Management of Layer Birds in Rainy Season

Management of Layer Birds in Rainy Season

The India Meteorological Department has forecasted normal rainfall during the monsoon months of June-September 2023 in India. During the rainy season there will be an increase in relative humidity and a reduction in temperature; rainfall affects both the quantity and quality of feeding, while wind speed and direction have an influence on the outbreak of diseases. Sometimes heavy rainfalls or cyclones may happen in this season and cause problems to the poultry farmers. Poultry famers should be prepared well in advance to face the challenges that may arise in this rainy season. The rainy season is usually synonymous with an increase in relative humidity and a reduction in temperature; rainfall affects both the quality and quantity of feeding, while wind speed has an impact on the outbreak of diseases.

With the arrival of monsoon, farmer needs to give a little bit more care and attention towards his/her birds , poultry farming is continuously growing as the most profitable agribusiness across the country . However, monsoon comes as a challenging season for poultry farmers which could be very tormenting. As rainy and cold season brings changes in temperature and weather conditions, it leaves a deep impact to the poultry farm. You need to know that weather conditions play a vital role in poultry farming as well. Hence, as a poultry farmer, it is very important to learn how to operate poultry farm during rainy seasons.

Problems in rainy season:

• In rainy season, sometimes severe wind waves or cyclones may cause interruptions in power supply in the poultry sheds and in feed plants.
• Cool weather in the poultry sheds due to continuous rainfall and cold waves along with interruptions in power supply may create serious brooding related problems for layer chicks.
• Stagnation of water in the surroundings of poultry farms may help in the growth of mosquitos and other insects. These insects will increase the chance of transmitting diseases like fowl pox etc.
• Due to heavy rains or floods, falling of trees across the roads and disruption in the road transport system may happen leading to difficulties in the transport of feed, live birds, and eggs etc.
• Sometimes drinking water may get contaminated with rainwater resulting in the increase in bacterial infections like E. Coli and Salmonella etc.
• High humidity in the atmosphere during the rainy season makes the poultry feed and feed raw materials wet.
• If the farmers are growing pullets in deep litter system, they need to take precautions to prevent wet litter condition. If the litter is wet, endo parasites like tapeworms and round worms will grow in the litter and enter the chickens. These endo parasites may slow down growth in chickens and cause several gut health issues. It is advisable to deworm the flock during the rainy season.
• High moisture content in the litter may increase the release of ammonia gas and predisposes the birds to respiratory diseases such as coryza and CRD.
• High humidity in the atmosphere, stagnated water in the farm and wet litter will increase the fly problems. Flies will spread coccidiosis, necrotic enteritis, and other bacterial and viral diseases.
• Wetting of finished feed or feed raw materials due to rain splash or accidental spillage of water may lead to the growth of molds and yeast in feed. These molds will produce harmful mycotoxins like aflatoxins etc.
• If the finished feed is stored for more than 30 days during this season, there will be increased chances of mycotoxin contamination and rancidity in the feed.
• During the monsoon season, there will be thick clouds in the sky and the daylight hours are less than 12 hours. If the artificial lighting in the farms is not adjusted accordingly, there will be reduced production of reproductive hormones like FSH and LH required for egg production in chickens.
• In this season there will be increased prevalence of coccidiosis, fowl pox, coryza, CRD, E. coli, salmonella, aspergillosis and mycotoxicosis.

Precautions to be taken during the rainy season:

• Any repairs to the roof, walls, and flooring of the poultry sheds / feed plants and godowns should be completed before the arrival of rainy season.
• In heavy rainfall regions, the floor should be raised with a generous roof overhang (4-5 feet from the wall), particularly over the entrance. This prevents rainwater from falling directly into the shed.
• The open sides of poultry sheds should be covered with polythene sheets. This prevents rainwater from falling directly into the shed and protects the chickens from severe cold waves.
• Prevent waterlogging around the sheds to minimize the mosquitos and other insect problems
• To control houseflies, regular spraying of insecticides is recommended. Use insecticides that will act both on the adult flies as well as larval stages. Electric fly repellent or pest control devices should be installed in the shed.
• Polythene curtains around the shed should be closed only when there is rain or severe cold winds, otherwise ventilation related problems may happen. Lack of proper ventilation in poultry sheds can lead to an increase in the percentage of ammonia gas, stunted growth in chickens, ascites, and respiratory diseases.

