Forages and Human

Health

Yvan Chouinard Ph.D., agronome

November 18th, 20145TH ANNUAL CANADIAN FORAGE &

GRASSLAND CONFERENCE

NSERC-Novalait-DFC-FPLQ-MAPAQ-Valacta Industrial Research Chair on Nutritional Control of the Production of Milk Components in Dairy Cows

Presentation Outline

Effects on Human Health• Nutritive Value

–Milk Fatty Acid Profile• Pleasure (Hedonicity)

–Milk Aromatic Profile• Environment

–Enteric Methane Emission

MILK FATTY ACID PROFILENutritive Value

Increasing ω-3 Fatty Acids in Milk

• Strategies :– Supplying ω-3 fatty acids in the diet– Inhibiting ruminal biohydrogenation

• Red Clover– Source of ω-3 fatty acids– Source of polyphenol oxidase

• Reduces lipolyse of glycerolipids• Prevents ruminal biohydrogenation http://www.rcsb.org/

Effect of Red Clover

Alfalfa Red CloverAlfalfa Silage 42.2 ---Red Clover Silage --- 38.2Barley Straw 6.0 10.0Flacked Corn 19.1 18.6Ground Corn 9.0 9.5Corn Starch 15.1 15.1Soybean Meal 7.0 7.0Minerals & Vitamines 1.6 1.6

Dietary Treatments

Leduc et al. 2014

Effect of Red Clover

ω-3 Fatty Acids(mg/g fat)

Alfalfa Red Clover0

2

4

6

8

10

Transfer Efficiency(g secreted/100 g ingested)

Alfalfa Red Clover0

4

8

12

16P < 0.01

Leduc et al. 2014

P < 0.01

A 5.3-ha field plot of timothy (Phleum pratense L. cultivar AC Alliance) was used for forage production• Alternate windrows harvested as silage• Remaining windrows harvested as hay

Same plot used as pasture during the feeding trial

Effects of Forage Type

Silage(plastic bags)

Hay(rectangular bales)

Pasture(strip grazing)

Villeneuve et al. 2013

Milk Fatty Acid Profile

α-Linolenic Acid (ω-3)

Hay Pasture Silage0

2

4

6

mg/g fat

b

a

c

P < 0.01SEM = 0.2

Conjugated Linoleic Acid

Hay Pasture Silage0

3

6

9

mg/g fat

b

a

b

P < 0.01SEM = 0.8

Villeneuve et al. 2013

Milk Conservation

• Susceptibility to oxidation

• Dietary Antioxidants– Alfalfa Protein Concentrate (carotenoids)

Extraluz, Désialis, France

Effect of Alfalfa Protein Concentrate

Treatment

Control Vitamin E Extraluz

Grass/Legume Silage 86.8 86.8 86.8

Ground Barley 2.0 2.0 2.0

Soybean Meal 9.1 9.1 ---

Extraluz (Alfalfa Protein Concentrate) --- --- 9.1

Vitamine E --- 0.03* ---

Vitamins & Minerals 2.0 2.0 2.0* Vitamin E : 300 IU / kg

Extraluz, Désialis, France

Effects of Alfalfa Protein Concentrates

Control Vitamin E Alfalfa0

50

100

150

200Redox Potential

(mV)P = 0.03

Control Vitamin E Alfalfa0

1

2

3

1-octen-3-one(µg / kg of milk)

P = 0.05

Control Vitamin E Alfalfa0

50

100

150

200

250

300Propanal

(µg / kg of milk)

Control Vitamin E Alfalfa0

1020304050607080

Hexanal(µg / kg of milk)

P = 0.03

P = 0.05

P = 0.07

Fauteux et al. 2013

MILK AROMATIC PROFILEPleasure (Hedonicity)

Character Impact Compound

Dimethyl sulphide

Butyric acid

Caproic acid

δ-Decalactone

Dimethylsulphone

Acetone

2-Butanone

Weed

Vomit, fetta cheese

Fatty, waxy

Coconut, hot milk, fruity

Hot milk, burnt

Cowy, feed-like

Varnish

• Last week of the feeding trial

• Milk collected and pooled by cow and by treatment

• Refrigerated in 250-L bulk tanks

• Transferred to the pilot plant

• Homogenized

• Standardized (3.25% milk fat)

