A New Generation of Feed Stock: Evidence That Microalgae Serve as High-quality, Sustainable Alternative Feed Protein

X. G. Lei

Professor of Molecular Nutrition

Department of Animal Science

Cornell University

Greatest Challenges of the 21st Century

•Food

•Energy

•Water

•Climate Change

Atmospheric Concentrations of CO2

Keeling et al., 2005

Food and Feed Security?

• Feeding 7 billion people, to 9

billion in 2030:

– 815 million hungry

– 2 billion at hidden hunger

– 1.2 billion at water scarcity

• Feeding: >50 billion animals:

– 18% calories, 25% protein (40 kg)

– 70-80% increase by 2050

– 75% land & 30% water for agric.

Global Feed Protein Crisis

• Total feed: 6 billion tons of dry matter

• Dependence on soybean meal:

– USA, 71% total

– China, 57% total, 17% self-sufficiency

– EU, 64% total, < 1/3 self-production

• Ban on meat and bone meal (50 mt off)

• Expansion of aquaculture/overfishing

• Pressure to lower feed/food competition

• Need: Alternative feed protein

Microalgae:

the Solution to Both Problems?

Research at Cornell

USDA/DOE Development Grant

• Feasibility

▫ microalgal biomass replace SBM/corn

▫ pigs, broilers, and layer hens

• Maximum % microalgae in diets

• Effects

▫ growth performance, health, and products

• Benefits and limits

• Microalgal species

▫ selection, culture, and processing

Are Microalgae Palatable?

A partial replacement of soybean meal by whole or defatted algal meal in

diet for weanling pigs does not affect their plasma biochemical indicators

• No effect on ADFI

– Defatted diatom

• 6.8 to 15%

– Full-fat diatom

• 7.2 to 12%

– Green algae 1

• 10 to 25%

– Green algae 2

• 7.5 to 21%

Microalgal Research at Cornell

Species Trials Animals

Broilers 10 1,938

Layers 10 630

Pigs 6 219

Mice

Total

13

33

380

3,167

In vitro n

Drop (-) Add (+)

SBM Amino acids

Corn Oil

Salt Acids

Limestone Enzymes

Phosphate Trace minerals

Time = 3 to 15 weeksHaematococcus pluvialis

Nannochloropsis oceanica

Desmodesmus sp (Green)

Staurosira sp (Diatom)

Nutritional Values of Microalgae as Animal Feed Protein

• Crude protein: • 5 types: 14, 19, 31, 38, and 43%

• Soybean meal (SBM): 44-48%

• Corn: 7-9%

• Fish Meal: 65%

• Digestibility: 70-90%

• Replacement:• Pigs: 7.5 to 15%, 5-8%SBM

• Broilers: 7.5 to 21%, 2 to 10%SBM

• Layers: 7.5 to 25%, 2 to 15% SBM

• )

2,263 million acres total, 19% cropland, corn 90% as feed

Table 1. Potential saving of corn and soybean meal and harvestable land in the U.S. with

microalgal inclusion into swine and poultry diets1

Dietary algae inclusion Corn/Soybean saved

thousand ton

Land saved

thousand hectares

5% 575 188-283

10% 1,150 375-567

20% 2,300 750-1,134

1Calculations based on the 1997/1999 yields from Bruinsma et al., 2003.

Is Algal Biomass Nutritious?

