1. Intestinal Integrity and the Impact of Losing It
Elanco Poultry Health Conference
International Poultry Exposition
Atlanta
17 January 2001

2. Digestive Tract Structure
Gut is a tube
Completely lined by epithelial cells (enterocytes)
Continuous with epithelial cells of skin at mouth and cloaca
Contents of gut are “outside” of the body
Selective absorption of nutrients
Courtesy of Dr. Fred Hoerr, AVDL

3. Digestive Tract Structure
Villi
Absorptive surface increased by finger-like folds in the lining
Courtesy of Dr. Fred Hoerr, AVDL

4. Courtesy of Dr. Fred Hoerr, AVDL
Epithelium
Epithelial cells
Continuously line villi
Physical barrier to foreign agents, materials
Surface further increased by microvilli
Courtesy of Dr. Fred Hoerr, AVDL

5. Courtesy of Dr. Fred Hoerr, AVDL
Intestinal Integrity
Biological barrier
Epithelial cells that line the intestine
Protective secretory products of epithelial cells
Tissues and processes that support integrity of the epithelial lining
Courtesy of Dr. Fred Hoerr, AVDL

6. Courtesy of Dr. Fred Hoerr, AVDL
Intestinal Fluid Dynamics
2 Grams fluid secretion for each 1 Gram digesta
Nutrient solution
Pathogen dilution and flushing
Secreted from crypts and sides of villi
Absorption from tip and from large intestine
Courtesy of Dr. Fred Hoerr, AVDL

7. Unbalanced Fluid Dynamics
Net secretion > absorption = diarrhea
Decreased absorption
Damaged absorptive cells
Increased osmolality of digesta
Increased secretion
Bacterial enterotoxins
Viruses
Inflammatory mediators
Courtesy of Dr. Fred Hoerr, AVDL

8. Courtesy of Dr. Fred Hoerr, AVDL
Mucus Secretion
Goblet cells
Water and glycoprotein
Lubricates flow of digesta
Protects from autodigestion by gastric acid, pepsin, and digestive enzymes
Increased secretion by noxious stimuli
Barrier to bacteria and fungi
Courtesy of Dr. Fred Hoerr, AVDL

9. Agents that Degrade Mucus
Candida albicans
Mucinolytic enzyme
Adherence and penetration
Helicobacter pylori
Secretes urease
Destroys protective gastric mucus
Under- heated soy meal
Urease
Courtesy of Dr. Fred Hoerr, AVDL

10. Courtesy of Dr. Fred Hoerr, AVDL
The Lamina Propria
Connective tissue to support villus
Blood and lymph vessels
GALT: Gut Associated Lymphoid Tissue
B and T lymphocytes
Plasma cells
Macrophages
Courtesy of Dr. Fred Hoerr, AVDL

11. The Lamina Propria Gut continuously exposed to foreign agents
Lamina propria and GALT responds with normal reactivity
Normal vs. Disease
Biological
Economic
Gut Histopathology of 88 Broiler Flocks
Courtesy of Dr. Fred Hoerr, AVDL

12. Injury to the Lamina Propria and GALT
Bursal Disease
Chicken Infectious Anemia
Marek’s Disease
Hemorrhagic Enteritis (turkeys)
Immunosuppressive mycotoxins
Courtesy of Dr. Fred Hoerr, AVDL

13. Virus Injury to Intestine
From: Moon, 1997
Courtesy of Dr. Fred Hoerr, AVDL

14. Courtesy of Dr. Fred Hoerr, AVDL
Bacterial Enteritis
Poultry litter
Exposure to opportunistic bacterial pathogens
Potential primary pathogens
Courtesy of Dr. Fred Hoerr, AVDL

15. Bacteria: Enterotoxins
Clostridium perfringens
Escherichia coli
Campylobacter
Courtesy of Dr. Fred Hoerr, AVDL

16. Bacteria: Attach and Efface
Clostridium perfringens
Escherichia coli
Courtesy of Dr. Fred Hoerr, AVDL

17. Courtesy of Dr. Fred Hoerr, AVDL
Bacteria: Invasion
Salmonella spp.
Liver
Courtesy of Dr. Fred Hoerr, AVDL

18. Courtesy of Dr. Fred Hoerr, AVDL
Protozoa
Coccidia
Histomonas
Liver
Courtesy of Dr. Fred Hoerr, AVDL

19. Courtesy of Dr. Fred Hoerr, AVDL
Intestinal Toxicity
Absorption
Digestion
Secretion
Immature Digestion
Renewal
Courtesy of Dr. Fred Hoerr, AVDL

