Is organic milk the cream of the crop?
Effect production organic and low input
production systems on the
nutritional composition of milk and meat
Gillian Butler and Carlo Leifert
Objectives
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carry out applied research addressing problems in
“low input” and organic food production systems
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carry out strategic research into the effects of
agronomic practices on sustainability and environmental
impact of agriculture and food quality and safety
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provide field research facilities for and collaborate with
fundamental research groups in the areas soil, plant,
animal, ecology, molecular and environmental science
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Provide technology transfer services to the “low input”
and organic food and farming industries
Farming practices/standards;
Livestock production
ORGANIC
CONVENTIONAL
FOCUS: welfare & on farm
sustainability
- access to outside
FOCUS: maximum
production efficiency
- indoor production
-
lower stocking density
no growth promoters
longer withdrawal periods
on farm feed production
ruminants (cattle, sheep)
on forage (= grass) diets
- high stocking densities
- ABGPs use (pigs/poultry)
- standard withdrawal period
- bought in feed
- ruminants (cattle, sheep)
on high concentrate
(=cereal maize) and
conserved forage diets
LIVESTOCK PRODUCTION
Milk composition survey
EU-Integrated project QualityLowInputFood
www.qlif.org
Experimental work
Nafferton Ecological Farming Group monitored milk from
25 farms in the UK
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2 production systems in North East England
(and also, Sweden, Denmark and Italy)
1. High input conventional
2. Low Input organic certified
3 production systems in Wales
1. High input conventional
2. Low Input organic certified (block calving)
3. Low Input non-certified (block calving)
Proportion of Holstein Friesian genetics in
conventional, organic, ‘low input’ dairy herds
a
100
%
Holstein
Friesian
genetics
b
c
80
60
40
20
0
Conventional
Organic
Low Input
Dairy production system
Diets of conventional, organic, and ‘low input’
dairy herds
Fresh forage
Conserved forage
Concentrate
100
%
of diet
80
60
+ synthetic
Vitamin E
40
20
0
Conventional
Organic
Low Input
Dairy production system
Proportion of cows receiving antibiotic
treatments for mastitis in conventional,
organic, ‘low input’ dairy herds
6
%
cows
treated
for
mastitis
a
4
b
2
b
0
Conventional
Organic
Low Input
Dairy production system
Milk yield per cow in conventional, organic,
‘low input’ dairy herds
30
a
%
Milk yield
per cow 20
b
b
10
0
Conventional
Organic
Low Input
Dairy production system
Protein and fat content in milk from
conventional, organic, ‘low input’ dairy herds
50
%
Protein
Fat
45
a
ab
b
40
A
35
B
C
30
Conventional
Organic
Low Input
Dairy production system
LIVESTOCK PRODUCTION
Milk composition
What is good and bad in milk?
EU-Integrated project QualityLowInputFood
www.qlif.org
Milk composition
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Milk is recognised to be a valuable sources of
1. protein,
2. minerals (especially Calcium)
3. and vitamins …
But also contains Milk fat!
For years milk fat (butter & cream) was mainly know
for its nutritionally undesirable components:
High levels of saturated fats, which are known to
increase
1. blood LDL (bad) cholesterol levels an
2. the risk of heart disease
Unsaturated milk fatty acids
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Milk fat also contains 25-40% unsaturated fats,
some of these have been linked to positive
effects on health
the main unsaturated fatty acids linked to
potential positive effects on health are:
1. α-linolenic acid (α-LA), C18:3c9c12c15
= the main omega-3 fatty acid (n-3) in milk
2. conjugated linoleic acid isomer C18:2c9 t11
(CLA9)
3. vaccinic acid (VA) C18:1t11, which the
human body can convert into CLA isomer
C18:2 c9 t11
Nutritionally desirable
polyunsaturated fatty acids
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Omega 3 fatty acids (n-3; mainly α-LA in milk)
(Hu et al., American Journal of Clinical Nutrition;69(5):890-897 and Horrobin,
American Journal of Clinical Nutrition;57:732S-736S)
– Reduced risk of diabetes and heart/cardiovascular diseases
– Important for nervous tissue development; linked to improved
brain function (especially the longer chain n-3 fatty acids)
– α-LA can be converted in humans to longer chain n-3 FAs;
whether the level of conversion if of health relevance is still
controversial.
