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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thank you