable fats, vegetable oils and soybean lecithin. One parti-
cularly preferred lipid source is a mixture of animal and
vegetable fat sold under the trademark HEF by the Proctor and
Gamble Company of Cincinnati, Ohio.
Lipid in the form of animal and vegetable fats is
preferably added in liquid form to the starch and NPN substances
prior to extrusion cooking. In this connection it has been found
that a lipid addition of from about 0.25 to 10% by weight meets
the requirements of the present invention, and more preferably
the added lipid ranges from about 0.5 to 6.0% by weight. Most
preferably, the lipid addition is from about 0.5 to 4% by weight,
all figures based on the weight of the starch-bearing carbohydrate
substance.
Although the ratio of NPN to starch-bearing material
may be varied as dictated by price considerations, availability
of constituents, processing requirements, and ultimate end use
parameters, the proportions are advantageously maintained within
certain limits not only from the standpoint of operability but
also commercial feasibility. For example, unless sufficient NPN ~-
is provided in the initial mixture to warrant inclusion thereof
from an economic as well as a nutritional standpoint, the cost
of processing the constituents is prohibitive. On the other
hand, if the quantity of NPN present in the admixture is increased
to a level where the final product is unpalatable even in a pro-
cessed condition because of excess NPN and the composition is
completely unmanageable in use, then the processed product has
'A~ '`~ g
10~6336
no significant utility as a ruminant ~eed. In the latter con-
nection, it has been found that the present invention involving
addition of lipid permits use of starch source-urea ratios on
the order of 4 to 1 or greater, which can be a significant ad-
vantage to livestock feeders since the additional NPN serves as
an extremely inexpensive protein source.
In particular, it has been found that addition of
lipid material such as animal fat permits utilization of starch-
NPN ratios yielding protein equivalent (P.E.) levels of between
about 24 to 125. Illustrative NPN compounds usable in the present
invention and the preferred ranges thereof in the final starch
reaction NPN product are set forth in Table I hereunder, where
the percentage of NPN is compared with a predetermined quantity
of grain sorghum:
--10-
.
~ j 104 6 3 3 6
U
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a
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.
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a ~
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04 ~U ~- O ~ ~ ~
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el c ~c ~ ~ c ~ ~ e ~ eu ¦
t ~ c ~ e ~ 1 a ~ ~ I
- 11
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~046336
~ NNNNNNNNNNNN
U ~ ~ ~
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.
SN~
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t:~ Z ~ ct~ ~ ~ N~DN O S
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z ¢ ¢a ~ m ~ ¢ ~ ~ 3 a H ~N
.
-- 12 _
. . . : ~ :
~04'~336
As is apparent from the above Table, the total P.E.
of the starch reactant-NPN product is preferably maintained
within the range of about 24 to approximately 125, based upon
the welght of the starch material. For the listed NPN sources,
this would amount to a percentage addition range of from about
3.5 (dicyanodiamide) to about 173 (ammonium phosphate). More
preferably, the P.E. level of the feed products hereof is main-
tained within the range of about 60 to 125, and most preferably
in the range of from about 85 to 125.
The amount of moisture required in the mixture of
starch-bearing material and NPN to assure necessary gelatiniza-
tion of the starches is variable within certain limits, but is
preferably within the range of from about 4 to 50~ by weight
based upon the weight of the starch-bearing material. Most
starch-bearing materials inherently contain a certain amount
of water as a part thereof and this quantity is included in the
; molsture content of the admixture ready for processing. For
example, dry corn may contain 12 to 14~ moisture and this quantity
18 taken into account in determlning the amount of water to be
added to the mixture prior to processing thereof. Sufficient
water must be available in the mixture of starch-bearing ma-
terial and NPN to cause at least a portion of the starch to be-
come disrupted and thereby gelatinized upon heating in the
presence of the water to thus produce a gel structure. In pre-
ferred forms however, the total moisture level and other relevant
processing cond~tions are ad~usted such that the starch-bearing
feed material is from about 50 to 100~ gelatinized. More prefer-
ably, this level i8 from about 75 to 100% gelatinization, and
most preferably ~rom about 90 to 100% gelatinization. In addition,
the total moisture content is preferably in the range from about
10 to 35~ by weight, and most preferably from about 15 to 25
by weight.
