COMMON POULTRY DISEASES DURING WINTER
Poultry birds are one of the important livestock species of food animals as they produce valuable foods of animal origin like meat and eggs. But their production is readily affected by seasonal fluctuations as well as climatic adversities. In cold season, feed intake of birds increases in order to generate metabolic heat so as to keep them warm. Whereas, feed consumption decreases and water intake increases in the hot season in order to cool their body. In extreme conditions, birds get stressed, thus their ability to withstand diseases and the immune response is seriously compromised. Additionally, the onset of winter favors the propagation and spread of the causative organisms of many infectious diseases due to improper temperature maintenance leading to high economic losses to the poultry owners. Maximum mortality are reported during winter season in brooding periods. If brooding is performed as per standard practices then the rest of the life period of the poultry flock is nearly safe.
Brooding is a period immediately after the hatch when special care and attention is given to chicks to support their health and survival. A recently hatched chick has not yet developed their own mechanism to regulate its own body temperature hence, it cannot maintain its body temperature properly for the first weeks and it is subject to chilling in the winter season when extra heat is not provided from externally; therefore the chicks will not take required feeds and water and this will decrease the growth and improper development of internal organs, responsible for digestion, thus the chick will not be able to digest the yolk completely.
Brooding is classified into natural and artificial brooding. In today’s time, artificial brooding practices are the most prevalent which is only practiced by a farmer. Nowadays for Broiler management during the first week of life the brooding operation is followed. Depending upon the season, brooding practices vary in tropical countries where large conventional open housing is normally practiced.
Winter – Use 1/3 area of the house for brooding.
Summer – Use 1/2 area of the house for brooding.
Characteristic of Brooder Guard
Make the guards from material, which can be properly sterilized or Plastic which is cheaper
Helps in preventing chilling and piling. Height of Guard should be approximately 16 inches to 18 inches. Guards will ensure chicks stay near the source of heat.
Location & Direction of Brooder House
The brooder house must be away from the all other poultry house. The minimum distance between brooder house and other poultry structure is minimum 100 meter, the construction of brooder house in such a direction that the fresh air should first enter in to the brooder house than it passes from other house. Farmer have to construct a poultry house in such a direction that sunlight directly not enter in to the poultry house so, house should be constructed in East to west direction so we may get the advantage of ventilation from north to south.
Preparation of Brooder House
Brooder house should be ready for the chicks before they are put in house. First the brooder house should be scrubbed and cleaned at least one week before the chicks arrive in brooder house. If old litter present in brooder house than first removed and clean all the required equipment with disinfected solution. When house and equipment are properly cleaned, the house should be allowed to dry out thoroughly. If house is air tight than better to fumigate brooder house and equipment using a three times higher concentration of formaldehyde gas. Normally for the fumigation take a two part of Formalin and one part of potassium permanganate. When two compound mixed together the fume will be generated and that fume will destroy the microbes present in brooder house e.g. 35 ml of formalin and 17.5 gm potassium permanganate is sufficient to disinfect 2.83m3 space which is known as 1X fumigation, but for fumigation we have to remember one thing in our mind that always add potassium permanganate in formalin.
If we are using deep litter system of rearing; litter materials like paddy husk, wood savings, ground maize cob, chopped straw, saw dust, groundnut shell, dried crushed sugar can pulp etc. Mostly the litter materials are selected based on the locally availability and cost. Spread the litter materials to a depth of 6 – 9 cm in winter season and 3 – 4 cm in summer season for better insulation. For the first few day spread a simple paper or news paper on litter materials along with sprinkle feed or ground maize grit. This will help to avoid the chicks eating the litter materials. After 3 days removed the paper and evenly distribute feeders and waterers around the brooder. The brooder switched on at least 24 hours before the chicks arrive. If we are using the hanging feeder in the brooder houses than provide three hanging feeder of 36 cm diameter with 12 kg capacity are enough to rear 100 chicks in brooder house.
Brooder House Temperature
Adjust the electric brooder for 24 hours before the arrival of chicks and adjust the temperature to 95°F (35°C) at the edge of the brooder 2 inches (5cm) above the litter during the first week. Lower the temperature by 5°F (2.8°C) each week until it reaches 70°F. A temperature of 21°C appears to be ideal during growing period. Too low or too high temperature will cause poor growth rate and ultimately poor performance of birds. The pattern of bedding down of chicks under electric hovers is shown. At low temperature, chicks will try to huddle below the light source. At high temperature, the chicks will try to huddle around the chick guard in away from light source.
