Note: Descriptions are shown in the official language in which they were submitted.
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Description
Feed Supplement for Ruminant Animals
Technical Field
This invention relates to compositions of matter
containing certain Ralts of volatile fatty acids and a
water-absorbing granular material. Such compositions
are useful as feed supplements for ruminant animals.
Background Art
There are numerous published articles reporting
~he differences in digestive processes of ruminant
animals as compared with those of monogastric
animals. Ruminant digestion is described in consider-
able detail, for example, by D. C. Church in
"Digestive Physiology and Nutrition of Ruminants",Vol. 1, published by D. C. Church, produced and dis-
tributed by O.S.U.Book Stores, Inc., Corvallis,Oregon.
The ruminant animal lives on ingested forage
consisting of large amounts of cellulose which it
cannot digest directly. Instead of direct conversion
of the forage, the ruminant animal has evolved a
symbiotic relationship with micxoorganisms, consisting
of a variety of bacteria and protozoa. The bacteria
digest forage for their own survival and growth and
the host ruminant animal later digests the micro-
organisms and their by-products.
Just as the ruminant animal requires certain pre-
formed nutrients for its growth, the microorganisms
upon which it depends for cellulose digestion have
their own requirements for essential nutrients. M. P.
Bryant and I. M. Robinson (~. Bacteriol. 1962, 84:605)
studied the effect of certain compositions, including
a mixture of acetic acid, isobutyric acid, valeric
acid, isovaleric acid, and 2-methylbutyric acid on
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essential nutrition for the growth of ruminant micro-
organisms. Prominent among these micxobes are the
cellulolytic organisms upon which the ruminant
depends. While it has also been shown by others that
not all of ~hese volatile fatty acids are required by
all of the organisms, at least one is required ~y each
of the 23 for which the combination was shown to
provide essential nutrients and each one was essential
for at least one of these same 23.
Volatile fatty acids (VFA) have been shown to be
incorporated into the structure of these micro-
organisms by conversion to characteristic lipids and
amino acids, such as ethanolamine plasmalogen, valine,
and isoleucine. Th~se acids are normally present in
the rumen as a result of catabolism by the micro-
organisms of amino acids derived from the protein in
the diet of the ruminant animal. Diets high in good
quality protein may contain a sufficient supply of
carbon chain nutrients precursors for optimal growth
of cellulolytic organisms on such diets. However,
high-protein diets are expensive and utilize either
feedstuffs alternatively convertible to use directly
by man or feedstuffs grown on land suitable for the
growth of human food crops. It would be desirable to
reduce the amount of expensive good quality protein in
ruminant feeds and still be able to efficiently
utilize cellulose, a foodstuff not utilizable directly
by man.
Ruminant nutritionists have shown that during the
digestive process, in the rumen of cattle, bacteria
break down feed protein to ammonia and fatty acids.
The bacteria then use the ammonia to synthesize
cellular protein. These bacteria pass from the rumen
to the abomasum and the intestine where they are
digested and serve as the major source of protein for
maintenance of body tissues and for milk production.
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Extensive ~tudies on the nu~rition of rumen bacteria
have shown that fiber-dige ting ~acteria require cer-
tain isoacids, such as isobutyric acid, as well as
a~monia for synthesis of bacterial pro~ein. ( ~
Notes, Nov., 1973, p. 7, Dr. Robert M. Cook, Michigan
State University publish~d by ~he Cooperative
Extension Service.) Without isoacids, urea or NH3
cannot be utilized by these rumen bacteria. For man~
years cattle rations have been supplemented with non-
protein-nitrogen in the form of urea or ammonia.
Patents of interest include U.S. Patents No.
2,154,449; 2,6B7,354, 3,441,539; 3,642,488: 3,934,041:
3,962,329 3,984,572 and 3,989,B46. Other patents of
interest include U.S. Patent No. 3,564,098 which dis-
closes a method of improving growth response inruminants which comprises or~lly administering certain
acids, including valeric acid. Also, U.S. Patent No.
