2. Single stomach Eat feed low in fiber Humans are also non-ruminants

3. 1. Mouth 2. Esophagus 3. Stomach 4. Small Intestine 5. Large Intestine

4. Breaks down feedstuffs into ….. simple chemical parts….. so the pig can absorb….. and utilize them.

5. Breaks down feed stuffs by chewing Adds saliva to help in digestion

6. Muscles contract to move the food down to the stomach

7. Adds digestive juices to break down food

9. The small intestine…. Mixes secretions Absorbs nutrients

10. Storage and formation of feces Absorption of water Secretion and reabsorption of electrolytes

12. Non-ruminant Abomasum- true stomach depends on digestive enzymes pepsin, rennin, trypsin, chymotrypsin, HCL Needs – energy (fat and CHO), protein (a.a.), minerals (Ca:P 1.2:1 to 1.5:1), vitamins, water, antibiotics and other additives

13. Swine Gastrointestinal Physiology 11/04

14. Digestive secretions: saliva Functions of saliva in non-ruminants: – Lubricates food to facilitate swallowing – Contains antibodies and lysozyme – Some amylase in saliva of swine and rats, but much less than in humans Functions of saliva in ruminants: – Maintains fluid consistency of rumen – Slightly alkaline; helps neutralize acids formed by fermentation – May help prevent frothing in rumen

15. Gastric pits in gastric mucosa Gastric pits are openings to ducts into which gastric glands empty their secretions

16. Exocrine gland Any gland that directs its secretions through a duct into a compartment that is contiguous with the exterior of the body

17. Glandular regions of simple stomach Cardiac Fundic Pyloric

18. Glandular regions of equine, porcine and ruminant stomachs Cardiac, fundic and pyloric gland regions are glandular Esophageal regions (“E”) are non- glandular epithelium

19. Cardiac gland region (cardiac mucosa) Cardiac Fundic Pyloric

20. Fundic gland region Mucous neck cells Parietal cells Chief cells Cardiac Fundic Pyloric

21. Fundic gland region Mucous neck cells secrete mucus Parietal cells secrete: – HCl – Intrinsic factor (not in cats); necessary for absorption of Vitamin B12

22. Fundic gland region Chief cells secrete pepsinogen – HCl converts pepsinogen into pepsin – Pepsin is a proteolytic enzyme (breaks down proteins into peptides)

23. Pyloric gland region Mucous secreting cells G cells Cardiac Fundic Pyloric

24. Pyloric gland region G cells are endocrine gland cells – secrete the endocrine hormone, gastrin Endocrine cells secrete hormones into the bloodstream – travel to a distant part of the body where they produce an effect on another cell type

25. Substances that stimulate HCl secretion by parietal cell Gastrin Acetylcholine Histamine – Histamine secreted by ECL cells in gastric mucosa Gastrin may interact with either receptor

26. Rennin Enzyme secreted by abomasal mucosa of young ruminant – Acts to coagulate milk protein, which facilitates its digestion

27. Hormone secretions of small intestine: cholecystokinin Site of secretion Stimuli for secretion Actions Primarily duodenal mucosa Chyme with a: High amino acid concentration High fatty acid concentration Low pH Inhibits gastric emptying ↑ secretion of pancreatic enzymes and HCO 3 - Stimulates gall bladder contractions

28. Hormone secretions of the small intestine: secretin Site of secretionStimuli for secretion Actions Duodenal mucosa Chyme with a: Low pH High fatty acid concentration ↓ HCl production in stomach ↑ pancreatic HCO 3 - secretion ↑ biliary HCO 3 - secretion

29. Exocrine pancreatic secretions Liquid rich in HCO 3 - Pancreatic digestive enzymes Both are secreted into duodenum

30. Pancreatic digestive enzymes Pancreatic proteolytic enzymes (pancreatic proteases) are secreted as proenzymes (zymogens)

31. Activation of pancreatic proteases in small intestine CCK stimulates duodenal mucosal cells to produce enteropeptidase ProelastaseElastase

32. Absorption of amino acids from small intestine