~04t~336
In practice, the starch-bearing material, NPN source,
and lipid material are initially admixed by conventional means
and thereafter delivered to the inlet of an extrusion cooker
for processing thereof,whereupon water is added to the mixture
in the form of steam and/or water. In certain cases, it may
be advantageous to precondition the admixture in a precondition-
ing zone wherein water and/or steam is blended therewith prior
to the actual extrusion treatment. In any event, the feed con-
stituents are conveyed along the length of the extruder by means
of the central auger conveyor while the constituents are sub-
~ected to high temperature, shear, pressure and compressive
forces. The temperature of the composition is gradually in- ~ -
creased as it approaches the end die so that the temperature
thereof immediately prior to extrusion is preferably from about
220 to 360 F. More preferably, this extrusion temperature
ranges from about 270 to 340 F., and most preferably from about
300 to 330 F. The extrusion die and auger also cause pressures
to be developed within the extruder on the order of from about
; 300 to 500 p8i, and such pressures are thereby maintained on
the composition as it moves through the extruder section in
order to facilitate relatively quick and complete processing.
The extruded product emerging from the extruder die
is in the form of elongated rods which are preferably cut by
conventional means (e.g., a variable speed knife) to a suitable
size and finally dried to a moisture lerel of less than about
15% by weight (and preferably less than about 6% by weight).
In some instances, the dry product may be sub~ected to well-
known crushing techniques in order to obtain a granular product
for easier handling.
The following examples are illustrative of the present
invention but are not to be taken as a limitation on the scope
thereof.
-14-
;
~0~i336
EXAMPLE I
In these tests a series of tuber starch-urea feed
products were prepared in accordance with the invention by in-
corporating within the normal feed constituents varying amounts
of liquid fats in order to determine the cooking and handling
qualities of the end products as well as the microbial protein
synthesis levels thereof. In particular, predetermined quanti-
ties of ground potato and tapioca were mixed with the specified
levels of water, urea and fat as listed in Table II hereunder.
The fat was heated to liquid form and was the trademarked HEF
product sold by the Proctor and Gamble Company. The feed consti-
tuents were thoroughly admixed in a conventional blender and sub-
sequently passed through a Wenger Model X-25 (trademark) extrusion
cooker (or in some cases through a Brabender (trademark) laboratory
size cooker) without preconditioning in order to provide the lipid-
modified starch-NPN ruminant feed products of the instant invention.
In this connection, attempts at producing feed using potato and
tapioca starch materials with no added fat led to clogging of the
extruder and a wholly unsatisfactory product; consequently, no data
was derivable from such runs, which emphasized the need for lipid
addition in processing starch sources in accordance with the inven-
tion. The cook temperatures referred to are those measured imme-
diately prior to extrusion. The results of this series of tests
are summarized in the following Table II:
-15-
- .. . . ,~ :
- : , -
1046336
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In 0~ 1~ ~O ~1 ~ ~ C~ '
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P u-l `.D ~O 00 ~ ~) ~D C~i
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~046336
~ study of the foregoing data will demonstrate
that addition of from l to 4~ fat in the starch-NPN admixture
synergistically enhances the microbial protein content of the
resultant feed product. In particular, addition of fat served
ln every case to lower the percent cook value (a measure of
starch gelatinization) of the samples, since such fat serves
as a lubrication for the extrudate and thus lessens the amount
of starch disruption and gelatinization. However, the tests
also indicate that the extent of protein synthesis was not ad-
versely affected in any appreciable manner by lower cook values,
but in fact were substantially maintained or even increased by
virtue of fat addition. Attention is directed to the right-hand
column of Table II wherein bacterial protein synthesis is cor-
rected for the degree of cook (B.P.~% cook). This data clearly
demon6trates that although cook values decrease with added lipid,
the protein synthesis levelæ derived from the samples are un-
expectedly increased. Although not completely understood, it
is evident that added lipid synergistically acts with the other
feed constituents to achleve the results alluded to above.
In thls connection, it will be understood that rumen
fermentation in a live animal is a dynamic process where ammonia
ls constantly belng produced, metabollzed, adsorbed or removed.
