U.S. patent application number 14/036178 was filed with the patent office on 2014-06-19 for method to evaluate the quantity of methane produced by a dairy ruminant and method to reduce and control this quantity.
This patent application is currently assigned to VALOREX. The applicant listed for this patent is Guillaume Chesneau, Yves Chilliard, Michel Doreau, Cecile Martin, Pierre Weill. Invention is credited to Guillaume Chesneau, Yves Chilliard, Michel Doreau, Cecile Martin, Pierre Weill.
Application Number | 20140170755 14/036178 |
Document ID | / |
Family ID | 40158605 |
Filed Date | 2014-06-19 |
United States Patent
Application |
20140170755 |
Kind Code |
A1 |
Weill; Pierre ; et
al. |
June 19, 2014 |
METHOD TO EVALUATE THE QUANTITY OF METHANE PRODUCED BY A DAIRY
RUMINANT AND METHOD TO REDUCE AND CONTROL THIS QUANTITY
Abstract
The present invention relates in particular to a method to
evaluate the quantity of methane produced by a dairy ruminant. The
method comprises determination of the ratio between the quantity of
fatty acids with 16 carbon atoms or less and the sum of the total
fatty acids of the milk, said quantity of methane being defined by
the following equation: Quantity CH.sub.4=(FA<C16/Total
FAs)*a*(milk production).sup.b in which: quantity CH.sub.4 (in
g/litre of milk)=quantity of methane produced; FA<C16=quantity
of fatty acids with 16 carbon atoms or less; Total FAs =total
quantity of fatty acids; expression of the ratio (FA<C16)/(Total
FAs) as a % of total FAs; milk production=quantity of milk produced
in kg of milk/animal and per year; a and b are numerical parameters
in which a lies between 10 and 13, and b lies between -0.40 and
-0.45.
Inventors: |
Weill; Pierre; (Vern Sur
Seiche, FR) ; Chesneau; Guillaume; (Luitre, FR)
; Chilliard; Yves; (Ceyrat, FR) ; Doreau;
Michel; (Saint Saturnin, FR) ; Martin; Cecile;
(Saint Saturnin, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Weill; Pierre
Chesneau; Guillaume
Chilliard; Yves
Doreau; Michel
Martin; Cecile |
Vern Sur Seiche
Luitre
Ceyrat
Saint Saturnin
Saint Saturnin |
|
FR
FR
FR
FR
FR |
|
|
Assignee: |
VALOREX
Combourtille
FR
|
Family ID: |
40158605 |
Appl. No.: |
14/036178 |
Filed: |
September 25, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12452243 |
Dec 18, 2009 |
8642100 |
|
|
PCT/EP2009/057919 |
Jun 24, 2009 |
|
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14036178 |
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Current U.S.
Class: |
436/23 ;
702/19 |
Current CPC
Class: |
G01N 33/06 20130101;
A23K 50/10 20160501; A23K 20/158 20160501 |
Class at
Publication: |
436/23 ;
702/19 |
International
Class: |
G01N 33/06 20060101
G01N033/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2008 |
FR |
08 54230 |
Claims
1. A method to evaluate the quantity of methane produced by a dairy
ruminant, comprising: determining the ratio between the quantity of
fatty acids with 16 carbon atoms or less, called FA<C16 and the
sum of the total fatty acids in the milk, said fatty acids being
those found in the milk produced by said ruminant, said quantity of
methane being defined by the following equation: Quantity
CH.sub.4=(FA<C16/Total FAs)*a*(milk production).sup.b in which:
quantity CH.sub.4 (in g/litre of milk)=quantity of methane
produced; FA<C16=quantity of fatty acids with 16 carbon atoms or
less; Total FAs=total quantity of fatty acids; expression of the
ratio (FA<C16)/(Total FAs) as a % of total FAs; milk
production=quantity of milk produced in kg of milk/animal and per
year; a and b are numerical parameters, with a lying between 10 and
13, and b lying between -0.40 and -0.45.
2. The method of claim 1, wherein a and b are respectively 11.368
and -0.4274.
