Climate change –influence on animal health and production

Ann Albihn, ProfessorNational Veterinary Institute (SVA) and

Deptm. Biomed Sci. and Veterinary Public Health, SLU

SLU SIANI 16 03 11 Livestock resources for food security in the light of climate change Ann Albihn

Different problems areseen for different:

• Species and breeds• Regions• Husbandry regimes

Climate change affect animals

• Immunosuppression• Production↓ growth, milk, egg,.. • Reproduction↓ sperm quality, embryo survival, heat symptoms Heat sensitive animals e.g.• Aquatic animals mostly has a narrow temperature window • Swine and poultry can not sweat• Full-fatted and winter coated outdoor cattle in the autumn• High yielding animals

Heat stress cause health effects

The high yielding dairy cow -an example of a heat sensitive animal

• Already high metabolism • Effects are seen on

– body temperature – reproduction – milk production– animal welfare

• Milk production is generally“well recorded”

Temperature-Humidity Index (THI) and expected reduction of milk yield for dairy cows in two different regions in Sweden for year 2025

Heat wavescenario

TemperatureºC

Relative Humidity% THI2

Durationno. of days

Reduction ofmilk yield 3

Middle

Extreme

2630

263033

8580

858077

7783

778387

103

1563

Small

Medium

2 THI = (1,8 Temp + 32) – ([0,55 – 0,0055 humidity [1,8 Temp – 26], 3 Reduction of milk yield on a yearly basis was expeted as small (<0,5 %), medium (0,5-2,0 %), large (> 2,0 %)

Eckersten, Djurle, Albihn, et al. 2015, SLU Report

Adaptation to increasing temperature– to reduce the negative effects

•Possibilities to change behavior •Grassing nighttime instead of daytime•Supplementary cooling, ventilation•Bedding material•Bathing•Adjustment of feed/feeding routines•Adjustment of stables, transportation,..

Photo Anna-Marja Kaddik, SSR

Cold spots are getting hot.Semi-domesticated reindeer are facing a new situation concerning climate change and ecosystem changes

Reindeer herding

Free-grazing, wide areas, adapted to harsh ecosystemsHighly specialized animals, sensitive to environmental perturbationsThe present grazing area depend on season and weather. By tradition high flexibility, today reduced access to alternative areas Migration or transportInfluencing northern ecosystems - feeding and migration patternsImportant for indigenous people as Sami and NenetsFrom nomadism to modern pastoralism

Photo Anna-Marja Kaddik, SSR

CC ads on another stressor on a heavily burdened animal production…..

Repeated thawing/freezing events causes icing on the ground Teethes may be seriously damaged while RD try to reach their forage Has to be fenced for supplementary feeding

This also causes increased morbidity and mortality due to; crowding and increases general stress load changed diet (e.g. tree-hanging lichen to hay and pellets)opportunistic infections (no harm to the host during optimal conditions)

Photos Ulrika Rockström, Gård och Djurhälsan

Secondary effects of ecosystem changes

• The thawing tundra may cause outbreaks of anthrax (Bacillus anthracis) in Russia

• Possible air-exposition of buried carcasses from earlier large epizootics of “Sibirski”

• 13000 burial grounds, more than half in permafrost (Revich & Podolnaya, 2011; Glob Health Action)

Photo Ulrika Rockström, Gård och Djurhälsan

• Shortage of water may cause wildlife density to increase in the neighborhood of water sources

• The spread of infectious diseases may be enhanced, both within and between species

• Animal production e.g. milk, needs much water• Contamination of water sources due to increased events of

surface run-off and flooding

CC affects both water availability and quality

• Increased risk: Heavy rain, delayed harvest, low dry matter content at harvest

• Fungus (Fusarium spp produce Deoxynivalenol, Vomitoxin and Zearalenon) in straw and seed

• Pigs are sensitive and may show decreased growth rate and fertility

CC may cause increased problems with mycotoxins in feed

Insects

Annoyance – rest and feed lessBlood suckling - anaemia, toxins, deathAs vectors - transmitt diseases

Insect larva may eat on live animals (blowfly strike, cutaneous myiasis)

Risk dependent on: TemperatureHumidityLength on seasonDensity of insect populationsBreed, age, flock sizeWorm burden - faecal soiling Adaptation by: Deworming Insecticide useFly traps(Mulesing!!)Earlier sheering of ewes in the spring

Arthropod vectors transmit diseases -between individuals and species

Climate sensitive infections (CSI)

Here defined as: Dependent on the natural environment for their spread or persistence, e.g. transmitted to a new host or species by arthropod vectors, water or soil, or they use wildlife as a reservoir.

CC may impact the epidemiology, geographical distribution, seasonality, prevalence, … of CSIBUT - many other anthropogenic environmental factors may also influence CSIOIE, 2008

(World Organisation of Animal Healt)

•

Photo C. Fugelsang

Globalisation -the most important way for spread of diseases

Vectorborne diseases (VBD)

Dependent on the abundance and density of arthropod vectors and other animals used to feed on, as intermediate hosts or as reservoir animals

CC may cause e.g. increased winter survival and more suitable habitats for vectors and other animals

A competent arthropod vector can carry, reproduce and transmit the pathogen, this is dependent on the ambient temperature and many other environmental factors

VBD mostly zoonotic infectionshumans - animals

Borreliosis/Lyme diseases • Tick has changed its distribution to

higher latitudes (Lindgren et al., 2000)

• Influence of temp., humidity, vegetation

• Rodents are reservoir species• Deer, humans and others

are mostly ”dead end host”

A surprisingly quick spread of a VBD

Schmallenberg virus (ortobunya) affect ruminants

Infection during first half of gestation causes dead or malformed offspring

In the end of 2011 in central EuropeSwedish survey 2012 of farm based

milk containers (Chenais et al. 2013)

May -1/ 723 farms pos.Nov – 521/ 723 (72%) pos.

Virus detected also in midges (Culicoides spp.) aborted lambs and calves, In wildlife as roedeer and moose

Bluetongue - an epizootic among ruminants• From Africa, 2006 to several EC countries, 2008 to Swe•Infected midgets (Cullicoides) windspread from Denmark•Hot summer and dense populations of midgets caused spread in Swe• Costly disease control, vaccination

Identification of ”epidemiological hotspots” -to predict VBD outbreaks

Decrease the cost for vector surveillance

Increase the success of handling of an outbreak

A process-based model includes temp, precipitation, vector abundance, biology/distribution, traits of pathogen

Prediction models – aim to model the potential transmission intensity of a pathogen

Good models need good data, but a model will never be perfect

Map source: www.nordrisk.dk

Prediction model for 2038 - no. of days with potential spread of Bluetongueby infectious midges vectors(Culicoides)

Observed Bluetongue infection in cattle and sheep in 2008

Healthy animals produce more Growth rate Egg, milk, …Live longerReproduce betterCentral for a sustainable intensification of animal productionAnimal welfare aspects

• Environmental and ecosystem changes affects animals in many ways as heat-stress, infectious diseases and availability of feed and water

• CC starts complex and dynamic interaction between ecosystems, vectors, pathogens, animals and humans

• For vector-borne diseases, changes are ongoing in geographical distribution, seasonality, prevalence,…

• Wildlife may be seriously affected themselves but also act as a disease regulators for domestic animals and humans

• Lessons learned from other regions - but adaptation needed to local conditions

• Healthy animals produce more

Conclusions

Climate change adaptation –to avoid that surprises turn into crises

As more we know as better we can adapt