Note: Descriptions are shown in the official language in which they were submitted.
ANIMAL FEED SUPPLEMENT
This invention relates to an animal feed
supplement, particularly, to sodium sesquicarbonate, a
mixture comprised of sodium carbonate, sodium bicarbonate
and water. It has been discovered that this mineral
possesses buffering and neutralizing characteristics in
the diets of animals, particularly ruminants.
It is known that buffers alter animal
performance through effecting changes in digestive tract
buffering capacity, pH and resulting nutrient flow.
Extensive studies have been conducted in the past,
particularly in the past decade, on the effectiveness of
buffers to counteract the negative effects of a high
concentrate diet and sudden changes in diet for dairy cows
and beef cattle. High energy intake in cattle is achieved
by feeding large amounts of concentrates. The
concentrates may often comprise up to 90% of the diet and
can often result in some depression in milk fat
percentage, a depression in feed intake, digestive upsets,
and depressions in digestibility of major nutrients,
especially starch.
The ruminant animal's existence is dependent
upon the symbiotic well being of two ecosystems: rumen
microorganisms and the host animal. The bacteria and
protozoa that live in the rumen are capable of digesting
cellulose, a component of the cell walls of stems and
leaves of plants. The end products of microbially
digested cellulose are utilized metabolically by the host
animal.
The end products of the cellulose digestion by
the microorganisms are the volatile fatty acids (VFA),
i.e. acetic, propionic, butyric, valeric and small amounts
of longer chain acids and isoacids. The slow degradation
of cellulose to glucose, pyruvic acid and finally VFAs
,~
- 2 - ~ 8~0~
results in a mixture of acids that is predominatly the
lipogenic acids, i.e. acetic and butyric acids. While
acetic and propionic acids may serve as precursors to the
carbon portion of several metabolites, they are the
precise building blocks of lipids, i.e. fats stored as
adipose tissue and secreted in milk.
The gluconic acids such as propionic are more
energy efficient. Once absorbed from the rumen, they are
converted to glucose in the liver. The g]ucose is then
metabolized in all tissues providing the energy necessary
to do work, grow, gestate and lactate.
Economic pressures have forced the dairyman to
maximize efficient utilization of costly feedstuffs by an
expensive cow. This is accomplished by replacing a
portion of the stems and leaves of forages with starch.
Starch is the predominant carbohydrate contained in the
seeds and roots of plants. While starch i9 readily
digested by animals, it is also digested in the rumen by
rumen microorganisms. The end products of
microbiologically digested starch are VFAs as with
cellulose digestion. However, instead of a mixture
consisting mostly of lipogenic acids, there is an increase
in the quantity of glucogenic acids, i.e. propionic acids.
Starch feeding, therefore, provides the host animal with a
mixture of VFAs which is metabolically more energy
efficient for milk production. In addition, a larger
quantity of VFAs are produced from a unit of starch than
from cellulose as it exists in forages. The result is
increased milk production.
A dietary regimen designed to increase milk
production will alter the metabolic schemes of both the
microorganisms and in animal tissues. As dietary starch
is increased, the quantity and rate of VFA production are
also increased. ~ormally, the free VFAs are at least
partially neutralized in the rumen by the association with
- ~L2~
-- 3
sodium from sodium bicarbonate, the sodium bicarbonate
having been produced by the animal and introduced to the
rumen by the saliva.
Both the undissociated and dissociated VFAs are
absorbed across the rumen wall against a concentration
gradient. In the course of passing through the epithelial
cells of the rumen wall, those acids previously
dissociated now become undissociated before entering the
blood flowing in the portal circulation. This
neutralizing process requires bicarbonate.
The above neutralizing or buffering in the rumen
and in the rumen epithelium is absolutely essential if the
homeostasis in the animal is to be maintained and the
animal is to live and produce. Therefore, when more VFAs
are produced at any given moment, there must be a
corresponding increase in buffering capability.
The predominant buffer involved in VFA
neutralizat;on by the host animal is sodium bicarbonate.
It is produced by the animal through combined pulmonary
and renal functions. Since there are limits to
respiratory rate and kidney function, sodium bicarbonate
production by the host animal is also limited. Therefore,
it has become common practice to provide additional buffer
exogenously through the diet.
