Note: Descriptions are shown in the official language in which they were submitted.
W094/02028 2 f ~ 7~ 9 5 PCT/GBg3/01499
RUMINANT FEEDSTUFFS AND THEIR PRODUCTION
This invention relates to ruminant feedstuffs and
to their production.
While the processes of fermentation and digestion
5 which take place in the rumen of rll~;n~nt animals are largely
beneficial to such animals under natural feeding conditions,
modern husbandry may require that, for optimum production of
meat and/or milk, such animals should be fed a proportion of
their dietary requirements in the form of nutrients which
10 ideally should not undergo alteration or degradation in the
rumen but be digested in the lower gut. Also it is necessary
that such nutrients should not interfere with the normal
processes of rumen fermentation.
In the case of protein metabolism, it is known
15 that at certain times during the period of growth and
development, and subsequent lactation in the case of a high-
yielding dairy cow, the rumen is not capable of producing
sufficient microbial protein to meet the animal's full
requirements for maximum growth or maximum production of
20 milk. It is therefore desirable that a proportion of the
animal's protein requirement be met by supplying a supplement
containing protein which is not degraded in, and thus passes
through, the rumen. This can result in an improvement in
feed conversion efficiency, growth rate and production as
25 compared with the use of an equal weight of degradable
protein, which degradable protein does not bypass the rumen.
Further it is beneficial to feed ruminant animals,
~ ~ 6 ~ PCT/GB93/01499
,;
in particular cows, with quantities of fat, particularly to
m~;m; se milk production. However if excess free fat or free
fatty acids are added to the feed, the free fat or free fatty
acids can physically coat fibrous or cellulosic material in
5 the rumen and thus prevent it from being broken down by the
rumen micro-organisms. This can have an adverse effect on
the total digestibility of the diet and resùlt in a reduced
yield of milk and/or butter fat. Further excess free fatty
acids and especially some unsaturated fatty acids are toxic
10 to certain micro-organisms in the rumen and this too can have
an adverse effect on the total digestibility of the diet. In
addition, under normal conditions, unsaturated fats fed to
ruminant animals are hydrogenated in the rumen with the
result that it is difficult to produce milk con~a;ning a high
15 proportion of unsaturated fats. The production of milk
containing increased amounts of unsaturated fat thus requires
that the fat be protected from normal rumen processes.
GB-PS 2113521 describes ruminant feedstuffs
comprising animal or vegetable protein nutritional material
20 dispersed in an edible, water-insoluble calcium or magnesium
salt of a fatty acid, the said salt constituting 50 to 80% of
the feedstuff. In such feedstuffs the nutritional material
is dispersed in the edible water-insoluble fatty acid salt or
salts. At the level of acidity or pH range normally found in
25 the rumen, the fatty acid salt is insoluble, and thus it
passes substantially unaltered through the rumen to the
relatively acidic conditions of the abomasum and small
W094/02028 ~1 G 7 4 9 ~ PCT/GB93/01499
-- 3
intestine, where the salt is converted to the free acid and
mineral ion which can then be utilised. This feedstuff can
be obtained by forming a dispersion of the protein material
in an aqueous solution of a water-soluble salt of the fatty
5 acid and then adding an aqueous solution of a compound
comprising a calcium or magnesium cation which forms a water-
insoluble salt with the fatty acid so that an edible water-
insoluble fatty acid is precipitated on the dispersed animal
or vegetable protein. Alternatively the animal or vegetable
10 protein may be dispersed in the fatty acid salt while the
latter is in the molten state and then the mixture is allowed
to cool.
US-PS 4826694 describes a dry friable, easy-to-
handle, rllm;n~nt feedstuff comprising edible water-insoluble
15 calcium or magnesium salt of fatty acid, extractable
triglycerides and edible calcium or magnesium oxide. This
feedstuff is produced by forming a mixture of basic oxide
such as calcium oxide, fatty acid and triglycerides and water
and allowing the oxide to react with the acid to form the
20 water-insoluble salt. There is also described such a
feedstuff containing up to 65% by weight of proteinaceous
nutritional material.
