Weathering the Storm: Climate Smart Sheep Farming by Barbara Johnstone Grimmer, P. Ag. Sheep Canada Magazine Vol. 31 No. 1

http://www.sheepcanada.com/sheep-canada-spring-2016/

         

         The summer of 2015 was the driest on record here, affecting our ability to bring in a decent hay crop and making it tough for the sheep to get enough grass.  Although dry seasons can happen, there is a growing consensus that we are in the midst of climate change, and unfortunately agriculture is viewed as both a villain and a victim of this shift in weather conditions.  Ranchers and farmers have always worked around changes in the weather, but the climate trends we are experiencing present new challenges and opportunities.  Increases in extreme and highly variable weather events such as droughts and floods, rising annual temperatures, and increasing winter precipitation over most of Canada, are expected to be the new normal. 

So what is behind our changing weather patterns? Climate change has been linked to the rise in “greenhouse gasses” carbon dioxide (CO₂), nitrous oxide (N₂O) and methane (CH₄), trapping the heat from the sun. These gasses are linked to the use of fossil fuels and human activities, such as agriculture.  Besides the natural atmospheric conditions that help keep our planet comfortable, there is good scientific agreement that human activities have tipped the scale towards increasing levels of greenhouse gasses and their effects on the warming of the earth.

 To limit the global increase in warming and the ongoing impacts to agriculture requires a global effort.  Canada intends to reduce emissions across the economy by 30% below 2005 levels by 2030.  “Climate-friendly” ranching and farming could help in this effort by reducing, removing or replacing greenhouse (GHG) emissions.   To take it a step further, farming could be “climate-smart” by improving production efficiencies and profitability, while at the same time adapting to climate change and reducing GHG.

Where do the agricultural GHG emissions come from?  Carbon dioxide can come from on-farm energy and machinery use, intensive tillage and overgrazing.  Methane primarily comes from the digestive processes of ruminants (enteric fermentation), as well as manure storage.  Nitrous oxide can come from fertilizers, manure applications to soil, nitrogen-fixing crops, and waterlogged soils.  These gases are found naturally in the atmosphere, but their levels rise significantly with human activities such as agriculture.  Carbon dioxide is the predominant greenhouse gas, but methane and nitrous oxide are more potent, at 25 and 298 times (respectively) the global warming potential of carbon dioxide. 

What can we expect to happen? Our northern latitude will give us some advantages over warmer regions.  There are indications that up until 2060, Canadian prairie grazing capacity will remain productive, with an increase in warm-season grasses. Earlier seeding dates, possibly improved soil moisture levels, warmer summers and earlier spring warming are predicted in most regions.  Although growing seasons will be extended, the hotter summers will shorten the season for cool season crops and grasses.    Extremes such as heat waves are expected to decrease productivity as evapotranspiration increases and soils become increasingly dry. The possibility of less snow, receding lakes, lower stream flows and retreating glaciers will have their effects.

Increased CO₂ levels could result in more plant growth, but could also negatively impact plant distribution and type, forage quality and quantity.  Rising CO₂ levels could favour weed growth and the general warming trend could expand the range of weeds, forbs and invasive species. 

Severe droughts are expected for many of the ranching ecoregions.  Forest fires are expected to increase with increased temperatures, summer droughts and insect infestations.

Coastal areas are likely to experience wetter winters, and with the warmer weather we will probably see greater problems with parasites. 

Besides changes to growing conditions and crops, livestock directly impacted by temperature extremes and heat stress can have reduced appetites, impaired reproduction, increases in stress hormones, decreases in thyroid hormones, water deprivation, nutrient imbalances and nutrient deficiencies.  Some of these effects arise from seeking shade during the heat of the day which reduces grazing time, and having insufficient water of quantity or quality necessary.  These changes reduce productivity and increase morbidity and mortality of livestock. 

Increased summer temperatures can also influence meat quality of livestock, with dehydration, weight loss, altered muscle metabolism and stress, especially during transport and handling to the abattoir or auction mart. 

Diseases such as Anthrax, haemonchosis, fascioliasis and Bluetongue are influenced by climate through changes in their range of distribution, timing of outbreaks or intensity of outbreaks. 

So what can we do? Adaptation to climate change can be short-term in reaction to observed changes, and long-term by planning for anticipated changes in climate.  Each farm will need to determine its own vulnerabilities and opportunities.  