Diets with a low percentage of forage (low
energy) result in less rumination and less saliva
production than high forage diets. An analysis of the
composition of saliva showed the presence of two buffers,
bicarbonate and diphospha-te. The bicarbonate being
present in greater concentration. A number of studies
have suggested that the addition of sodium or potassium
bicarbonate to high concentrate diets returns the rumen pH
to near normal levels. The sodium bicarbonate appears to
increase rumen pH. Conventional feeding systems employ
forage feed techniques which are supplemented with high
-- 4 --
concentrate feed rations. The conventional feeding system
typically uses hay and pasture as forage which is usually
supplemented with concentrate fed twice daily in the
milking par]or or feed barn. By contrast, a complete
ration feeding system employs a mixture of all feed
components, blended thoroughly to prevent separation and
sorting and offered free choice throughout the day. The
twice daily feeding of large amounts of concentrate
creates sharp disturbances in rumen fermentation
characterized by large cyclic changes in pH and volatile
fatty acid (VFA) production which may depress feed intake
and induce digestive disorders. Digestive upsets are also
common during dietary changes, particularly when cattle
are transferred from high forage (high fiber) diets to
high concentrate (high energy) rations. Dairy cows, for
example, are usually transferred from high forage diets
prepartum to high concentrate rations postpartum in a
short period of time. Studies also indicate that several
hours before parturition, rumen pH and bicarbonate
concentration drop, which may be the result of diminished
salivation, since rumination generally stops several hours
prior to parturition. These studies indicate that the
prepartum diet as well as the postpartum diet requires a
buffer to alleviate the digestive upsets.
Whenever the buffering capacity is exceeded in
the microbial environment of the rumen or in the systemic
tissues of the animal, numerous undesirable metabolic
reactions may occur. The accumulation of unbuffered
(dissociated) VFAs in the rumen lowers the pH of the rumen
fluid. Numerous chemical reactions requiring the action
of numerous enzymes are involved in converting cellulose
and starch to VFAs. Some of these enzymes are pH
sensitive. That is, they will not perform their normal
catalytic function above or below a certain environmental
pH. Metabolism stops in the sequence where the enzyme
normaLly functions. The product which accumulates becomes
the metabolic intermediate rather than the desired VFA.
For example, cellulose is an enzyme produced by the rumen
bacteria and protozoa, and is essential in forming free
glucose from beta linked glucose as it occurs in
cellulose. Cellulose activity is destroyed at a pH less
than 6.2. Therefore, without adequate rumen buffering,
the cellulose contained in dietary forage will not be
digested.
In the absence of suitable quantities of
buffers, some species of rumen bacteria and protozoa may
be destroyed. Lactic acid is a normal metabolic
intermediate produced when glucose is converted to
propionic acid. The particular microorganisms which
produce lactic acid can survive in high acid (low pH)
environments while those organisms that utilize lactic
acid cannot. With lactic acid accumulation, the pH drops
farther and eventually halts rumen activity. Excessive
lactic acid accumulation in the blood and tissues can lead
to kidney malfunction.
The desirability of providing ruminant animals
with an exogenous source of buffering materials has been
demonstrated. The feeding of sodium bicarbonate to
ruminants has become standard practice in the dairy
industry.
In the past decade, research of the buffering
and neutralizing characteristics of various minerals and
compounds has been intensified and buffers have been
generally accepted in the animal feed industry to
facilitate adaptation to rapid dietary changes immediately
postpartum, to increase intake, to increase digestibility,
to aid in the maintenance of acid-base balance, as well as
to increase milk yield and composition. Compounds which
neutralize as well as buffer also have value for high
concentrate (high energy) feeding. Research indicates
- 6 ~
that the neutralizing effectiveness of potassium carbonate
compares very favorably in effectiveness to potassium
bicarbonate and sodium bicarbonate in studies wlth
lactating cows. Sodium carbonate has chemical properties
similar to potassium carbonate and both compounds are
alkaline in aqueous solution.
