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