Digestive tract:

• Monogastric non-ruminant herbivore = one stomach, can't regurgitate and eats plants.
• Evolved to live on low quality roughage in large amounts.
• Monogastric = one stomach compartment.
• Hindgut is the location of fermentation.
• Horses eat structural plant material.
• 16-18 hours a day spent feeding.
• Trickle feeders = eat little and often.
• Buccal cavity = mouth.
• Hindgut = everything after the small intestine.
• Foregut = everything up until the small intestine.
• Digestive tract functions = ingestion, mastication, digestion, fermentation, energy/nutrient absorption and excretion.
• Digestion can be mechanical or chemical.
• Heat is a by-product of fermentation.
• Prehension = getting food in their mouth.
• Buccal cavity components = lips, tongue, teeth and salivary glands.
• Swallowing is involuntary.
• Horses can't regurgitate food.
• Hypsodont = constantly erupting teeth.
• Intensive mastication by slow ingestion.
• 1.6mm is the ideal chewed forage size for microbes to ferment them.
• Silica from plants continuously wears teeth down rapidly.
• Hay average chewing rate = 3,400 chews/Kg - 40 minutes.
• Oats average chewing rate = 850 chews/Kg - 10 minutes.
• Forage is chewed in a circular motion and cereal in an up/down motion.
• Too much up/down chewing results in tooth issues like hooks.
• Glands producing saliva = parotid, mandibula and sublingual.
• 10-12 litres of saliva a day.
• Saliva helps move food down the Oesophagus.
• Saliva content = water, mucin, bicarbonate and amylase.
• Amylase is in small quantities in the saliva which is so low that digestion starts in the stomach instead.
• Digestion starts in the stomach.
• Saliva functions = lubrication, bolus formation and buffering stomach acid.
• Stomach acid is produced constantly.
• Oesophagus = 1.5m long approximately, smooth muscle, peristalsis and runs from the buccal cavity to the cardiac sphincter.
• Stomach = 9-15 litre capacity, doesn't expand and is 8% of the GIT volume.
• Stomachs can rupture.
• The cardiac sphincter stops regurgitation.
• Pyloric sphincter is at the end of the stomach and food can move in and out with contraction.
• Glands to release stomach acid are found in the glandular section of the stomach.
• Ulcers are usually found in the non-glandular section of the stomach near the margo plicatus due to no mucous membrane.