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Environmentally Friendly Cows – Reducing our environmental hoof print. Paul Boettcher 1 Benjamin Henderson 1 Mark Powell 2 1 Animal Production and Health Division, Food and Agriculture Organization of the UN
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Environmentally Friendly Cows – Reducing our environmental hoof print Paul Boettcher1 Benjamin Henderson1 Mark Powell2 1Animal Production and Health Division, Food and Agriculture Organization of the UN 2U.S. Dairy Forage Research Center, U.S. Department of Agriculture-Agriculture Research Service
The Importance of Livestock • Livestock and their production provide many benefits to humankind • Food security • Wealth generation and maintenance • Rural development • Cultural significance • Environmental services
Livestock and the Environment • The importance of livestock is expected to increase in the future • World’s population 33% by 2050 • mostly in developing countries • Consumption of milk 62% and meat 76% • Livestock can have negative impacts on the environment • Among top 2 to 3 sources of environmental degradation
Impacts of Livestock Production • One-third of arable land is used for the production of livestock feed • One-quarter of the ice-free terrestrial surface is used for grazing • One-fifth of the Earth’s animal biomass is livestock • Livestock produce up to 18% of GHG • Dairying contributes significantly to these impacts
Impacts of Milk Production Five main areas of impact • Landscapes and soil • Water • Biodiversity • Non-renewable resources • Greenhouse gases Type and scale of impacts depend on production system
Landscapes and Soil • Feed crop production has various negative direct and indirect consequences • Soil compaction, erosion and flooding • Nutrient overload • Deforestation • Pasturing can cause trampling and degradation • Intensification of production can diminish the aesthetics of the countryside
Water • Majority of water used in feed crop production • leaching of nutrients and agro-chemicals • In the dairy, water is used in many processes, from cleaning and sanitation to cooling of cattle • Lactating cattle consume 40 – 70 litres/d • Nutrients from poorly managed manure can seep into ground and surface water
Biodiversity • Selection for genetic improvement tends to decrease genetic diversity both within and across breeds • Feed production involves plant monoculture • decreases the biodiversity of wild fauna, flora and soil micro-organisms • Poorly managed grazing can reduce the species richness and ecosystem function of grasslands
Non-renewable Resources • Feed crop production consumes fossil fuels • Crop tillage and harvesting • Fertilizers • Animal housing and milk collection and cooling consumes electricity • 800 to 1200 kWh/cow/yr (US data)
Greenhouse Gases • Cattle emit methane as a by-product of rumination • Manure can release nitrous oxide and methane • Feed crop production releases carbon dioxide • The global dairy sector produces 4% of global antrhopogenic GHG emissions • 2.4 kg CO2 per kg of fat/protein corrected milk
Shrinking the Hoof print • Two general approaches can be taken to increase the environmental impact of dairying • Improving the system and production environment • Breeding a “greener” Holstein cow • Involves enhanced resource usage • Energy • Water • Nutrients • Biodiversity • Greenhouse gases
The System: Crop Production • Many of the environmental impacts of dairying result from feed crop production • Applying “good practices” will reduce impacts • Soil testing and judicious fertilizer application • Soil, water, energy • Proper application of herbicides and pesticides • Water and wild biodiversity • Controlled irrigation • Water and soil • Well-managed land use changes • Greenhouse gases, landscapes and wild biodiversity
System: The Dairy • Develop (and use) a nutrient management plan • Assure adequate land mass for off-farm nutrients • Properly store and apply manure • Reduce impacts on soil, water, wild biodivesity and greenhouse gases • Take steps to reduce electricity usage • install high-efficiency milk cooling systems • properly maintain electrical equipment • use automatic controls for lighting and ventilation • Recycle and reuse water
The System: The Cows • Increase production per cow • Less resources used/methane produced for maintenance • Balance rations • Nitrogen is generally overfed • Must be balanced with other nutrients • Improve reproduction and health • Under-producing animals emit more GHG per unit of output • Replacement heifers emit GHG for two years prior to yielding outputs
Breeding a “Greener” Holstein • Breeding and genetics are powerful tools with long-lasting effects • Possible option to reduce environmental impact of individual cows and the Holstein breed • Is it also a feasible option?
