Sudden Death Syndrome of Broiler Chickens

Sudden death syndrome (SDS) is also known as flip-over disease. Birds show no outward signs of disease but suddenly extend their necks, gasp, or squawk. They flap their wings, typically resulting in the birds flipping over on their backs (hence the name flip-over disease). The majority of the birds affected are males, especially those of the larger breeds. The incidence in a rapidly growing, healthy broiler flock is typically 1% to 4%. With reduced growth rates, the incidence of SDS is considerably lower.

The cause of SDS is not clear, but it is believed to be a metabolic disease related to high carbohydrate intake. SDS can occur as early as three days of age and may continue until birds reach market weight. Peak mortality generally occurs when birds are between 12 and 28 days of age.

This is due to their unnaturally fast growth rate coupled with their excessively large body mass, relative to the size of their organs---specifically their respiratory system and heart. Heart failure occurs when the bird's heart can no longer cope with pumping the full amount of blood needed in each heartbeat.

This may only affect the right ventricle (known as right-sided heart failure) or the left ventricle (left-sided heart failure), or both.

What are the Clinical Signs?

When chickens have left heart failure, they usually develop signs relating to having a more difficult time breathing and show reduced exercise tolerance. Chickens with right heart failure are more likely to develop ascites and a build-up of excess fluid in their abdomen, or cause an increase in size of the liver.

Clinical Signs:

• Difficulty breathing
• Coughing
• Weakness
• Reduced exercise tolerance
• Sudden death
• Edema
• Enlarged abdomen
• Temporary loss in consciousness

Treatment

1. Diet modification - restrict their diet, for they will eat any food put in front of them and don't know when to stop (they were breed to do this).
2. Housing - don't house them with other chicken breeds if they are given free access to any feed that smaller breeds may require.
3. Fish oil supplements has been shown to help reduce the risk of worsening heart failure and death in humans.
4. Increase the dark hours and avoid feeding the birds at night.

Prevention

1. Restrict their diet, for they will eat any food put in front of them and don't know when to stop (they were breed to do this).
2. Always provide unlimited access to fresh, clean water.
3. Do not feed them nutrient-dense feed. Nutrient dilution is even advisable to correct the situation.
4. Ad-lib feeding method is not always recommended in broiler production. Avoid giving them feed during the hot-hours of the day and ensure they have a sound night-sleep, (i.e. No night feeding. Switch off the light and let them sleep).

Culling the big 'poultry-jargons'...diluting the content

Sudden death occurs when broiler grows at a supersonic speed. This can occur as early as 7 days or late (around 4 weeks and above).

Having 2kgs' broilers within 35 days of rearing is a good sight to behold until the biggie suddenly flaps its wing and died miraculously. In a simple sentence, it’s a case of chicken having baby/immature organs (heart, intestine) inside an adult body.

To do list…

• Avoid the 'Super'- feed at the moment (Super-starter... Super-finisher et.al). It's even advisable to dilute the feed nutrient with fillers like wheat bran.
• Avoid feeding during the hot hours of the day and give enough access to clean water, adequate ventilation.
• This is not the best time for growth booster. SDS is common among super-big birds (mostly common in males). Adding booster to the feed is a faster & efficient technique to shorten the bird’s life span.
• There is a time for everything...a time to eat…and a time to sleep. Once your broiler starts giving you that impressive body weight (200 grams in 7 days, 2kgs in 35 days)…then, its high time to let them sleep well in the night. As a matter of fact, 17-hours day-length is enough to support good growth (3 weeks and above). Anything above 17 hours of light per day wouldn't only be counter-productive but also lead to speedy death.
• Moreover, for a body system that pull such incredulous stunt, don't you think it deserves enough time to rest at night?
• They can also go vegan. Introducing veggies to them is also a nice idea.

Long & Short

All the points listed above are just for 3 major objectives;

1. Slow down the broiler growth rate to a safe level (speed kills).
2. Protect the chicken welfare by reducing stress through promoting night rest and introduction of veggies.
3. Reduce body stress.

Note: If broiler is growing at that speed that amazes the farmer and caution isn't applied to reduce the speed, it will get to a certain speed-level that would make the broiler to trip-off and suddenly flip-over!