Water management:

• Due to heavy rains, wastewater from agriculture and urban areas, which might contain high levels of pathogenic microorganisms and other contaminants, are carried to the superficial and underground waters along with the rainwater.
• Chlorinate the water, using the most adequate method for your farm.
• Assess levels of residual chlorine daily. The presence of residual chlorine in the water pipes at an adequate concentration (2-5 ppm) assures the absence of microorganisms pathogenic to the birds.
• Regular use of good quality sanitizer in water can inactivate the harmful bacteria in the water.
• Water consumption is generally low during monsoon. Chickens should always be provided with clean water and water storage tanks should be cleaned frequently.

Lighting management:

• Daylight hours are short during the rainy season, providing adequate artificial light will help to maintain the optimum feed intake and egg production.
• The laying hen needs 16 hours of lighting per day. In addition to the 12 hours of natural day light, artificial lighting should be provided in the morning or evening or at both times.
• In addition to the light duration, light intensity also affects the productivity of laying hens. The light intensity should be 20-40 watts.

Health management:

Coccidiosis:

• The causative agent for this disease is a protozoan parasite of the genus Eimeria.
• Typical symptoms of this disease include bloody diarrhea, stunted growth, dehydration, anemia, listlessness, ruffled feathers, death, and drop in egg production.
• Coccidiosis can be prevented by adding coccidiostats in the feed, as the chances of coccidiosis are high during the monsoon season.

Necrotic Enteritis:

• The disease is caused by the bacterial toxins of Clostridium perfringens
• Chickens infected with coccidiosis are more likely to develop the disease.

1. coli:

• E. coli is transmitted to chickens due to use of contaminated water during monsoon.
• This problem can be avoided by cleaning the water tanks frequently, adding acidifier to the feed and sanitizers to the water.

Coryza / CRD:

• Bacterial diseases such as Coryza / CRD are also more common during the rainy season. In addition, the use of contaminated water can exacerbate the problem.

Mycotoxicosis:

• Accidental wetting of feed raw materials or finished feeds in the godowns, during transport or due to rain splashes in the feeders and storage of feeds for longer duration may result in mold growth and mycotoxin production.
• The problem of toxins is very high during the rainy season due to high moisture content in the atmosphere.
• Consumption of mycotoxin contaminated feed by the poultry will cause liver damage, lameness, decreased egg production & egg weight, reduced feed efficiency, reduced antibody titers to vaccines. If the problem persists for long time, there will be mortality also.
• To prevent this problem, care should be taken to use quality raw materials in feed preparation and storage.
• Adding high quality mycotoxin deactivators and acidifiers in the feed will help in reducing the mycotoxin problems.

Feeding management:

• During the monsoon season there will be high humidity in the atmosphere, and the floor in the feed plant/godown is also likely to be moist. Hence, the feed raw materials should be placed on a high place like wooden tables instead of being placed directly on the ground.
• Feed bags and other feed raw materials should be kept 1-2 feet away from the wall in feed plants.
• Due to the possible disruption of road transport system due to heavy rains or floods, it is always advisable to store adequate feed for 4-5 days.
• In case of rainwater in the feed trough, the feed should be removed, and feeders should be cleaned thoroughly.
• Do not store feed for more than 30 days during monsoon. This may lead to fungal growth and the formation of mycotoxins.
• Quality acidifier should be used in the feed to prevent the growth of fungus / mycotoxins in the feed due to high humidity in the atmosphere.

Use of feed acidifier in poultry diets:

Organic acids like benzoic, formic, propionic, and butyric acids etc. are commonly used in poultry diets as feed acidifiers. The supplementation of organic acids at the right doses in animal feed can increase the weight gain in pullets, improves feed conversion ratio, and reduces colonization of pathogens in the intestine. Almost all the organic acids used in animal nutrition, have an aliphatic structure, and represent a source of energy for the cells. Benzoic acid, instead, is built on an aromatic ring and has different metabolic and absorption characteristics.

