How Goat Digestive System Works
Goats are Ruminants, like sheep, cows, and deer; the goat digestive system is made up of 4 stomach chambers. These chambers are called the Reticulum, Rumen, Omasum, and Abomasum. Humans are monogastric, we have one stomach that breaks down our food.
For humans, digestion begins with chewing, our food is swallowed down to our stomach where it goes through acidic breakdown. It is then passed into our small intestine where it is further broken down by enzymes. The small intestine is also where we absorb the nutrients from the food we’ve consumed. After absorbing useful nutrients, the rest passes through our large intestine where water is reabsorbed. Finally, our bodies pass the un-useful byproducts as solid waste.
Reticulum and Rumen or Reticulo-rumen
Ruminants differ from monogastric by having the four chambers. Digestion also begins with chewing after which food is swallowed into the Reticulum. In the reticulum, it undergoes microbial breakdown. The reticulum works in tandem with the next chamber called the Rumen. Food particles can be passed back and forth between the reticulum and the rumen during digestion. In the rumen, food undergoes further microbial breakdown. This is what set ruminants apart from monogastrics, the microbes that live in these chambers. The first two chambers function as a microbial fermentation chamber that breaks down hard plant fibers like hay, grass, and leaves.
Goats often eat quickly by comparison to humans by swallowing food in chunks up to almost 2 inches long. This allows them to browse on the move as we’ve all seen when hiking down trail. These large chunks of food are ‘sorted’ by the reticulum. Particles that are small enough are passed to the rumen, and larger particles are later regurgitated by their bi-directional esophagus and chewed more thoroughly.
Ruminants spend a significant amount of time chewing cud but they can’t while they are active. Therefore goats and other ruminants need down time to digest properly. Chewing cud breaks up larger particles into smaller pieces. This also increases the surface area of the fibrous material. Greater surface area allows the microbial breakdown to be much more efficient and is why monogastrics can’t digest fiber like this. Chewing is essential to goat’s health. Check out this video on floating goat’s teeth to help lengthen healthy longevity.
Omasum and Abomasum
After the first two chambers, food is then passed into the Omasum. The omasum functions as a filter where water is reabsorbed and food is pushed along to the Abomasum. The Abomasum is the last compartment and is the true stomach. This compartment functions like our stomachs by breaking down food with acids and enzymes. Bicarbonate ‘insulates’ the lining of the stomach as a buffer to the low pH in the stomach.
Finally, digested food passes to the small intestine where nutrients are absorbed. Remaining water is then reabsorbed in the large intestine before being passed from the body as solid waste.
Other Benefits for Ruminants
Other benefits of the digestive system other than allowing goats to digest dense plant fibers are the ability to synthesize vitamins and proteins. Thanks to the bacteria that live in the rumen, these microbes can synthesize all necessary B vitamins. Goats can also synthesize protein from nitrogen gas left over from the digestive process in addition to protein that’s been ingested. Finally, goat’s digestive systems have some protective qualities such as the ability to detoxify certain levels of tannin found in browse and feed. However, high concentrations of tannins can have negative effects on goat health.
Knowing the goat digestive system is important for every goat owner. Understanding this process helps in planning dietary plans, feed strategies on trail, and overall nutrition. This information also helps understand what is toxic, harmful, and beneficial for goat digestive health. Understanding this article will help you understand what plants are toxic to goats and how they affect them.
For much more detailed research please refer to the links below. Purdue University, Mississippi State University, and Washington State University all have a wealth of scholarly resources and great small ruminant research programs.
Mississippi State University: http://extension.msstate.edu/publications/publications/understanding-the-ruminant-animal-digestive-system
Washington State University: https://extension.wsu.edu/animalag/resources/small-ruminants/