The key difference between pseudo ruminant and ruminant systems is that pseudo ruminant digestive system has only three compartments in the stomach and it lacks a rumen, while the ruminant digestive system has four compartments in the large stomach including the rumen.
There are four basic types of digestive systems. They are the monogastric digestive system, polygastric digestive system, pseudo ruminant digestive system and avian digestive system. Non-ruminant animals have a simple stomach or monogastric digestive system. In contrast, ruminant animals have a polygastric digestive system, generally having a four-chambered stomach. Pseudo ruminant digestive systems can be seen in animals that eat large amounts of roughages like ruminants. However, their digestive system has only three chambers or compartments in the stomach. Thus, the pseudo ruminant digestive system does not have a rumen.
CONTENTS
1. Overview and Key Difference
2. What are Pseudo Ruminant Systems
3. What are Ruminant Systems
4. Similarities Between Pseudo Ruminant and Ruminant Systems
5. Side by Side Comparison – Pseudo Ruminant vs Ruminant Systems in Tabular Form
6. Summary
What are Pseudo Ruminant Systems?
Pseudo ruminants are animals that utilize large amounts of roughages or fibre as well as grains and other concentrated feeds. Some examples of pseudo ruminants are horses, camels, alpacas, hippopotamus, rabbits, guinea pigs, and hamsters. These animals have a digestive system comprised of a three-chambered stomach. They lack a rumen. But, they possess omasum, abomasum, and reticulum. The cecum of pseudo ruminants contains many microorganisms needed for digestion of a large amount of plants materials they consume. It is an enlarged structure which allows fermentation and digestion of roughage.
What are Ruminant Systems?
Ruminants are the animals that have a polygastric digestive system comprising of a four-chambered or a multi-chambered stomach. These animals are mainly herbivores, such as cows, sheep, and goats, etc. They generally eat a large amount of roughage or fibre. Thus, ruminants have a large stomach which has four compartments: rumen, reticulum, omasum, and abomasum. The complexity of its digestive system allows the complete digestion of the high cellulose-containing food matter ingested by these animals.
Organisms with polygastric digestive systems do not undergo extensive mechanical and chemical digestion in the mouth. Instead, they swallow their food in very large amounts, facilitating very minute chewing process. With time, they will ruminate or take back the swallowed food, further chew it and swallow again. The ball of food that is brought up and re-chewed is called the cud.
Figure 01: Ruminant Digestive System
The four compartments contain microorganisms which play a very important role in the digestion of cellulose. These microbes, especially rumen and reticulum bacteria, break down cellulose and ferment ingested food. They engage in complete digestion of cellulose converting cellulose to volatile fatty acids. The omasum and the reticulum participate mainly in the grinding process of the food.
What are the Similarities Between Pseudo Ruminant and Ruminant Systems?
- Both pseudo ruminant and ruminant animals eat large amounts of roughage or fibre.
- Moreover, both digestive systems carry out the same function.
- The two types of digestive systems have more than one chamber in their stomach.
- Both digestive systems have omasum, abomasum, and reticulum.
What is the Difference Between Pseudo Ruminant and Ruminant Systems?
The pseudo ruminant digestive system has a stomach with three compartments. Meanwhile, the ruminant digestive system has a stomach with four compartments. So, this is the key difference between pseudo ruminant and ruminant systems. Furthermore, the pseudo ruminant digestive system lacks a rumen, while the ruminant digestive system has a rumen. Therefore, this is another difference between pseudo ruminant and ruminant systems. For example, horse, camels, alpacas, hippopotamus, rabbits, guinea pigs, and hamsters are some pseudo ruminants that have a three-chambered stomach, while goat, cow and sheep are some ruminants that have a four-chambered stomach.
Summary – Pseudo Ruminant vs Ruminant Systems
Pseudo ruminant and ruminant digestive systems are two types of digestive systems among the four types. Both pseudo ruminants and ruminants eat a large amount of roughage or fibre. However, the pseudo ruminant digestive system has a stomach with three compartments while the ruminant digestive system has a stomach with four compartments. The pseudo ruminant digestive system lacks a rumen while the ruminant digestive system has a rumen. Thus, this is the key difference between pseudo ruminant and ruminant systems.
Reference:
1. “Boundless Biology.” Lumen, Available here.
2. “Ruminant.” Wikipedia, Wikimedia Foundation, 4 Oct. 2019, Available here.
Image Courtesy:
1. “Abomasum (PSF)” By Pearson Scott Foresman – Archives of Pearson Scott Foresman, donated to the Wikimedia FoundationThis file has been extracted from another file: PSF A-10005.png (Public Domain) via Commons Wikimedia