3.-6. (canceled)
7. A method to evaluate the quantity of methane produced by a dairy
ruminant, comprising: (a) assaying fatty acids of milk produced by
a dairy ruminant; (b) determining the ratio between the quantity of
fatty acids with 16 carbon atoms or less, called FA<C16, and the
sum of the total fatty acids in the milk, said fatty acids being
those found in the milk produced by said ruminant; (c) calculating
said quantity of methane which is defined by the following
equation: Quantity CH.sub.4=(FA<C16/Total FAs)*a*(milk
production).sup.b in which: quantity CH.sub.4 (in g/litre of
milk)=quantity of methane produced; FA<C16=quantity of fatty
acids with 16 carbon atoms or less; Total FAs=total quantity of
fatty acids; expression of the ratio (FA<C16)/(Total FAs) as a %
of total FAs; milk production=quantity of milk produced in kg of
milk/animal and per year; a and b are numerical parameters, with a
lying between 10 and 13, and b lying between -0.40 and -0.45.
8. The method of claim 7, wherein a and b are respectively 11.368
and -0.4274.
9. A method to evaluate the quantity of methane produced by a dairy
ruminant for use in reducing or controlling the quantity of methane
produced by the ruminant, comprising: (a) assaying fatty acids of
milk produced by a dairy ruminant by: (i) determining the total
content of fatty acids in the milk; and (ii) determining the
content of fatty acids with 16 carbons or less in the milk; (b)
determining the ratio between the content of fatty acids with 16
carbon atoms or less and the total content of fatty acids in the
milk; (c) determining the milk production of said ruminant, wherein
said milk production is the quantity of milk produced in kg of milk
per animal per year; and (d) calculating said quantity of methane
which is defined by the following equation: Quantity
CH.sub.4=(FA<C16/Total FAs)*a*(milk production).sup.b in which:
quantity CH.sub.4 (in g/litre of milk)=quantity of methane
produced; FA<C16=content of fatty acids with 16 carbon atoms or
less; Total FAs=total content of fatty acids; expression of the
ratio (FA<C16)/(Total FAs) as a % of total FAs; milk
production=quantity of milk produced in kg of milk/animal and per
year; a and b are numerical parameters, with a lying between 10 and
13, and b lying between -0.40 and -0.45.
10. The method of claim 9, wherein a and b are respectively 11.368
and -0.4274.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This present application is a continuation of U.S. patent
application Ser. No. 12/452,243, filed Dec. 18, 2009, which is a
national phase entry under 35 U.S.C. .sctn.371 of International
Application No. PCT/EP2009/057919, filed Jun. 24, 2009, which
claims benefit of French Application No. 08 54230 filed Jun. 25,
2008. The disclosures of all of said applications are incorporated
by reference herein.
BACKGROUND OF THE INVENTION
[0002] The present invention lies in the area of animal feed, and
more precisely in the area of feed for milk-producing animals.
[0003] It more particularly concerns a method to evaluate the
quantity of methane produced by a dairy ruminant, and a method to
control the quantity of methane produced by a dairy ruminant.
[0004] The digestion of organic matter by ruminants comprises a
microbial fermentation phase in the rumen. During this phase, plant
polysaccharides (such as cellulose, hemicellulose, pectin, and
starch) are broken down by the anaerobic bacteria living in the
rumen.
[0005] This gives rise to the production of various volatile fatty
acids (VFAs) (acetate, propionate, and butyrate [in increasing
order of importance], carbon dioxide [CO.sub.2] and hydrogen
[H.sub.2]).
[0006] Since the rumen is an anaerobic medium, the production of
energy (ATP) occurs by "hydrogen transfer".
[0007] Hydrogen inhibits the activity of most bacteria via
different mechanisms. The hydrogen produced must therefore be
eliminated by the rumen to promote good microbial digestion.
[0008] Methanogenesis, leading to the formation of methane
(CH.sub.4), is the main route allowing this elimination. It can be
symbolized by the following reaction:
[CO.sub.2+4H.sub.2]=CH.sub.4+2H.sub.2O
[0009] This conversion is ensured by methanogenic bacteria which
live in association with protozoa (which form the rumen's
microfauna).
