ABIOTIC STRESS IN ANIMALS AND ITS MANAGEMENT

Dr. V.K.GuptaSenior Scientist,

Medicine DivisionI.V.R.I.IZATNAGAR(UP)

INTRODUCTION

• Abiotic stress: the negative impact of non-living factors on the living organisms in a specific environment

(Kumar et al., 2012)

• Naturally occurring• Unavoidable

• Most harmful factor affecting growth and productivity (Gao et al., 2007)

• Biodiversity:As the level of abiotic stress↑, the number of species ↓

• Melting of ice: removes hunting ground for polar

bear and reduced body weight

• Flood and water scarcity: deteriorates water quality

and habitat destruction

• Food availability: alter food availability to migratory

species eg: red foxes introduction to Australia

• Major species affected: Polar bear, Indian tiger,

migratory water fowl

HISTORY

• Extinction of Dinosaur: asteroid collision (66 billion years ago) (Alvarez, 1980)

• The cellular stress response was first observed in Drosophila busckii salivary glands that had been exposed to an increased temperature (Ritossa, 1962)

• Stress proteins are named heat shock proteins (hsp), due to their inducibility by increase in temperature

(Tissieres et al., 1974)

ABIOTIC STRESSORS

• Extreme temperature (Palta et al., 2006)

• Humidity• Intense solar radiation in summer, drought

(Pal et al., 2013)

• Flood, high winds, natural disasters• Salinity, acidity, mineral toxicity

• Nutrient deficiency (Peden et al., 2007)

Global warming and Heat stress

Global average surface temperature rise between 1.8-4˚C by 2100. ( IPCC,2007)

Global warming refers to the gradual increase of the

Earth’s temperature because of energy trapped by the

atmosphere.

CO2

• Large amounts from the burning of fossil fuels• Fertilizer is used to grow crops• CO2 is emitted during livestock feed production

• Deforestation - forests are harvested or burned large amounts of CO2 are released into the atmosphere

Source of greenhouse Gases

N2O

• “Unmanaged” manure also emits greenhouse gases• From feedlots, chemical plants, auto emissions,

agricultural practices- Ammonia fertilizers

Nitrous oxide

Carbon dioxide

(CO2, N2O, O3, CH4, CFCs)

• Methane : natural by-product of Enteric Fermentation• Ruminant animals are the major emitters of methane - unique

digestive process that occurs in a large “fore-stomach”• Anaerobic decomposition of manure • Decaying vegetation.• Agriculture, especially rice paddies with anaerobic bacteria.

Methane (CH4)

Methane

Global GHG emission (IPCC, 2007)

Source: Carbon Dioxide Information Analysis Center 

Over past 200 years the atmospheric concentration of CO2 increased about 31%

Observed Changes and Effects

Drought

Floods,

Storms

Air quality

Vectors

climate

Forest fire livestock

Ice melting- sea level rise

• Heat stress is the most stressful of all abiotic stressors in animals

• Due to overexposure or overexertion in extreme environmental temperature

(Seijan et al., 2015)

• Thermal comfort zone 5-15˚C in temperate region (Sirohi & Michaelowa, 2007)

• TCZ 13-27˚C for Indian goats (Mishra, 2009)

Prasad et al., 2015

ADAPTIVE MECHANISMS TO ENVIRONMENTAL STRESS

(Seijan 2013)

• Physiological adaptation mechanisms:rectal temperature, pulse

rate and respiration rate↑ in small ruminants

(Sharma et al.,2013)

• Hormonal changes: prolactin , cortisol ↑

: T3 and T4 , plasma aldosterone level ↓

(Sivakumar et al.,2010)

• Haematology : decrease in hemoglobin and PCV (Temizel et al., 2009 )

• Serum biochemistry: increase in SOD level in goats during heat stress (Kumar et al.,2011)

• Concentration of vitamin C and vitamin E lowered during heat stress in goats (Kumar et al., 2011)

• Decrease in total protein concentration and increase in HSP concentrations in goats have been reported during heat stress

(Dangi et al., 2012)

• Blood glucose and total cholesterol level decreases during summer season and increases during winter season in goats

(Ocak et al.,2010)

• Lowers the alkaline phosphatase (ALP) and lactic dehydrogease (LDH) activity due to decrease in thyroid activity

(Helal et al., 2010)

• Serum ALT value found to be increased during heat stress in goats (Sharma and Kataria, 2011).