Adaptation measures can include securing and enhancing water supplies, installing drainage and irrigation, diversifying the farm, altering planting and harvest dates or breeding and lambing times, improving livestock shelters and infrastructure.

Mitigation refers to efforts to reduce the net amount of heat trapping greenhouse gases (GHG) released into the atmosphere.  Mitigation strategies are frequently linked to adaptive strategies i.e. planting trees for shade and shelterbelts for the comfort of the livestock, also sequesters carbon and reduces greenhouse gas emissions.  Strategies include:

·         Improving whole-farm productivity and resource efficiency

·         Maintaining optimal animal health and productivity

·         Sequestering carbon in trees, grass and soils

·         Minimizing leakages of GHG emissions through efficient and minimal fertilizer and manure applications and using nutrient management planning

·         Reducing soil disturbances, tillage, summer fallow and overgrazing

·         Exploring carbon-replacing renewable energy technologies (wind, water, solar, biofuels)

To help with mitigation, Agriculture and Agrifood Canada has produced a whole-farm modelling program that estimates greenhouse gas emissions for farmers at no cost.  The “Holos” program allows the producer to test different farm scenarios to aid in reducing GHG emissions and it is continually being updated.

Each operation should conduct a climate audit.  The climate audit identifies each climate trend (precipitation, temperature, extremes) and determines the impact of each trend on farm inputs, animal production, logistics and farm exports.  Another useful activity would be to conduct an energy-use audit which could reduce energy use, and CO₂ emissions.  An energy audit combined with a climate audit may reveal opportunities for replacement of greenhouse gas emissions with renewable energy resources, such as wind, solar, micro-hydro or biofuel production.  This could provide a cost savings, while also providing a new income stream through the sale of surplus energy and mitigating climate change. 

Producers should have an emergency drought plan.  This can include improving forage resources, modifying grazing strategy, improving water resources and/or diversifying.  If climate conditions lead to reduced forage resources over extended times, de-stocking might be necessary. 

            Pasture management strategies can also improve feed efficiency and reduce nitrous oxide and methane emissions by the incorporation of digestible grass and legume mixes.  The legumes fix nitrogen from the atmosphere, increasing crude protein of the grass mix and replacing some or all of the nitrogen requirement for grass growth.  This reduces the amount of fertilizer required, avoiding some greenhouse gas emissions.  Extended grazing seasons due to climate change, coupled with grazing systems like management intensive grazing that manage the grass and soil first, could provide some opportunities for improvements to productivity.  This could result in a lower requirement for stored winter feed, but unpredictability would require planning for the worst case scenario, like extended droughts or crop failures.

The number of lambs reared per ewe, lamb growth rates, percentage of bred ewes, and level of nutrition are all linked to improved resource efficiency (and reduced emissions) and increased productivity. Flock health management, good biosecurity measures and disease surveillance are especially important with climate change, based on the northern migration of disease vectors and the adaptability of disease-causing organisms.  Healthy stock is more productive and more feed efficient.

            Managing water resources is important due to the increased possibility of elevated temperatures heat waves during the growing season, increasing water demand while impacting supply.  Both quantity and quality of water are important for flock health and welfare.  Precipitation may be reduced in the growing season, critical for pasture and rangelands that are rain fed and not irrigated and increasing the incidence of droughts.  An adaptive strategy to limited water resources may be to reduce stocking density, for herd health and welfare and to reduce overgrazing and soil erosion.

            If sufficient feed has been stockpiled, and water resources are adequate for livestock needs, one strategy may be to establish “drought pens or paddocks”, supplementing with grain if possible.  This can be done through early weaning of lambs, feedlot feeding them until market size.  Adult stock may be fed separately to avoid overgrazing.  Australians often implement this strategy, and I found it to be very effective last summer.

            Canada has the advantage of having a climate known for its cold, ice and snow.  For some, a bit of warming would be a welcome change and give us more of an advantage globally.  At this point, the level of uncertainty and the projected extreme weather events for the future make it hard to be totally confident in that view.  Perhaps “hope for the best and plan for worst” might be some good advice for the future.

