24/10/2026
A great explanation
🐴 🌾 🪣
🪻 𝗟𝘂𝗽𝗶𝗻𝘀 𝘃𝘀 𝗟𝘂𝗽𝗶𝗻 𝗛𝘂𝗹𝗹𝘀: 𝗪𝗵𝗮𝘁’𝘀 𝘁𝗵𝗲 𝗗𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝗰𝗲?
Lupins have become an increasingly popular ingredient in equine diets, and for good reason. They are naturally low in sugar and starch, making them an excellent option for many horses requiring a low-NSC diet. But one question I am asked regularly is:
“Should I feed whole lupins, cracked lupins, micronised lupins, extruded lupins, or lupin hulls?”
Although they all originate from the same plant, the whole legume and the hull of the legume are actually very different feeds with different nutritional profiles and purposes.
Let’s break them down.
𝗪𝗵𝗼𝗹𝗲 𝗟𝘂𝗽𝗶𝗻𝘀
Whole lupins are exactly as they sound — the entire legume remains intact.
Nutritionally, they are one of the richest protein sources commonly fed to horses while also providing a useful amount of slow-release energy.
Whole lupins typically contain:
•Around 30–35% crude protein
•Approximately 5–7% fat
•Very low starch (generally under 3%)
•Low sugar
•Moderate levels of digestible fibre
Whole lupins must be soaked prior to feeding as the seed coat remains intact and needs to be softened well enough that the horse is able to chew efficiently. Most horses without dental issues do a perfectly good job of chewing whole lupins, although some may swallow a proportion of whole seeds.
Whole lupins are ideal when additional quality protein and calories are required without significantly increasing sugar or starch intake.
When soaking whole lupins, they generally require a longer soaking period of around 12–24 hours to soften adequately. The downside to this soaking timeframe is the increased risk of bacterial contamination, particularly in warmer climates.
𝗖𝗿𝗮𝗰𝗸𝗲𝗱 𝗟𝘂𝗽𝗶𝗻𝘀
Cracked lupins are simply whole lupins that have been mechanically broken into smaller pieces.
Cracking doesn’t significantly change the nutritional composition—it simply reduces particle size, which may help some horses chew them more easily and can reduce the likelihood of whole seeds passing through undigested.
For many horses, cracked lupins are a practical alternative to whole lupins while providing essentially the same nutritional benefits.
Because they are already broken, cracked lupins absorb water much more quickly. They can begin to soften in as little as 10–20 minutes, although longer soaking may still be used if desired.
𝗠𝗶𝗰𝗿𝗼𝗻𝗶𝘀𝗲𝗱 𝗟𝘂𝗽𝗶𝗻𝘀
Micronisation uses infrared heat to cook the lupin before rolling or flaking it.
This process helps soften the seed, improve palatability and may improve digestibility of some nutrients. It also reduces naturally occurring anti-nutritional factors present within raw legumes.
Importantly, contrary to common misconceptions, micronisation does not significantly impact the sugar and starch content of lupins. Lupins are naturally low in non-structural carbohydrates (NSC), and while heat processing can alter starch structure and improve its digestibility in higher-starch feed ingredients, this offers little nutritional advantage in lupins from an NSC perspective. Micronisation should therefore not be interpreted as making lupins inherently lower in sugar or starch than their unprocessed counterparts.
For most horses, the nutritional differences between whole and micronised lupins are relatively modest.
Micronised lupins do not require soaking prior to feeding, although soaking may be helpful for horses with dental challenges.
𝗘𝘅𝘁𝗿𝘂𝗱𝗲𝗱 𝗟𝘂𝗽𝗶𝗻𝘀
Extrusion combines heat, moisture and pressure to cook the lupin before forcing it through an extruder.
Like micronisation, extrusion improves digestibility and produces a more uniform product. The process can also improve pellet quality when incorporated into commercial feeds.
Again, despite being heat processed, extruded lupins are not any lower in sugar and starch than raw/unprocessed lupins.
Extruded lupins also do not require soaking, unless feeding to horses that have difficulty chewing.
𝗦𝗼 𝗪𝗵𝗮𝘁 𝗔𝗯𝗼𝘂𝘁 𝗟𝘂𝗽𝗶𝗻 𝗛𝘂𝗹𝗹𝘀?
This is where things become quite different.
Lupin hulls are not the whole lupin seed.
Instead, they are the fibrous outer coating that is removed during processing.
Removing the protein-rich kernel leaves behind a feed that is:
•Extremely high in fibre
•Much lower in protein
•Lower in energy than whole lupins
•Still naturally low in sugar and starch
Think of lupin hulls as more of a forage booster than a protein supplement.
Because of their exceptionally high fermentable fibre content, lupin hulls are digested primarily by the microbes within the hindgut, producing volatile fatty acids that provide a slow and steady source of energy.
Lupin hulls can be fed dry or soaked, however a brief soaking is often preferred to increase water intake, reduce dust inhalation and most importantly, decrease the risk of choke.
𝗜𝗳 𝗡𝗼𝘁 𝗕𝗼𝘁𝗵, 𝗪𝗵𝗶𝗰𝗵 𝗢𝗻𝗲 𝗦𝗵𝗼𝘂𝗹𝗱 𝗬𝗼𝘂 𝗖𝗵𝗼𝗼𝘀𝗲?
The answer depends entirely on what you’re trying to achieve.
If your horse requires:
•More protein to support muscle development or topline
•Additional calories for weight gain
•Higher-quality amino acid intake
Whole, cracked, micronised or extruded lupins are generally the better choice.
If your horse would instead benefit from:
•Additional fibre
•A lower-calorie forage extender
•More chewing time
•Increased hindgut fermentable fibre
Lupin hulls may be the better option.
𝗣𝗿𝗼𝗰𝗲𝘀𝘀𝗶𝗻𝗴 𝗜𝘀𝗻’𝘁 𝗘𝘃𝗲𝗿𝘆𝘁𝗵𝗶𝗻𝗴
Many horse owners assume that micronised or extruded automatically means “better.”
In reality, the processing method often has less impact than people think.
Whole, cracked, micronised and extruded lupins all provide very similar nutritional profiles. The biggest difference lies in convenience, digestibility and manufacturing processes rather than dramatic changes in protein, energy or starch content.
The real nutritional outlier is lupin hulls.
While they originate from the same plant, nutritionally they behave almost like an entirely different feed.
Whether you’re feeding whole, cracked, micronised or extruded lupins, you’re providing a highly nutritious ingredient that is naturally low in sugar and starch while supplying valuable protein, fibre and slow-release energy.
Lupin hulls are equally valuable—but for very different reasons. Rather than being a protein-rich conditioning feed, they are an outstanding source of fermentable fibre that can help support hindgut health while contributing very little sugar or starch. Lupin hulls are also a decent source of digestible energy (calories), but would need to be fed at a higher rate to match the calorie content of the legume in its whole form.
Neither is “better” than the other—they simply fill different roles within the diet. Both options are highly nutritious, species-appropriate and palatable inclusions for most horses.