3,982,028 discloses that volatile fatty acids are
absorbed through the rumen walls and are utilized by
the animal as primary energy sources. The effects of
isoacids (isobutyric, isovaleric, 2-methylbutyric and
valeric) on milk production were reported in 1980
J. Dairy Sci. 63:1098-1103.
United States Pate.~t 4,376,790 relates to ammonium
salts of certain ~ and 5 carbon atom volatile fatty acids
and their use as ruminant feed.
Other publications of interest include Chem. Abs.,
Vol. 72, 1970, 19522e J. Bacteriol-826,605, 1962
pages 605-614; J. Bacteriol-83:523-532; and J.
Nutrition, 101:101-112.
It is therefore known that VFA with branched and
straight chains ~re essential nutrients for growth of
rumen cellulolytic microorganisms. VFA are utili~ed
by the cellulolytic microorganisms as precursors for
biosynthesi5 of fatty acids, amino acids, and other
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cellular constituents. It has been reported that
supplementation with VFA in diets fo~ ruminant animals
stimulated growth of many rumen microorganisms and
increased the rate or exten~ of ruminal cellulose
digestion and microbial protein synthesis,
particularly when poor quality diets were fed. The
beneficial effects obtained by supplementing
branched-chain VFA in feeds include increased ~eed
intake, increased nitrogen retention, increased micro-
bial protein formation for ~he improvement of the
protein nutrition to the host animal, and increased
meat and milk production. However, in practice, VFA
suffer from some serious drawbacks. One of the major
drawbacks is the obnoxious odor of the free acids
which has made the handling of VFA very unpleasant for
the farmers and the animal feed operators. Another
major drawback is the corrosivity of volatile fatty
acids which causes the apparatus in contact with it to
be easily worn out and presents a hazard to the skin
and eyes of human beings and animals.
It has been suggested that certain salts of VFA
are less corrosive and odorous than free acids, but as
efficacious as VFA. German Patent No. DT-1965923
teaches that lower branched-chain volatile acids can
be used in the form o sodium, potassium, magnesium,
or calcium salts to stimulate ruminal microbial
activity and to increase the appetite of the animals.
British Patent No. GB-1309863 discloses the use of
a mixture of lower fatty acid sodium salts as a feed
supplement for ruminants. The feed supplement des-
cribed in this patent is either in the form of anaqueous solution or, after further processing, in the
form of a dry powder. U.S. Patent No. 3,958,009
discloses the use of ammonium and potassium
isobutyrate as a means for inhibiting the gxowth of
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, .
plant and animal pathogenic and nonpathoqenic micro~
organisms and the improvement in the rate of weight
gain in animals which have been fed with these iso-
butyrates. U.S. Patent No. 4,179,552 discloses a
liquid composition comprising a C3~C8 carboxylic
acid, and ion selected from NH4 , and cations of
Group Ia and Group IIa elements according to the
Periodic Table and water. The ratio of acid to cation
is between 2:1 and 4:1 on a chemical equivalent
10 basis.
It is known that alkaline and alkaline earth metal
salts of VFA are hygroscopic. In an open environment,
these salts absorb mois~ure quickly at ambient condi-
tions and undertake hydrolysis to generate a small
amount of free VFA resulting in the characteristic
unpleasant odor. Unless the dry salts are kept in a
sealed container, it is very difficult to maintain the
dry powder form of the salts and to prevent generation
of odor at typical warm and humid stoxage and operat
ing conditions of a farm or feed mill.
The above-mentioned patents have not addressed the
problems of hydrolytic stability of the salts of VFA,
and the odor caused by interaction of VFA salts and
moisture at ambient conditions. Furthermore, these
patents do not disclose a process of producing a
solid, flowable, nonodorous product while still main-
taining water in the finished product.