The concentration of ammonla or mlcroblal protein ln the animal
at a given time can depend upon all of these factors. High rumen
microbial protein concentration may result from slower microbial
protein removal from the rumen, and there~ore, not really re-
flect increased mlcrobial protein synthesis. In order to ob-
viate this factor the in vitro fermentation studies discussed
above were undertaken to develop the microbial bacterial protein
synthesis data presented. In the in vitro fermentation, ammonia
cannot leave the "rumen" by absorptlon or passage and microbial
protein cannot leave by passage. Therefore, the ammonia levels
-17-
.
~Q4~336
and microbial protein levels of the in vitro studies represent
an easy method for accurately determining proten synthesis.
In practice, samples of the control and test feed
products were placed in identical quantities of rumen fluid
and allowed to ferment for equal periods of time. The total
protein levels derived from such fermentation were then measured,
and following correction for the protein equivalent from the
feed protein and rumen fluid, the microbial protein synthesis
levels were determined.
This series of tests also demonstrated that the pro-
cessed feeds hereof containing lipid were much easier to process
and handle. Specifically, the added lipid products did not ex-
hibit the property of adhering to the die and knife mechanism
but rather could be quite easily cut into discrete pieces to
greatly facilitate further drying and treatment. -
EXAMPLE II
In this example additional starch-bearing materials
were tested in order to demonstrate the utility of added fat in
various other NPN-starch admixtures. In particular, the test
proceeded exactly as described in connection with Example I
with varying levels of fat, urea, and water being processed in
the Wenger extruder. In addition, cook temperatures were varied
to determine optimum operating conditions. The data summarizing
this series of tests is set forth in the following Table III:
.~ .
.
-18-
~046336
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.~ ~ ~ ~ ~D u~ ~D ~ ~ u~ I~ ~ ~ ~ ~
~ ~ u~ ~O ~O . ~ ~ `D ~ 'D ~D u~ ~ ~O
~o
_l u~ 0~ 0~ n o~ ~ cr~ O oO ~ u~ ,1
E OD ~ `;t ~ `D ~` ~ ~ ~`I a~ c~i ~
~ 1~ . u~ ~ o~ ~ ~ ~ o. I~ o, ~
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_l ~0 ~ _i ~_( _1 cr~ o~ o~ o~ ~D CO
~ . E~
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:~ _1 _1 ~ ~ ~ ~o ~ _1 ~1 ~ ~ ~1 ~ .
i~ ~ : ~
~ O O O O O O O o o o o o
~ ~ ~ U~ ,i C~ ~ 'O ,i ~ o _i ~ ~
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19
la46~36
An analysis of Table III will demonstrate that fat
addition serves to at least substantially maintain and in most
cases actually increase the microbial protein level of the re-
sultant feed products. In order to demonstrate the effective-
ness of lipid addition in this context, the cook values asso-
ciated with each of the runs of this example have been calcu-
lated and are presented in Table III, along with the bacterial
protein synthesis levels corrected for the degree of cook. These
figures are indicative of the extent of gelatinization of the
starch-bearing material in each test, with higher magnitude
numbers in general representing greater gelatinization. In this
connection it will be noted that in all cases additional fat
served to substantially maintain or increase the cook-corrected
protei~ synthesis level notwithstanding the fact that cook values
go down with such fat addition. Thus, it is evident that the
lipid addition served to synergistically enhance microbial pro-
tein synthesis.
Finally, the products of this test were also very easy
to cut, dry, handle and store and accordingly are preferred over
otherwise identical feeds free of lipid addition.
EXAMPLE III
In thls test separate corn samples were employed as
the starch-bearing material in order to demonstrate the utility
of the present invention in connection with waxy materials. In
particular, samples 1-4 contain 8.9~ protein and 14.4% moisture,
whereas samples 5 and 6 contain about 8.9% protein and 15.04
moisture. In all other respects, tests of this example were
identical with those undertaken in Examples II above. A study
of Table IV hereunder will again demonstrate the unexpected find-
ing that while fat addition lowers cook value, the protein syn-
thesis derived from the feed is not adversely affected but rather
is increased. Moreover, the resultant feed products are very
-20-
~0~t;336
easy to process and in every way represent commercia~y salable
feeds, As such, the synergistic nature of lipid addition as
herein set forth iB conclusively demonstrated.
-21-
1~)46336
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22