 Appendix 1. Sheep Farm, Canada

Climate trends	Farm inputs	Animal production	Logistics	Exports
PRECIPITATION More precipitation in winter months, Drier in summer	Hay crop would be affected unless there is irrigation , perhaps grain also since it is usually grown without irrigation in prairies; higher prices, may need to plant different crops	Production may be affected if there isn’t shelter for winter rain or summer sun, warm rain can exacerbate parasite problems in pasture systems, foot problems	May not get on field in spring early enough if still wet, may have trouble harvesting if weather is unstable, mud and rain makes it difficult to handle livestock, transport.  Drought can impact grazing operations, reduce carrying capacity of the land	May experience price crash if animals are shipped at same time to save feed, price may also rise in long drought with less supply, but costs will be higher too
TEMPERATURE Increasing temperatures year round, especially hotter in summer months, warm winter	Add to reduced crop yield in non-irrigated areas, may need to plant different crops Higher prices	Heat stress impacting reproduction, feed intake, growth and production,   insect and parasites may over-winter and no longer have winter-kill effect, could have a hot summer kill effect on parasites (positive),  insects carrying disease could move north	Hot weather can’t ship livestock, may need to delay breeding later if too hot,  may need to feed animals if grass dries up and to prevent overgrazing, may need to ship livestock to save grass and hay for rest of year, hard to plan, shipping planned in advance but animals might not be ready or it may be too hot to ship	Hard to ship at peak of the market sometimes if there are heat waves,  may not sell as much hay if saving for own stock
EXTREMES More heat waves in summer, winter storms with wind and rain, perhaps heavy snow storms.	Higher feed costs Electrical disruptions, power outages, shelter requirement for livestock might be adjusted, generators needed	Less production in both low and high extremes, very hard on farmers and staff to work in extreme weather events	Stressful on stock, farmers and employees.  Hard to plan.  Focus on preparation for the worst,	Hard to predict best time to sell in advance or how to time the market

 Resources:

1.       Australian Wool Innovation (2013) Managing sheep in drought lots: a best practice guide https://www.wool.com/globalassets/start/on-farm-research-and-development/sheep-health-welfare-and-productivity/sheep-nutrition/awi-drought-resources/gd0458_managing-sheep-in-droughtlots.pdf

2.       Holos http://www.agr.gc.ca/eng/science-and-innovation/science-publications-and-resources/holos/?id=1349181297838

3.       USDA (2015) Animal Agriculture in a Changing Climate  http://animalagclimatechange.org

Determining the Carbon Hoofprint of Canadian Lamb - by Barbara Johnstone Grimmer, P. Ag. Sheep Canada Magazine, Vol 31 No. 2 Summer 2016

The Carbon Footprint of Lamb in Canada – More Research Needed

http://www.sheepcanada.com/sheep-canada-summer-2016/

    

     Lamb doesn’t often make global headlines, but a few years ago the greenhouse gas emissions from lamb production were reported to be higher than any other meat.  Headlines like “Eating lamb is worst for the environment¹” didn’t match with the image most people have of healthy lambs frolicking in healthy pastures.  Recent suggestions to tax red meat through a carbon food tax doesn’t help either².  Higher reported emissions for lamb translate into a higher carbon footprint, the shorthand term for global warming impact, usually expressed per unit product.  The global warming impact for agriculture relies on three main greenhouse gases (GHG); methane, nitrous oxide and carbon dioxide.  Rising carbon dioxide (CO₂) levels have been associated with the burning of fossil fuels. Methane, from enteric fermentation in the rumen and from manure, is 25 times more potent than CO₂, the main greenhouse gas.  Nitrous oxide from soil management and manure is 298 times more potent than CO₂. The carbon footprint adjusts these impacts and expresses them in CO₂ equivalents, or CO₂e per functional unit.  A functional unit may be kg live weight (LW), for example.

