What are the two types of teeth?
Hypsodont and brachyodont teeth
Describe hypsodont teeth
These teeth continually grow and need to be worn down. They are suited to animals that have evolved to eat a gritty fibrous diet, such as horses, cows and deer.
Describe brachyodont teeth
These teeth are a set size and are more suited to holding, tearing and shredding food.
What is the issue with feeding high levels of concentrates?
As horses have hysodont teeth that need to be worn down, high levels of concentrates do not do this, so the teeth are able to grow too long.
What are the 4 compartments of the ruminent stomach?
- the rumen
- the reticulum
- the omasum
- the abomasum
Describe the reticulum
Has a honeycomb lining and no secretions. This is where bolus is formed, regurgitation is initiated and things that should not be eaten are collected.
Describe the rumen
The portion of the stomach that is full of good bacteria where forage is fermented. It has the enzyme cellulase which breaks down cellulose. The first portion of the stomach.
Describe the omasum
Has a laminae lining and muscular folds and no secretions. Reduces particle size and absorbs 60% of water and volatile fatty acids to prevent buffering of the abomasum.
Describe the abomasum
Produces pepsin, the enzyme for breaking down proteins. It is the last portion of the stomach.
What are the components of the equine GIT?
The oesophagus, the stomach, small intestine, large intestine, rectum, anus
Define SALIVA
Saliva is a watery liquid secreted into the mouth by glands, providing lubrication for chewing and swallowing, and aiding digestion.
Where and when is saliva produced in a horse?
Saliva is secreted only when the horse chews, which can be between 10-12l.
It is produced by the paratoid, sub-lingual and mandibular glands.
What is the size of each of the horse’s gut compartments?
Stomach - 8% of total GIT
Small intestine - 30%
Large intestine - 62%
Describe the equine stomach
- has around 25l of secretions per day, which are triggered by the presence of food.
- secretions are controlled by hormones and by nerve stretch receptors
- ## pepsinogen is the inactive form of pepsin and is there to ensure that the stomach does not digest itself.
What is secreted in the small intestine?
duodenal juice (acts as a lubricant),
pancreatic juice (controlled by the two hormones secretin and CCK-PZ),
bile (constantly release and aids the digestion of lipids. Can damage the SI if there is no food)
succus entericus (intestinal fluid of which a small amount is secreted in the SI).
Describe the small intestine
Made up of the duodenum jejunum and the ileum.
Describe the large intestine
Made up of the caecum, the large and small colon and the rectum. Microbial digestion takes place, but no enzymes are produced. Lots of water is absorbed here.
What are the micro organisms in the gut?
These mosty reside in the hindgut and require a constant internal environment in order to stay effective. They ferment fibre and release nutrient that the horse can absorb, such as VFA and vitamins B and complex K
What is the significance of the liver/pancreas?
- they are accessory organs to the digestive process
- the liver produces bile
- the pancreas produces pancreatic juice and digestive enzymes
