SUMMER MANAGEMENT IN BROILER POULTRY FARMING FOR BETTER PRODUCTION

As the hot summer months approach producers’ attention is turned to management methods designed to maintain productivity during elevated ambient temperatures. In the course of production, management of broiler in summer is the most difficult period for the poultry farmers as heat stress is frequently observed. As the temperature raise above 35°c,it disrupts in the physiological phenomenon of the body . Heat stress releases the corticosterone which finally reduces the efficiency of flock. For maintaining of body temperature, control of heat is done by following ways as broiler lacks the sweat glands.

• By spreading of wings i.e. heat loss by radiation without any medium.

• By conduction through touching on pipeline, walls or by digging in to the litter.

• By convection, loss of heat in the surrounding air which is the best and the effective one.

However, the above mechanism of heat loss diminishes if the temperature is above 40°c. There is rapid respiration 10 times the resting period through mouth breathing which results in low feed intake and increase water intake. There is excess co2 exhaled , as a result blood become more alkaline which reduces the capability of oxygen carrying resulting the reduced bone strength and low body weight. Hence, proper care and management is must to maintain the proper growth and development of broiler along with opening the gate way for optimization of profitability.

The management of birds is different in different season. In India summer management play an important role as temperature in summer is too high which is harmful to the birds.

Natural physiological response of broilers to heat stress————

Broilers subject to high environmental temperatures exhibit many behavioral changes which allow them to re-establish heat balance with their surroundings. Broilers rest more during heat stress periods. Some birds will stand quietly while others simply crouch near walls (or) waterers. Usually, their wings are spread away from the body to promote cooling by reducing body insulation. Within the bird, blood flow is diverted from certain internal body organs such as the liver, kidneys and intestines to dilated blood vessels of the peripheral tissue (skin) in order to facilitate heat loss. Hyperventilation or “panting” increases during high environmental temperature. Heat loss through evaporative cooling allows the broiler to dissipate the heat. However, panting requires increased muscle activity and this results in an increased energy requirement which is associated with heat stress. Therefore, decreased energy efficiency also accompanies hot weather. Relative humidity influences evaporative heat loss through panting. Broilers, as well as other domestic poultry, cannot tolerate high temperature coupled with high relative humidity. Death due to heat exhaustion will occur very quickly, especially in heavier birds, if both temperature and humidity are high. In normal birds, panting will remove approximately 540 calories per gram of water lost by the lungs.

Panting influence pH or acid-base balance————

Normally, blood pH is controlled by the lungs and kidneys along with the various buffer systems which prevent rapid changes in the pH. However, as the respiratory rate increases in heat stressed broilers, there is a corresponding decrease in the levels of blood carbon dioxide, which results in respiratory alkalosis (elevated blood pH). Heat stress also depletes potassium and other minerals in the body, altering the delicate electrolyte balance in the body

Decrease in feed intake during heat stress———–

Broilers maintained in hot environments reduce their feed consumption. This is a part of their physiological adaptation to heat stress. The reduction in feed intake results in a decrease in the daily intake of nutrients responsible for growth. Thus, even though growth is slowed, the broiler can now more easily cope with the heat because of the lessened need for heat dissipation. The survival rate of broilers decreases as feed intake increases during heat stress, especially during the hottest part of the day.

Ideal temperatures————

• Birds perform well within a relatively wide range of temperatures. • This range extends between 10 and 27°C. • Found that the highest growth rate of broilers occurs in the range of 10-22°C, while maximum feed efficiency is at about 27°C (Kampen, 1984). For growing broilers it is 18- 22°C (Charles, 2002). • It is known, however, that what is ideal for growth is not ideal for feed efficiency. The overall optimum range mainly depends on the market value of the product produced, relative to feed cost. As the price ratio widens, the best temperature falls, and vice versa.

Effect of heat

1) Stress on birds increase cause viral and bacterial infection to birds.

2) Increasing in percentage of mortality.

3) Diarrhea

4) Poor FCR and Lower body weight.

These result in reducing chicken production.

Clinical Sign and Symptom :

The following clinical signs will be observed in heat stressed birds :

 Panting/rapid respiration

 More intake of water

 Reduced appetite.

 Reduction of egg production

 Poor egg shell quality

 Less body weight gain in broilers

 Reduced feed efficiency

 Increase in body temperature

 Death

Post Mortem Lesions :

 Dehydrated carcass

 Mucoid exudates in mouth and nostrils

 Pale/cyanotic combs

 Pale breast muscles

 Congestion of liver, spleen, kidney and lungs.

 Fluid contents in intestines.

 Rapid decomposition of carcass

Steps In Heat Stress management

> Housing management

> Water and Feed Management

> General Management

Housing Management:

• Well ventilation room for the sufficient air exchange.

• Removal of heat from the bird by control of air speed.

• Water sprinkle time and again on the roof, it’s will be beneficial of growing and maintaining vegetables like snap beans, bottle gourd, and cucumber on the roof.

• Adequate evaporating cooling of incoming air.

• Maintenance of thatches on roof helps to prevent from direct heat of sunlight.

It is the first and most important things in all seasons,which help birds from sunlight in summer, and from rain in rainy season.

– Direction of shed is East-West to avoid direct sunlight on birds.

– Width should not be greater than 30 feet,for good air movement inside the shed.

– Use asbestos sheet for roofing as it never be get hot.

Asbestos sheet

– Thatching of roof using sugarcane leaves,paddy straw or whitewashing the roof.

– Use sprinkler on roof of shed which helps to maintain temperature inside the shed.

– Use wet gunny bags on lateral side of shed above 3 feet from ground.