[0010] Methane (CH.sub.4), together with carbon dioxide (CO.sub.2),
nitrous oxide (N.sub.2O), and the three halogen carbons
(Chlorofluorocarbons CFCs, hydrofluorocarbons HFCs, and
perfluorocarbons PFCs), is one of the main greenhouse gases
(GGs).
[0011] Its contribution to the greenhouse effect is very
considerable. One molecule of CH.sub.4 is effectively equivalent to
21 molecules of CO.sub.2, according to official equivalence
tables.
[0012] These GGs are believed to have an effect on climate change
and in particular on global warming. Since the World Earth Summit
in Rio in 1992, the fight against these changes has become an
international commitment which, in 1997, translated as quantitative
commitments taken under the Kyoto protocol.
[0013] The European Council has set itself the target of reducing
GGs by 20% between now and 2020. In 2003, livestock farming
generated 47.7 MMTCDE (million metric tons of carbon dioxide
equivalent) of which 28.3 MMTCDE in the form of methane derived
from the digestive fermentation of ruminants (Leseur, 2006; Martin
et al., 2006).
[0014] These methane emissions represent 26% of emissions by the
farming sector and 5% of French GG emissions (Leseur, 2006).
[0015] It therefore appears necessary to reduce the methane
emissions of ruminants.
[0016] Different solutions have been put forward to reach this
objective.
[0017] The first consists of limiting the consumption of products
derived from ruminants and in particular dairy products, the effect
of which would be to reduce the number of these dairy ruminants and
hence logically the emissions of methane.
[0018] However, dairy products have been present in the food of
human beings since time began. Man is known to be the only animal
species to eat dairy products after weaning. Also, at nutritional
level, these dairy products contain calcium, proteins, and lipids
with very special nutritional properties which cannot be
dissociated from a balanced diet at all stages of life.
[0019] Additionally, the increase in the planet's population
appears scarcely compatible with a reduction in numbers of
livestock intended to feed this increasing population.
[0020] Another solution consists of changing the feed of dairy
ruminants (cows, sheep, goats, etc.) by directing the mechanisms of
rumination towards decreased methane production.
[0021] Different techniques have been suggested to reach this
objective.
[0022] The first consists of increasing the quantity of milk
produced per cow (intensified livestock farming).
[0023] The second provides for additives in the feed that are toxic
for protozoa and/or methanogenic bacteria so that milk can be
produced with a reduction in the emitted quantities of methane.
[0024] Finally, a third technique consists of adding sources of
plant lipids high in unsaturated fatty acids to the feed of dairy
ruminants, preferably from the Omega-3 family, or in the form of
other unsaturated fatty acids although their effects on
methanogenesis are less powerful (than those of Omega-3 fatty
acids). These fatty acids are toxic for methanogenic bacteria,
either directly or via the toxic effects on protozoa which live in
association with these methanogenic bacteria.
[0025] However, these different techniques can only be of real
interest if there is a practical method, that is easy to implement,
to evaluate the quantity of methane produced by ruminants.
[0026] Yet, measurement of methane emissions at the present time is
only possible at experimental stations, but in cumbersome costly
manner.
[0027] The present invention sets out to overcome this
shortcoming.
SUMMARY OF THE INVENTION
[0028] Therefore, according to a first aspect, the present
invention concerns a method to evaluate the quantity of methane
produced by a dairy ruminant, characterized by the fact that it
comprises determination of the ratio between the quantity of fatty
acids with 16 carbon atoms or less, called FA<C16, and the sum
of the total fatty acids in the milk, said fatty acids being those
present in the milk produced by said ruminant, said quantity of
methane being defined by the following equation:
Quantity CH.sub.4=(FA<C16/total FAs)*a*(milk
production).sup.b
in which: [0029] quantity CH.sub.4 (in g/litre of milk)=quantity of
methane produced; [0030] FA<C16=quantity of fatty acids with 16
carbon atoms or less; [0031] Total FAs=total quantity of fatty
acids; [0032] expression of the ratio (FA<C16)/(Total FAs) as a
% of Total FAs; [0033] milk production=quantity of milk produced in
kg milk/per animal/per year; [0034] a and b are numerical
parameters, with a lying between 10 and 13 and b lying between
-0.40 and -0.45.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a graph which shows the prediction of production
of CH.sub.4 based on the production of Volatile Fatty Acids
(VFAs).
