Oats are a solid feed ingredient for pigs, offering useful protein, gut-friendly fiber, and immune-supporting compounds. They work well across most life stages when included at the right levels, though their lower energy density compared to corn means they shouldn’t be the sole grain in the diet.
Nutritional Profile of Oats for Pigs
Feed-grade oats contain about 11.5% crude protein, which is higher than corn. They also carry roughly 5% fat and 39% starch, making them a reasonably well-rounded grain. The amino acid profile is decent but not exceptional: lysine, the most important amino acid for pig growth, sits at around 0.40%, which is lower than soybean meal but comparable to other cereal grains.
Where oats fall short is energy. The metabolizable energy of oats runs about 2,730 calories per kilogram of dry matter, compared to roughly 3,320 for corn. That 18% gap matters, especially for fast-growing finishing pigs that need calorie-dense rations. The fiber content, at around 10.5 to 10.7%, is the main reason for this energy difference. Much of that fiber sits in the hull, which pigs digest poorly.
Hull-less Oats vs. Standard Oats
Hull-less (also called naked) oats strip away most of that fibrous outer layer, boosting the available energy and protein. In a trial with 160 weanling pigs, hull-less oats fully replaced wheat grain in the diet without hurting daily weight gain or feed intake over 28 days. The one trade-off was a small, steady decline in feed efficiency: for every third of the wheat replaced by hull-less oats, gain-to-feed ratio dropped by about 0.01 grams per gram. That’s a measurable but minor hit, and for many producers the cost savings or availability of oats makes it worthwhile.
If you’re feeding standard hulled oats, expect lower digestibility across the board. Grinding helps. Medium-ground oats (not too coarse, not dust-fine) yielded the highest metabolizable energy in one feeding trial, about 3,329 calories per kilogram of dry matter on a dry basis, compared to 3,162 for coarsely ground oats. So how you process oats matters almost as much as which type you use.
Oats for Piglets and Weanlings
Young pigs benefit from oats in starter diets, primarily because of what the fiber does in the gut. Rolled or finely processed oats have been reported to reduce the incidence of diarrhea in newly weaned piglets. Scours are one of the leading causes of poor performance and death in the nursery phase, so any ingredient that helps firm up stool is valuable during that vulnerable window.
Research on oat groats (oats with the hull removed and lightly processed) in nursery diets has tested inclusion levels of 5%, 10%, and 15%, replacing corn. These moderate levels keep energy density high enough while capturing the digestive benefits. Going much beyond 15% in a young pig’s diet risks diluting the calorie content too much, since piglets have small stomachs and high energy demands relative to their body size.
Oats for Gestating Sows
Gestating sows are where oats really shine. Pregnant sows commonly develop constipation in late gestation, and the consequences ripple outward: constipation can lead to imbalanced gut bacteria, poor nutrient absorption, longer farrowing times, and higher piglet death rates at birth. Dietary fiber promotes gut movement and regular stool passage, which helps prevent these problems.
Oat bran and oat straw are both used as fiber sources in sow gestation diets. Oat bran provides a moderate fiber boost (about 11% total dietary fiber) and fits easily into a mixed ration. Oat straw is much higher in fiber, over 25% total dietary fiber, and is sometimes added in late gestation specifically to keep things moving. One additional benefit: fiber-rich diets help prevent sows from becoming overweight during pregnancy, and leaner sows tend to have shorter, easier farrowing.
Gut Health and Immune Benefits
Oats contain beta-glucans, a type of soluble fiber found in the cell walls of the grain. In pigs, beta-glucans act as a broad-spectrum immune booster. They strengthen the mucous lining of the intestine, which is the body’s first physical barrier against pathogens. They also influence the composition of gut bacteria in ways that support the gut-associated immune tissue, which is the largest immune organ in a pig’s body.
Studies in both weaning and finishing pigs have documented several immune responses to beta-glucan supplementation: increased antibody production, enhanced activity of immune cells that engulf bacteria, reduced levels of inflammatory signaling molecules, and some protection against parasitic infections. That said, results aren’t universal. Some trials found only marginal immune benefits and no clear growth advantage, suggesting that the response depends on the dose, the source of the beta-glucan, and the health challenges the pigs are actually facing. Pigs in clean, low-stress environments may not show the same immune boost as pigs dealing with disease pressure.
Practical Feeding Guidelines
The best way to use oats in a pig diet depends on the animal’s age and your goals:
- Nursery pigs (weanlings): Include oat groats or rolled oats at 5% to 15% of the diet, replacing a portion of corn. This range supports gut health and reduces scours without sacrificing too much energy density.
- Growing and finishing pigs: Oats can make up a larger share of the grain portion, but keep the energy gap in mind. You may need to add a fat source or increase the calorie density elsewhere in the ration to maintain growth rates comparable to a corn-based diet.
- Gestating sows: Oat bran, oat hulls, or oat straw can be added specifically to increase fiber intake during pregnancy. The fiber helps prevent constipation, supports gut health, and may contribute to easier farrowing.
Grinding oats to a medium particle size gives you the best energy extraction. Going too fine creates a powdery feed that pigs may refuse, and very coarse particles pass through without being fully digested. Rolling or crimping is another common approach, especially for on-farm processing, and works well for most pig classes.
Oats are not a complete feed on their own. Their lysine content is too low to meet the needs of growing pigs without supplementation, and their energy density will limit growth if they’re the only grain. But as one component in a balanced ration, they bring fiber, protein, fat, and immune-active compounds that corn alone doesn’t provide.