future use as feed and to inhibit enteric methane emission

Seaweed:

Mette Olaf NielsenDepartment of Veterinary and Animal Sciences

mette.olaf.nielsen@sund.ku.dk

CPH Cattle Seminar 31 October 2018

Marine plant biomass:An alternative to imported (GMO) soya ?

� Macroalgae (seaweed) collected from beaches:

� Used as feed for 1000’s of years

� Basis for European macroalgae industry hitherto

� Now: Macroalgae can be cultivated with increased efficiency

� 4-10x production potential of terrestrial crops

� Yields: up to 15-25 tons dry matter (DM)/ha

� Largest cultivation potential in open waters

� Environmentally friendly crop

� Filters nutrients (eg in fjords)

� C-sink: capturing CO2 from air

� Marine forests

2

Composition widely different from terrestrial plants

• Macroalgae do not contain lignin (structure/stiffness) !!!!

• But a range of carbohydrates not found in terrestrial plants:

• Laminarin (5-50% of DM)

• Fucoidan (5-10% of DM)

• Alginate (17-45% of DM)

• Composition varies with season, area and of course between species:

• Main classes:

Brown Green Red

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Manns et al. 2014. RSC adv 4:25736

Digestibility in cattle (in vitro, enzymatic): Large variation – potentially high

Macroalgae class(several species tested)

Average Lowest Highest

Brown 62.9 31.0 87.4

Green 54.5 44.4 75.4

Red 81.1 74.5 90.6

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Weisbjerg et al. 2016. http://www.algecenterdanmark.dk/conferences/nordic-seaweed-conference-2016.aspxMakkar et al. 2016. Animal Feed Science and Technology 212:1–17

In ruminants: Digestibility can increase after adaptation of rumen microbiota to dietary addition

Most interesting feature presently: Bioactive compounds in macroalgae

� Part of the plant’s protection strategy towards environmental stressors

� Oxygen poor environment: Microorganisms, predators, reactive oxygen species (ROS)

� Anti-microbial, anti-oxidant and anti-inflammatory effects

� Polyphenoles (antioxidants)

� Phlorotannins (only in brown algae)

� Isoprenoids/terpens (hydrocarbons; essential oils)

� Special carbohydrates:

� Laminarin (β(1→3):β(1→6) glucan)

� Fucoidans (sulphated fucose polysaccharide)

� Alginate (linear β(1–>4) d-mannuronic acid and β(1–>4) l-guluronic acid units)

� Lower molecular weight metabolites + ???

Holdt & Krahn, 2011; Synytsya et al., 2010; O’Sullivan et al, 2010 mfl.

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https://commons.wikimedia.org/w/index.php?curid=11406386

Phlorotannin from A. nodossum

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Machado et al. 2014. PLOSone 9(1):e85289

Freshwater green algae Marine green algae

Brown algae Red algae

Certain tropical macroalgae: eliminated methane formation during fermentation of feed in rumen fluid in vitro

Dictyota bartayresii Asparagopsis taxiformis

Asparagopsis is not solution to methane emission

• Active compounds: Bromoform (CHBR3) and bromochloroform

• Bromine: same chemical group as Flourine and Chlorine

• Feeding trials:

• With sheep:

• 2% Asparagopsis added to feed => 50-70% reduction in methane emission

• Observed: unwanted changes in the ruminal wall (in several sheep)

• With steers:

• ~2 g bromoform/100 kg body weight => 93% reduction methane emission

• Accumulation in meat; close to threshold values for human consumption

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Inputs:

- Inoculum

Rumen fluid

- Different feeds(CHO/protein composition)

Silage Sugarbeet pulp Other feeds

- +/- Different seaweed compounds

Whole plants Processed

Output:

- Gas release

- Gas composition (methane etc)

- Degraded feed component

- Fermentation products

- Microbiota profile

Cum

ulat

ive

pres

sure

Time

PS

I

Triplicates

Fermentation (48):

Studies in vitro: Can temperate macroalgae species inhibit methane emission without reducing rumen feed degradability?

Rumen fermentability of makroalgae compared to maizesilage (MS)

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0

50

100

150

200

250

0 3 6 9 12 18 24 36 48

TG

P in

ml p

er g

OM

Incubation time in hours

MS

AE

EP900

OFS

SL

Incubation time (hours)

Acc

um

ula

ted

gas

pro

du

ctio

n(m

l/g

org

an

icm

att

er)

MS

Alaria esculenta, Saccharina latissima

Ocean Feed Swine, Ascophyllum nodossum

Impact of makroalgae on fermentability of maize silage

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0

50

100

150

200

250

0 3 6 9 12 18 24 36 48

TG

P in

ml p

er g

OM

Incubation time in hours

MS

AE

EP900

OFS

SL

MS+AE

MS+EP900

MS+OFS

MS+SL

Incubation time (hours)

Acc

um

ula

ted

gas

pro

du

ctio

n(m

l/g

org

an

icm

att

er)

MS (pure)

MS+AE/OFS/SL

MS+AN

Alaria esculenta, Saccharina latissima

Ocean Feed Swine, Ascophyllum nodissum

Maize silage + macroalgae

Pure feeds

Basal feed: Additive: Reduction (%)

Maize Silage

Alaria esculenta 18.8

Ascophyllumnodossum

20.8

Ocean Feed Swine

19.8

Saccharinalatissima

19.8

Sugar Beet Pulp

Ocean Feed Swine

6.1

Saccharinalatissima

10.8

Reduction of methane emission from rumen fermentation

Certain macroalgae species:

- Inhibited methane formation up to 21%

- Without any negative impacton feed degradability

- Specific macroalgae CHO fractions partly induce the same response

Conclusion - 1

• Huge potential for marine plant biomasse production in DK

• Can eliminate competition between humans and animals for arable land for food or feed production !

• Certain macroalgae species have future potential as (protein) feed:

• Reasonably high protein content

• High digestibility in cattle for certain species

• Can be used by organic farmers

• But: Price !!!

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Conclusion - 2

• Huge unexploited potential for utilization of bioactive components

• Can reduce enteric methane production markedly

• Without reducing degradation of the basal diet

• Can contribute to de-criminalize cattle in the climate debate !!!

• Our knowledge is still incomplete regarding the value of macroalgae species and compounds as feed/feed additives

• A targeted research effort is needed to clarify:

• Which species are the right to use – with ”safe” bioactive compounds ?

• Nature of bioactive compounds and their targeted action(s)?

• What are consequences for biogas production from animal manure?

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Acknowledgements

• Collaborators :

• Assoc. Prof. Hanne H Hansen, PhD stud Gizaw Dabessa Satessa and research assistent Rajan Dhakal, Department of Veterinary and Animal Sciences, University of Copenhagen

• Professor Lene Lange, Lla Bioeconomy, Denmark

• Post doc Georgios E. Anasontzis, DTU BIOENGINEERING, Technical University of Denmark

• Director Jens Legarth, Fermentation Experts, Denmark

• Innovation Foundation Denmark: Macro Algae Biorefinery 4 (MAB4)

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