Using feed acidifier will have following benefits:

• Inhibition of gram-negative microflora in the gastro-intestinal tract
• Reduced pH, buffering capacity as well as antibacterial and antifungal effects in feed
• Improved protein digestibility & mineral bio availability
• Reduced subclinical diseases and general mortality in chickens
• Reduces wet droppings and cracked/ dirty eggs problems

Organic acids with a high pKa value are weaker acids and therefore more effective preservatives for feed. A strong acid (with low pKa) will acidify the feed and the stomach but will not have strong direct effects on the microflora in the intestine. If we use salt forms of organic acids considerably higher dosages are needed in feed to get measurable effects on animal performance. The bactericidal effect of the organic acids is: benzoic acid > fumaric acid > lactic acid > butyric acid > formic acid > propionic acid. Benzoic acid is superior to other acids in exhibiting bactericidal effect on coliforms and other harmful bacteria in both stomach and small intestine.

Advantages of using Benzoic acid:

• It is a long-established preservative in the feed industry and particularly effective against fungi and yeasts.
• Inhibits the growth of Aspergillus flavus, reduces the spore count and mycotoxin production. It blocks an enzymatic step in the biosynthetic pathway of mycotoxins.
• Better feed preservation can help improve intake and performance.
• Helps in reducing the number of many pathogenic bacteria like Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica etc.
• Moderates the gut microflora, thereby reducing dysbiosis and improving digestion.
• Reduces ammonia production providing better environment for the chickens and the farm personnel
• By including pure Benzoic acid (Vevovitall) in poultry diets in this rainy season, producers can: improve the growth rate in pullets, enhance egg production & feed efficiency, reduced dirty eggs, or cracked egg problems and general mortality in layers.

Poultry farmers can overcome the problems during the monsoon season and reap good profits by taking appropriate precautions as described above.

 Poultry Litter Management during Rainy Season——-

 Now southwest monsoon rain is pouring in southern states of our country. Every year from July to September southwest monsoon and from October to December northeast monsoon we are getting the rains. Because of the rains getting from monsoon, the poultry farmers getting disease problems. The litter and manure management become the key thing in commercial chicken rearing. The most important job in commercial poultry operations is the proper management of litter. Litter management Litter is where the chickens spend all their life, in deep litter system, from the time they are housed until they are sold to the consumers. Paddy husk, saw dust, coir pith, fallen leaves and wood shavings are commonly used litter materials in poultry farming.

The qualities of good quality litter are as follows:

• The litter should be highly absorbent, • Light in weight with medium or small particle size and dry rapidly, • Have least tendency to form cakes, • It should absorb effectively moisture, dilute the concentration of droppings, • It must be free from mould growth, • Help insulate floor from the ground moisture and • Create a stimulus in the birds to scratch and dust bathe.

 Condition of the litter

Normally the ideal moisture content of the litter should be 25%. If the moisture contents falls to 20%, the litter becomes too dusty, not good and if the moisture goes up to 40%, the litter gets wet and caked up, not good at all. Ammonia build-up is high in a wet and caked up litter. the permissible level of ammonia level in the litter is 20 ppm only. Ammonia irritates the eyes and by inhalation it damages the inner lining of the respiratory track of the birds exposing them to infections. If the litter is too dry, the air becomes quite dusty and the respiratory system gets irritated and then easily invaded by microbes, in the process, the resistance against respiratory diseases goes down tremendously.

 Managing litter

The litter thickness of 3 cm during summer and 5 cm during winter is recommended. The final litter size should be 10-12 cm depending on the season and growing period. Waterers should not be filled to their full capacity because it can cause spoilage and wet the litter. The height of the waterer should be equal to the back of the bird. If the litter is wet, it should be removed immediately and replaced with fresh litter. The properly maintained litter must be friable and it will not form cakes. The moisture level in a used litter should be 20%. If the moisture level is more than 25%,this could lead to high ammonia level in the poultry house and in due course lead to other respiratory disease problems. The moisture level in fresh litter material should not exceed 10%. Hence, the litter material should be neither too dry nor too wet. To examine this, take a sample of litter on the hand, press it harder in the palm and gentle spread the fingers. If the litter condition is optional, the compressed litter material shows crevices and gently falls apart. If the litter is too wet, it will form a cohesive ball. If the litter is too dry, it will form no impression, it will crumble easily and fall apart. High moisture in litter is very problematic, resulting in caking or forming a non-absorbent crust. Caking especially occurs under waterers or other high impact areas. Wet litter causes breast blisters and sores on the foot pads and hocks of the birds. It also provides conducive environment for pathogens and parasites such as coccidian to grow well. In wet litter, uric acid is converted by bacteria to ammonia. Ammonia is a toxic gas that can damage the respiratory system of the birds and make them susceptible to infections.

