Gut Health and Feed Withdrawal in Broiler Breeders

Extended overnight feed withdrawal in broiler breeders can severely compromise gastrointestinal health. The mucosal lining, particularly the protective mucin layer, deteriorates under prolonged fasting, leading to increased intestinal permeability (“leaky gut”), pathogen translocation, and systemic infections including yolk peritonitis. These effects are magnified during early lay when metabolic demands and gut stress are already elevated.

Scientific Basis and Clinical Manifestations

Mucin is a glycoprotein essential to maintaining intestinal barrier function. Its synthesis is heavily dependent on dietary threonine, and production is downregulated during fasting. Research has shown that birds deprived of feed for >12 hours show decreased villus height, reduced mucin expression, and compromised tight junction integrity (Horn et al., 2009; Uni & Ferket, 2004). When ovulation abnormalities result in yolk deposition into the abdominal cavity, the weakened gut barrier facilitates bacterial translocation—particularly of opportunistic pathogens like E. coli. This can lead to yolk peritonitis, especially if compounded by coccidial challenge or environmental stress.

Clinical indicators include:

• Intermittent mortality during early lay

• Pale combs, wet litter, or decreased feed intake

• Loose droppings, foamy caecal contents

• Increase in non-specific peritonitis at necropsy

Risk Pathways and Contributing Factors

• Fasting periods exceeding 12–14 hours, especially post-lights-off

• Low-fibre diets that accelerate gut clearance

• Subclinical coccidiosis, especially E. acervulina and E. maxima

• Poor water hygiene (biofilms, oxidised iron, or organic debris)

• Feed with low threonine-to-lysine ratio (<0.6)

Nutritional and Preventive Strategies

• Supplement threonine to ≥0.7 threonine:lysine ratio to support mucin production

• Use fermentable and prebiotic fibre sources (e.g., lignocellulose, oat hulls) to slow transit and maintain

mucosal stimulation

• Apply night-time fibre supplementation (e.g., low-energy wheat bran mash) in at-risk flocks

• Implement routine flushing of drinker lines and clean header tanks weekly

• Apply organic acid blends (formic, lactic) in water to control gut flora and support pH balance

References

• Uni, Z., & Ferket, P. R. (2004). Methods for early nutrition and their potential. Journal of Applied Poultry

Research, 13(3), 645–653

• Horn, N. L., Donkin, S. S., Applegate, T. J., & Adeola, O. (2009). Intestinal mucin dynamics: responses to

feed withdrawal. Poultry Science, 88(2), 422–429

• Yegani, M., & Korver, D. R. (2008). Factors affecting intestinal health in poultry. Poultry Science, 87(10),

2052–2063

• Bryden, W. L. (2012). Mycotoxin contamination in poultry feed. Animal Feed Science and Technology,

173(1), 134–158

Prepared by Dr Alex-Kate Langfield | BVetBiol/BVetSc