Disclosure of the Invention
According to the present invention, homogeneous
particles of material adapte~ to be orally
administered to ruminants are provided. These
particles are characterized by being solid, flowable,
and hydrolytically stable. The particles comprise
a) from about 15 to about 95% by wt. of the
reaction product of at least one metal cation
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selected from the group consisting of Group
Ia and Group IIa elemen~s of the Periodic
Table with at least one aliphatic, mono-
carboxylic acid having 3 to 8 carbon atoms,
S and
b) from about 5 ~o about 85~ by wt. of a water-
absorbing, granular, edible material having a
pH suf f iciently high that the resulting pH of
the mixture with a) i5 greater than about
7.0-
The percentages of a) and b) are based on their
total dry combined weight. The particles contain less
than about 30% by weight of moisture.
These particles are especially desirable for
ruminant animal feed supplementation because of a
number of reasons. The particles are solid and flow-
able allowing them to be easily handled. ~eing metal
salts of the volatile fatty acids, they do not have an
objectionable odor, which is commonly found with the
free acids as well as some of the other salts. Due to
the presence of the water-absorbing edible material,
the particles are hydrolytically stable, whereas with-
out the presence of such material, the salts absorb
enough water from the atmosph0re alone to become
liquid or semi-solid- By providing a basic environ-
ment, the water-absorbing material prevents the forma-
tion of the free acids which would cause objectionable
odor. Once ingested by a ruminant animal, the salts
are broken down into the individual acids from which
they are derived, allowing the animal to receive all
the benefits from such acids described hereinbefore.
The metal cations used in reacting with the mono-
carboxylic acid are selected from the Group la and
Group IIa elements of the Periodic Table. Preferably,
these cations are sodium, potassium, calcium or
1:~0~0$3
-- 7 --
magnesium. Sodium and potassium are especially pre-
ferred.
The aliphatic monocarboxylic acids having 3 to 8
carbon atoms used in reacting with the cations are
preferably isobutyric, n-butyric, 2-methylbutyric,
n-valeric and isovaleric, or a combination thereof.
Most desirably, the acids are a combination of iso-
butyric, valeric, isovaleric and 2-methylbutyric.
The metal cation and acid are reacted in a manner
well known in the art to form the salts. For example,
sodium hydroxide may be mixed with a blend of the
acids to form sodium salts.
The water-absorbing material used in this inven-
tion is selected from basic water-absorbing minerals
such as metal oxides, metal hydroxide, basic inorganic
salts, clays, natural cellulosic and proteinaceous
materials, synthetic polymeric materials such as poly-
acrylamide and polyethylene glycol, and a combination
of these materials. ~ combination of these materials
which provides a wAter-absorbing capability and yields
a saturated solution or dispersion with a pH of about
7~0 or above after absorbing a sufficient amount of
watex is particularly useful in this invention.
Feed-grade minerals and natural cellulosic and
proteinaceous materials which satisfy the
above-mentioned properties are most prefexred in this
invention. Typical examples are listed below.
Metal oxides such as magnesium oxide, calcium
oxide, aluminum oxide, and silicon dioxide;
Metal hydr~xides such as magnesium hydroxide and
calcium hydroxide;
Salts such as sodium carbonate, sodium
bicarbonate, magne ium carbonate, calcium carbonate,
rock phosphate, mono-, diand tricalcium phosphate,
anhydrous calcium sulfate, anhydrous zinc sulfate,
anhydrous calcium chloride;
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Clay such as bentonite, kaolinite, talc and
vermiculite;
Cellulosic materials such as bran, dehydrated
alfalfa, vegetable gums, and dry hays.
The water-absorbing materials have a pH
sufficiently high that the resulting mixture with the
reaction product of metal cation and acid has a pH of
at least 7.0, preferably at least about 9.5. Thus,
formation of free acid from moisture in the environ
~ent is minimized.
The salts can be prepared by reacting one or a
blend of acids with an essentially stoichiometric
amount of a base containing the desired cation in an
aqueous medium.
A volatile fatty acid salt with an alkaline or
alkaline earth cation is usually prepared by reacting
the free acid and the respective metal oxide or
hydroxide in an aqueous medium, and then evaporating
water to obtain a dry powder product. Since one mole
of water is generated in the neutralization reaction
for each mole of free volatile fatty acid, the process
of separating water from the reaction products in
order to get a dry powder form of salt is unavoidable
and usually energy- and time-consuming. Concentrated
aqueous solutions of sodium hydroxide, or potassium
hydroxide, about 50~ or above are preferred to be used
in the reaction in order to minimize the total amount
of water to be absorbed by water-absorbing carriers.