Opportunities in Breeding Possibilities for breeding are limited: • Direct impacts on landscapes, non-renewable resources are largely on an herd-level, rather than an animal-by-animal basis • Water consumption has a genetic component, but... • not well studied • correlated with milk yield • consumption by cattle is relatively insignificant • This leaves within-species biodiversity, nutrients and GHG and as possible targets for breeding programmes and selection
Within-breed Diversity The Holstein has benefited from strong breed associations, pedigree and performance recording and artificial insemination
Within-breed Diversity These tools allowed selection for a highly productive...
Within-breed Diversity ... and highly uniform animal
Within-breed Diversity • but some diversity is necessary to allow for continued • selection and for optimal reproduction and fitness
Within-breed Biodiversity • Interventions are possible within the sire selection and utilization programmes to achieve greater within-breed genetic diversity • more balanced use of sires with decreased genetic relationships among them • Would likely require cooperation across countries and breeding companies • contrary to short-term economic goals
Within-species Biodiversity • The high production of the Holstein has made it the world’s most ubiquitous livestock breed • invaluable contribution to food security • reduced across-breed biodiversity • Their superior genes are not being used optimally • often not adapted to the environment • cross-breeding is done haphazardly • Capacity development is needed to improve breeding programmes • breeders’ associations and recording and evaluation systems • conservation and sustainable use of local breeds • genomics for identification of optimal hybrids
Within-species Biodiversity Countries reporting the presence of Holstein cattle Source: FAO 2007
Within-species Biodiversity • The high production of the Holstein has made it the world’s most ubiquitous livestock breed • invaluable contribution to food security • reduced across-breed biodiversity • Their superior genes are not being used optimally • often not adapted to the environment • cross-breeding is done haphazardly • Capacity development is needed to improve breeding programmes • breeders’ associations and recording and evaluation systems • conservation and sustainable use of local breeds • genomics for identification of optimal hybrids
Selection: Nutrients/Nitrogen Nitrogen utilization is nearly an “ideal” trait • Measurable • Milk urea nitrogen (MUN) already routinely recorded • Variable • wide differences exist among cattle • Genetically controlled • moderately heritable (h2 = 0.20 to 0.40) • no antagonistic genetic correlations • Economically important • protein supplementation is costly • MUN is related to “wasted” nitrogen • may also reduce nitrous oxide emission
Selection: Methane Emission • Direct selection may be possible • Situation less favorable than for MUN • not routinely or inexpensively recorded • There are several favorable circumstances • preliminary results show genetic variation • various technologies allow measurement • there is strong political interest • research support • genomics could yield more accurate selection
Lack of economic drivers no penalties or incentives for GHG emission overfeeding of protein is generally economical Inclusion in selection index would decrease genetic response for other traits Assessment of farm-by-farm differences in genetics of GHG production may be difficult breed-wise selection goal incentives for using superior sires Obstacles to Direct Selection
Alternative Approaches • Indirect selection may be the best alternative • Historical selection for production has already greatly decreased the environmental footprint of the Holstein cow
Relationship between milk production, feed efficiency and CH4 emissions Knapp et al., 2010
Impacts of Improved Production Resources/waste per 1 billion kg of milk (US data) (Capper et al., 2009)
Selection for Total Efficiency • But increased production is not a “magic bullet” • Reproductive fitness has decreased over time • Longevity has decreased • Both of these factors are associated with greater GHG on a herd-wise basis • Fortunately, current selection indexes account for these factors
Action is required to decrease the present and future impacts of dairy production on the environment Interventions are needed for management of both the cow and her production system Current breeding goals are likely to continue to decrease GHG emissions per cow Goals may change with new environmental policies research is needed to facilitate selection and establish economic values Conclusions and Recommendations
Holstein genetics has the potential to increase food security in developing countries while decreasing environmental impact HOWEVER – the genetics needs to match the environment pure Holsteins in situations with good management for intensive production well-planned crossbreeding in less-suitable environments capacity building in management, recording breeding and breed associations conservation of local genetic resources where warranted Conclusions and Recommendations