beef and sheep: plant breeding for animal production efficiency and emission reduction - heather...
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This presentation forms part of the Farming Futures workshop 'Making livestock farming fit for the future' 9th December 2009TRANSCRIPT
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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Live
wei
ght g
ain
(firs
t su
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/d)
Grass G/Red 0
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Live
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ght g
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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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Mea
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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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1200
AberDart Fennema
Liveweightgain
g/day
Live weight gain increased by 18 -
35%
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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t gai
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Lamb performance Pre-Weaning
Lamb performance
Post-Weaning
Grass+
150N
Grass +Clover
Grass+
150N
Grass +Clover
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
3.123.143.163.183.2
3.223.24
Grass 50%RC 100% RC4.55
4.6
4.65
4.7
4.75
4.8
Grass 50%RC 100% RC
9.5
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Grass 50%RC 100% RC
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
X
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!