Although the added fatty acid in the feedstuffs of
GB-PS Z113521 and US-PS 4826694 is in a form substantially
2s unaltered in the rumen, the protein in the feedstuff of GB-PS
2113521 and any protein in the product of US-PS 4826694 is
substantially in its native or unprocessed state and any
.
W094/02028 PCT/GB93/01499
2~6~
4 _
protection of the protein within the rumen is provided by the
presence of the water-insoluble fatty acid salt. Although
elevated temperatures occur in the production of these
products, for example as a result of the exothermic formation
5 of the fatty acid salt, the conditions are not such as to
allow the rumen degradability of the protein material to be
substantially affected. Accordingly these processes are not
suitable for producing rumen-bypass protein.
According to the present invention there is
10 provided a rll~;n~nt feedstuff which comprises, in admixture,
one or more edible, water-insoluble calcium or magnesium
salts of one or more saturated or unsaturated fatty acids,
and animal or vegetable protein nutritional material, the
protein nutritional material having been converted during
15 formation of the fatty acid salt, e.g. by interacting fatty
acid and calcium or magnesium compound, into a form which is
substantially non-degradable in the rumen but which is
digestible in the lower gut.
The animal or vegetable protein material contained
20 within the feedstuff according to the present invention is of
improved non-degradability and by-passes the rumen with
substantially reduced loss of protein within the rumen
compared to that shown by the animal/vegetable protein when
in its native or unprocessed state. Moreover, the protein
25 material in the feedstuff according to the present invention
is digested in the lower gut with a high level of efficiency,
for example not less than 60~ and preferably better than 75~
W094/02028 21~ 7 ~ 9 5 PCT/GB93/01499
digestible.
By the term "substantially non-degradable in the
rumen" is to be understood that less than 50%, preferably
less than 30%, of nitrogen in the feedstuff is lost from a
5 sample of the feedstuff suspended in a bag, e.g. Dacron bag,
in the rumen for 16 hours. tDacron is a trade mark.]
The feedstuff according to the present invention
cannot be obtained by simple mixing. The conditions of
processing of the ingredients are important and must be such
10 as to render the protein material substantially rumen non-
degradable on the one hand but, on the other hand, must not
be so severe as to render it also lower gut non-digestible.
For example excessive heat treatment can render proteins both
rumen-non-degradable and lower gut non-digestible (Wilson PN
lS and Strachan PJ, Undegradable protein and the protein
requirement of dairy cows, Recent Advances in Animal
Nutrition 1980, Butterworths). The processing conditions
will of course vary according to the amount and type of
protein material being processed.
The feedstuff according to the present invention
usually is in particulate form and comprises a substantially
homogenous mixture of the ingredients.
The proportions of the ingredients in the
feedstuff can be adjusted to satisfy or meet the energy and
25 protein requirements of the animals to be fed. Generally the
feedstuff will contain at least 30~ by weight protein
material and up to 70~ by weight calcium or magnesium fatty
WO 94/02028 i PCr/GB93/01499
-- 6
acid salt. For example the feedstuff may contain 30 to 90%
by weight, preferably 40 to 7596, alternatively 55 to 8096 by
weight, protein material and, respectively, 70 to 10%, 60 to
259~ or 45 to 25% by weight fatty acid salt.
The feedstuff according to the present invention
may contain other conventional ingredients, including further
ingredients as described in GB-PS 2113521 and US-PS 4826694.
The present invention also provides a process for
the production of rllrirl~nt feedstuff, which process comprises
lo forming a substantially homogeneous mixture of animal or
vegetable protein nutritional material, one or more fatty
acids and a calcium or magnesium compound capable of forming
an edible water-insoluble salt with the fatty acid(s) at
elevated-temperature such that salt formation is initiated
15 and maintaining the processing conditions until the protein
material is rendered substantially rumen non-degradable but
digestible in the lower gut, and then cooling the product.
This is a particularly convenient production process, in
which the calcium or magnesium salt is formed, with the heat
20 of reaction being employed to provide at least part of the
conditions required for treatment of the protein material to
render it rumen non-degradable.
The process according to the invention may be
carried out batchwise using a reactor or, more conveniently,
25 continuously e.g. using a reactor conveyor.
In order to initiate the salt formation, the
process ingredients must be raised to elevated temperature.