Trona, a naturally occurring sesquicarbonate
mineral, is composed of about 35% sodium bicarbonate and
44% sodium carbonate, with calcium and magnesium
carbonates the remaining primary ingredients. The studies
of the present disclosure have found that trona is equal
to or superior to sodium bicarbonate in its
buffering/neutralizing capability. Sodium carbonate is a
stronger neutralizer and expands the range of
neutralization. Sodium carbonate immediately neutralizes,
while sodium bicarbonate only buffers and can neutralize
only within a range of pH. Furthermore, the s~udies show
that while trona and sodium bicarbonate are similar
overall for a high grain diet, trona produces a more
stable pH especially shortly after feeding and during
early morning hours, providing a more desirable long term
environment for digestive activity. Trona has a
substantial positive effect on maintaining a more stable
digestive tract pH, especially in the upper portions of
the digestive tract.
It is clear, therefore, that buffering minerals
and compounds in this field of chemistry cannot be
predicted from the prior knowledge of compounds which have
been demonstrated to exhibit buffering characteristics.
Objects of this invention include providing a
buffering compound which is effective in a variety of
diets and rapid dietary changes and at concentrations
within-the diet without effecting total feed intake. It
is also an object of this invention to provide a buffer
~48404
compound to maintain a substantially stable digestive
tract pH.
It has been discovered that the mineral trona meets
the above objects and needs more nearly than previously
known minerals and/or compounds. Experimental data shows
that trona has a positive effect on maintaining a substan-
tially stable digestive tract pH providing a more desirable
long term environment for digestive activity.
Thus, according to one aspect of the invention there
is provided an animal feed mixture including sodium sesqui-
carbonate in particulate form as an ingredient of said
animal feed mixture in an amount sufficient to maintain
rumen pH within the range of 5.5 to 7Ø
According to another aspect of the invention there
is provided a method for maintaining ruminant digestive
tract pH, which comprises adding sodium sesquicarbonate to
the ruminant diet at a rate and in an amount sufficient to
maintain rumen pH within the range of 5.5 to 7Ø
According to another aspect of the invention there
2~ is provided a feed mixture for a ruminant animal including
trona in particulate form as an ingredient of said feed
mixture in an amount sufficient to maintain rumen pH
within the range of 5.5 to 7Ø
According to yet another aspect of the invention
there is provided a method of regulating digestive tract
pH of cattle, which comprises adding trona to the diet of
the cattle at a rate and in an amount sufficient to
maintain rumen pH within the range of 5.5 to 7Ø
The effectiveness of the present invention is illus-
trated by the following results obtained in conducting
studies to compare the acceptance of the mineral trona and
its buffering/ neutralizing action to sodium bicarbonate
or the absence of a buffer in diets for lactating dairy
cows and beef cattle, the following experimental results
being representative of the results obtained. The studies
~2~04
- 7a -
demonstrate the effectiveness of the present invention
in maintaining digestive tract pH and fermentative and
digestive function.
EXPERIMENT ONE
In experiment one, thirty holstein cows which had
calves without complications were assigned to one of three
treatments one day postpartu~ in order of calving date.
The treatments were three complete rations with dry matter
of 15% whole cotton seed, 30% corn silage, and 55% corn
soybean meal concentrate mixtures. The concentrate mixture
formulations are shown in Table 1, the first mixture
including no buffer, the second mixture including 1.5~ by
weight of sodium bicarbonate, and the third mixture
including 1.5% by weight of trona.
~8~0~
-- 8 --
TABLE 1 - CONCENTRATE MIXTURE
Treatment Number
1 2 3
Ground Corn69.35 66.35 66.35
SBM 44 26.00 26.00 26.00
Defluorinated Phosphate 1.20 1.20 1.20
Limestone 2.65 2.65 2.65
Plain Salt .45 .45 .45
MgO .20 .20 .20
TM Premix .10 .10 .10
Vitamin A Premixa .05 .05 .05
NaHCO3-Corn Premixb -- 3.00 --
Trona-Corn Premixb -- -- 3.00
TOTAL 100.00 100.00 100.00
20 a4.54 IU/ton.
bComposed of equal parts of buffer and ground corn.
The prepartum environment of all cows was
uniform. Following parturition, the calf was permitted
one feeding and then taken to a cow hutch. The cows were
moved to the experimental cow lot which provided access to
a free stall barn with at least one stall per cow and
30 water available continuously. At about 0800 and 2000
hours, the cows were brought into the nutrition barn where
they received their rations ad libitum in individual
stalls with mangers that permitted measurement of feed
consumed. Water was available at each stall. Cows were
continued on this regimen for seven weeks of lactation.
