Digestive system of herbivores Flashcards
How are ruminants able to digest forage?
Because of the microbes in their digestive system.
What is the physiological definition of Digestion?
The catabolic process in the digestive tract where ingested food is converted to simpler, soluble, and diffusible substances that can be assimilated by the body.
What is the microbiological definition of Digestion?
The process of decomposing organic matter through microbial activity.
What are the three categories of digestion?
- Mechanical
- Chemical
- Microbial
What is mastication?
When animals can bring food up again to chew it even more. This is a form of mechanical digestion.
In what ways does the mouth aid in digestion for herbivores?
- It is a prehension tool meaning that it can help sense the diffent types of plants around it.
- Grinds food
- Mixes food with saliva.
In what ways do the lips aid in digestion for herbivores?
- Immobile for cattle and bisons
- Split for sheet
- Very mobile for deep, goat and horses.
How do teeth in ruminants differ from teeth in horses?
Ruminants only have lower teeth and upper dental pads.
Horses have upper and lower incisors. They can bite closer to the ground. They also have wolf teeth that are not present in the ruminants.
How close can the different animals graze to the ground?
Cattle and Bison: Graze 5-7cm.
Sheep and goat: Graze <5cm
Horses: Graze much closer to the ground.
What kind of characteristics help animals graze close to the ground?
Mobile lips and teeth present at the top and bottom.
Hoe does saliva help the animal?
- Lubricant
- Digestion: Makes food easier to pass through the esophagus.
- Antimicrobial: Prevents plaque.
- Ion reservoir: Maintains pH between 6.2 - 7.
- Recycles nutrients : Urea, Sulfate, Ca, Mg.
Name some of the salivary glands.
- Parotid gland: These are the main glands.
- Mandibular gland
- Polystomatic sublingual gland
- Monostomatic sublingual gland
What are the 4 compartments of a ruminant?
- Reticulum
- Rumen
- Omasum
- Abomasum
Where in the cattle does methane production take place?
Rumen
What is the biggest part of the ruminant’s digestive tract?
Rumen
Why are ruminants called foregut fermentators?
Because some of the fermentation takes place prior to entering the stomach and small intestines.
What is Rumination?
Rumination is the process of rechewing ruminal content that has previously been ingested.
What is the average residence time in the rumen for diets?
- Diets low in fiber is about 20 hrs.
- Diets high in fiber is about 60 hours.
What is the most abundant organism in the rumen?
Protozoa. Contributes of about 50% of the microbial biomass.
What are some functions of the protozoa in the rumen?
- Aids in the stability of rumen fermentation.
- Consume bacteria and keep the populations of bacteria balances.
- Contribute to ammonia production.
- Ferment carbs at a much slower rate than bacteria, resulting in a more uniform prolonged release of VFA.
When does the population of protozoa start to decrease?
When rumen pH falls bellow 6.0.
What are some characteristics of bacteria found in the rumen?
- They produce NH3 and VFA.
- Found in liquid, attached to feed and rumen epithelium.
- Classification is based on the substrate preferred.
Cellulose, hemi cellulose,
amino acid, starch, pectin. - Sensitive to reduction in pH.
What are the primary methane producing microbes?
Archaea.
What percentage of the microbial population consists of archaea?
2-4%
