Weather fluctuations, particularly during seasonal transitions, create significant stress in poultry production systems. Sudden changes in temperature, humidity, ventilation patterns, and air quality weaken the birds’ immune defenses and predispose them to respiratory infections. Among these, Mycoplasmosis is one of the most economically important diseases affecting both commercial layers and breeder flocks.

The two major pathogenic species affecting poultry are:
– Mycoplasma gallisepticum infection (MG)
– Mycoplasma synoviae infection (MS)
These organisms are highly contagious and often become more problematic during changing weather conditions due to increased environmental stress and compromised flock immunity.

Why Changing Weather Increases Mycoplasma Problems
During weather transitions such as:
– Summer to monsoon
– Monsoon to winter
– Sudden cold or heat waves
birds experience physiological stress that suppresses their immune response. Several environmental factors contribute to Mycoplasma outbreaks:
1. Temperature Fluctuation
Rapid day-night temperature variation stresses birds and damages the respiratory mucosa, making it easier for Mycoplasma organisms to colonize the respiratory tract.
2. Poor Ventilation
Farmers often reduce ventilation during cold weather to conserve heat. This increases:
– Ammonia levels
– Dust accumulation
– Humidity
– Carbon dioxide concentration
Such conditions irritate the respiratory tract and favor Mycoplasma multiplication.
3. High Humidity and Wet Litter
During monsoon seasons, excessive moisture increases pathogen survival and worsens respiratory stress.
4. Secondary Infections
Changing weather also favors bacterial and viral co-infections such as:
– Newcastle disease
– Infectious bronchitis
– Escherichia coli infection

These infections intensify the severity of Mycoplasma disease.
Clinical Signs in Layers and Breeders
Affected birds may show:
– Coughing and sneezing
– Nasal discharge
– Rales and respiratory sounds
– Swollen sinuses
– Watery eyes
– Reduced feed intake
– Depression and poor growth
– Increased mortality in severe cases

In breeder flocks, fertility and hatchability may decline significantly.

Impact on Layer Performance
Mycoplasma infection severely affects commercial egg production.
1. Drop in Egg Production
Layers infected with MG or MS commonly show:
-Sudden reduction in egg production
– Irregular laying patterns
– Delayed peak production
Production losses may range from 5–20% depending on flock condition and secondary infections.
2. Poor Egg Quality
Infected layers may produce:
– Thin-shelled eggs
– Misshapen eggs
– Smaller eggs
– Poor shell strength
This increases breakage and market rejection.
3. Increased Feed Conversion Ratio (FCR)
Respiratory stress reduces feed efficiency, increasing production cost per egg.
4. Increased Culling and Mortality
Chronically affected birds become poor performers and require early culling.

Impact on Breeder Performance
The economic effect of Mycoplasma is even more serious in breeder operations.
1. Reduced Fertility
Mycoplasma infection negatively affects reproductive performance, lowering fertility percentage.
2. Poor Hatchability
Vertical transmission through eggs can infect embryos, causing:
– Embryonic mortality
– Weak chicks
– Poor hatchability
3. Transmission to Progeny
MG and MS can spread from infected breeders to chicks through eggs, creating long-term farm problems.
4. Reduced Chick Quality
Chicks from infected breeder flocks often show:
– Weakness
– Respiratory distress
– Poor growth potential
– Higher early mortality

Economic Losses
Mycoplasma outbreaks during changing weather can lead to major financial losses through:
– Reduced egg production
– Poor hatchability
– Increased medication costs
– Mortality and culling
– Lower chick quality
– Increased feed costs
– Trade restrictions in breeder operations

Diagnosis
Accurate diagnosis is essential for effective control. Common diagnostic methods include:
– Serological testing (ELISA, SPA)
– PCR testing
– Culture and isolation
– Postmortem examination

Typical lesions include:
– Air sacculitis
– Tracheitis
– Foamy air sacs
– Pneumonia