- 9- ~12~8~
Individual feed consumption was recorded daily.
Feed consumption was expressed as dry matter (DM) per
hundred weight (CWT), DM per kilogram of metabolic body
size and DM intake per unit of dairy merit, computed on a
weekly average basis.
Feed DM intake per CWT of body size and per unit
of metabolic body size are shown in Table 2. Differences
among groups were inconsistent the first three weeks.
From weeks four through seven, the cows fed the diet with
trona ate more feed DM than the cows fed the other two
diets. The experimental data shows that cows fed the diet
with trona sustained greater DM intake after week three
when cows in early to mid lactation are switched abruptly
to a high energy concentrate diet. Generally, lactating
cows experience sharp reductions in body weight. This
probably occurs because milk energy demands peak before
feed energy intake. This lag in feed energy eaten
postpartum is well recognized, but explanations for its
occurrence or solutions to its presence are not known.
The experimental results shown in Table 2 indicate that
cows fed a diet containing trona accept more feed earlier
in the postpartum period than a diet containing no buffer
or a diet containing sodium bicarbonate. This increase in
feed intake may be attributable to the presence of sodium
carbonate in trona which has stronger neutralizing power
than sodium bicarbonate. Greater feed intake earlier in
the postpartum period reduces the time and magnitude of
negative energy balance and reduces the likelihood of
ketosis.
Urine samples were obtained and pH was measured
on days two, four, six and eight postpartum, and weekly
thereafter. Rumen pH was taken immediately following
urine sampling by stomach tube during weeks two, four and
six. About one liter of the lnitial sample was discarded
to reduce contamination by saliva. Rumen samples were
- 10- ~2~a~4~
filtered through two layers of cheese cloth and stored at
-5C. Volatile fatty acids (VFA) were determined by gas
chromatograph. Body weights were taken weekly.
TABLE 2 - FEED INTAKE
Treatment Week Mean
1 2 3 4 5 6 7
---- -- Dry feed/100 kg body weight ------
10 Control 1.95 2.43 2.96 3.33 3.46 3.64 3.64 3.04
Sodium
bicarb- 2.08 2.72 3.14 3.25 3.44 3.53 3.50 3.09
onate
Trona 2.28 2.41 3.04 3.85 3.69 3.86 3.89 3.25
~ ----- Dry feed/W kg ------_______
Control .090 .117 .142 .160 .167 .174 .175 .146
Sodium
bicarb- .103 .135 .155 .160 .170 .175 .173 .153
20 onate
Trona .110 .116 .146 .169 .179 .187 .188 .157
Rumen pH and VFA values are shown in Table 3.
Rumen pH is a reflection of diet composition and the
quantity eaten. The higher the proportion of concentrate
and the greater the amount eaten, the lower the pH, and
thus the greater the acidity in the rumen. On the first
day of postpartum, all cows in the experiment were
switched abruptly from their dry cow d~et of high forage
(grass, hay and concentrate) to a high energy diet of 55~
concentrate formulated for high milk production. The most
critical -time for digestive upsets in cows is during the
transition from the prepartum, high forage diet to the
high concentrate (high energy) diet.
1~48~
-- 1].
In experlment one, a complete ration feeding
system was used in whish all components are blended,and
fed free choice. In this system, cows eat many small
meals throughout the day and are less prone to digestive
upsets and rumen aci~osis. The addi-tlon of buffers to
high concentrate dairy diets often increases rumen pH and
results in a higher molar percentage of acetic acid, a
lower molar percentage of propionic acid with wider acetic
to propionate ratio. The experimental results tabulated
in Table 3 support this generalization. The data shows
that a diet including trona as an additive has buffering
and neutralizing properties which are greater than a diet
containing no buffer or a diet containing sodium
bicarbonate as an additive.
TABLE 3 - RUMEN pH
Average of Three Weeks
Total AC/PR
Diet pH Acids Acetic Propionic Acetic Propionlc Ratio
------ mmol/ml ----------- ------ Molar % -------
Control 6.58 73.9 39.1 27.4 53.1 36.7 1.49
Sodium 6.67 75.6 39.9 27.7 52.4 36.8 1.49
bicarb.