Fresh air is required for well being and good health of chicks. Poor ventilation results in accumulation of carbon monoxide, ammonia and wet litter condition in brooder house. If concentration of carbon monoxide higher than 0.01 percent it will be poisonous to chicks. Ammonia irritates the eyes of chicks and retards growth. The level of ammonia should be less than 10 PPM. Coccidiosis is result from high amount of moisture in litter
45 – 60 sq cm space is enough per chicks in electric brooder for first week than for broiler birds 1 sq foot space/bird is enough to rear but if space is not a problem than we may provide 1.5 sq foot space/bird is better to get more growth in broiler birds.
Majority of Broiler farmer provide a 23 hour photoperiod and one hour darkness in young stock is advantageous over the continues lighting as the former allows maximum growth while giving the birds some experience of darkness so that they are less apt to panic during electricity failure. Light effect on growth rate is mainly due to the type of chick activity which has a bearing on their food intake induced by the period of lighting.
Only three vaccines are required in for broiler rearing. Vaccination against Marek’s Disease, New Castle Disease (Ranikhet) and Gumboro Disease are done.
It is help in preventing pecking injuries and cannibalism among chicks. It is carried out during the one day and 6 weeks of age but mostly broiler farmer never cut the beak of birds. Whenever incidence of cannibalism is occur in flock than debeaking operation should carried out with electric debeaking equipment.
Problems that occur during brooding operation
Coccidiosis control – It is the most common disease of poultry at young age. Coccidiostats are added to feed in sufficient quantity to suppress the multiplication of oocytes.
Stress – Majority of stress occurs when birds are being handled, during the vaccination and due to birds huddling together. To overcome the problem we may increase the brooder temperature to fill birds comfortable or we may add anti stressor compound in water/feed to overcome stress.
Inclement Weather – Environmental heat mat create a severe stress although young chicks can tolerate higher temperatures than older birds. When the temperature is more, the birds will eat less and drink more water. To overcome this problem increase the feed and water along with an increase in the floor space allowance.
Unabsorbed yolk – High temperature of chicks during the first two days under the brooder also lowers the yolk absorption. Diseases that raise the body temperature prevent utilization of the yolk material in young chicks. Feeding chicks soon after hatching also causes a slower absorption of yolk materials in young chicks.
Mortality Standards – Chick mortality during the first week in the brooder house is higher than any week. Losses during the second week should be slightly less.
Some of the poultry diseases common during the winter season are:
1. Bacillary White Diarrhoea (Pullorum Disease)
Bacillary White Diarrhoea is caused by bacteria, Salmonella Pullorum. Transmission of the diseases can occur from infected birds, their feces, and their eggs; ingestion of contaminated food, water or bedding, and contact transmission; mechanical spread; vertical transmission may occur in newly-hatched chicks due to transovarial transmission. Thus, chicks are highly susceptible to this condition than adult birds and may show extensive mortality up to 3 weeks of age. Clinically young birds show pasted vent, white diarrhea, huddling, lameness, somnolence (sleepy), labored breathing and blindness etc. Morbidity may range from 10 to 80% and mortality usually increases at 7 to 10 days in stressed or immune-compromised flocks and may reach up to 100%. Adults are usually subclinical and a drop in egg production, fertility or hatchability may occur. Depression, anorexia, diarrhea, and dehydration are occasionally seen.
Treatment, Prevention and Control
Salmonellosis, E. coli and Pullorum diseases can be treated by administering a broad-spectrum antibiotic to the infected bed and all the flock. High-level farm/pen hygiene and sanitation must be maintained. Biosecurity measures should be in place. Avoid feeding birds with contaminated feeds.
2. Fowl Cholera
Fowl cholera is a bacterial disease of birds caused by organism Pasteurella multocida, affecting birds of 6 weeks old and above. It is a serious and highly contagious disease which can range from acute septicemia to chronic and localized infections and the morbidity and mortality may be up to 100%. The disease gets transmitted via nasal exudates, feces, contaminated soil, equipment, and people. Clinical findings vary greatly depending on the course of the disease. In the acute form, witnessing a large number of mortality without any prior clinical signs is usually the first indication of disease. In more protracted cases, depression, anorexia, mucoid discharge from the mouth, ruffled feathers, diarrhea, and increased respiratory rate are usually seen. In chronic form of fowl cholera, signs and lesions are generally related to localized infections of the sternal bursae, wattles, joints, tendon sheaths, and footpads, etc. which often are swollen. There may be exudative conjunctivitis and pharyngitis. Torticollis may result when the meninges of the brain and spinal cord, middle ear, or cranial bones are affected.