Prevention and Control Measures
1. Maintain Proper Ventilation
Ensure adequate airflow without creating drafts.
2. Reduce Environmental Stress
– Maintain uniform temperature
– Avoid sudden temperature changes
w Control humidity levels
3. Strengthen Biosecurity
– Restrict visitor movement
– Disinfect equipment
– Control wild birds and rodents
4. Vaccination
Vaccination programs against MG and MS should be followed according to veterinary recommendations.
5. Early Medication
Prompt treatment using appropriate antimicrobials under veterinary guidance can reduce severity.
6. Improve Litter and Air Quality
Regular litter management helps reduce ammonia and dust.
7. Nutritional Support
Provide vitamins, electrolytes, and immune boosters during stressful weather periods.

Conclusion
Changing weather conditions significantly increase the risk and severity of Mycoplasma infections in poultry farms. Layers suffer from reduced egg production and poor egg quality, while breeders face severe reproductive and hatchability losses. Because Mycoplasma infections often become chronic and difficult to eliminate, prevention through good management, ventilation, biosecurity, and stress reduction remains the most effective strategy.

Early detection and timely intervention are essential to maintain flock health, productivity, and profitability during seasonal

Breathing Trouble: A Glimpse into the World of CRD in Poultry
India ranks second globally in egg production and fifth in poultry meat production. The Indian poultry market, despite being one of the largest globally, remains a developing sector due to its fragmented infrastructure, inconsistent biosecurity standards, and varying degrees of modernization across regions.

A significant portion of poultry production still relies on open housing systems, limited automation, and minimal veterinary oversight, especially among smallholder and backyard farmers. These conditions foster high disease prevalence, as poor sanitation, overcrowding, and lack of structured vaccination programs create ideal environments for the spread of infectious agents like Mycoplasma gallisepticum, E. coli, and coccidia. Consequently, the industry faces substantial economic losses through reduced productivity, higher mortality, increased medication costs, and trade restrictions. Bridging the gap between traditional practices and scientific poultry management is critical for improving flock health and sustaining long-term growth.

One Breath at a Time: Poultry Farmers Battle Chronic Respiratory Disease

Before any effective fight against Chronic Respiratory Disease (CRD) can begin, the poultry industry must first understand the enemy it faces. CRD is not just another seasonal illness—it’s a complex, persistent infection primarily caused by Mycoplasma gallisepticum, capable of silently spreading through flocks and leaving devastating economic consequences in its wake. Its symptoms often mimic those of other respiratory illnesses, making early detection a challenge. Without a clear understanding of its pathogenesis, transmission, and triggers, efforts to control CRD remain reactive and insufficient. Knowledge is the first line of defense—only with education, diagnosis, and structured prevention can farmers hope to break the cycle of recurring outbreaks. The battle against CRD must begin with awareness and be fought with science, vigilance, and unity across the industry.

Unmasking the Culprit: The Hidden Cause of CRD in Poultry

CRD is caused by Mycoplasma gallisepticum (MG), a wall-less bacterium that affects the respiratory tract of poultry. Secondary infections with Escherichia coli, Ornithobacterium rhinotracheale, and viral pathogens (NDV, IBV) often exacerbate disease severity.

Silent Spread: How CRD Continues to Lurk in Poultry Farms
CRD in poultry, caused by Mycoplasma gallisepticum, spreads through both horizontal and vertical transmission. Infected birds release the pathogen via respiratory secretions, contaminating air, water, feed, and equipment. Vertical transmission from breeder hens to chicks via eggs further fuels early infection. Recovered birds often remain silent carriers, shedding the organism under stress. This makes CRD hard to eradicate and highlights the need for strong biosecurity, breeder screening, and flock management to control its spread.