20. Bağırsak Sağlığının Kaybı
Sindirilmemiş yem ve ishal
Büyüme geriliği
Bağırsak hastalığı
Sistemik hastalık
Mortalite
Courtesy of Dr. Fred Hoerr, AVDL

21. Sindirilmemiş Yem ve İshal
Dışkıda sindirilmemiş yem parçaları
Yemin emiliminde aksama
Malabsorption/maldigestion
Şunlarla ilişkilidir:
FCR ve canlı ağırlık artışında
bozulma
Karkas veriminde azalma
Üretim maliyetinde artış
Management sorunları
Courtesy of Dr. Fred Hoerr, AVDL

22. Sindirilmemiş Yem Sendromunun Mekanizması
Secretory ishal
Ozmotik ishal
Malabsorpsiyon
Exudative hastalık
Courtesy of Dr. Fred Hoerr, AVDL

23. Courtesy of Dr. Fred Hoerr, AVDL
Secretory İshal
Bağırsak mukozasından aşırı sıvı sızması
Virüsler
Bakteriyel enterotoksinler
Courtesy of Dr. Fred Hoerr, AVDL

24. Courtesy of Dr. Fred Hoerr, AVDL
Ozmotik İshal
Ozmotik güçlerin artışı
Yüksek tuz oranına sahip rasyonlar
Ozmotik ve fiziksel faktörlerin bileşkesi
Rasyon kaynaklı faktörler (non-starch polysaccharides) in barley, rye, wheat, and other grains
Courtesy of Dr. Fred Hoerr, AVDL

25. Beta-glucans in Barley
Gelling effect blocks digestive enzymes, bile acids, and absorption of nutrients
undigested sugars cecum overload
opportunistic bacteria
need for antibiotics
size GI tract
Supplemental enzymes partially alleviate
Courtesy of Dr. Fred Hoerr, AVDL

26. Courtesy of Dr. Fred Hoerr, AVDL
Malabsorption
Output of voluminous, bulky feces with increased osmolarity owing to unabsorbed nutrients
Defective intraluminal digestion
Antinutritional factors
Damaged mucosa with immature enterocytes
Decreased digestive secretions (lipase, amylase)
Courtesy of Dr. Fred Hoerr, AVDL

27. Courtesy of Dr. Fred Hoerr, AVDL
Exudative Disease
Diarrhea with presence of hemorrhage and detritus from necrotic tissue and inflammation
Loss of enterocytes, fluid, electrolytes, and plasma
Escape of pathogen to other tissues
Diversion of nutrients for inflammation and repair
Courtesy of Dr. Fred Hoerr, AVDL

28. Courtesy of Dr. Fred Hoerr, AVDL
Exudative Disease
Necrotic enteritis
Coccidiosis
Salmonellosis
Histomoniasis
Courtesy of Dr. Fred Hoerr, AVDL

29. Courtesy of Dr. Fred Hoerr, AVDL
Intestinal Integrity
Maintained
Host defenses: intestinal lining cells, secretory products, and support tissues
Challenged
Exposure to opportunistic and virulent pathogens
Dietary and management factors that increase exposure
Destroyed
Virulent, primary pathogens
Additive, synergistic injury by variable exposure to opportunistic pathogens
Courtesy of Dr. Fred Hoerr, AVDL

31. Virulence of Pathogens
Dose of Pathogens
Emerging Issues
Host Resistance
Virulence of Pathogens

32. Dose of Pathogens Goal: Decreased exposure
Feed ingredient production and poultry rearing are biological systems
Diminishing list of pharmacological products to suppress bacteria
Actions to reduce exposure must meet biological, economic, and regulatory justification

33. Virulence of Pathogen
Ability to colonize, establish and maintain infection
Least practical control point
Under genetic control of pathogen
Antibiotics may influence bacterial virulence
Inhibit protein metabolism

34. Improved Host Resistance
Genetic selection in presence of limited pharmacological and biological products
Understanding and preventing immunosuppression
Diet selection and enzyme efficacy
Improved oral vaccines to protect mucosal surfaces

35. Thank you