Combatting Third Quarter Syndrome in Poultry

Written by Zamira Australia

What is Third Quarter Syndrome and How Does it Affect Poultry?

Third Quarter Syndrome (TQS) refers to the slowdown in chicken production that occurs from July to September due to extreme weather conditions. These changing conditions make chickens more prone to sickness, particularly broilers, in Southeast Asia. Environmental changes, including heavy rainfall and high temperatures, negatively impact economic performance. Despite ongoing mitigation efforts, TQS consistently results in significant economic losses during these months.

Mycotoxins: The Hidden Enemy in Third Quarter Syndrome

Mycotoxins play a crucial role in TQS. Hot and humid conditions during the third quarter, coinciding with the corn harvest in Southeast Asia, lead to corn contamination by moulds. Corn, preferred in poultry feed for its high energy value, often carries mycotoxins that survive feed milling and are ingested by chickens. The most common moulds, Aspergillus spp, produce aflatoxins that negatively impact chicken health and metabolism:

  • Nutrient Absorption: Aflatoxins in feed can reduce nutrient absorption, especially B vitamins, lowering growth rates and feed conversion efficiency. Supplementing B vitamins via drinking water for one week may help.
  • Immune Suppression: Aflatoxins weaken the immune response to infections like Infectious Bursal Disease and coccidiosis.
  • Reproductive Issues: Aflatoxins decrease egg production and hatchability.

Gut Health Under Siege During Third Quarter Syndrome

Heat stress in conventional broiler houses during hot and humid conditions exacerbates TQS. Chickens eat less and drink more, leading to increased moisture in droppings, reduced anticoccidial dosage intake and subsequent coccidiosis. Coccidiosis in turn causes intestinal cell damage, promoting Clostridia growth and resulting in Necrotic Enteritis.    

Strategies to Combat Third Quarter Syndrome

Controlling TQS starts with preventing corn contamination at production and storage sites. Implementing toxin binders in feed is highly recommended. On poultry farms, monitor for diseases like Coccidiosis, Necrotic Enteritis, and heat stress. Be prepared to adjust anticoccidial and antibacterial programs to manage the challenges posed by TQS effectively.

Zamira Australia has a range of medicated feed additives and probiotics to help combat the effects of seasonal weather changes on your flock, including TQS.

ZAMBAC ZN150, containing bacitracin zinc, is a vital management tool for broiler, layer and breeder farms in the prevention and control of Necrotic Enteritis, as well as combatting heat stress. 

ZAMIDAN 10 contains the ionophore maduramicin ammonium, which kills Eimeria before it can infect the bird, preventing damage to the host cells. Additionally, ZAMIDAN 10 has been shown to reduce heat stress compared to other anticoccidials, making it an especially good product to use during summer.

ZAMIQUIN 60 with decoquinate, is a new chemical coccidiostat, which is highly effective in controlling Coccidia. Incorporating this product into your next shuttle program can significantly reduce Eimeria infection pressure.

Zamira’s ZamiPro range of products contains probiotic strains that improve immunity and gut health, ideal for use during temperature fluctuations.

ZAMIPRO SL: This high-concentration probiotic uses a powerful blend of Bacillus subtilis and Bacillus licheniformis strains, which are heat stable during pelleting, offer reliable performance and help combat heat stress.

ZAMIPRO LSL: A highly concentrated water-soluble probiotic containing Lactobacillus plantarum, Bacillus subtilis, and Bacillus licheniformis, it’s packaged in a convenient pouch for water delivery, ideal for chickens when they are eating less and drinking more during the third quarter. Its quick onset of action helps stabilise the gut during stressful situations associated with feed changes, transportation, and temperature fluctuations.


Zamira is an Australian animal health company with a mission to improve the health, wellbeing and productivity of animals across the world. Read more about us here.


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