W094/02028 21 6 74 9 ~ PCT/GB93/01499
The actual temperature will vary according to the particular
fatty acid and calcium or magnesium compound to be reacted
but generally a temperature of the order of 50 to 70C may be
sufficient. Clearly, for a practically useful process, it is
5 important that the initiation is achieved quickly. This may
be achieved suitably by injection of steam into the
substantially homogeneous mixture formed, preferably together
with preheating of one or more of the mixture components. If
preheating of the ingredients is to a sufficiently high
10 temperature, then the injection of steam or other addition of
water to the system may be unnecessary for adequate
initiation. Mechanical friction e.g. extrusion or other heat
transfer e.g. thermal screw could be used for preheating.
According to a preferred process according to the
lS present invention, ruminant feedstuff may be obtained by
forming a substantially homogeneous mixture of animal or
vegetable protein nutritional material, one or more fatty
acids, suitably in liquid form, and a calcium or magnesium
compound capable of forming an edible water-insoluble salt
20 with the fatty acid(s) under the conditions employed,
initiating reaction of the fatty acid(s) and calcium or
magnesium compound, suitably by injecting steam into the
substantially homogeneous mixture formed, maintaining the
mixture at elevated temperature, e.g. 110 to 115C, until the
25 protein nutritional material is rendered substantially non-
degradable in the rumen while remaining digestible in the
lower gut, and then cooling the product, which may then if
--
W094/02028 ~ 5 ~ PCT/GB93/01499
necessary be disintegrated to the desired particle size, and
packed.
The process according to the invention may
suitably be carried out on apparatus which comprises means
5 for feeding metered amounts of animal or vegetable protein
nutritional material, of one or more fatty acids, and of a
calcium or magnesium compound to the inlet of a continuously
operatable mixer, means for injecting steam into the mixer
downstream from the inlet, an outlet for discharge of mixture
lO from the mixer, and a conveyor mounted below said outlet.
The animal or vegetable protein nutritional
material used according to the present invention is
preferably a good quality animal or vegetable protein.
Examples of such nutritional materials are grass meal,
15 lucerne meal, field beans, peas, lupin seed, coconut meal,
cottonseed, groundnut, linseed, palm kernel, soya bean,
sunflower seed, rape seed, fish meal, meat and bone meal,
skimmed milk, whey protein, distillers' by-products, barley,
maize, oats, rye, rice, gluten meal, locust bean, canola,
20 feather meal, sorghum, safflower seed, single cell protein,
and yeast, all of which are suitable for feeding to ruminants
to improve the quality of their protein intake. Such
materials may be ground as necessary before inclusion in the
feedstuffs according to the present invention. It will be
25 understood that references to seed, kernel and fruit
nutritional materials include references to corresponding
meals (which may be defatted) made therefrom, e.g. rapeseed
W094/02028 ~1 6 7 4 ~ ~ PCT/GB93/0l499
and soya bean meals.
When oleaginous protein material is employed, e.g.
full fat seeds, then it is possible that, under the
conditions of treatment, the oil or fat contained therein may
5 be converted, at least partly, into free fatty acids which,
in turn, will react with the calcium or magnesium compound
resulting in the presence of additional fatty acid salt in
the feedstuff.
The fatty acids used in the invention are edible,
10 saturated or unsaturated fatty acids suitably contA; n; ng 14,
16, 18 and 20 carbon atoms per molecule, preferably myristic
acid, palmitic acid, stearic acid, oleic acid, linoleic acid
or linolenic acid. However higher and lower carbon content
acids may also be used such as lauric and arachidic. It is
15 normally preferred to use a naturally occurring mixture of
such fatty acids derived for example from beef or mutton
tallow, lard, palm oil, rapeseed oil, olive oil, soya bean
oil or groundnut oil. Such materials are produced as by-
products of edible oil refining.
Calcium oxide is the preferred basic oxide for use
in the process according to the present invention but
magnesium oxide may also be used. Burnt (calcined) limestone
is a suitable commercial source of lime. It usually contains
94 to 96% CaO and not more than 7% (usually 3 to 5%) of CaCO3.
