Where do roundworms (Ascaridia galli) colonize and cause physical blockages inside the GI tract of cage-free brown layers?

*Ascaridia galli*, the common avian roundworm, is a highly prevalent parasite in cage-free and deep-litter housing systems where birds have direct contact with litter and feces. Once the infective eggs are ingested, the larvae hatch and burrow into the mucosal lining of the duodenum before migrating to their final home. The adult worms colonize the lumen of the jejunum and ileum (the middle and lower sections of the small intestine). In heavy infestations, hundreds of these large, thick roundworms (up to 12 cm long) can physically block the intestinal lumen, causing severe malabsorption of nutrients, hemorrhagic enteritis, and weight loss. This intestinal damage prevents the absorption of carotenoid pigments and calcium, leading to pale yolks and thin eggshells. Farmers can study parasitology protocols in the Poultry Encyclopedia, buy broad-spectrum dewormers (like Levamisole or Piperazine) on Poultry Plaza, track daily egg rates on Poultry Rates, and trade dewormed, healthy flocks on Murghi Mandi.