0

200

400

600

800

1000

1200

DM CP EE ADF NDF Lys Met Thr Trp Ca P Ash

% R

elat

ive

to S

oyb

ean DFA

FFADGA-1DGA-2

Dry matter: retention/digestibility: —/—Nitrogen retention/digestibility: —/—Inorganic phosphorus retention/digestibility: ↑/↓

2-16% DGA-2 (Gatrell et al., 2018)

AA retention: 70% (Control) vs. 76% (DGA-1) vs. 76%(WFA) —AA digestibility: 82% (Control) vs. 91% (DGA-1) vs. 88% (WFA) ↑

25% DGA-1/ 11.7%WFA (Ekmay et al., 2015)

Dry matter digestibility: 76% vs. 85% ↑Amino acids digestibility:

ASP, GLC, SER, GLY, ARG, ALA, TYR, VAL, PHE, ILE, LEU, LYS: ↑GLN: —

7.5-15% DFA (Manor et al., 2017)

Dry matter: retention/digestibility: ↓/ —Nitrogen retention/digestibility: —/—Ether extract retention/digestibility:↑/—Amino acid digestibility: ↓/↓

10% DGA-3 (Sun et al., 2016)

Broiler

Layer

Pig

Impact on Nutrient Digestibility & Retention

Down: ALT, uric acidSame: AKP, cholesterol, triglyceride, NEFA (Austic et al., 2013)

Same: amino acid, uric acid(Ekmay et al., 2014)

Same: plasma protein, uric acid (Gatrell et al., 2018)

DFA

DGA-1

DGA-2

Down: uric acid, Same: AKP, ALT, cholesterol, glucose(Leng, et al,. 2014)

Down: 3-MH, TRAPSame: AKP, corticosterone, glutamine, insulin, P, uric acid(Ekmay et al., 2015; Kim et al., 2016)

DFA

Down: 3-MH, TRAP, AKPSame: corticosterone, glutamine, insulin, P, uric acid(Ekmay et al., 2015; Kim et al., 2016)

WFA

DGA-1

Same: AKP, phosphorus, cholesterol, triglyceride, uric acid (Kim et al., 2016)

DGA-2

Same: Urea nitrogen(Manor et al., 2017)

Up: AKPDown: Urea nitrogenSame: TRAP, ALT amino acid, uric acid (Manor et al., 2017)

DGA-3

DGA-1

Broiler Layer Pig

Impact on Blood Measures

Impacts on Protease Activity in Digesta and Brush Borders

Digesta

Inte

stin

e

Protease Activity

Protease Activity

Dud

.

Juj

.

Ile.

H

H

H

25% DG1

11.7% DF

B

H

25% DG1Dud

.Juj.

Ile.

H

H

H

11.7% DF

11.7% DF

DG1; Desmodesmus spp. FD; Staurosira spp

DG2; Nannochloropsis oceanicaH

B

25% DG1

25% DG1 &

11.7 FD

H

H,B

DG2

Liver Muscle Amino acid

transporters

Cat1

pept1

H

Inte

stin

e

Lat1H

25% DG 1

AMPK

mTOR

P70

S6

EIF4E

Protein Synthesis

P

PS6& PS6: S6 25% DG1 H

S

6 8% DG2

B

11.7% DF HB

BB

AMPK

mTOR

P70 EIF4E

S6P

Protein Synthesis

B

2% DG2

B

4% DG2

B

B

PS6:

S6 4-8% DG2B

4-8% DG2

B

DG1 ; Desmodesmus spp.

FD; Staurosira spp.DG 2; Nannochloropsis oceanica

B

B B

B

Impacts on Amino Acid Transporters and Protein Synthesis Signaling

Impacts on Egg Albumin, Broiler Muscle and Pig Lean Mass

11.7% DF Egg weight

Egg albumin weight/height

25% DG+

protease Yolk weight

2-16 %DG

Breast dry matter

Breast crud protein

Breast relative weight

Percent body lean mass

Roles and Synthesis of EPA/DHAOmega-3 Fatty Acids (n3)

C18:3n-3Α-Linolenic acid (ALA)

C20:5n-3Eicosapentaenoic acid (EPA)

C22:6n-3Docosahexaenoic acid (DHA)

EicosanoidsAnti-inflammatory

Fish oils

• Increased EPA and DHA intakes are linked to Decreased:

• CVD, diabetes, etc

(Simopoulos, 1999 and 2002) 18

Human Nutrition of EPA/DHA

• De novo FA synthesis is low in mammals

• Western diet is low in ω-3 fatty acids

– Ideal ω6:ω3 ratio is 1

– US consumption is ~15-20:1

• Recommended: 200-400 mg EPA+DHA/day

– US: ~100 mg EPA+DHA/day

– > 5 times less in non-fish eaters

(Simopoulos, A.P., 2002; Smet, 2012)

What can we do about this deficiency?