25 Calcined magnesite is a suitable source of magnesium oxide.
If desired calcium oxide and magnesium oxide can be used in
admixture.
W094/02028 PCT/GB93/01499
2~7 ~ o -
The exothermic heat generated in the process
according to the present invention under the alkaline
reaction conditions may also be sufficient very significantly
to detoxify any feed or food mycotoxins which may be present;
s e.g. aflatoxin-contaminated protein meals are substantially
detoxified. Thus, it is a particular advantage of the
present invention that, when the starting protein material
contains mycotoxins, the protein material may be detoxified
under the processing conditions and accordingly that no
10 separate detoxification step is required.
The invention also includes within its scope a
method for detoxifying a nutritional material, especially one
of those mentioned above, which may contain a mycotoxin,
which comprises subjecting said feedstuff to a temperature in
15 the range 105 to 120C in the presence of interacting fatty
acid and calcium or magnesium-containing base. Preferably
the nutritional material is maintained at about 110C to
115C in the presence of reacting calcium oxide and fatty
acid for a sufficient time to bring about the desired
20 detoxification; a period of 20 to 90 minutes at 105 to 120C
is generally enough.
The invention is further illustrated, by way of
example, in the accompanying drawing in which there is shown
diagrammatically in cross-section apparatus for use in the
25 manufacture of feedstuff.
The apparatus shown in the drawing comprises a
first hopper 1 for protein meal or concentrate, in granular
W094/02028 2 ~ ~ 7 ~ 9 ~ PCT/GBg3/01499
form, which is to be incorporated into the feedstuff
according to the present invention. At its base, hopper 1 is
provided with a screw feed 2 in a duct 3, whereby the
granular protein meal or concentrate from hopper 1 is
5 forwarded by means of the screw feed 2 along duct 3 and
discharged, in metered amount, from the open end 4 of duct 3.
Similarly there is provided a second hopper 6 for compound
comprising a calcium or magnesium cation which forms a water-
insoluble salt with the fatty acid used. Suitably the
10 compound in hopper 6 is pulverised calcium oxide. Second
hopper 6 is provided with a screw feed 7 in duct 8.
Accordingly, in similar manner to that for hopper 1, material
from hopper 6 may be fed along duct 8 by means of screw feed
7 and discharged in metered amounts from open end 9.
Instead of hopper 1 there may alternatively be
employed an extruder or thermal screw or other heat transfer
to impart heat to the protein material.
Additionally there is provided a fixed head
orifice 10 for the fatty acid or fatty acid mixture to be
20 used in the manufacture of the feedstuff. The fixed head 11
above the orifice 10 is maintained by means of addition of
fatty acid at inlet 12 and overflow 13 above the fixed head.
Hoppers 1 and 6 and fixed head orifice 10 are all
positioned such that the discharge open ends 4 and 9 from the
- 25 hoppers and the orifice 10 are above the inlet 15 of a high
speed, in line, continuous mixer 16. The high speed mixer 16
is driven by drive 17.
W094/02028 PCT/GB93/01499
2~ $
- 12 -
Downstream from the inlet 15 there is injected
into the mixer 16 steam via a steam inlet point 18.
Further downstream in the mixer 16 there is
provided a discharge chute 19 whereby the contents from the
5 mixer are discharged onto a conveyer 20 which travels in the
direction indicated by the arrow.
In use of the apparatus, the fatty acid or fatty
acid mixture, suitably comprising essentially of C14, C16,
C18 and C20 fatty acids at generally 80C to 130C,
10 preferably about 110C, is metered via orifice 10 into the
high speed continuous mixer 16. Simultaneously protein meal
or concentrate and calcium (or magnesium) oxide are fed in
the desired amounts from hoppers 1 and 6 to open discharge
ends 4 and 9 respectively and into the inlet 15 of high speed
15 continuous mixer 16.
Suitably the ingredients are fed to the inlet of
mixer 16 in the following proportions:
Protein meal or
concentrate : 30 to 90%, preferably 55 to 80%
or 40 to 75%
Fatty acid or
fatty acid mixture: 8.5 to 60.9%, preferably 17 to
39% or 22 to 50%
Calcium oxide : 1.5 to 9.1~, preferably 3 to 6%
or 3 to 10%
.