Disposing litter

Care should be taken to remove and dispose the litter after the grow- out so that the biosecurity precautions are observed strictly. After removal from the house, manure and litter can be spread on agricultural fields. In many areas, the poultry manure contains valuable nutrients like Nitrogen, Phosphorus and potassium to the soil. Poultry manure has 3.84 per cent nitrogen,2 percent phosphorus and 1.42 percent potassium on dry matter basis. Practically, the amount of manure is equal to the amount of feed provided to the birds. Composting the litter adds further value to the manure because compost is an excellent soil amendment. More carbon material usually needs to be added to increase the carbon to nitrogen ratio. During composting, ammonia is released to the atmosphere, which lowers nitrogen in the final product.

Factors influencing the litter quality

• Insufficient litter material • Insufficient ventilation • Overcrowding • Side walls of the poultry house too high • Leaky waterers • High water consumption by the birds
• Poor litter management • Pellet feeding increase the water intake and thereby cause wet litter condition • Excess salt in feed or water • Excess levels of fibre in the feed • Opening the foggers to cool the house during summer will increase the humidity and wet litter condition. Hence, the poultry farmers of our country are requested to take utmost care of the litter management in the poultry house in the coming months.

 Summer Management

Chickens are very sensitive to environmental temperature. Their growth, egg production and health are severely affected during extremes of weather. Therefore, within the economically feasible limits, ideal temperature has to be provided to the birds, in order to obtain optimal growth rate and returns from the birds. For optimum feed efficiency, an ideal temperature range of 21oC- 24oC is needed. However in tropical climates, these temperature ranges may be obtained during winter only. During other seasons especially during summer, the ambient temperature goes several degrees higher than the ideal zone causing severe depression in the growth rate and egg production thereby leading to great economic loss to the poultry farmer. By proper summer management, these losses can be overcome to a great extent.

Adverse Effects

The various physiological and pathological changes that take place in the flock, during high summer temperature are as follows:  

1. Energy intake and thereby feed consumption and other nutrients intake reduce as the environmental temperature increases. This is because birds need less energy for maintenance of body temperature, when the ambient temperature is high. Consequently, growth rate and body weight of birds will become lower.
2. There will be early two-fold increase in the water consumption of birds during summer; because during high environmental temperature the major way to lose the excess heat produced in the body is by loss of water vapour through expired air.
3. High ambient temperature increases the respiratory rate and body temperature. Since there are no sweat glands in Poultry, they will start panting vigorously, in order to lose the excess body heat produced. As the outside temperature increases the heat production as well as the heat loss from the body decreases. For every 1C increase in ambient temperature, the heat production in the body decreases by about one per cent. On the other hand, water loss through respiration increases, with increase in ambient temperature.
4. High environmental temperature on the other hand decreases oxygen consumption, blood pressure, pulse rate, thyroid size and activity, blood calcium level and body weight.
5. The problems with ectoparasites will be more during summer and the following monsoon. Moreover, high environmental temperature associated with high relative humidity (>70%) may lead to outbreaks of Coccidiosis. Low feed intake and thereby low coccidiostat consumption will further aggravate Coccidiosis outbreaks.
6. Incidences of Fatty Liver Haemorrhagic Syndrome and other metabolic disorders like heat stroke, liver rupture etc. are more during summer; especially in case of heavy broilers.
7. Birds will shed more feathers during summer, in order to lose the excess body heat produced.
8. At high environmental temperatures, nearing the body temperature of the birds, vapourisation of body water through respired air is the only way to lose substantial amount of heat from the body. However, this is possible only when the inspired air has very low moisture levels. But if both temperature and relative humidity are high, birds will not be able to lose the excess body heat and will finally die of heat prostration. Fatty birds succumb first, perhaps because their air sacs are rather constricted and thereby not able to evaporate moisture and produce coolness efficiently.
9. Caged birds and birds reared on slatted floors will suffer more due to high environmental temperature than birds reared on litter floors; because birds on litter can cool themselves to some extent by dusting themselves in the litter.
10. Heavy mortality due to heat stroke will be noticed among heavy broilers, in the late afternoon and evening.
11. Temperature affects egg breakage. Elevated environmental temperature is associated with decrease in shell quality.
12. Reduction of shell thickness produced by heat stress is apparently due to respiratory alkalosis which causes lowering of partial pressure of carbon dioxide in the lungs and raises blood pH.
13. As the ambient temperature increases above 26oC, the egg size declines.

