How to handle Ascites disorder in most broilers

The term Ascites refers to the accumulation of fluid in the abdominal cavity because of heart failure. It is also commonly referred to as a water belly.

Although most people refer to it as a disease, it is a metabolic disorder that is commonly seen in fast-growing birds during the cooler months of the year. Broilers by their nature are fast-growing birds. They can double their day-old weight by the fourth day, and by the seventh, they will weigh four times their placement weight.

Causes of water belly

Water belly condition occurs when the heart is unable to pump enough blood through the lungs. This then creates backup pressure from the lungs, through the heart, liver, blood vessels, especially around the intestines. This pressure results in fluid being squeezed out of the veins into the abdominal cavity, creating ‘water belly’.

This condition is also referred to as pulmonary hypertension.

If birds are reared properly and organs are fully developed, the heart can accommodate any pressure, and rarely do you see birds succumbing to hypertension. However, when there is an excessive increase in demand for oxygen coupled with factors of errors that farmers make during the cold season, it can exacerbate the condition.

The following situations will cause an increase in oxygen demand and tilt the heart into pulmonary hypertension.

Chilling chicks during cold weather. Fully feathered birds can comfortably regulate their body temperatures and generate internal heat to keep warm.

However, if temperatures fall below 21 degrees Celsius, there is an upsurge in oxygen demand, leading to water belly. During the cold season, farmers tend to close the units, diminishing the supply of oxygen, and this can trigger ascites.

Try to avoid chilling of birds by providing more warmth.

Fluctuating brooding temperature

Birds can withstand a constant low temperature and adjust accordingly; however, they are extremely sensitive to fluctuating temperatures.

Rises and drops of three degrees Celsius can cause an increase in oxygen demand. If day temperatures rise to 27 degrees and at night drop to 16 degrees, this will be a disaster for young birds.

Poor air quality

In addition to proper temperature regulation, air quality and ventilation need to be considered.

Ventilation distributes heat evenly throughout the house and maintains optimum air quality in the brooding area. If the chicken house has excessive ammonia or extremely dusty air, the lungs will have a problem getting enough oxygen, and its net demand for the same will lead to ascites. In extreme cases of ammonia, the lung tissues get damaged, resulting in increased demands; ammonia levels should always be kept below 10 ppm. ‘Minimum ventilation’ should always be provided to remove waste gases and moisture from the units.

Management stress

Managers or poultry attendants must be well conversant with the flock or individual birds’ requirements and be ready to offer responsive management actions that will reduce stress.

The following stressors will lead to higher oxygen demand as the birds struggle to cope with unusual occurrences.

These include high stocking density, inadequate ventilation, extremely bright lighting, inadequate feed and water supply, suboptimal nutrition, poor health and welfare issues. These will ultimately trigger ascites in fast-growing birds.

In summary, during the cold weather, it is imperative that brooding temperatures are constantly monitored and never go below 21 degrees Celsius.

Supplement more burners in the unit if need be. Maintain minimum ventilation in the poultry unit throughout the rearing and finishing phases.

Do not cover the units with impermeable curtains such as plastic in the guise of reducing the cost of brooding, as ascites kills big birds that have taken quite a chunk of your feed.

Keep your litter dry all the time to minimise ammonia build-up; remember, good air quality will lead to less damage to lung tissues that are important for oxygen exchange. It’s important to reduce stress in birds during the cold season.

Ensure feed and water are available all the time, reduce light intensity to the level of one candlelight, and walk the birds at least twice per day in the unit.

Boost your diet with supplementary vitamins and minerals during this period.

  Dr Messo is the company veterinarian, Kenchic; [email protected]