The feed composition according to this invention is
then prepared by adding, while applying rigorous mix-
ing, a desired amount of water-absorbing material to
the aqueous medium until a solid, flowable product has
formed. The amount of water in the product may be
reduced by evaporation either before or after a~ding
water-absorbing carriers. Preferably, the finished
product prepared by this meth~d contains at least 25
~0~3()$3
(by weight on dry basis) salts of VFA. The solid,
flowable, VFA salts on carriers may be uæed as a feed
supplement or mixed with pelleting aids or other feed
ingredients to make a final product in pellet form.
The feed supplement is fed to ruminants in
quantities sufficient to result in weight gain and
increases in milk production. The reaction product of
the metal cation and acids is broken down by the
ruminant animal to the metal cation and acids. The
quantity of feed supplement fed per day is determined
so as to result in an in~ake of about 5 to about 150
grams of the acids.
The amount of VFA salts of Group I and Group II
cations required to result in these amounts of acids
can be calculated using the ratio of the VFA molecular
weight to the molecular weight of the VFA salt. Such
stoichiometric calculations are well known to those
skilled in the art. For example, to find the weight
of acid to be derived from given weight of a VFA salt,
the following equations apply:
I. Conversion Factor for Group Ia Elements
Molecular Weight of VFA
(Molecular Weight of VFA-l) + Atomic ~t. of
Group Ia Element
II. Conversion Factor for Group IIa Elements
2(Molecular Weight of VFA)
2(Molecular Weight of VFA-l)(Atomic Wt. of
Group IIa Element)
Thus, for example, to find the equivalent weight
of acid in the sodium salt of a mixture of C-4 and C-5
acids (31.5% isobutyric, 68.5% mix~ure of valeric,
i~ovaleric and 2-methylbutyric), the following
calculation is made:
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Equivalen~ VFA in Sodium VFA (from Formula I~
= M.W. of the acids
(M.W. of the acids -1~ + atomic wt. of Sodium
= 97.7 - 81.62%
g7.7 - 1 + 23
Therefore, for a ration of 5-lS0 grams acid per
day, and for compositions containing about 15-95%
sodium salts, it is calculated that the weight of
sodium salts fed per animal per day is between about 6
and about 1250 grams. Thus, the desired ration and
the concentration of sodium salts in the composition
will determine the quantity of composition to be fed.
The following examples are submitted for a better
understanding of the invention.
EXAMPLE 1
This example illustrates the process, stoichio-
metry, and reaction conditions for the preparation of
a product disclosed herein.
An amount of 50~ aqueous fiolution of sodium
hydroxide (32.8 grams) is added to a mixture of
volatile fatty acids (40.0 grams) containing 31.5%
isobutyric acid and 68 ~ 5~ mixed C5-isoacids
(n-valeric acid, isovaleric acid, and 2-methylbutyric
acid) so as to neutralize the acids completely. It is
observed that the temperature of the mixture rises
very rapidly because of the exothermic neutralization
seaction. The mixture is essentially colorless until
the temperature reaches about 90C., above which an
instantaneous yellowing of solution is observed. If
the temperature of the mixture is lower than 80Co ~
the mixture gradually solidifies to a waxy solid and
the reaction appeared to be incomplete. To ensure the
completion of the neutralization reaction, the
temperature of the reaction mass is raised to the
range of 95-110C. by con~rolling the rate of addition
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of NaOH, and/or by supplying heat to the reaction mass
until the yellowing of the ~olution is observed. A
quantity of bentonite (110 grams) is added to the
yellow salt sol~tion, which contains 67.4~ salt and
32.6% water. The mass is thoroughly mixed and cooled
to obtain a solid, granular, flowable, product with a
mild pleasant odor which contains ~6.8% sodium salt of
VFA on dry basis, 55.9% bentonite, and 18.2~ water.
