Have you ever wondered about the digestibility of grain in horses? In this informative video by Rick Lamb, he delves into the topic of understanding how horses digest grain. With his expertise in equine nutrition, Rick Lamb shares valuable insights and explores the factors that affect the digestion process. This Nutrition Nuggets video is a must-watch for horse owners and enthusiasts who are curious about optimizing their horse’s nutrition for overall health and well-being. So sit back, relax, and let Rick Lamb guide you through the fascinating world of grain digestibility in horses.

Understanding the Digestive System of Horses

An overview of the horse’s digestive system

The digestive system of a horse is a complex and highly specialized system that allows them to efficiently extract nutrients from their food. Horses are herbivores, which means their digestive system is primarily designed to process plant material. Unlike humans, horses are unable to regurgitate and chew their food again, which is why the initial breakdown of food is crucial.

The horse’s digestive system consists of several parts, including the mouth, esophagus, stomach, small intestine, large intestine, and cecum. The process begins in the mouth, where the horse chews the food, mixing it with saliva to form a bolus. This bolus then moves down the esophagus and into the stomach, where the initial breakdown of food occurs through the action of stomach acids. From the stomach, the partially digested food enters the small intestine, where further digestion and absorption of nutrients take place. Finally, any undigested material moves into the large intestine and cecum, where it undergoes fermentation by beneficial bacteria.

How horses process grains compared to other foods

Grains, such as oats, corn, and barley, are commonly included in a horse’s diet, providing a concentrated and easily digestible source of energy. When horses consume grains, enzymes in their saliva begin the initial breakdown of starches. As the partially digested grain enters the stomach, it undergoes further enzymatic breakdown and mixing with gastric juices. From there, it moves into the small intestine, where the majority of nutrient absorption occurs.

Compared to other types of food, grains are rapidly digested by horses due to their high starch content. This rapid digestion can lead to spikes in blood sugar and insulin levels, making it important to carefully consider the amount and type of grain fed to horses, particularly those prone to metabolic disorders such as insulin resistance or laminitis.

Types of Grains Commonly Fed to Horses

Common types of grain in the equine diet

There are several types of grains commonly fed to horses, each with its own nutritional profile and benefits. Some of the most commonly fed grains include oats, corn, barley, and wheat. Oats are a popular choice due to their high fiber content and lower starch content compared to other grains. Corn, on the other hand, provides a higher energy content but can be more challenging to digest. Barley is another commonly fed grain, known for its moderate starch content and palatability. Wheat, although less commonly fed to horses, can also be included in their diet.

Nutritional content of different grains

Each grain has its own nutritional content, which makes it important to understand the specific needs of your horse and choose grains accordingly. Oats, for example, are rich in fiber, protein, and essential nutrients such as vitamin B, E, and minerals like calcium and phosphorus. Corn, although high in energy, is lower in fiber and protein compared to oats. Barley, like oats, provides fiber and essential nutrients but has a higher starch content. Wheat is similar to barley in terms of nutritional content but should be fed in smaller quantities due to a higher probability of causing digestive upset.

Factors Influencing Grain Digestibility in Horses

Age of the horse

The age of a horse can significantly impact its ability to digest grains. Young horses, such as foals or weanlings, have a less developed digestive system and may struggle to digest grains effectively. It is important to introduce grains gradually and monitor their response. As horses age and develop, they become better equipped to digest and utilize the nutrients from grains.

Physical condition of the horse

The physical condition of a horse plays a role in grain digestibility as well. Horses in good body condition with healthy digestive systems are better able to process and absorb nutrients from grains. Conversely, horses with digestive issues or those experiencing illness, such as gastrointestinal disorders or colic, may have reduced grain digestibility. Regular veterinary check-ups and monitoring of a horse’s body condition can help identify any potential issues affecting grain digestion.

Amount of grain intake

The amount of grain a horse consumes can directly impact its digestibility. Feeding too much grain at once, especially in relation to the horse’s size and activity level, can overwhelm the digestive system and hinder effective digestion. Providing smaller, more frequent meals throughout the day can aid in the proper digestion and utilization of the nutrients present in grains. Additionally, carefully monitoring the horse’s body condition and adjusting the grain intake accordingly is essential for maintaining optimum digestibility.

Processing of Grains for Improved Digestibility

Methods of grain processing

Grain processing refers to various methods used to alter the physical structure of grains, making them easier for horses to digest. Common methods of grain processing include rolling, cracking, grinding, and steam rolling. Rolling involves flattening the grains, which breaks the hard outer shell and makes it easier for the horse’s digestive enzymes to access the inner starch content. Cracking, on the other hand, involves breaking the grains into smaller pieces without fully pulverizing them. Grinding is a more intensive process that turns grains into a fine powder, while steam rolling involves steaming and flattening grains, somewhat similar to rolling.

How processing affects grain digestibility

Processing grains can enhance their digestibility by breaking down the outer layers and increasing the surface area available for enzymatic breakdown. By exposing more of the starches to saliva and digestive enzymes, processing aids in the efficient digestion of grains. Additionally, processing can also improve the palatability of grains, making them more appetizing to horses. However, it is important to note that excessive processing can also lead to nutrient loss, particularly vitamins and enzymes that are heat sensitive. Finding a balance between effective processing and nutrient preservation is key to optimizing grain digestibility.

