SUMMER STRESS IN LIVESTOCK AND STRATEGIES TO PREVENT IT
Dr.M.S.Saravanan ,B.V.Sc.,M.A.,PGDCM.,LME., Madurai
What is Summer stress in livestock
https://www.pashudhanpraharee.com/summer-stress-management-in-livestock/
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It is a condition in which thermoregulatory mechanisms of livestock are unable to adjust with the high environmental climate during summer months.
How summer stress occur
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Livestock such as cattle and poultry,use metabolic heat to maintain a stable internal temperature,often one different from the environment.Livestock have their own adaptation methods,which are the characteristics developed by the natural selections which help them to maintain their healthy body temperature.
The critical situation occur during summer months like high atmospheric temperature ,High relative humidity
,insufficient air circulation ,lead to a situation in which livestock not able to apply the adaption methods,and adjust the thermoregulatory mechanism to over come the summer stress.
Factors contribute to summer stress in Livestock:
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1.Livestock shed
2.floor space
3.ventilation
4.fodder and feed availablity
5.water
6.breed character
7.local climate
1.livestock shed:
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Shed structure play a vital role in increasing the summer stress.Roof height and quality of roof play a vital role in summer stress.Livestock shed structure must be constructed according to the need of the livestock maintained.Proper roof height is essential for the good airflow. Roof materials selection must be based on the local climate and level of rain fall.
Standards of livestock shed:
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Cattle:
Height-12 feet
Width-3.80 to 4.25 metres (single row system)7.90 to 8.70 metres (double row system)
Sheep and goat:
Height of ewe 2.5 meter
Height at ridge 3.5 meter
Breadth of shelter is 8 meter.Height of chain link used for open space -4 feet.No Restriction for length of shelter.
Poultry:
Shed height at centre 10 to 12 feet and heights of sides from foundation to roof line should be 6 to 7 feet.
Width:The open sided poultry houses in tropical countries should have a width not more than 22 to 25 feet in order to allow ample ventilation.
The side wall should be of 1 to 1.5 feet height.
Gable type of roof ststem preferred in tropical countries.
Pigs:Roof height should be 8 to 10 feet.
Side walls of the sheds should be 4 to 5 feet.
Ventilation:
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Good ventilation is essential for the livestock shed.It will allow the sufficient air flow in and out of the livestock shed.Improper ventilation in the livestock shed lead to summer stress in livestock.
Ventilation standards:
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A wind velocity of 0.2m/s is generally regarded as a minimum requirement,but it can be increased to 1.0m/s when the temperature is nearing the upper critical,or more when it goes beyond that.
Floor space requirement:
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Proper floor space allotment is essential for the health and productivity of livestock.
Insufficient floor space allotment lead to summer stress and production loss in livestock farms.
Standard floor space requirement for livestock:
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Cattle:covered area-3.5 sq.m,open area-7.0sq.m
Sheep and goat:
6 to 12 month age-
Covered area-1.0 sq.m
Open space 2.0 sq.m
Adult sheep-1.5 sq.m covered space and 3.0 sq.m open space.
Male,pregnant or lactating ewe-2sq.m covered space and 4 sq.m open space.
Poultry:
Egg type chicken
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0-8 weeks-0.60 sq.ft in deep litter and cages .20 sq.ft.
9 to 18 weeks-in deep litre system 1.25 sq.ft and in cage system 0.30 sq.ft
For above 18 weeks-1.50 sq.ft in deep litter 0.50 in cage system.
Meat type chicken
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Age 0-4 weeks 0.30 sq.ft
In deep litter
For 4 to 8 weeks-0.75 sq.ft in deep litter
Pigs:
Weaner- cover area 10 to 15 sq.ft open space 15 -20 sq.ft.
Grower-cover area 12 to 20 sq.ft and open space 20-30sq.ft
Lactating sow-cover area 70-100 sq.ft open space 70 to 100 sq.ft
Boar-cover area 35 to 50 sq.ft and open space 50-70 sq.ft.