When the salt solution is allowed to cool alone, it
solidifies at about 60C. to a soft, waxy solid.
EXAMPLE 2
This example illustrates the use of a highly con-
centrated NaOH solution in the process to ~inimize the
amount of water-absorbing carrier in the finished
product.
A solution of VFA sodium salt is prepared by
reacting 100 grams of mixed volatile fatty acids (same
VFA composition as in Example 1) with a stoichiometric
amount of 73% aqueous solution of NaOH at 100C.
Seventy-five grams of magnesium oxide or bentonite is
required to blend with the salt solution to obtain a
granular, solid, flowable, mildly aromatic product.
The content of sodium VFA in the product is 53% by
weight, which is substantially higher than the sodium
VFA content in Example 1. When the hot solution is
allowed to cool at an ambient condition, it solidifies
at about 80C. to a waxy solid.
EXAMPLE 3
This example illustrates the hygroscopic nature of
sodium VFA and the effect of basic inorganic water-
absorbing minerals on odor quality of the product.
A stock solution of sodium VFA prepared as
described in ~xample 1 is dried under reduced pressure
in an oven at 110C. for 24 hours to yield a flaky,
anhydrous, crystalline product. Four grams of
anhydrOus sodium V~A is placed in a closed chamber at
100% relative humidity at 25C. Similarly, a 15-gram
sample of a sodium VFA/bentonite product from Example
1 is placed in another chamber at 100~ relative
humidi~y at 25C. After two days, anhydrous sodium
VFA absorbed a sufficient amount of water to yield a
clear solution. A faint obnoxious odor is detected
when the chamber is opened. However, in the same
period of time, sample from Example 1 became a mushy
solid, but no detectable odor is sensed when the
chamber is opened.
EXAMPLE 4
This example illustrates the use of three natural
cellulosic materials as water-absorbing carriers for
the preparation of a product disclosed in the inven-
tion.
A stock solution of sodium VFA is prepared as
described in Example 1. The stock solution contains
67~4% sodium VFA and 32.6% water. A sample of dry hay
is chopped and ground cryogenically. Thirty grams of
ground hay is added to a 30-gram solution of sodium
VFA at 60C. The mixture is thoroughly mixed and
allowed to cool to yield a solid, flowable, product
with a mild, not unpleasant odor which contains 33.7
sodium VFA.
A sample of alfalfa pellets, commonly used as an
animal feed ingredient, is ground to fine particles.
Thirty grams of ground alfalfa was added to a 30-gram
solution of sodium VFA at 60C. The mixture is
thorou~hly mixed to yield a solid, granular, non-
odorous product which contains 33.7~ sodium VFA.
A similar product i5 also prepared by using wheat
bran as the water-absorbing carrier at the same ratio
as dry hay or alfalfa. Natural cellulosic materials
~2~
such as dry hay, dehydrated alfalfa, and bran absorb
sodium VFA solution very quickly, but the products
usually emit a different odor, although nonodious, but
much stronger than the odor of the products using
inorganic water-absorbing carriers such as magnesium
oxide and bentonite.
EXAMPLE 5
This example illustrates $he use of a combination
of water-absorbing basic inorganic materials and
natural cellulosic materials as carriers for preparing
a product in pellet form.
A sodium stock solutin is prepared as described in
Example 1. An amount of sodium VFA solution is
blended with an equal amount of a mixture of
dehydrated alfalfa/bentonite ~1:1 by weight) to yield
a soft, paste-like product. The product is nonodious
and less odorous than products described in Example
4. The paste-like material i~ fabricated into
cylindrical tablets with a diameter of about lJ4~3/8
of an inch and a length/diame~er ratio of about 1-2 by
a Parr pellet press or spherical boluses with a dia-
meter of about 1/4-3/8 of an inch by rolling and
tumbling in a Hobart mixer. Soft pellets may be
hardened by ~rying in air or in an oven. Dry, hard
pellets are odor-free, easy to handle, and contain
about 40% by weight sodium VFA.