The Role of Enzymes in Grain Digestion

Definition and function of enzymes in digestion

Enzymes are specialized proteins that act as catalysts in various chemical reactions within the body, including digestion. In the context of grain digestion in horses, enzymes play a crucial role in breaking down complex carbohydrates into simpler sugars that can be absorbed by the horse’s body. Specifically, enzymes such as amylase and maltase are responsible for breaking down starches into glucose molecules, which can then be readily utilized by the horse for energy.

Specific enzymes at work in grain digestion

Several enzymes are involved in grain digestion in horses. Salivary amylase is the first enzyme to come into contact with grains, present in the horse’s saliva. It initiates the breakdown of starches into smaller sugar chains. Once in the stomach, gastric amylase, along with hydrochloric acid, continues the hydrolysis of starches. In the small intestine, pancreatic amylase and brush border enzymes, such as maltase, finish the job, breaking down the remaining starches and disaccharides into absorbable monosaccharides. The presence of these enzymes is pivotal in the successful digestion and utilization of grains in horses.

Importance of Fiber for Grain Digestibility

The role of fiber in digestion

Fiber plays a fundamental role in the digestion process of horses, even when grains are being fed. The presence of fiber slows down the rate at which food passes through the digestive system, allowing for more thorough digestion and absorption of nutrients. Additionally, fiber helps promote proper gut motility and stimulates the growth of beneficial bacteria in the large intestine, which aids in the fermentation of fiber and the production of volatile fatty acids. These fatty acids serve as an additional source of energy for the horse.

Balancing grain intake with fiber intake

Balancing the intake of grains with an adequate amount of fiber is crucial for maintaining optimal grain digestibility. The fiber content in a horse’s diet can come from sources such as hay, pasture, or other forage options. By ensuring a sufficient intake of fiber alongside grains, the overall digestive health of the horse is supported, and the risk of digestive issues, such as colic or hindgut acidosis, is reduced. Careful consideration should be given to the quality and quantity of fiber provided to ensure it meets the horse’s individual needs.

Risk of Overfeeding Grains

The effects of overfeeding grains

Overfeeding grains can have detrimental effects on a horse’s health and overall well-being. When horses consume excess amounts of grains, especially those high in starch, the rapid fermentation and absorption of sugars can lead to spikes in blood sugar and insulin levels. This can predispose them to metabolic disorders, such as insulin resistance or equine metabolic syndrome. Excessive starch intake can also disrupt the balance of beneficial bacteria in the horse’s gut, potentially leading to digestive upset or colic.

Preventing overfeeding grains

Preventing the overfeeding of grains requires careful attention to the horse’s individual needs and monitoring their body condition. Consultation with an equine nutritionist or veterinarian can help determine the appropriate amount and type of grains suitable for a specific horse. It is essential to feed grains in moderation, providing smaller, more frequent meals rather than large, infrequent feedings. Regularly reviewing and adjusting the horse’s diet based on their body condition and activity level is key to preventing overfeeding and maintaining grain digestibility.

The Impact of Grain Digestibility on a Horse’s Overall Health

Relationship between digestion and horse’s health

The digestibility of grain plays a vital role in a horse’s overall health and well-being. Efficient digestion of grains ensures the horse receives the necessary nutrients for proper growth, performance, and maintenance of bodily functions. Conversely, poor digestibility can lead to nutrient deficiencies, reduced energy levels, and compromised immune function. Additionally, improper grain digestion can contribute to the development of metabolic disorders, digestive issues, and weight management problems.

Possible health issues caused by poor digestibility of grain

Poor digestibility of grains can contribute to various health issues in horses. When grains are not properly digested, the undigested portions pass into the large intestine and cecum, where fermentation occurs. High-starch or high-sugar contents in the cecum can disrupt the balance of beneficial bacteria, leading to imbalances in gut flora and an increased risk of digestive upset, such as colic or diarrhea. Furthermore, poor grain digestibility can contribute to weight gain, insulin resistance, and laminitis in horses that are genetically predisposed or have underlying metabolic conditions.

Managing Feed for Optimum Grain Digestibility

Proper feeding schedules for horses

Establishing and following a proper feeding schedule is essential for maintaining optimum grain digestibility. Horses are naturally grazing animals, and their digestive systems are designed for continuous intake of small amounts of food. Providing regular access to forage, such as hay or pasture, allows horses to maintain a healthier gut environment and promotes proper digestion. When feeding grains, it is best to divide the daily ration into multiple smaller meals spread throughout the day, rather than large infrequent ones. This approach better mimics the horse’s natural feeding behavior and aids in the effective digestion of grains.

Grain-to-forage ratio in a horse’s diet

Maintaining a proper grain-to-forage ratio is crucial for optimizing grain digestibility and ensuring the overall health of the horse. While the specific ratio may vary depending on the horse’s individual needs, a general guideline is to provide a higher portion of forage, such as hay or pasture, compared to grains. The roughage provided by forage helps regulate the rate of digestion, preventing spikes in blood sugar and insulin levels associated with excessive grain consumption. A balanced diet that incorporates an appropriate amount of forage alongside grains promotes healthy digestion and supports the horse’s nutritional requirements.


In conclusion, understanding the digestive system of horses and the factors influencing the digestibility of grains is vital for horse owners and caretakers. By considering the age, physical condition, and grain intake of the horse, as well as the methods of grain processing, role of enzymes, and importance of fiber, one can ensure optimal grain digestibility and overall health. Managing feed schedules, preventing overfeeding, and maintaining a proper grain-to-forage ratio further contribute to the digestive well-being of horses. By following these guidelines and seeking professional guidance when needed, horse owners and caretakers can make informed decisions regarding grain feeding strategies, promoting the health and happiness of their equine companions.