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CLA9 (C18:2c9t11)
(Whigham, Cook and Atkinson, Pharmacological Research 2000;42(6):503-10)
– Reducing cancer risk
– Preventing heart disease
– Improving immune function
Unsaturated milk fatty acids
However
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Some of the unsaturated fats are less desirable
these include:
1. omega-6 fatty acids (n-6) , because it is
thought that we take up too much omega-6
and too little omega 3 fatty acids in our diet
2. CLA isomer C18:2c10 c121 (CLA10), which
was linked to both beneficial and negative
health effects
Omega 3 and omega 6 levels in milk from
conventional, organic, and ‘low input’
dairy herds (outdoor grazing period)
omega 3 FA (α-LA)
omega 6 FA
25
g kg-1
milk fat 20
a
b
15
A
10
A
c
B
5
0
Conventional
Organic
Low Input
Dairy production system
Omega 3 : 6 ratio in milk from conventional,
organic, and ‘low input’ dairy herds
(outdoor grazing period)
1
n-3:n6
FA 0.8
ratio
a
a
0.6
b
0.4
0.2
0
Conventional
Organic
Low Input
Dairy production system
Sources of omega-3 fatty acids and CLA9
in the human diet
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Most foods are low in omega 3 fatty acids; except
for oily fish which is high in omega 3 fatty acids
The only source of CLA9 is ruminant fat in milk,
dairy products or meat from cows, sheep and goats
CLA9 can be produced from vaccenic acid (VA) in
the human body by the ∆-9 desaturase enzyme
C18:1 t11
VA
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∆-9 d
C18:2 c9 t11
CLA
The total potential CLA content in the diet is
therefore CLA9 +VA
VA, CLA9 and CLA10 levels in milk from
conventional, organic, and ‘low input’
dairy herds (outdoor grazing period)
VA (C18:1 t11)
40
CLA9 (C18:2 c9 t11)
A
g kg-1
milk fat
CLA10 (C18:3 t10 c12)
A
30
B
c
20
10
b
a
ns
ns
ns
0
Conventional
Organic
Low Input
Dairy production system
Fat soluble Antioxidants
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Milk is a valuable source of fat soluble vitamins and
antioxidants
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Vitamin E levels in butter are higher than in most
fruit and vegetables
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β carotene levels of butter are higher than in many
fruits
Antioxidants have 3 important functions
– linked to protection against cancer and heart disease in
humans
– Improve the health of dairy cows (Vit E especially;
reduced mastitis and improved fertility)
– Prolong shelf life of unsaturated fats – in dairy products
3R and 2R stereoisomers of α-tocopherol in
milk from conventional, organic, and ‘low input’
dairy herds (outdoor grazing period)
3R alpha-tocopherol
2R alpha-tocopherol
mg kg-1 40
milk fat
a
b
30
c
20
10
ns
ns
ns
0
Conventional
Organic
Low Input
Dairy production system
Carotenoids (pro-vitamin A) in milk from
conventional, organic, and ‘low input’
dairy herds (outdoor grazing period)
beta carotene
lutein
A
mg kg-1 10
milk fat
8
6
zeaxantin
B
C
4
2
a
b
c
0
Conventional
Organic
Low Input
Dairy production system
Composition differences between organic and e
conventional milk during the outdoor grazing
and winter indoor period
outdoor grazing
%
difference
compared
to
conventional
winter indoor
60
40
20
0
-20
-40
Omega 3 Omega 6
CLA9
Vit E
Milk components
β-Car
Dairy production
Multi-variate analyses
Dairy - Multivariate analyses
Feed components as drivers
Fatty acid groups as response variables
0.5
Concentrate
CON
Conserved
CFforage
PUFA •
-1 MUFA •
• SFA
FF
Fresh
forage
-0.5
1.5
SFA = saturate fatty acids
MUFA = monounsaturated FA
PUFA = polyunsaturated FA
Dairy - Multivariate analyses
Feed components as drivers
Individual Fatty acids as response variables
1
Concentrate
CON
γLA •
. • 16:0
-1.5
1.5
VA •
CLA •
Fresh
FF
forage
Conserved forage
CF
.• 14:0
• αLA
-1
VA = vaccenic acid (C18:1 t11)
CLA = conjugated linoleic acid
(isomer C18:2 c9 t11)
LA = linolenic acid (C18:3 c9 c12 c15)
Dairy - Multivariate analyses
Feed components and vitamin supplements as drivers
Individual antioxidants as response variables
1
α-tocopherol
2RT = 2R steroisomers
3RT = 3R stereoisomer
Conserved
forage
CF
carotenoids
βC = β-carotene
LUT = lutein
ZEA = zeaxanthine
βC •
• ZEA
-1.5
LUT •
• 2RT
Vitamin
supplements
1.5
TM
• 3RT
CON
Concentrate
FF
Fresh
forage
-0.5
Influence of organic diet on the amount of conjugated
linoleic acids in breastmilk of lactating women in the NL
Lukas Rist, Andre Mueller, Christiane Barthel, Bianca Snijders, Margje Jansen,
A.Paula Simoes-Wust, Machteld Huber, Ischa Kummeling, Ursula von Mandach,
Hans Steinhart and Carel Thijs
British Journal of Nutrition (2007) 97: 735-743
Fatty acid and fat-soluble antioxidant concentrations in
milk from high- and low-input conventional and organic
systems: seasonal variation
Gillian Butler, Jacob H Nielsen, Tina Slots, Cris Seal, Mick D. Eyre, Roy Sanderson
and Carlo Leifert
Journal of the Science of Food and Agriculture (2008) 88: 1431-1441
Consumption of organic foods and risk of atopic disease
during the first 2 years of life in the Netherlands
Ischa Kummeling, Carel Thijs, Machteld Huber, Lucy P. L. van de Vijver, Bianca E.
P. Snijders, John Penders, Foekje Stelma, Ronald van Ree, Piet A. van den Brandt
and Pieter C. Dagnelie
British Journal of Nutrition (2008) 99: 598-605
Thank you very much