The preceding portion of this specification has
dealt with the preparation of a ruminant feed composi-
tion which co~prises salts of aliphatic monocarboxylicacids having 3 to 8 carbon atoms and a moisture
absorber. The function of the moisture absorbing
basic matarial is described hereinbefore. It is known
in the art that as the salts of the acids are fed to
animals, they hydrolyze to the corresponding acid and
base. See, for example, ~.S. Patent No. 3,708,578,
12~$3
column 1, lines 4~-S0. Thus, the alkali metal salts
(e.g. sodium and/or potassium) of one or more of the
acids are converted to the alkali metal and the free
acid(s). Similarly, ammonium salts of the acids are
converted to ammonia and the free acid(s). In each
case, i~provement in performance such as milk produc-
tion and weight gain is derived, at least to a large
extent, from the acid(s), as described herein.
The results of efficacy feeding trials in dairy
cows at three geographic locations using the composi-
tions according to this invention are summarized below
in Tables 1 and 2. Six combinations of ammonium iso-
butyrate, ammonium isovalerate, ammonium valerate andammonium 2-me~hylbutyrate from which response surfaces
could be computed, and a control are tested. Each
treatment consists of 23 cows for a total of 161 cows
in the experiment. The experimental period for each
cow starts approximately 3-6 weeks prior to calving
and include the ensuing lactation and dry periods.
Response surfaces of a surface fitting design,
based on milk yield, defined an optimum blend compoced
of 61 g of the 5-carbon salts plus 28 g ammonium iso-
butyrate per cow per day. The optimum blend is very
similar to the CP blend. The cows receiving the CP
blend peak at a higher level and produce significantly
more milk than the control cows. In addition, the
COW5 on the CP blend produce significantly more milk
protein and solids-not-fat than the controls. The
production of fat is higher in the CP ~reatment than
the control but the difference is not significant.
The diference in total feed dry matter intake is
smaller (and statistically not significant~ than the
increase in milk production indica~ing a higher
efficiency of feed utilization for the cows receiving
the CP blend compared to the controls. There is no
1)$~
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adverse blend effect on the health, reproduction, and
body weight of the supplemented cows.
The responses are substantially similar in all
trials suggesting that the conclusions of this experi- -
ment are applicable to other locations.
Table 1
Milk Production, kg/cow/day
Days From Average Percent
Beginning of Number of Increase
Standardization Days From Blend Blend Blend Blend Blend Blend CP Over
PeriQd Calving Control _ A E B CP D CControl
21 36 31.0 31.1 30.9 31.9 33.~ 30.6 31.79.1 1 ~`
63 78 29.4 30.1 29.~ 31.0 32.4 29.9 31.010.4
1~5 12~ 27.8 28.9 28.5 29.4 30.9 28.5 29.611.3
1~7 162 26.2 27.3 2~.8 27.7 29.1 26.9 28.111.0
189 204 24.7 26.1 25.7 26.0 27.3 25.2 26.510.5
231 246 23.2 24.5 24.1 2~.2 25.5 23.5 25.110.1
253 ZS8 22.3 23.~ 23.3 23.3 24.6 22.5 24.39.9
;
Table 2
Weight kg/cow
Weight ControlBlend ABlend E Blend BBlend CP Blend D Blend C
Day 1 574 596 583 578 606 589 585
Day 105 585 602 584 595 605 612 59
Day 253 638 647 623 658 656 670 652
Weight gain 0-104 ll.0 2.5 2.2 17.0 6.3 22.8 13.6
Weight gain 0-250 64.7 47.7 47.1 79.7 57.6 80.7 67! 4
_l
o
0~30$3
A small amount of animal feed flavors may also be
incorporated into the product composition to mask any
residual odor of VFA salts.
Unless otherwise indicated, all parts, percent-
ages, ratios, etc., are by weight.
The invention has ~een described in detail wi~hparticular reference to preferred embodiments thereof,
but it will be understood that variations and modii-
cations can be effected within the spirit and scope of
the invention.