Trona 6.79 69.7 38.0 24.2 54.9 34.2 1.71
Urine pH data are shown in Table 4. For days
two, four, six and eight postpartum a higher urine pH was
observed for cows fed the two buffered diets. During the
period of weeks two through seven, the urine pH average
for the cows fed the diet including trona was greater than
cows of the other two groups. While the mean pH values
did not differ dramatically, this data is remarkable in
view of the feed intake data shown in Table 2 which
~2~84~
- 12 -
distinctly shows a greater intake in the diet lncluding
trona. As a generalization, the greater the feed intake,
the lower the urine pH if the diet composition is held
uniform, as it was in this experiment by the total mixed
ration. In nearly all measurements of rumen and urine pH,
the experimental data indicates that buffers are valuable
in the diet of early postpartum cows. The data in Tables
3 and 4 indicates that cows fed the diet containing trona
had average urine and rumen pH values greater than cows
fed the diet containing sodium bicarbonate or the diet
with no buffer.
TABLE 4 - URI~E pH
Days Postpartum Means
Diets 2 4 6 8
--------------------pH---------------------
Control 8.08 7.98 8.09 8.16 8.09
20 Sodium
bicarbonate 8.29 8.43 8.30 8.33 8.34
Trona 8.15 8.28 8.27 8.31 8.25
Weeks
2 3 4 5 6 7
-------------------pH--____________________
Control 8.48 8.26 8.17 8.07 8.09 8.18 8.22
Sodium
bicarbonate 8.35 8.12 8.10 8.16 8.23 8.18 8.18
Trona 8.30 8.28 8.16 8.27 8.31 8.24 8.25
~2~4~4
- 13 -
EXPERIMENT TW0
In experiment two, a study was conducted to
determine the effectiveness of trona on digestive track
function in beef cattle. Six multi-cannulated steers were
assigned to individual pens. All steers were fed an
adaptation diet consisting of 30% roughage and 70%
concentrate for a period of seven days. The steers were
then fed assigned diets of either 50% roughage and 50%
concentrate or 10% roughage and 90% concentrate as shown
in Table 5 during an ad~ustment period of seven days.
These diets included a control diet with no buffer, a diet
including 1% by weight of sodium bicarbonate, and a diet
including 1% by weight of trona. The steers were fed the
same diet as in the adjustment period for the following
six days and samples were collected during this period.
The steers were moved through the individual pens for six
trials, each trial consisting of an adaptation, adjustment
and collection period. All feeds fed and refusals were
recorded daily.
Rumen volatile fatty acids (VFA) levels are
shown in Table 5. Acetate levels were similar for cattle
fed all diets and ranged from 29~4 to 36.3 mmol/liter.
Prop;onate levels differed significantly between diets, an
average 16.5 and 11.5 mmol/liter for the high grain 10%
and 50% roughage diets, respectively. Butyrate levels
were greater for the high grain 10~ roughage diet versus
the 50% roughage diet. The total VFA level was similar
for the high grain and roughage diets averaging 52.9 and
48.7 mmol/liter, respectively. The acetate/propionate
ratio was lower for the high grain 10% roughage diet
versus the 50% roughage diet, averaging 2.06 and 3.00
mmol/liter, respectively.
Arithmetically, for the steers consuming the 10%
roughage or beef diet, the trona fed group produced 2.41%
more total VFA than the bicarbonate fed group, and 11%
- 14 - ~2~84~
more total VFA than the control group. For those animals
fed the 50~ roughage or clairy d;et, the total VFA with
both bicarbonate and trona buffers were increased 9.4~ and
10.5% respectively. Also significant is the
acetate/propionate ratio in the 50% roughage or dairy
diet, which increased from 2.63 in the bicarbonate fed
group to 3.37 in the trona fed group. This increase in
relative acetate production is important since acetate is
the VFA most important in milk production. These results
indicate that trona performs equal to or better than
sodium bicarbonate in production of specific volatile
fatty acids used in milk production.
