Plant breeding for animal production efficiency and emission reduction

Heather McCalmanGrassland Development Centre

Developing Research into Practice

Livestock’s Long Shadow ‘Livestock a major threat to environment’

(FAO Newsroom, 2006)

Major issues relate to Nitrogen, Phosphorus and Methane

Efficiency of conversion in ruminantsNitrogen: 55 - 95% of ingested N is excreted

Phosphorus: 20 – 70% of ingested P is excretedMethane: 2 – 12% of gross energy intake is lost in

CH4

Producing food sustainably: environmental and resource challenges

• reduce dependency of the food chain on fossil fuels

• address the depletion of the natural resources and ecosystem services on which food production depends (i.e soil and water)

• radically reduce greenhouse gas emissions produced by food system

UK Agricultural CH4 and N2O emissionsper activity

2005 – Carbon equivalent

43.8%

8.1%

10.5%

19%

12.3%

6.3%

Enteric Fermentation & Inorganic Fertilisers – Key!!

Make use of improved genetics

• Animals– Faster growing/higher yielding individual

animals are more efficient– Dilution of maintenance effect– Improved ‘robustness’ – longevity, fertility

• Plants (food)/Microbes– Improved digestibility– Better energy availability– Better protein characteristics

• Forage• ‘Concentrates’

• Energy• Protein

• BALANCINGTo meet livestock needs profitably

Can also help with emission reductionAs they say .... ITS A ‘WIN WIN’!

Quality forageNo concentrates or supplements

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Simmentals Welsh Black

The Research:

The relationship between live weight gain (LWG) of cattle and methane production

per kg of gain

(Kurihara et al 1997, Klieve. and Ouwerkerk 2007, Howden and Reyenga 1999)

High sugar grass = grass with enhancedlevels of water soluble carbohydrate.

Water soluble carbohydrates (WSC) - natural storage compounds – mainly sugars.

ABER high sugar grasses - significantly higher WSC levels through the season

What are High Sugar Grasses?

Emphasis on perennial ryegrass ... Higher digestibility than secondary species..Advances include HSG

Improvements in WSC content of intermediate-heading perennial ryegrasses

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S321 AberDart +9%AberStar +16% AberMagic +30%

High Sugar grasses - is it all hype?AberEchoAberStormAberDartAberAvonAberMagic

Higher sugars

More sugars in rumen

Better use of protein

More N for milk and meat

More sugars to drive fermentation

Higher intakes and LWG

Beef Production

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Liveweightgain

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Live weight gain increased by 18 -

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Impact on nutrient use efficiency

Animals and the environment

White CloverRed Clover

Bacteria in root nodules convert

atmospheric N into nitrogen which clover

and companion grasses can use

Clover benefitsSoils - N fixation

30% clover (DM) fixes 150 kg N per ha each year. ( 50-350).

Same as ‘bag muck N’ BUT clover fixed N does not all arrive at once and is delivered at the rooting zone.

Leakage is minimal, low levels of run off, leaching and losses to the air.

Soils - structureClover plants improve soil structure.

Root growth opens up the soil, letting air in,

improving drainage and improving nutrient uptake.

The benefits of cloverAnimal performance

CLOVER….less fibrous than grass & has easily digestible cell walls

has twice as much protein as grass

up to 20% higher intakesfrom clover & grass/clover swards and less chewing energy

required. (fresh and conserved)

is good for finishing lambs in late summer

gives higher milk yields and milk protein levels

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Lamb performance Pre-Weaning

Lamb performance

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Low input beef productionAnimal performance

GrassGrass/whiteclover

Grass/redclover

DM Intake (kg/d) 6.8 9.0 9.2

Liveweight gain (g/d) 830 1088 1172

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Grass 50%RC 100% RC

3.063.083.1

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Grass 50%RC 100% RC4.55

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Red clover silage for milk production

Dewhurst et al 2000

Food, diet and health Healthy Beef – an example

Making the most of grass and legumes

New Breeding LINK project• Clovers & ryegrasses• N use efficiency ( soil, plant, rumen)• P use efficiency ( soil & plant)• Water use efficiency ( uptake & within

plant)

Major aim• Develop new varieties of grasses and legumes,

meeting farmers’ and funders needs and give options for the future

• Contribute to:-Mitigation of climate changeAdaptation to climate changeCleaner waterHealthier soilsQuality products

Primary Goals• Perennial ryegrass

– Further increase WSC content by 8% above currently marketed varieties and improve agronomic traits.

• White clover– Reduce crude protein content by 5 – 10% below

currently marketed varieties.• Animal study

– Determine the effects of high WSC grasses with low protein clover on feed intake, milk output and whole-body nitrogen partitioning in dairy cows.

4 projects

LK0686 Genetic improvement of perennial ryegrass and red clover to increase nitrogen use efficiency and reduce N losses from pastures and silo

LK0687 Genetic improvement of perennial ryegrass and white clover to increase the efficiency of nitrogen use in the rumen

LK0685 Genetic improvement of forage grasses and white clover to improve phosphorus use efficiency and reduce phosphorus losses to water from UK grasslands

LK0688 Development of productive and persistent high quality forage grasses and white clover with increased water-use efficiency and resilience to summer droughts

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Improving perennial ryegrass and red clover to increase nitrogen use efficiency (NUE)

Aim : breed grasses with high yields and high quality with reduced fertiliser

Aim- breed red clover with high agronomic performance AND reduce nitrogen leaching

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Water Framework Directive ‐ encourages farmers to reduce nitrogen use to protect water 

courses and ground water

Cost and availability of nitrogen fertiliser

Poor conversion of  forage nitrogen into milk and meat

Why?