– Use Foggers and Fans inside the shed.

Water Management:

Water consumption increases during hot weather due to high heat stress. It is estimated that the consumption of water increase by 6%for every 1°c rise in temperature from 20°c where is approximately 1.8-2 times feed quantity. Addition of Sodium carbonate per 100 liters of water is beneficial. Fortification of water along with glucose, electrolyte,vitamin etc helps to reduce the heat stress.

In summer water consumption of birds is 3-4 times more than remaining season. So it important to provide them plenty of clean and cold water for that

– Use good quality of sanitizer for sanitization of water.

– Increase no of waterer by 25-30 percent.

– Cover a water tank with wet gunny bags.

– Add 10% of ice in tank during hot hours.

– Provide electrolyte from water during hot hours.

– If possible cover pipeline

Feed Management———–

Feeding strategy——-

Feeding of more digestible feed along with the minimization of crude protein in feed is beneficial as stock consumes less feed due to high heat stress. Feed intake reduces by 1.25 % for every 1°c increase in temperature, further it is observed that the feed intake reduce by 5% per degree rise between 32°c -38°c. So there is need to be ensured in the quality of feed, pellets, mesh. The feed must not to be kept for more than a week which may results the development of mycotoxin, preceding the poor quality of feed. It’s better to feed the stocks in the cooler time-morning and evening hours. Remove feeding 4-6 hours prior to an anticipated heat stress period. Maintenance of dim light helps to minimize the activity of the flock which is beneficial to reduce the heat load. The flock should not be disturbed during the hottest period of the day. Addition of antioxidant like vitamin E(250gm/kg), Vitamin C(400 gm/kg) helps to improve the performance of calcium and helps to reduce the mortality. Increase the use of fat as compared to carbohydrates as well as synthetic amino acid by decreasing the formula protein by 0.5 % to reduce the heat stress by digestion

In birds 7 to 12 % of body heat increased during 2 hours after eating of feed, so body temperature of birds goes in increasing which result in heatstroke and mortality goes on increased. for that

– Feeding done to the birds during cool hours i.e. from 5.30 pm to 9.00 am.

– Put feeder on hanging position during hot hours i.e. from 9.00 am to 5.30pm.

– Increase number of feeder during cool hours.

– Do shaking after each 2 hours during cool hours.

– Do change in feed formulation

– 20-25% extra vitamines.

– Increase Energy level in feed.

– Reduce protein level in feed.

– Increase Fat level in feed.

– Use biotin and toxin binder in feed.

– If possible use pellet feed.

General Management

– Use 10% extra floorspace.

– Avoid birds movement like shifting,grading,vaccination during hot hours.

– Provide Enough ventilation.

– 2-3 time stirring of litter during cool hours.

– Provide proper doses of medicine.

. Litter Management ———–

Proper management of litter is must. High moisture litter due to improper drinker and poor ventilation will lead to the accumulation of ammonia which increases the respiratory problems, ocular lesion as well as favoring the intestinal infection. So proper turning of litter with the help of rake along with the application of bleaching powder helps to minimize the spread of disease.

WAYS OF HANDLING HEAT STRESS DURING SUMMER —–

1. Plant shade trees around the poultry house.

2. 2. Reduce the thickness of the old built-up litter. Two inches of fresh litter may be provided in the place of old litter.

3. 3. Hang wet gunny bags on the sides.

4. 4. Stocking density If the higher the bird density in farm, more heat will be produced. Birds in density stocked barns tend to absorb each other’s radiant heat load, which makes more difficult heat management for broilers. Reducing the bird density in summer will give more floor space per bird and allow more heat to escape from underneath their bodies and from the litter.

5. 5. Evaporative cooling Sprinklers are commonly used for evaporative cooling when temperatures are more then 79- 86°F (26-30°C). Too much water can actually increases the barn to dangerous level. Generally foggers reduce the temperature of shed up to 5-10°C.

6. 6. Ventilation Proper ventilation is crucial for heat stress management. A good ventilation system performs the following • Remove moisture laden air from the broiler house. • Brings in an equal amount of fresh outside air. • Directs incoming air to all areas equally. • Keeps inside air moving to flush hot, humid air from between the birds. • Providing exhaust fans on one side and pad cooling on other side with complete sealing of sheds side will bring down the temperature of below 8°C.

7. 7. Flock walking helps to alleviate heat stress The purpose of flock walking is to make birds release heat trapped under body. If this is carried out before birds shows the signs of stress. If the birds are very quite (or) have heads drooping, it is probably best not to disturb them any further.

8. 8. Nutritional strategies to reduce heat stress in broilers The most important factor affecting performance in broilers subjected to high temperature is reduced feed intake. Feed conversion in broilers is subject to marked fluctuations because of seasonal as well as ambient temperature changes. High temperatures reduce the efficiency of utilizing feed energy for productive purposes. Broilers not only eat less at high temperature, but also gain less per unit of intake, especially at temperatures above 30°C.

. Benefits of fasting during heat stress ————-

In addition to heat-stress mortality, economic losses associated with broiler heat stress also occur as a result of lowered growth rate and decreased feed efficiency. Therefore, it is natural for producers to want to stimulate feed consumption in hot weather. However, any management technique which promotes feed consumption (or) increased activity during the peak hot periods may be counterproductive. The extra feed consumed will increase the bird’s heat load and probably result in additional mortality. Fasting the broiler prior to (or) during peak hot periods of the day lessens the heat load and enhances survival. During heat wave is not to feed between 8 am and 8 pm. Fasting will probably result in reduced weight gain, a longer growing period and thus a delay in marketing age, but also reduced mortality.

Reference-on request