How CRD Takes Hold: Understanding the Disease’s Journey in Poultry
The pathogenesis of Chronic Respiratory Disease (CRD) in poultry begins when birds inhale aerosolized Mycoplasma gallisepticum, the primary causative agent. The pathogen adheres to the ciliated epithelial cells lining the upper respiratory tract, disrupting the mucociliary clearance mechanism. This allows the bacteria to colonize and multiply, triggering a chronic inflammatory response that leads to thick mucus secretion, tracheitis, and air-sacculitis. The damaged respiratory lining also becomes highly susceptible to secondary bacterial infections, particularly from E. coli, compounding respiratory distress and systemic illness.

In commercial poultry, stress factors such as poor ventilation, high stocking density, and concurrent viral infections (like IBV or NDV) can further exacerbate disease progression, resulting in reduced growth rates, poor feed conversion, decreased egg production, and increased mortality.

Signs & Symptoms with Postmortem (PM) Findings
CRD in poultry typically presents with a range of respiratory signs that can vary in severity based on age, immune status, and presence of co-infections. Common clinical signs include coughing, sneezing, nasal discharge, tracheal rales, conjunctivitis, reduced feed intake, stunted growth, and a noticeable drop in egg production in layers. Birds may also exhibit open-mouth breathing and watery eyes. In chronic stages, swelling of infraorbital sinuses and air-sacculitis becomes evident. On postmortem examination, the most consistent findings include thickened, cloudy air sacs (airsacculitis), catarrhal to caseous exudate in the trachea and bronchi, perihepatitis, pericarditis, and fibrinous pneumonia. In cases complicated by secondary infections like E. coli, lesions become more severe, showing a classic “CRD complex.”

Integrated Strategy to Fight CRD
An integrated CRD control strategy combines biosecurity, vaccination, early detection, nutritional support, and precision medication.

Preventive Phase: Reducing the Latent Load
Forlutin 10% (Tiamulin 10%) a high-quality feed additive by Stallen South Asia Pvt. Ltd. serves as the cornerstone for preventive management. Administering it to growers between 7 to 14 weeks of age or just before expected stress periods such as vaccination or peak lay helps reduce the latent load of Mycoplasma. This approach prepares the flock by lowering the pathogen load before the birds reach a vulnerable stage.

Outbreak Management: When Clinical Signs Appear
At the onset of clinical signs indicative of Mycoplasmosis, immediate action is required. Stalmicosin (Tilmicosin Phosphate 250mg) oral solution – a high-quality product manufactured by Stallen South Asia Pvt. Ltd. in its own manufacturing facility to ensure the highest Quality standards, administered via drinking water at 15–20 mg/kg body weight, is highly effective due to its deep lung penetration and prolonged action. This should be continued for 3 to 5 days but not exceeded.

Following the Stalmicosin course, a 24–48hour break should be observed before beginning treatment with Forlutin 80% (Tiamulin 80%) water soluble powder. A dosage of 25–50 mg/kg body weight for another 3 to 5 days helps eliminate residual Mycoplasma and prevents recurrence. Integrating these antimicrobials into a scheduled rotation can significantly reduce disease recurrence and resistance development.

Monitoring and Biosecurity: Supporting the Antimicrobial Strategy
Surveillance using PCR and ELISA tests at regular intervals is vital to detect Mycoplasma presence, especially during and after stress periods. Swab sampling and necropsy examinations for lesions such as air sacculitis or swollen joints provide further evidence. Strict biosecurity—enforcing all-in/all-out practices, staff segregation, and regular disinfection using NADCC, quaternary ammonium compounds, or glutaraldehyde—is essential to support the medical interventions.

References
1. Indian Journal of Veterinary Science & Poultry Health, 2023. Comparative Efficacy of Antibiotics in CRD.
2. Practical Poultry Guide, Vol 18, 2024 – Antimicrobial Resistance Trends in Poultry Pathogens.
4. McOrist et al. (2002) – Tilmicosin pharmacokinetics and tissue distribution in avian models.
5. Poultry Science Journal, 2022 – Mycoplasma Control Strategies in South Asia.