DETAILED DESCRIPTION
[0036] Therefore, according to a first aspect, the present
invention concerns a method to evaluate the quantity of methane
produced by a dairy ruminant, characterized by the fact that it
comprises determination of the ratio between the quantity of fatty
acids with 16 carbon atoms or less, called FA<C16, and the sum
of the total fatty acids in the milk, said fatty acids being those
present in the milk produced by said ruminant, said quantity of
methane being defined by the following equation:
Quantity CH.sub.4=(FA<C16/total FAs)*a*(milk
production).sup.b
in which: [0037] quantity CH.sub.4 (in g/litre of milk)=quantity of
methane produced; [0038] FA<C16=quantity of fatty acids with 16
carbon atoms or less; [0039] Total FAs=total quantity of fatty
acids; [0040] expression of the ratio (FA<C16)/(Total FAs) as a
% of Total FAs; [0041] milk production=quantity of milk produced in
kg milk/per animal/per year; [0042] a and b are numerical
parameters, with a lying between 10 and 13 and b lying between
-0.40 and -0.45.
[0043] This method is easy to implement since the present applicant
has evidenced that the quantity of methane produced is directly
related to the quantity of fatty acids in the milk. Also, the assay
of fatty acids in milk is an operation that is currently given very
wide application and does not require any sophisticated or costly
means.
[0044] In one preferred embodiment, a and b are respectively 11.368
and -0.4274.
[0045] Another aspect of the invention relates to a method to
reduce and control the quantity of methane produced by a dairy
ruminant.
[0046] This method is noteworthy in that it consists of: [0047]
giving the ruminant a food ration which meets at least one of the
following criteria:
[0048] a) it excludes all fat of animal origin;
[0049] b) it limits the exogenous intake of vegetable oil
containing more than 30% Total FA in the form of saturated FAs, in
the natural state, hydrogenated, or saponified, to no more than 15
grams/animal and per 100 kg live weight;
[0050] c) it contains at least one lipid source high in omega-3
alpha-linolenic acid (ALA), i.e. of which more than 30% of the
Total FAs are in the form of omega-3 FAs;
[0051] and of controlling said quantity of methane by applying the
method according to one of the preceding characteristics.
[0052] Preferably, this lipid source is in the form of grazed
fodder or conserved forage (wilted grass, silage, wrapped round
bale, dehydrated, etc.) or oil seeds (in the natural state, raw, or
cooked) high in ALA and oil-cakes of these same oil seeds.
[0053] Advantageously, said source includes flax (linseed).
[0054] Other characteristics and advantages of the invention will
become apparent from the following detailed description.
1--Production of Volatile Fatty Acids (VFAs) And Production of
Methane (CH.sub.4)
[0055] The link between the production of VFAs in the rumen and the
production of methane has been known and researched for many
years.
[0056] It has been shown for example that the production of acetate
and butyrate releases hydrogen, and therefore promotes the
production of methane, whereas the production of propionate allows
the hydrogen to be used and hence limits methane production
(Gworgwor et al., 2006).
[0057] This can be illustrated by the following equations:
[0058] 1 Glucose (C6) gives 2 Pyruvates (C3) [+4H]
[0059] 1 Pyruvate (C3)+H.sub.2O=1 Acetate+CO.sub.2 [+2H] and:
[0060] 1 Pyruvate=1 propionate (C3) [-4H]
[0061] A predictive equation has therefore been developed to
predict the production of CH.sub.4 from the production of VFAs,
using the graph given in appended FIG. 1 (Moss et al., 2000).
Therefore, the greater the production of C2 and C4 by fermentations
in the rumen, the greater the production of CH.sub.4.
[0062] Conversely, the greater the production of C3 by
fermentations in the rumen, the more the production of CH.sub.4 is
reduced.