Signs of Fowl Cholera
In acute cases, birds that appear healthy die suddenly while in chronic cases the affected birds show the following:
• Yellow, green or grey diarrhoea
• Loss of appetite
• Laboured breathing
• Drooped wings and tail feathers
• Ruffled feathers
• Swelling of the leg joints, sinuses, wattle and foot pad
• Twisting of the neck (torticolis)
• Discharge from the nostril or beak
• Note: The above signs are also similar to those of fowl typhoid.
Treatment, Prevention and Control
Fowl cholera can be treated using sulfa drugs, tetracycline and erythromycin. Poultry birds can vaccinated against Fowl cholera by administering a fowl cholera vaccine. Maintain proper hygiene and sanitation. Practice a high level of biosecurity and prevent rodents, wild birds and other animals.
3. Aspergillosis/ Brooder’s Pneumonia
Aspergillosis is the fungal disease caused by Aspergillus fumigatus in poultry birds. In wet and cold season due to the high humidity and insufficient sunlight, feed or litter dampens is common, thus creating a favorable environment for fungal growth in poultry environment. The spores of aspergillus are inhaled by birds and these spores subsequently develop into lesions filling the lungs, thus causing respiratory problems with very typical signs like are gasping or open mouth breathing. Birds under intensive management systems would experience high disease spread if the stocking density is high and ventilation facility is inadequate. Factors causing the spread of disease are aerosol of spores, which are common in the hatchery, contaminated dust, and litter in the house.
Aspergillosis may exhibit 2 forms viz. acute or chronic:
A) Acute form:
This occurs generally in young chicks which are reared under brooders hence called as brooder pneumonia. Onset is very quick causing high morbidity and mortality. Death of affected birds occurs within a few days of onset of infection. The most common signs include; Lethargy, depression, loss of appetite, labored breathing, and cyanosis (bluish/ purplish comb) and mortality.
B) Chronic form:
This may take several weeks or months to develop. It commonly occurs in older birds, having malnutrition, stress, concurrent illness, or prolonged antibiotic/ corticosteroid use. The most common clinical signs include weight loss, reduced appetite, exercise intolerance, increased respiratory rate, changes in vocalization (voice) often more apparent in roosters, audible respiratory sounds (rales), tail bobbing, open-mouthed breathing (gasping).
Coccidiosis is a protozoal disease caused by various intracellular species of genus Eimeria in poultry, characterized by enteritis and bloody diarrhea. Coccidial parasites are ubiquitous in poultry environment and can cause the clinical disease in favorable conditions, thereby exhibit the opportunistic behavior. The infectious process is rapid (4–7 days) results in parasite replication in host cells with extensive damage to the intestinal mucosa. Poultry coccidia is generally host-specific, and the different species parasitize specific parts of the intestine. The wet litter and the hot pen temperature commonly observed in the rainy season favors the sporulation of the coccidial oocyst and therefore, the outbreak of coccidiosis. Clinically bloody feces, ruffled feathers, anemia, and somnolence are observed. Other signs of coccidiosis range from decreased growth rate to a high percentage of visibly sick birds, severe diarrhea, and high mortality. Reduced feed and water consumption, weight loss, development of culls, decreased egg production, and increased mortality may accompany outbreaks. Mild infections which can be classed as subclinical, may cause depigmentation of feathers and potentially lead to secondary infection, particularly of Clostridium spp. Survivors of severe infections recover in 10–14 days but may never recover lost performance. The lesions are almost entirely in the intestinal tract and often have a distinctive location and appearance that is useful in diagnosis such as blackish red to brown colored hemorrhages in caecae.
5. Bumblefoot (Ulcerative pododermatitis)
Bumblefoot is the term used for swelling of a chicken’s toe or footpad (the spongy bottom of the foot). This is an inflammatory condition, extremely common problem for older backyard hens and bird reared on unhygienic floors or on damp litter. The bacteria, such as Staphylococcus are in ample number on such floors and thus, invade and cause infection in the skin of a chicken’s foot, creating a pus-filled abscess. A cut, scrape, injury or even simply a raw spot on the skin caused by walking on wet, dirty bedding can be the entry point for bacteria and may aggravate the severity of foot lesions manifold. The most common behavioral symptoms of bumblefoot include limping and the affected bird doesn’t use the leg at all due to unbearable pain. By the time limping is noticed, the infection has most likely been festering for quite some time. Footpad examination may reveal redness, swelling, abscess and either a callouslike lesion, a lump between the toes or a black scab on the footpad.