Dietary Sources of DHA and EPA

• Fish/fish oil: availability, oxidation, and flavor

• Flaxseed/oil: largely ALA

• Terrestrial meat is low in PUFA

• Average American consumes:

– 40 kg broiler chicken/year

– 250 chicken eggs/year

– Relatively high in ω-6 and low in ω-3 fatty acids

(USDA Economic Research Service, 2016)20

Marine Microalgal Biomass• Defatted biomass (DFA) from biofuel

production research

– Residual long chain n3 fatty acids

– High protein content (44%)

• Moderate levels of inclusion have no effect on growth performance and digestibility

(Austic et al., 2013, Gatrell et al., 2014)

Enrichment of n-3 Fatty Acids in Breast and Thigh

Breast Thigh

Gatrell et al., 2015

Summary of Broiler Study

• Omega-3 content and ω6:ω3 ratios were improved at all levels of microalgal biomass inclusion.

• Consuming 200 g of chicken breast/day can supplement up to 35 mg of EPA/DHA.

0

10

20

30

40

50

60

L* a* b*

Co

lor

Val

ue

Color Value

0% 2.85% 5.75% 11.5% 23%Algae

Effects of Dietary Microalgae on Yolk Color

24

P-Value ≤ 0.0001dc c

b

a

a

b cd d

b b b ba

(Darker) (redder) (Bluer)

y = 0.16x + 1.95R² = 0.94

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

0 5 10 15 20 25

mg

/g s

amp

le

Algae (%)

P ≤ 0.0001

Yolk EPA + DHA

25

3-Fold

Yolk ω6:ω3

26

y = -0.36x + 11.5R² = 0.65

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

0 5 10 15 20 25

mg

/g s

amp

le

Algae (%)

P = 0.0004

3-Fold

Summary of Laying Hen Study

• Defatted microalgae enriched egg yolk with EPA and

DHA and decreased ω6:ω3 ratios in the yolk.

• Liver, breast, and thigh also had increased levels of

EPA and DHA.

• Microalgae affected expression of key genes involved

in EPA/DHA metabolism.

Regulation of Hepatic EPA/DHA

Synthesis by Microalgae

28

2

2

5

ACOT4

Elongase3Elongase4Malic Enzyme

Recent Progress

• Feeding DHA-enriched microalgae:

– > 200 mg/egg

– 80-100 mg/100 g fresh muscle tissue

• Effects of corn oil, Se, and vitamin E

• Regulation of P450 enzyme genes

• Enhancing enrichment

• Amount: 1 egg + 100 g chicken = 300 mg DHA

• Flavor: no difference

• Bioavailability: mouse study

• Health benefits: ?

Just Eat Chicken & Eggs for EPA/DHA

Enrichment of Astaxanthin in Egg Yolk

Magnuson et al., 2018

Microalgae as a Dual Source of Protein and Iron

• Contained > 2,600 mg Fe/kg

• Anemic pig model

• 0.5% was effective

• 15% was safe

• Fe deficiency affects 30-40% global population

Take-Home Message

• Microalgae can become an excellent source of feed protein.

• Microalgae can help enrich n-3 fatty acids in chicken and eggs.

• Microalgae can serve as a dual source of protein and micronutrients (Fe and phytochemicals).

Acknowledgements

• USDA/DOE Biomass R&D Initiative

Grant

• Cornell Hatch grants

• MAGIC grant (DOE)

• Heliae, DSM, Cellana

• Kreher Farms