Alleviating Measures

The above adverse effects due to high environmental temperature can be overcome to a considerable extent by proper management of the flock, house, feed etc. during summer, as indicated below:

1. By proper roofing, the temperature inside the poultry houses can be kept at 5C – 10C below the outside temperature. Thatched roofing of about six inches thickness provides optimum comfort to the birds during summer, than any other roofing material. However, due to the risk of fire, less durability, more depreciation and rodent problem, thatched roofing is not preferred, especially by large farms.
2. In large farms, aluminium roof is preferred due to its durability, resale value and rear reflecting properties.
3. In case of non-insulated houses, the roof must be raised to a sufficient height from the floor level; because higher the roof, cooler will be the poultry house. The minimum height between the floor and the roof must be 4.0 and 3.5 metres at the ridge and eaves, respectively.
4. The eaves at the roof shall project out atleast one metre on all the four sides as over hang to prevent direct sun light and rain water entering into the house.
5. Further, where the summer is very severe, the roof may be insulated either by covering with a layer of thatch or by painting the upper surface of the roof with a white paint such as white water proof paint, or aluminium paint, to reflect the sun’s rays back and the inner surface may be painted with a black paint or tar to absorb the heat from within.
6. In tropics, in order to prevent direct sun light falling into poultry houses, the long axis of the houses have to face north and south i.e. the houses must be orientated east to west; with a slight tilt towards southern side in the east and towards north in the west. This type of orientation also prevents severe drafts and rain water sprinkling into poultry houses during monsoon.
7. Open type, cross-ventilation is recommended in tropics. Except for a 20cm height wall, all the four sides upto the roof should be provided with 12mm size and 18 gauge chicken wire mesh or 25mm size chain link mesh.
8. Sprinklers may be fixed on the top of the roof and operated continuously from 10 to 18 hours, to cool the roof.
9. Foggers may be fixed inside the broiler house and operated during hot and dry weather, to produce evaporative coolness.
10. Grow “fast-growing” shady trees around poultry houses in order to reduce the severity of the summer heat waves and also to break wind drafts during monsoon.
11. Rear relatively more heat tolerant strains of broilers suitable for tropical climate.
12. During hot weather, birds consume twice the amount of water than that is normally consumed. Therefore, double the watering space in poultry houses during summer. Provide plenty of fresh, clean and cool drinking water during hot weather. The water pipes should not be exposed to sun light. Change the water two or more times a day, if it gets heated up.
13. In order to encourage the feed intake of birds during summer, reduce the energy content of the feed by about 10 percent. It is also advisable to provide an addition of one or two percent protein and slightly increase the levels of vitamins, minerals, and essential amino acids and coccidiostat.
14. Large farms in hot and dry climate may opt for environmentally controlled poultry houses.
15. Drugs and chemicals like electrolytes, ascorbic acid, sodium bicarbonate, tranquilisers, sodium salicylate, paracetamol, chlorpromazine hydrochloride, cyproheptadine hydrochloride may be administered through feed or water, to make the birds to withstand hot weather.
16. Thick and wet litter produce/ generates more heat. Therefore, during summer, the litter thickness must not be more than 6cm. Moreover, remove caked up and wet litter immediately from the poultry house, to stop excess heat production.
17. Avoid over crowding. Increase floor space by atleast 10% during summer.
18. If mechanical ventilation is provided, increase the air flow rate and air exchanges by atleast 25%, during summer.
19. Do not disturb the birds and make them panic during hot weather.
20. For birds kept in cages, the centre height of building should be a minimum of 14 feet.

 DR. MANASH DASH,POULTRY CONSULTANT,KOLKATA

Compiled  & Shared by- Team, LITD (Livestock Institute of Training & Development)

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 Reference-On Request.

CARE OF COMMERCIAL POULTRY DURING RAINY SEASON