6. Infectious Bursal Disease (Gumboro, IBD, infectious bursitis, infectious avian nephrosis)
A highly contagious and fatal viral disease mostly affecting young birds aged between 3-6 weeks, caused by RNA virus belonging to the family Birnaviridae. The disease attacks the bursal component of the immune system resulting in immunosuppression due to the destruction of immature B lymphocytes and thereby increases susceptibility to secondary infections. Disease gets transmitted by bird-to-bird contact, as well as by contact with contaminated people and equipment. Birds shed virus in droppings and can be spread by air on dust particles. Dead birds are also a source of the virus and should be incinerated. The disease may appear suddenly with a sudden drop in feed and water consumption. Chickens may exhibit severe prostration, incoordination, watery diarrhea leading to soiling of feathers around the vent feathers, vent picking, and inflammation of the cloaca, etc. Flock morbidity is typically 100%, and mortality can range from 5%–20%. Chickens infected when less than 3 weeks of age do not develop the clinical disease but show severe and permanent immunosuppression due to the destruction of bursal plecae and subsequent atrophy.
Signs of Gumboro diseases or IBD
• Severe prostration
• Watery diarrhoea
• Inflammation of the cloaca
• Soiled vent feathers
• Vent picking
Treatment, Prevention and Control
Gumboro disease is highly contagious and a flock owner should expect as high as 100% morbidity rate and 20% mortality rate. This disease has no cure or treatment but it can be prevented through vaccination of birds before an outbreak occur. In a situation where the disease has already occurred within a flock, the flock should be culled and the pens should be disinfected. Gumboro Infectious bursal disease vaccine (IBDV) should be administered to chickens at their 2nd week and 4th week of age.
How to Manage Poultry Birds Optimally in the Cold?
To manage poultry such as chickens, turkeys, quails, duck and pheasants during cold, poultry farmers have to do the following:
1. Add oil or fat to the diet of the birds or reduce the level of nutrients that are not required by the birds to generate heat. This is necessary to avoid wastage and reduce feed production costs, since birds consume more feed to generate heat.
2. Install electric bulbs or heater in the pen to serve as a secondary source of heat for the birds. This would help the birds drink enough water and stay warm without getting the reserved energy used up in the process.
3. Though very rare in an intensive system but rampant in a free-range system, birds drink from the stagnant water around, thus pick up eggs of parasitic organisms such as intestinal worms. That is why it is important to deworm poultry birds bi-monthly with effective dewormers such as piperazine. A broad-spectrum antibiotic like oxytetracycline should be administered to the birds every month.
4. Construct a generous roof overhang over the entrance and sides of pens to prevent rainwater from getting into the pen whenever it rains. Construct a foot dip at the entrances of the pens and a strong disinfectant solution should be in the foot dip always.
5. Vaccinate birds at the right time.
Common preventive measures to be taken to minimize disease outbreaks
• Basic hygiene is the first step in the prevention of contagious diseases. It is good to ensure that the poultry house is generally clean and dry.
• Ensure that the water is clean and fresh. Keep feeding areas clean and dry.
• Ensure that the birds have enough living space i.e. overcrowding should be prevented as it is a predisposing factor for many diseases. Chickens need an average of a square meter for 3-5 birds.
• An all-in all-out method should be employed in order to prevent a horizontal transfer of infection. If this method is not feasible, quarantine the new batch for a minimum of two weeks, to protect the current stock.
• Electric bulbs or heater should be provided in the pen to serve as a secondary source of
heat for the birds. This would help the birds drink enough water and stay warm without getting the reserved energy used up in the process.
• Ensure the adequate air movement in the shed to clear the dampness and ammonia from the shed and therefore to keep litter dry and clean.
• Construction of a generous roof overhangs over the entrance and sides of poultry house to prevent rainwater from getting into the pen whenever it rains.
• Construct a foot dip at the entrances of the poultry house and a strong disinfectant solution should be added in the foot dip always.
• Follow the vaccination schedule strictly against the diseases for which vaccines are available.
• Practice a high level of biosecurity and prevent entry of rodents, wild birds, other animals and unauthorized personnel in the farm area, which may be the sources of infection.