TABLE 5
Rumen Volatile Fatty Acids (mmol/liter)
Beef DietDairy Diet
Diet: 10% roughage50% roughage
Buffer: None Bicarb Trona None Bicarb Trona SEM
Item
Mo. obs. 6 6 6 6 6 6
Acetate29.432.2 34.0 32.5 34.7 36.3 2.5
Propionate 15.1 16.8 17.6 11.1 13.3 11.4 1.3
Butyrate5.2 5.0 3.5 2.2 2.0 2.8 .6
Total 49.7 53.9 55.2 45.7 50.0 50.5 3.5
Acetate/
propionate2.28 1.99 1.92 3.00 2.63 3.37 .21
The results of the feeding test on the di~estive
tract pH are summarized in Table 6. Rumen pH was higher
for the 50~ roughage diet than for the 10~ roughage high
- 15 - ~2~0~
grain dlet. This was expected as high grain diets
normally produce a more acidotic rumen. Both the sodium
bicarbonate and trona increased rumen pH when cattle were
fed the high grain diet. However, with the 50% roughage
diet, the sodium bicarbonate had no effect on the pH and
trona tended to increase the pH from 5.89 to 5.99. These
responses indicate that sodium bicarbonate and trona were
of equal effectiveness in elevating the depressed rumen pH
in cattle fed high grain diets. However, with the 50%
roughage diet, pH was already elevated and only trona was
effective in modifyin~ the rumen pH.
Rumen pH also changed markedly with time
reflecting feeding patterns and rumen fermentative
activity. As was expected, rumen pH dropped greatly
following feeding, this being the result of a large intake
of feed and the activation of the digestive system. The
pH drop after feeding was modulated slightly by sodium
bicarbonate and was greatly reduced by trona, indicating
that trona had a greater stabilizing effect on the rumen
environment than did sodium bicarbonate, especially in
cattle fed the mixed grain 50~ roughage diet where
maintenance of a stable pH is essential to rumen fiber
digestion. Rumen pH of cattle fed the control diet
reached the lowest points at 0400 hours and at 1~00 to
2000 hours. At these same times, the rumen pH of cattle
fed trona were much higher and near or above the overall
daily average pH of cattle fed respective control diets.
This stabilizing effect of trona modulates surges in rumen
fermentative and digestive activity, facilitating rumen
feed stuff digestion.
The duodenal pH was low and in expected ranges
for cattle fed the high grain 10% forage diet and the 50%
forage diet. The sodium bicarbonate buffer appears to
have been of little or no effect on the duodenal pH.
Trona, however, increased the pH in cattle fed both the
- 16 _ ~8~
high grain and high forage diets, providing a better
environment for small intestinal enzymatic nutrient
hydrolysis. As with the rumen, duodenal pH changed
significantly over time reflecting feeding pa~terns, rumen
fermentative activity and buffering capacity.
The ideal pH was at or near neutral and higher
than the pH in any other digestive tract site. Diet
significantly impacted the pH in the ileum with an average
pH of 6.9 and 7.14 for cattle fed high grain or high
roughage diets. While ideal pH tended to be higher when
sodium bicarhonate or trona were included in the diet,
these differences were not significant.
The fecal pH reflected the diet fed and was
lower for the high grain diet than for the 50% forage
diet. The fecal pH was in a normal range and indicates no
significant effect of either the sodium bicarbonate or
trona additive to the diet.
TABLE 6
Buffer Effects on Digestive Tract pH
Diet: 10% roughage 50% roughage
Buffer: None Bicarb Trona None Bicarb Trona SEM
Digestive
tract site
Rumen 5.54 5.61 5.61 5.89 5.89 5.99 .70
Duodenum 2.55 2.61 2.68 2.74 2.70 2.76 .33
Ileum 6.36 6.40 6.43 7.08 7.18 7.16 .89
Fecal 5.78 5.74 5.73 6.13 6.01 6.11 .72
~;~48D~04
- 17 -
~`
The foregoing studies indicate that trona has a
substantial positive effect on maintaining a more stable
digestive tract pH, especially in the upper portions of
the digestive tract. In Figs. 1 and 2, the acid
neutralization efficiency of trona versus sodium
bicarbonate is plotted as a function of volume of acid
(Fig. 1) and as a function of weight of reagent (Fig. 2).
The studies show that trona produces a more stable pH
especially shortly after feeding and during early morning
hours, providing a more desirable long term environment
for digestive activity.
While the foregoing is directed to the preferred
embodiment of the present invention, other and further
embodiments of the invention may be devised without
departing from the basic scope thereof, and the scope
thereof is determined by the claims which follow.