[0063] The synthesis equation following therefrom is defined as
follows: [CH.sub.4]=0.45 [acetate]+0.40 [Butyrate]-0.275
[Propionate]
where [x]=quantity of x, as a % of Total VFAs.
2--Influence of the Intake of A Source (Digestible In the Rumen) of
Omega-3 Alpha-Linolenic Acid (ALA) On the Production of VFAs And
CH.sub.4
[0064] Omega-3-alpha-linolenic acid or C18: 3 n-3 or "ALA" is one
of the mass constituents of growing plants.
[0065] It is found in abundance for example in young grass and in
algae in which it accounts for the vast majority (50 to 75%) of the
fatty acids in these plants. ALA is a basic constituent of
chlorophyll membranes.
[0066] ALA is also found in some oilseeds such as flax seed (45% to
70%), hemp (around 15%), rapeseed or soy (around 10%).
[0067] The ALA content in the ration of dairy ruminants modifies
the microbial population present in the rumen. ALA, directly and
indirectly, effectively inhibits methanogenic bacteria and
significantly modifies the proportions of VFAs produced, in
particular by lowering the quantities of acetate and butyrate
produced.
[0068] According to numerous sources in the scientific literature,
when an ALA source is added to the ration of a ruminant, the
production of propionic acid (C3) increases, and the proportions of
acetic acid (C2) and butyric acid (C4) are reduced.
[0069] It therefore appears that: [0070] the ratio [(C2+C4) to C3]
is a very good index for the production of methane in the rumen;
[0071] the intake of ALA in the diets of dairy ruminants has a
linear effect on the ratio (C2+C4)/C3 which is regularly decreased
when, all other things being equivalent, the quantity of ALA
ingested by the ruminant is increased.
[0072] It is to be noted, however that ALA sources can have
different effects depending on the site of ALA digestion.
[0073] For example, raw flax seeds only bring a scarce reduction in
the ratio [(C2+C4)/C3)], whereas extruded flax seeds and flax seed
oils bring a strong increase.
[0074] The ability to modify this ratio [(C2+C4)/C3)] is therefore
related to the quantity of ALA in animal diet but also to the
availability of ALA in the rumen.
3--Influence of the Ratio [(C2+C4)/C3)] On Milk Composition
[0075] VFAs (C2, C3, or C4) produced by the rumen are diffused
through its walls, or move on further through the intestinal
barrier to enter circulating fluids.
[0076] Propionic acid (C3) is used as "glucogenic" source and
contributes towards milk production as lactose precursor.
[0077] On the contrary, acetic (C2) and butyric (C4) acids are used
by the de novo synthesis mechanisms to produce the saturated fatty
acids of milk with 2 to 16 carbon atoms.
[0078] This synthesis, which takes place in the mammary epithelial
cells, uses acetyl coA, a compound derived from C2 and/or C4 for
these syntheses of C14: 0 and C16: 0.
[0079] These 2 fatty acids are then "shortened" (peroxisomal
beta-oxidation) to produce short and medium-chain fatty acids of
milk. These fatty acids can then optionally be desaturated into
mono-unsaturated fatty acids under mammary desaturase activity.
4--Theoretical Model
[0080] The quantity of CH.sub.4 produced per litre of milk
therefore takes into account:
[0081] a) the animal's yearly milk production.
[0082] The more a dairy cow (for example) produces milk, the more
the production of methane per litre of milk is decreased.
Therefore, some authors propose the following equation:
Quantity of methane produced (kg per cow per
year)=55.7+0.0098*(milk production, in kg per year and per
animal).
[0083] b) ration composition, and in particular the quantity of
available ALA in the rumen.
[0084] c) the ratio (C2+C4)/C3 in the rumen of these animals.
[0085] This VFA ratio is to be read as having a strong biological
causal link with milk composition, in the form of the ratio
between:
[0086] i) the sum of milk FAs with 16 or less than 16 carbon
atoms,
[0087] and
[0088] ii) the sum of all the milk FAs.
[0089] The quantity of CH.sub.4 produced per dairy female can
therefore be calculated in relation to milk production (kg milk,
per year, per animal) and to the FA composition of the milk from
this animal.