     This may seem straightforward, but all carbon footprints are not created equal.  Methods and calculations differ, lack of reliable data results in generalizations and assumptions with lots of resultant variability and uncertainty.  Many calculations are within a specific “cradle to farm gate” boundary for a farm level assessment using a method called “life cycle assessment”, or LCA.  Then there are direct emissions, such as rumen emissions, versus the indirect emissions, which may arise from processes traced back to the production of the feed that the lamb eats (fertilizers, land clearing).  In general, it is not advised to compare carbon footprints using different methods, but that doesn’t stop researchers from doing that.  One paper, aware of this reality, compared the carbon footprint of New Zealand to Welsh lamb and clearly demonstrated that the variability between sheep farms undermined any attempts to generalize about the claims made for the carbon footprints of lamb for a region or country³.  The authors advised that more on-farm research was needed to collect sufficient data from similar farms within regions to aid in the understanding of the variation in carbon footprints.  Another Welsh study five years later compared 64 sheep farms, and found that carbon footprints can vary with local conditions and management choices⁴.  In particular, regardless of type of farm, the number of lambs reared per ewe, lamb growth rate, percentage of ewe and replacement ewe lambs not mated, and concentrate use had the greatest impact on the carbon footprint of lamb.  Although Welsh lamb carbon footprints varied by farm type with lowland 10.85, upland 12.85 and hill 17.86 kg CO₂e/kg LW, the authors concluded that nationally, the carbon footprint of lamb could be reduced by improving the productivity of the poor producing farms and reducing the productivity gap between farms.

     Canada covers several ecoregions with varying climates and sheep production systems and breeds.  Cattle are the main ruminant species in Canada, producing over 95% of enteric fermentation emissions.  Cattle production systems are well-characterized and have been thoroughly studied regarding environmental impacts.  Sheep are a minor species in Canada, although consumer demand for lamb is growing and over half of the lamb consumed is an imported product.  There is little Canadian research regarding sheep production environmental impacts through tools such as LCA or carbon footprinting.  Estimation of greenhouse gas emission intensities from sheep are generally based on values from the UN’s Intergovernmental Panel on Climate Change (IPCC). For sheep in Canada, IPCC Tier 1 emission factors are used for enteric fermentation, and IPCC Tier1/ 2 values are used for manure emissions.

     The IPCC methodology to determine GHG emissions is rated by its level of detail and accuracy.  Tier 1 is the lowest level, and emissions are obtained by multiplying by the population of animals in a livestock category by an emission factor (EF).  For Tier 2, climate and type of manure storage is taken into account, but a lot more data is needed for Tier 2, especially in a country like Canada with such a wide range of climates and farming types.

     The Canadian carbon footprint for sheep was recently reported to be significantly higher than the beef carbon footprint using national livestock population data and modelling using Tier 1/Tier 2 methodologies⁵.  However, the uncertainty of the IPCC Tier 2 Canadian livestock model has been determined to be especially high for lamb methane emissions, primarily when values are assigned at the national scale⁶.  Developing parameters that are country-specific with regional refinements, and using appropriate production stages for livestock, would reduce the uncertainties and produce more accurate greenhouse gas emission values and carbon footprints.  The Canadian enteric methane values for sheep are based on Tier 1, at 8 kg methane/head/year regardless of age.  In contrast, the UK enteric methane emission factors for sheep are age specific, at 8 kg methane/head/year for adult sheep, but 40% of that value for lambs less than one-year-old (3.2 kg methane/head/year), allowing for a further adjustment to the average age lamb is shipped.  As to why lamb would have higher emissions, there are suggestions that wool is not counted as a product in these calculations (GHG), and would contribute to lower dressing percentages.  The study also made broad management and feed assumptions which should be verified, and assumed a shorter reproductive lifespan for ewes than has been reported.  More on-farm research, industry collaboration with scientists, better regional data and better models for sheep are definitely needed.

      Based on the need for more production and regional-specific research, a carbon footprint project was conducted in the Gulf Islands of BC using my farm as an example.  My farm is typical for the region, with a mild temperate Mediterranean-type climate, home-grown feed, and an extended grazing season.  We supplement our pasture and grass hay with Sheep-Lyx nutrient block supplement according to the nutrient value of the forage and balanced with the nutrient needs of the sheep.  The carbon footprint calculated using the cradle to gate LCA method included most emissions related to the production of lamb. 