• Pasteurised

• Sensory evaluation

• Triangle test

• Ranking test

Sensory Analysis

Aldehydes

• Attribute :

- Herbaceous (Moio et al., 1993)

• Straight-chain aldehydes can derive from lipid degradation (Toso et al., 2002)

• More lipids in pasture and silage as compared with hay

Hay Pasture Silage3.0

3.5

4.0

4.5

5.0

B

AA

Pentanal

P < 0.01SEM = 0.13

Hay Pasture Silage4.0

4.2

4.4

4.6

4.8

Sulphur Compounds

B

A

AB

• Attributes :

– Sulphurous, hot milk, burnt (Moio et al., 1993)

• Contribute to the « normal » flavor of milk

• Derived from the catabolism of sulfur amino acids (methionine) (Taylor and Kiene, 1989)

• In line with dietary supply of protein, as a source of methionine, which was high in pasture, intermediate in silage, and low in hay

Dimethylsulphone

P = 0.03SEM = 0.08

γ-decalactone γ-dodecalactone γ-dodecaenolactone3.0

3.2

3.4

3.6

3.8

4.0

4.2

4.4 HaySilagePasture

Lactones• Attributes :

– Sweet, peach, coconut, fruity

• Synthisized from dietary long chain fatty acids (Urbach, 1990)

• Synthesis affected by ruminal conditions(Urbach et Stark 1978)

P < 0.05

A

B AB

A

B

B

A

B

AB

Triangle Tests - 30 Assessors

RetainedResponse

CorrectResponse

Significance(Risk)

Silage vs. Hay 30 12 0.28

Pasture vs. Hay 30 20 < 0.01

0

2

4

6

8

10

Number ofassessors

Sensory attributes identified by assessors to discriminate between samples

Ranking Test - 30 Assessors

0

20

40

60

80

Grassy Flavor (grass, leafy vegetable, plant)

SilageHay Pasture

P < 0.05

Sums ofrankings

from 1 to 3

b

a

b

Ranking Test - 30 Assessors

0

20

40

60

80

Sweet Flavor (empyreumatic, vanilla, caramel,

sugar)

SilageHay Pasture

P < 0.05

Sums ofrankings

from 1 to 3

aba

b

ENTERIC METHANE EMISSIONEnvironment

Carbon Footprint

Feed Rations19%

Enteric Methane25%

Manure Management24%

Farm Energy4%

Transport, Processing, distribution

17%

Retail6%

Consumption, Disposal 5%

2.05 kg CO2e / kg of milk consumed

University of Arkansas & Michigan Technological University 2010

Barley Silage vs. Corn Silage

Barley Silage 50/50 Corn Silage11.0

11.8

12.6

13.4

14.2

15.0

Methane Emission

g/kg energy corrected

milk

Linear Effect : P = 0.33Quadratic Effect : P = 0.15SEM = 0.51

Benchaar et al. 2014

Alfalfa Silage vs. Corn Silage

Alfalfa Silage 50/50 Corn Silage11.0

11.8

12.6

13.4

14.2

15.0

Methane Emission

g/kg energy corrected

milk

Linear Effect : P = 0.43Quadratic Effect : P < 0.01SEM = 1.67

Hassanat et al. 2013

Timothy Silage vs. Alfalfa Silage

Timothy Silage 50/50 Alfalfa Silage11.0

11.4

11.8

12.2

12.6

13.0

Methane Emission

g/kg energy corrected

milk

Linear Effect : P = 0.05Quadratic Effect : P = 0.99SEM = 0.37

Hassanat et al. 2014

Presentation Summary

• Milk fatty acid profile (ω-3, CLA)– Red clover– Pasture

• Milk aromatic profile– Volatile organic compounds responsible

for sensory attributes• Enteric methane emission

– Variations between dietary forages