• Single stomach• Eat feed low in fiber• Humans are also
non-ruminants
• 1. Mouth• 2. Esophagus• 3. Stomach• 4. Small Intestine• 5. Large Intestine
• Breaks down feedstuffs into …..
• simple chemical parts…..
• so the pig can absorb…..
• and utilize them .
• Breaks down feed stuffs by chewing
• Adds saliva to help in digestion
• Muscles contract to move the food down to the stomach
• Adds digestive juices to break down food
The small intestine….
• Mixes secretions• Absorbs nutrients
• Storage and formation of feces
• Absorption of water• Secretion and
reabsorption of electrolytes
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
Swine Gastrointestinal Physiology
11/04
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
Gastric pits in gastric mucosa
• Gastric pits are openings to ducts into which gastric glands empty their secretions
Exocrine gland
• Any gland that directs its secretions through a duct into a compartment that is contiguous with the exterior of the body
Glandular regions of
simple stomach
Cardiac
FundicPyloric
Glandular regions of equine, porcine and ruminant stomachs
• Cardiac, fundic and pyloric gland regions are glandular
• Esophageal regions (“E”) are non-glandular epithelium
Cardiac gland region
(cardiac mucosa)
Cardiac
FundicPyloric
Fundic gland
region
• Mucous neck cells
• Parietal cells• Chief cells
Cardiac
FundicPyloric
Fundic gland region
• Mucous neck cells secrete mucus
• Parietal cells secrete:– HCl– Intrinsic factor
(not in cats); necessary for absorption of Vitamin B12
Fundic gland region
• Chief cells secrete pepsinogen– HCl converts
pepsinogen into pepsin
– Pepsin is a proteolytic enzyme (breaks down proteins into peptides)
Pyloric gland
region
• Mucous secreting cells
• G cells
Cardiac
FundicPyloric
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
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
Rennin
• Enzyme secreted by abomasal mucosa of young ruminant– Acts to coagulate milk protein, which facilitates its
digestion
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 HCO3
-
•Stimulates gall bladder contractions
Hormone secretions of the small intestine: secretin
Site of secretion Stimuli for secretion
Actions
Duodenal mucosa
Chyme with a:•Low pH•High fatty acid concentration
•↓ HCl production in stomach•↑ pancreatic HCO3
- secretion•↑ biliary HCO3
- secretion
Exocrine pancreatic secretions
• Liquid rich in HCO3
- • Pancreatic
digestive enzymes
• Both are secreted into duodenum
Pancreatic digestive enzymes
• Pancreatic proteolytic enzymes (pancreatic proteases) are secreted as proenzymes (zymogens)
Activation of pancreatic
proteases in small intestine
• CCK stimulates duodenal mucosal cells to produce enteropeptidase
Proelastase Elastase
Absorption of amino acids from
small intestine
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