MOLECULAR MECHANISM• HSP: Expression of many HSPs including HSP32, HSP40,

HSP60, HSP70, HSP90, HSP110 (Sharma et al., 2013 )

stressors

•C-reactive protein (CRP), p53, p21, interleukin-6, interleukin-8, VEGF(Vascular endothelial growth factor), cNOS, iNOS

(Sonna et al., 2002)

IMPACT ON LIVESTOCK PRODUCTION

Deleterious effects are the result of

1. The hyperthermia associated with heat stress

2. The physiological adjustments made by the

stressed animal to regulate homeostasis

• Affecting organisms on ecological, organismal,

cellular and molecular levels

(Hochachka & Somero, 2002)

EFFECT OF ABIOTIC STRESSES ON LIVESTOCK PRODUCTION

• Growth

• Milk production (West, 2003)

• Negative impacts on reproduction (Hansen, 2007; Marai&Habeeb, 2010)

• Heat stress reduces the performance of laying hens by reducing egg production, egg weight, shell thickness body weight and feed consumption

(Mashaly et al., 2004)

• Availability of feed and water• Distribution of livestock pest and disease

• Immune function (Elvinger et al., 1992)

GROWTH

• Reduced voluntary feed intake

• Reduced anabolism (Seijan et al., 2010)

• Increased catacholamines and glucocorticoids ↑catabolism (Marai et al., 2007)

• Redistribution of blood flow to body surface → GI ischaemia and hypoxia→ ↓ food assimilation

(Leon, 2008)

REPRODUCTIVE FUNCTION

Length of oestrous cycle and degree of expression of

oestrus in buffaloes↓

Affect FSH-R signalling pathway in the granulosa cells

of growing follicles, causing decreased estrogen levels,

which are known to produce increased follicular atresia (Ozawa et al., 2005)

Suppress aromatase activity in granulosa cells and decrease the estradiol concentrations in the follicular fluid and plasma of dairy cows

(Badinga et al., 1993)

↓ the fertility of dairy cows in summer by decreased

estradiol secretion from the dominant follicle

(De Rensis and Scaramuzzi, 2003).

Oocyte development and maturation by altering progesterone, luteinizing hormone and follicle-stimulating hormone and dynamics (Ronchi et al., 2001)

Impairment of embryo development and ↑ embryo mortality in

cattle, mares and pig (Hansen, 2007; Mortensen et al., 2009)

A drop in conception rates (cattle& rabbits) about 20–27% can

occur in summer (Chebel et al., 2004; Lucy, 2002; Marrai et al., 2001)

Disruptions in spermatogenesis (Perez-Crespo et al., 2008)

Semen concentration, number of spermatozoa per ejaculate of

bulls are lower in heat stress condition

(Mathevon et al., 1998; Nichi et al., 2006)

MILK PRODUCTION• Lactose production: primary osmoregulator and determinant of

milk yield- • reduction of glucose availability and reduction of feed intake

under hot conditions leads to the reduction of milk yield (Baumgard et al., 2007)

• India:losing 2% of the total milk production, (>Rs 2,660 C )• ↓ the milk secretion by up regulating the activity of milk borne

negative feedback regulatory system (Silanikove et al., 2000)

DISTRIBUTION OF LIVESTOCK DISEASE AND VECTORS

• Altered pattern of diseases in animals

• Emergence of new disease

• Change in prevalence of existing disease

• Change in the distribution and abundance of vectors

• The reduction in the amount of saliva produced and

salivary HCO3− increase the susceptibility to sub-clinical

and acute rumen acidosis

(Kadzere et al., 2002)

• higher incidence of mastitis during periods of hot weather

(Chirico et al., 1997)

DISEASE EMERGENCE AND REEMERGENCE

• Since 1975 nearly 30 new disease has emerged and some diseases re emerged (WHO)

IPCC AR4, 2007

The climatic changes induced by global warming exert a selection

pressure that will modify the biodiversity of pathogens and the

epidemiology of the infections (Lovejoy, 2008)

1. On pathogen- changing behaviour

bacteria developed mechanisms to survive and grow in unfavorable

stress conditions eg. E.coli O157:H7 survive in acidic condition at pH 2

(Mirski et al., 2011)

Gene transfer between related and unrelated bacterial species (Mirski et al., 2011)

eg. Non toxigenic V. cholerae strains acquired the genes encoding cholera

toxin from bacteriophage

Gene transfer and Environmental adaptation eg.. MRSA

EFFECT ON DISEASE

Increasing CO2 concentrations leads to stimulation of microbial

growth (Blatchford, 2009)

