The Ruminant Digestive System

(Day 2)

Created by: Arlene Barrett, Dennis Bratton, Mariah Gumphry, Haley Vrazel

Objectives Define the functions of ruminant animals.Analyze ruminant digestive system. Analyze the first two components of the

digestive system of ruminant animals.

Ruminant Digestive SystemsFunctions of the digestive system

of animals include:ingestion (eating)chewing (mastication)swallowing (deglutition)absorption of nutrientselimination of solid wastes (defecation)

Ruminant Digestive SystemsThe digestive system changes food nutrients into compounds that are easily absorbed into the bloodstream.

Ruminant Digestive SystemsRuminants are those animals that

contain a multi-chambered digestive system (polygastric) that allows the animal to gain the majority of their nutritional needs from forages and other roughages.cattle, sheep/goats, deer and elk

Forage refers to grasses, roughages refers to other high-fiber food sources.

Ruminant Digestive SystemsThe digestive tract extends from

the lips to the anus. It includes the mouth, pharynx, esophagus, stomach, and the small and large intestines.

Accessory glands include the salivary glands, the liver, and the pancreas.

Ruminant Digestive Systems

Picture of digestive system of cow

Rectum

Anus

Colon

Cecum

Small IntestineRumen

Kidney

Pancreas

Liver Esophagus

Pharynx

Teeth

Tongue

Salivary Gland

Reticulum

Omasum

Abomasum

Ruminant Digestive SystemsThe digestive system of ruminant animals

includes the:Mouth - grasps the foodTeeth - grind the food

Ruminants have only one set of teeth in the front of the mouth (incisors), and two sets in the back (molars).

Tongue - covered with finger-like projections (papillae) that contain taste buds.

Salivary glands - secrete saliva, that moistens food and is mixed with the food material to aid in swallowing.

Ruminant Digestive SystemsPharynx - funnels food into the esophagus, preventing food material from entering the lungs.

Esophagus - food tube that leads from the mouth to the stomach.

Ruminant Stomach

Compartment Capacity

11

Reticulum 5% of capacity

Rumen 80% of capacity

Omasum 7% of capacity

Abomasum 8% of capacity

Ruminant Digestive SystemsAt this point, ruminant animals have a multi-chambered “stomach”Reticulum - honeycomb-like interior surface, this part

helps to remove foreign matter from the food material.Esophagus empties here

Prone to hardware diseaseCattle swallow small pieces of metalCan irritate or pierce the lining Helped by putting a small magnet into the reticulum

Holding area for food; also site of regurgitation

Reticulum - cleaned

Ruminant Digestive SystemsRuminant animals grasp mouthfuls of food

and swallow it before it is chewed.They wrap their tongue around a mouthful of grass, clamp down their teeth, and pull to break the grass at its weakest point, and swallow.

Ruminants will “chew their cud” (regurgitate) their food material and then grind it with their molars at a time when the animal is resting.

This is done until the food particles are small enough to pass through the reticulum into the rumen.

Ruminant Digestive SystemsRumen - the organ that allows for bacterial

and chemical breakdown of fiber.The rumen has a very thick, muscular wallIt fills most of the left-side of the abdomen

Looks like carpet due to papillae lining itFermentation vat

Primary digestion site for ruminantsMicrobial digestion takes place hereBreakdown cellulose, simple sugars, and

Nitrogen containing compounds like proteinPhysical mixing and breakdownNot active in the early stages of life

Papillae in Rumen

Summary Define the functions of ruminant animals.Analyze ruminant digestive system. Analyze the first two components of the

digestive system of ruminant animals.

ResourcesResources: Rakowitz-McMillian Sam

Houston State Univeristy Animal Science Note Packet