W094/02028 21 6 74 ~ ~ PCT/GB93/01499
- 13 -
The percentages given are by weight.
The ingredients are mixed within high speed
J continuous mixer 16. The mixer 16 is operated at a shear
rate of 500 to 2000 rpm, preferably about 1000 rpm.
Downstream from inlet 15 steam is injected into
the mixture at steam inlet point 18. The steam has the dual
function of raising the temperature of the mixture while at
the same time initiating the salt formation reaction between
the fatty acid(s) and the calcium or magnesium compound. The
10 steam is suitably injected at 241-801 kPa (1.4-7.0 gauge
pressure bar), e.g. 376 kPa (2.75 gauge pressure bar), at a
temperature of 126 to 170C, e.g. 141C. Water is generally
not separately added, although the starting materials will
usually have a water content. Suitably the amount of water
15 present (as steam, within the starting material and any added
water) is 4 to 18%.
Where the protein nutritional material is
preheated, for example, by extrusion, steam injection may not
be necessary.
The thoroughly mixed matrix is discharged from
mixer 16 via discharge chute 19 onto the slowly moving
conveyor 20. The temperature of the discharged mixture is
generally in the region of 60 to 100C, suitably about 80C.
On the slowly moving conveyor salt formation takes place and
25 the associated exotherm causes the temperature of the mass tG
increase, generally to between 105 to 120C, suitably about
.
W O 94/02028 PC~r/GB93/01499
~6~ ~ 14 -
llo to 115C. The mixture should not be spread out on the
conveyor but retained in a compact mass on the conveyor in
order to m;ni~;Se heat loss through evolution of steam and
delay cooling for the required processing period.
The product is retained on the conveyor 20
suitably for 20 to 90 minutes, generally 35 to 60 minutes,
preferably 45 minutes or such further period of time as is
needed to achieve the required rumen undegradability in the
final product. The product from conveyor 20 is cooled,
10 disintegrated and/or pelleted, and packed.
The exposure of the protein meal or concentrate to
the heat released under the salt formation conditions during
the preparation of the feedstuff according to the present
invention substantially reduces the degradability of the
15 protein in the rumen such that less than 50% of the protein
is lost in the rumen but leaves the protein in a condition
digestible in the lower gut. Moreover, the conditions of the
process are sufficient very significantly to detoxify any
feed or food mycotoxins which may be present; e.g. aflatoxin-
20 contaminated protein meals are substantially detoxified. Theuse of base (lime) in the salt formation, in combination with
the steam and the heat of the ensuing exotherm is believed to
bring about this detoxification.
The invention is further illustrated in the
25 following Example.
EXAMPLE
Using apparatus as illustrated in the accompanying
W094/02028 ~ 4 ~ 5 PCT/G~93/01499
- 15 -
drawing, there are introduced into the mixer 16, rapeseed
meal from hopper 1, a fatty acid mixture derived from tallow
oil, preheated to a temperature of 110C, via orifice 10, and
granular lime from hopper 6. The ingredients were fed to the
5 mixer in the following proportions:
Rapeseed meal - 61.5%
Fatty acid mixture - 33%
Lime _ 5.5%
The percentages are by weight.
Within mixer 16, the ingredients are mixed with
the mixer being operated at a shear rate of 1000 rpm.
Downstream from the inlet 15 of mixer 16, steam, at 376 kPa
and 141C, is introduced.
The thoroughly mixed mixture is discharged from
15 mixer 16 at approximately 80C via discharge chute 19 onto
the slowly moving conveyor 20. The mixture is discharged
onto the conveyor in a compact mass with a view to m; n; m; sing
heat loss. The salt formation reaction ensues within the
mass on the conveyor and the temperature of the mass
20 increases to 110 to 115C. The mixture is retained at this
temperature for about 50 minutes, the time being sufficient
under the conditions on the conveyor to render the rapeseed
meal substantially non-degradable in the rumen while
remaining digestible in the lower gut. Also under these
25 conditions any mycotoxins in the starting meal are
.
W094/02028 PCT/GB93/01499
- 16 -
substantially destroyed.
The product is then removed from the conveyor,
cooled, disintegrated and/or pelleted, and packed.