Higher humidity favors microorganisms to more invasive in the host and development of disease (Petzoldt , 2005)

High temperatures and moisture have on growth of mycotoxin-

producing fungi (Lacetera et al., 2003; Vitali et al., 2004)

2. Rising sea levels will lead to coastal flooding and risks for

water-borne zoonoses

3. ↑ rainfall more crops and food, ↑ rodent populations and rodent-borne zoonoses eg. Hanta virus infection

4. The heavy rainfalls eg. Rift Valley fever outbreaks in East Africa

5. Migration of wild birds is involved in disease transmission. With alteration in seasons, changes in migration patterns eg. WNF

6. ↑ temperature and rainfall leads to emergence of vector borne diseases (vectors are the most sensitive to climatic temperature variability)

(Naicker et al., 2011)

EFFECT ON VECTORS• Increased rain may increase larval habitat

• Heavy rainfall events can synchronize vector host-seeking and virus

transmission

• Due to increase in global temperature tropical insects expand to their

territories to further latitudes & find the living conditions at higher

altitudes.• Increasing vector population growth rate• Increasing length of transmission period• invertebrate metabolic rate• egg production amount• feeding frequency• reducing duration of development periods

DIRECT EFFECTS OF CLIMATE CHANGE ON VECTOR-BORNE DISEASE

• Climate change has the potential to – Increase range or abundance of animal reservoirs and/or

arthropod vectors (e.g., Lyme disease, Malaria, Schistosomiasis)

– Enhance transmission (e.g., West Nile virus and other arboviruses)

– Increase importation of vectors or pathogens (e.g., Dengue, Chikungunya, West Nile virus)

– Increase animal disease risk and potential human risk (e.g., African trypanosomiasis)

(Greer et al., 2008)

http://www.onehealthinitiative.com/index.php

Climate-disease links: Bluetongue

Holding Temperature (C)

History of bluetongue (BT) in Europe

Kyasanur forest disease (KFD)

Kyasanur forest disease virus (KFDV), Flavivirus, zoonotic

Hosts: small rodents, bats and monkeys may also carry the

virus. Infected tick (Haemaphysalis spinigera - major

vector).

Deer Mouse Cotton Rat

Rice Rat White-footed mouse

Ixodes ticks of Lyme disease in North America

has been expanding north into southern Ontario

and, more recently, into western Ontario

(Ogden, 2009)

Avian influenza

Narrowing of habitats crowding of several species of birds into smaller areas of remaining resources & ↑chances of intra & inter species disease transmission - AVIAN INFLUENZA PANDEMIC THREATS

Viruses deposited by migratory waterfowl during summer breeding at higher latitudes may be stored in permafrost conditions in sub arctic regions and survive for centuries (Zhang et al., 2006)

MANAGEMENT OF ABIOTIC STRESS

• Genetic modification:

1. Identification of stress resilient genes

2. Identification of thermotolerant gene

3. Genetic selection for heat tolerance

4. Cellular and molecular therapies

Genomic technologies for unravelling heat and abiotic stress towards climate resilient animals

DIETARY STRATEGIES

• The manipulation of dietary protein content and energy density, and calcium (Nayyar and Jindal, 2010)

• Fat feeding• Adequate fiber feeding (Beatty, 2005)

• Mineral supplementation• Antioxidant supplementation (Sathya et al., 2007)

• Vitamin supplementation • Cool drinking water

• Usage of vitamin C & E are practices believed to alleviate the effects of heat stress

(Pardue &Thaxton, 1986; Bollengier-Lee et al., 1998)

• The inhibitory action of AA on adrenal steroidogenesis is mediated via modulation of steroid hydroxylating enzymes in the adrenal gland

(Seijan et al., 2015)

MANAGEMENT STRATEGIES

• Shading• Estrus detection and timely AI• Hormonal treatment• Care during pregnancy• Local breeds having high adaptability• Strengthen local breeds by cross breeding with

heat tolerant breeds• Rain water harvesting• Forecasting and crisis preparedness (Seijan et al., 2015)

SHELTER DESIGN

• Shelter materials• Site of shelter• Wind breaks• Partially or totally enclosed shelters• Provision for cooling

(Collier et al., 2006)

THANK YOU

Thank you