Fodder and feed availability:
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Fodder and feed scarcity during summer months lead to summer stress.Provision of insufficient green grass and dry fodder during summer months lead to summer stress in cattle sheep and goat.Provision of high concentrate feed during summer months also lead to summer stress.Insufficient grass in grazing area predispose to summer stress in sheep and goat.
Feed which generate more heat in body predispose to summer stress in poultry.
Water:
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Most of the livestock consume more water during summer months.During the peak of the summer water requirement for livestock doubled the requirement of winter.So insufficient water provision to livestock during summer months predispose to summer stress.
Breed characteristics:
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Livestock native to a particular area well adopted to the climate of the area and able to adjust with the summer stress.Where as high breed livestock not able to adopt to the climatic fluctuations when Reared in a different climatic zone,more prone to summer stress.
Local climate:
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Temperature:
For most livestock a mean daily temperature in the range 10 to 20’C is referred to as the comfort zone.In this range the animal’s heat exchange can be regulated solely by physical means such as constriction and dilatation of blood vessels in the skin,rufflung up of fur or feathers and regulation of the evaporation from lungs and skin.At the upper critical temperature the physical regulation will not be sufficient to maintain a constant body temperature and animal increase its metabolic heat production and if temperature go beyond 27’C summer stress start to appear in livestock.
When local climate if temperature is between 27’C to 30’C summer stress will start.And if temperature reached 35 to 45 ‘C visible signs of summer stress appear.
Humidity:
Poultry do not have sweat glands, so all evaporative heat loss must originate from the respiratory tract. Other livestock species have varying abilities to sweat.
In hot dry climate evaporation is rapid,but in hot humid climate the ability of the air to absorb additional moisture is limited and inadequate cooling may result in summer stress.Too low humidity in the air will cause irritation of the mucus membranes, while too high humidity may promote growth of fungus infections. High humidity may also contribute to decay in structures. If possible keep the relative humidity in the range between 40 to 80.
Symptoms of summer stress in livestock:
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Normal body temperature of different livestock:
Dairy cow:38.0-39.3 ‘c
Beef cow:36.7-39.1’c
Pig:38.7 -39.8
Sheep:38.3-39.9
Goat:38.7-40.7
Chicken:40.6-43.0
According to livestock metabolic standard body temperature,livestock show different types of symptoms.
Cattle:
Due to the more body surface area summer stress symptoms were prominent in dairy cattle.
High body temperature,panting,salivation,enteritis,acidosis,loss of milk yield and downer cow syndrome in full term pregnant cow and fresh cows.
Sheep and goat:
Enteritis,acidosis,weight loss,panting,hair loss and abortion.
Poultry:
Frequent death of birds,high chick mortality,loss of egg production,panting,off feed,starvation and death.
Pigs:
Reduced feed intake,more intake of water,enteritis,weight loss,abortion.
Strategies to control Heat stress in livestock:
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Cattle:
Provision of proper floor space,Roof materials according to climatic zone.Provision of fodder and feed suitable to the local climate.Provision of sufficient cool fresh water.
Management technics for cattle:
Milk once per day.Milking at 12 hours interval at morning 6am and evening 6pm.Provision of fan per rhree cows.Provision of cooling system like water sprinklers. Culling of poor body score cattle before summer months.
Sheep and goat:
Managing the grazing time. Prevent the grazing between 12noon to 4pm.Provide water 4 times per day instead of 2 times.Culling of poor weight gained sheep and goat prior to summer months.
Poultry:
Proper ventilation during day time.change of grazing time for native chicken.Provision of feed suitable to the hot summer. Arrangements around poultry shed to prevent summer stress.Selection of poultry breeds according to climatic zone.
Pigs:
Suitable breed selection is very important to aviod summer stress.Sellings of pigs before summer peak temperature.Provision of feed suitable to summer months.Culling of poor weight gained pigs before summer months.
References
1.Housing for dairy cattle-vikaspedia
2.Housing management of cattand Buffalo
3.poultry house construction-Tamilnadu Agriculture university
4.housing of sheep and goats-TAU
5.ventilation of sheep and goat barns-pudmed
