Highland cows are famous for grazing in rugged pastures and thriving on grasses most animals would struggle to digest. But how do they actually break down all that tough plant material? The secret lies in their complex digestive system — one built specifically for fibre-heavy diets. So, how do Highland cows digest food? In this post, we’ll walk through the fascinating process of digestion in Highland cows, from chewing to cud, and explain how their four stomach chambers work together to turn grass into energy.
Are Highland Cows Ruminants?
Yes — like all cattle, Highland cows are ruminants. This means they have a specialised digestive system designed to break down fibrous plant material like grass and hay. Unlike humans, who have one stomach, ruminants have four stomach chambers, each playing a unique role in digestion.
This system allows Highland cows to extract nutrients from food sources that monogastric animals (like pigs or humans) couldn’t survive on alone.
The 4 Stomach Chambers of a Highland Cow
1. Rumen — The Fermentation Chamber
The rumen is the largest stomach chamber, holding up to 150 litres of partially digested food. It acts as a giant fermentation vat, filled with billions of microbes (bacteria, protozoa, and fungi) that begin to break down tough fibres through microbial digestion.
Key role: Soften food and begin nutrient extraction via fermentation.
2. Reticulum — The Filter
This honeycomb-textured chamber sits next to the rumen and works closely with it. It catches denser materials and foreign objects (like rocks or wire — which is why cattle can develop “hardware disease”).
It also forms and sends food “cud” back up to the mouth for rechewing — an essential part of digestion.
3. Omasum — The Water Absorber
Once food is chewed again and swallowed, it moves to the omasum. This chamber has many folds, like book pages, and its main function is to absorb water and minerals from the food slurry.
Fun fact: The folds increase surface area massively — a clever design for maximum absorption.
4. Abomasum — The True Stomach
This is the only chamber similar to a human stomach. It uses enzymes and acids to break down proteins and kill remaining microbes before the food continues through the intestines for nutrient absorption.
Key function: Final digestion stage before nutrients are absorbed.
What Is Cud and Why Do Cows Chew It?
After the first round of chewing and fermentation in the rumen, Highland cows will regurgitate partially digested food — called cud — back into their mouths. They chew it again thoroughly to break it down even further.
This second chewing stage improves digestion and increases the surface area for microbial action. It’s a natural and necessary behaviour that takes place multiple times a day — often while resting or lying down.
What Do Highland Cows Eat?
Their diet mainly consists of:
- Grass (fresh or hay)
- Pasture forage and roughage
- Silage (fermented grass or legumes, in winter)
- Mineral supplements or salt licks (when needed)
Highland cows are incredibly efficient grazers — they can thrive on rough pasture, tolerate poor forage, and graze in steep or brushy environments where other cattle might struggle.
How Long Does It Take for Highland Cows to Digest Food?
Digestion in Highland cows is a slow and continuous process. It can take up to 70–100 hours for a full digestive cycle, from ingestion to waste. Chewing cud, fermenting fibre, and moving food through four stomachs is not fast — but it’s very effective.
Do Highland Cows Ever Have Digestive Problems?
While generally hardy, Highland cows can develop digestive issues if fed improperly:
- Bloat: Caused by excessive gas buildup, often from lush legumes like clover or sudden dietary changes.
- Acidosis: From high-grain diets that drop rumen pH and damage the microbial balance.
- Hardware disease: When metal or sharp objects enter the reticulum. Some farmers feed magnets to catch these items.
For hobby farmers or pet cow owners, it’s important to stick with natural forage, limit treats, and provide fresh water at all times. More tips are covered in our guide on keeping Highland cows as pets.
Why Is Their Digestive System So Effective?
Their 4-chamber stomach system is one of nature’s most advanced biological digesters. It allows Highland cows to:
- Extract nutrients from low-quality forage
- Survive in rugged, cold environments
- Thrive on hillsides, moorland, and heather
- Waste very little energy during digestion
This efficiency is one reason why Highland cows are so popular for sustainable and low-input farming.
Conclusion
So, how do Highland cows digest food? Through a complex but incredibly efficient system of microbial fermentation, multi-stage digestion, and the legendary four-chamber stomach. This unique system allows them to thrive on natural forage in some of the harshest climates — turning grass into energy, muscle, and milk without the need for rich feed or grain.
Next time you see a Highland cow chewing away in a field, remember — there’s a lot more going on under the surface than meets the eye.