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Future work will :- map the genes that control NUE in ryegrass so they can

be combined by ‘marker-assisted selection’

- investigate how NUE is affected by lower nitrogen inputs & different nitrogen sources (ammonium vs nitrate)

Improving ryegrass nitrogen use efficiency

The goal is to breed grass varieties with high yields and high quality with reduced fertiliser inputs

Red clover selection to reduce nitrate leaching

Future work will investigate leaching under field conditions and multiply seed

from the most promising varieties

The goal is to breed red clover varieties with high agronomic performance that can reduce nitrogen leaching

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Polyphenol oxidase (PPO) in red clover

The PPO enzyme protects protein molecules from breaking down – so boosts silage quality and reduces in-silo losses

Once cut, the PPO enzyme darkens the clover leaf and stem.

Food N100%

Milk N15‐40%

Faeces N (nitrates)25‐40%

Urine N (urea)15‐45%

Body5%Nitrogen Use Efficiency (NUE)

On average, 75% of consumed N is ‘wasted’ (ammonia, nitrous oxide, urea and nitrates)

Improving perennial ryegrass and white clover to increase nitrogen use efficiency (NUE) in the rumen

Aim to reduce wasted

protein that is excreted, &

then there will be less nitrogen

emissions

More sugarsboosts rumenfermentation

efficiency leading

to improved NUE

We need to convert nitrogen more efficiently into meat and milk

Improving perennial ryegrass and white clover to increase nitrogen use efficiency (NUE) in the rumen

Aim 1: new grasses with 8% more sugars and improved yield and ground

cover

Aim 2: Clovers with 5-10% less protein

Aim 3: Find out how growth, milk production

and feed intake is affected by high sugar, low protein grass and

clover

Improving perennial ryegrass and white clover to increase nitrogen use efficiency (NUE) in the rumen

White clover

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Improving perennial ryegrass and white clover to increase phosphorus use efficiency (PUE)

Phosphorus- an important determinant of yield and environmental

quality in agriculture

Crops typically recover< 10% of applied fertiliser P

Phosphorus is at the heart of modern farming and has no

synthetic alternative

The Livestock sector needs maintain production & profitability

and protect the environment

Source : Professor Cynthia Mitchell The Institute of Sustainable Futures at the University of Technology, Sydney

Human urine may be our last hope to stop the ‘P’ shortage!!

New varieties of grass and clovers that need less P fertiliser and leach less P to water courses

• Make the plant better (by 10%) at taking up, using and keeping

phosphate• Make white clover perform better

on low or moderate P status soils without using more P

• Optimise phosphorus use efficiency in ruminants when fed forage

legumes

•Financial savings from lower fertiliser use

•More efficient animal production

•Reduced pollution from grassland into water

courses

Aim

How

What does it give us?

Components of PUE• Acquisition/uptake

• Utilisation/ P productivity• Retention/loss to environment

Aim 1: Increase PUE in forage grasses and legumes

Flowing solution cultureHorizontal sand-bed

lysimetersSand box mini-swards

Systems to phenotype PUE in mapping families

Selection of white clover lines for a 20% improvement in performance on low P soils

compared to current varieties

A sward that combines high clover and grass yields with high levels of species diversity

Aim 2: Improving the performance of white clover on Low P soils

Measure new clover use in the animal

Aim 3: Effect of the new clovers on P balances in sheep and cattle

Drought resistant grasses and clovers which make better use of water

White clover

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Why?

More dry summers !!Less water available from soils means

lower yieldsDEFRA: need to conserve water and

adapt to climate change

Breeders aim: a 5 to 10% improvement

F. pratensis

F. arundinacea

F. glaucescens

Using Festuca species naturally adapted to these areas and from the Atlas mountains for resistance to extreme droughts and for

large strong root systems

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Testing in rain out shelters

Tall Fescue species with good ground cover and growth after 15 weeks

compared with Ryegrass

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Glasshouse droughttrials

Only those plants with fescue genes survive combined heat and drought

and recover

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Superior root systems forimproved soil and water

uptakeare found in fescues and

festulolium cultivars comparedto ryegrass

Lm x Fg AberStar Dovey AberEpic Prior Bf993

Clover with betterwater use efficiency

Stolon Branch Flower head

Terminal bud

Axillary budsRoots and Nodules

Nodes

Thickness and number of stolons is related to root density

Work to use the differences in root

growth so that new plants use water more efficiently

Water use efficiency= g of plant DM per ml of water taken up by the plant

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Drought resistant clovers

Plants with stolons and rhizomes: Interspecific hybrids

T. repens T. ambiguum(Caucasian clover)

Very persistentStress tolerant

RhizomesDrought tolerant

Persistent Good DM yield

Variable seed yieldStoloniferous

Improved persistence, stress tolerance

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New cultivars contain drought tolerant genesfrom T. ambiguum

Aim: to develop best material into white clovervarieties

Drought tolerant clovers

Breeders will evaluate the new white clovers in the field in mixtures with high sugar grasses

and test agronomic, nutritional and environmental benefits of reduced protein content

OAT BREEDINGHistory of successful oat breeding at IBERS

In addition to yield and quality for milling new objectives

Oil can reduce methane BUT reduce feed efficiency in ruminants

Naked oats yield less and don’t fit well to LCF

Developing high oil low lignin husked oats for ruminants

Developing naked oat varieties for pigs and poultry

OatLINKPartners include ORC Elm Farm

Selecting for improved NUETest in organic and conventional systems

Quality of oats in organic systems

Practical solutions for today?Sow it: Select best seeds mixture for the ‘job’ you want it to do ( ST? LT? Sheep? Beef?)- include cloverGrow it- get soils right, manage swards to maintain quality and harvest for optimum silage

Use it- Balance diet, graze for optimum intake and livestock need. Make the most of clover!