[0090] It therefore appears that the person skilled in the art may
have at hand a precious tool to evaluate the production of methane
by dairy animals, in relation to their production level (easy to
measure) and to the composition of the milk (easy to measure).
[0091] This indirect, but accurate, measurement of methane
production can be used as a guide for the rationing systems of
dairy ruminant animals, so as to reduce their contribution towards
the greenhouse effect and to allow rapid measurement of the effects
of these changes.
5--Test And Interpretation of Results
[0092] Numerous tests are available in the general bibliography
which describe the effects of an intake of a food ALA source (most
often in the form of flax) on the production of methane by cows,
goats, and other female dairy ruminants.
[0093] Other tests are available which describe the effects of
these same ALA sources, in the form of flax, on the fatty acid (FA)
composition of milk.
[0094] Matching and synthesis of these results have been carried
out to validate the theoretical model. These results are given in
Table 1 below.
[0095] The focus here was to measure the production of CH.sub.4 per
litre of milk as a function of: [0096] milk production
(kg/animal/year); [0097] the ratio between milk FAs having 16
carbon atoms or less as a % of total FAs.
[0098] Evidently, we could have chosen other FAs or other sums or
ratios of FAs to illustrate the effects of de novo synthesis of
saturated FAs in the udder, using the C2 produced in the rumen with
CH.sub.4 emission.
[0099] However, the sum of saturated FAs with 16 carbon atoms or
less is particularly representative of this de novo synthesis from
C2. Additionally, reading of the C16 fatty acids or of the sums of
FAs with 12, 14, 16 carbon atoms, even the ratio between C16 and
the sum of saturated FAs would also be relevant criteria.
[0100] This compiling of results was notably made from tests which
firstly gave the FA profiles of milk and secondly gave measurements
of methane produced per litre of milk, in tests using extruded flax
seeds as ALA source and on cows having different production
levels.
TABLE-US-00001 TABLE 1 Production of methane per litre of milk in
relation to milk production per animal and to milk FA profile, over
a given range of milk FA profile MP FA 4 000 5 000 6 000 7 000 8
000 9 000 10 000 11 000 12 000 13 000 14 000 70 23.7 20.9 19.1 17.8
16.8 16.0 15.4 14.9 14.4 14.1 13.8 68 23.0 20.3 18.5 17.2 16.3 15.5
14.9 14.4 14.0 13.7 13.4 66 22.4 19.7 18.0 16.7 15.8 15.1 14.5 14.0
13.6 13.3 13.0 64 21.7 19.1 17.4 16.2 15.3 14.6 14.1 13.6 13.2 12.9
12.6 62 21.0 18.5 16.9 15.7 14.8 14.2 13.6 13.2 12.8 12.5 12.2 60
20.3 17.9 16.4 15.2 14.4 13.7 13.2 12.7 12.4 12.1 11.8 58 19.7 17.4
15.8 14.7 13.9 13.2 12.7 12.3 12.0 11.7 11.4 56 19.0 16.8 15.3 14.2
13.4 12.8 12.3 11.9 11.6 11.3 11.0 54 18.3 16.2 14.7 13.7 12.9 12.3
11.9 11.5 11.1 10.9 10.6 52 17.6 15.6 14.2 13.2 12.5 11.9 11.4 11.0
10.7 10.5 10.2 50 16.9 15.0 13.6 12.7 12.0 11.4 11.0 10.6 10.3 10.1
9.8 48 16.3 14.4 13.1 12.2 11.5 11.0 10.5 10.2 9.9 9.7 9.4 46 15.6
13.8 12.5 11.7 11.0 10.5 10.1 9.8 9.5 9.3 9.1 44 14.9 13.2 12.0
11.2 10.5 10.1 9.7 9.3 9.1 8.9 8.7 42 14.2 12.6 11.5 10.7 10.1 9.6
9.2 8.9 8.7 8.5 8.3 NB: This range of milk FA profile was
deliberately limited to the range in which FAs with 16 carbon atoms
or less account for 70 to 42% of the milk FAs. Not because the
ensuing biological model or equation is limited to this range, but
because beyond the limits of this range the composition of the
milks produced can be considered firstly to be nutritionally
doubtful and secondly ncompatible with the above-defined means used
to obtain these milks.