     Three modelling systems were used to estimate the carbon footprint of lamb.  Farm data was put into the models.  The results were as follows:

UK- All-Tech Sheep E-CO₂ “What If?” Tool (2015): 9.4 kg CO₂e/ kg LW lamb

UK/US- Cool Farm Tool (Excel version 2.0): 5.13 kg CO₂e/ kg LW lamb

Canada-Holos (version 2.2): 7.53 kg CO₂e/ kg LW lamb

    The variability in carbon footprint can be partly attributed to the different default values used for each model which can reduce the complexity and simplify the results.  In general, a UK model may be used as a proxy for the Gulf Islands because of similarities in sheep breeds and climate.  However, there are differences in feed sources, energy sources, management and resources such as soil.  Based on other studies, 90% or more of the carbon footprint was expected to be on-farm.  The other 10% was expected to come from upstream emissions (fertilizer, off-farm feed) and can inform the producer regarding sourcing of inputs to the farm and their impact. The majority of the emissions from this project were from methane, regardless of the tool or model used.  The primary source of methane was from enteric fermentation.

     The simplest system to use was the Alltech E-CO₂ tool.  The tool models UK scenarios based on industry data. The Tool has three basic farm systems; rearing lambs to finishing, rearing to store sale, and stores purchased to finish.  Basic information from farm records are used, and “what-if” scenarios can help advise management decisions to improve the carbon footprint.  This tool is useful for exploring different scenarios for sheep management, but is not sensitive enough to provide an accurate carbon footprint.

     The Cool Farm Tool (CFT) has an online version as well as an Excel spreadsheet version.  The CFT is useful for farm level calculations to estimate GHG emissions.  The calculator is based on peer-reviewed data and goes beyond simple Tier 1 by including geographic locations.  However, Canada was a single region for this model, reducing the model’s reliability.

     Holos is a farm level GHG calculator developed by Agriculture and Agri-Food Canada, and it includes a research version⁷. Holos is specific for Canada using ecodistricts to account for climatic, soil type, topography and precipitation differences.  Soil carbon factors are incorporated into the model.  Estimates of uncertainty are identified. Holos allows for the estimation of carbon accumulation and losses, by calculating the impact of land use change such as land-clearing or planting of trees. Looking at the entire farm, our farm is a carbon sink because of the amount of forest we have.   Holos is also being developed as a carbon footprinting tool and beyond carbon footprinting to include more environmental impacts⁸.

     All three tools are easily accessed and free on the Internet for producers to use.

     The carbon footprint results for my farm are being used to help determine hotspots for improvements in management, and to adjust future data collection so that a follow-up carbon footprint project can fine-tune the emission estimates.  The results are a first step in understanding the impact of our local sheep production systems on greenhouse gas emissions, and to identify the gaps in data and modelling methods for regional, provincial and national carbon footprint projects.

References

¹Brown, L. (2011). Eating lamb is worst for the environment, 19 July 2011. Earth Times. www.earthtimes.org.

²Ong, S. (2016). Taxing red meat to fight climate change, 24 May 2016. Science Line. www.scienceline.org.

³Edwards-Jones, G., Plassmann, K., Harris, I. (2008). The carbon footprint of sheep farming in Wales. Bangor University, Wales. Available to download at http://hccmpw.org.uk/medialibrary/publications/carbonfootprintsheepreportapril1508FINAL%20REPORT-1.pdf

⁴Jones, A., Jones, D., Cross, P.  (2013).  The carbon footprint of lamb: Sources of variation and opportunities for mitigation.  Agricultural Systems 123, 97-107. Doi: 10.1016/j.agsy.2013.09.006.

⁵Dyer, J., Verge, X., Desjardins, R., Worth, D. (2014). A comparison of greenhouse gas emissions from the sheep industry with beef production in Canada. Sustainable Agriculture Research 3,65-75.

⁶ Karimi-Zindashty, Y., MacDonald, J., Desjardins, R. Worth, D., Hutchinson, J., Verge, X. (2011). Climate Change and Agriculture Paper: Sources of uncertainty in the IPCC Tier 2 Canadian Livestock Model.  Journal of Agricultural Science.  1-14.  doi: 10.1017/S002185961100092X.

⁷Little, S.M., J. Lindeman, K. Maclean and H.H. Janzen (2008). Holos - A tool to estimate and reduce GHGs from farms. Methodology and algorithms for Version 1.1.x. Agriculture & Agri-Food Canada, Ottawa, Ontario.

⁸ Krobel, R., Janzen, H., Beauchemin, K., Bonesmo, H., Little, S., McAllister, T. (2013). A proposed approach to estimate and reduce the environmental impact from whole farms.  Acta Agriculturae Scand Section A  dx.doi.org/10.1080/09064702.2013.770912