[0101] In this table: MP (horizontally)=milk production
(kg/animal/year) and FA=[FA<C16/Total FAs], as a %.
[0102] We have therefore drawn up a predictive table for emitted
CH.sub.4 values on the basis of milk production data and the FA
profiles of these milks so produced:
TABLE-US-00002 TABLE 2 MP FA 4 000 5 000 6 000 7 000 8 000 9 000 10
000 11 000 12 000 13 000 14 000 70 23.0 20.9 19.3 18.1 17.1 16.2
15.5 14.9 14.4 13.9 13.5 68 22.3 20.3 18.8 17.6 16.6 15.8 15.1 14.5
14.0 13.5 13.1 66 21.7 19.7 18.2 17.1 16.1 15.3 14.6 14.1 13.5 13.1
12.7 64 21.0 19.1 17.7 16.5 15.6 14.9 14.2 13.6 13.1 12.7 12.3 62
20.3 18.5 17.1 16.0 15.1 14.4 13.8 13.2 12.7 12.3 11.9 60 19.7 17.9
16.6 15.5 14.6 13.9 13.3 12.8 12.3 11.9 11.5 58 19.0 17.3 16.0 15.0
14.2 13.5 12.9 12.4 11.9 11.5 11.1 56 18.4 16.7 15.5 14.5 13.7 13.0
12.4 11.9 11.5 11.1 10.8 54 17.7 16.1 14.9 14.0 13.2 12.5 12.0 11.5
11.1 10.7 10.4 52 17.1 15.5 14.4 13.4 12.7 12.1 11.5 11.1 10.7 10.3
10.0 50 16.4 14.9 13.8 12.9 12.2 11.6 11.1 10.7 10.3 9.9 9.6 48
15.8 14.3 13.2 12.4 11.7 11.1 10.6 10.2 9.9 9.5 9.2 46 15.1 13.7
12.7 11.9 11.2 10.7 10.2 9.8 9.4 9.1 8.8 44 14.4 13.1 12.1 11.4
10.7 10.2 9.8 9.4 9.0 8.7 8.5 42 13.8 12.5 11.6 10.9 10.3 9.7 9.3
8.9 8.6 8.3 8.1
6--Validation of This Model
[0103] We have the results of several tests which accurately
measured: [0104] the quantity of ALA (available in the rumen) in
the rations of dairy cows; [0105] the effects of this ALA on the
ratio (C2+C4)/C3; [0106] the effects of these rations on the milk
FA profile; [0107] and finally tests which compared the production
of CH.sub.4 per litre of milk with different ALA contents in the
rations.
[0108] The table below compares the measured values with the values
"predicted" from the above-mentioned tables.
TABLE-US-00003 TABLE 3 Tests 1 2 3 4 5 6 Milk 6 000 6 000 7 000 7
000 7 000 6 000 production FA >=C16 61 42 66 64 56 42 CH.sub.4
in g/l 16.8 11.8 17.2 16.2 13.8 10.9 milk "Prediction" in g/l As
per Table 1 16.4 11.5 17.2 16.2 14.2 11.5 As per Table 2 16.4 11.5
17.2 15.7 14.2 11.5
[0109] The present applicant has inferred from these tests that the
quantity of methane can be defined by the following equation:
Quantity CH.sub.4=(FA<C16/Total FAs)*a*(milk
production).sup.b
in which: [0110] quantity CH.sub.4 (in g/litre of milk)=quantity of
methane produced; [0111] FA<C16=quantity of fatty acids with 16
carbon atoms or less; [0112] Total FAs=total quantity of fatty
acids; [0113] milk production=quantity of milk produced in kg per
animal per year [0114] a and b=numerical parameters in which a lies
between 10 and 13, and b lies between -0.40 and -0.45.
[0115] Preferably, parameters a and b are 11.368 and -0.4274
respectively.
* * * * *