Peat might not be the prettiest bedding for your horse’s stall, but new study results suggest that it might be better for his health than wood shavings.

Finnish researchers recently determined that peat bedding releases less ammonia into the environment and horses (and humans) show fewer signs of respiratory problems compared to when wood shavings are used. The horses’ hooves also have a better moisture content.

“Peat can keep the stable free from detrimental gases,” said Markku Saastamoinen, PhD, docent, principal research scientist, in the Natural Resources Institute Finland LUKE, Equines, in Ypäjä.

“The particle size of peat is so large that it is not harmful to the airways of the horse, meaning the particles can’t go so deep into the lungs of the horse,” he said. While their study focused only on a comparison between wood shavings and peat, Saastamoinen said peat’s composition would probably be healthier for horses than straw, as well. “Peat does not contain molds or other such harmful microorganisms, such as could be found in straw, straw pellets, and other similar materials.”

In their study, Saastamoinen and his fellow researchers examined the effects of wood shavings and peat bedding on 12 Finnhorse broodmares aged 5 to 17 (four of which were in foal). The stable included one section bedded with wood shavings and one section bedded with peat, which allowed the scientists to easily distinguish the bedding’s effects on the air inside the barn.

They conducted the study over 84 days in autumn with outdoor temperatures reaching -20$deg;C (-4$deg;F). The horses were housed indoors except for five hours a day when they were either let free in an outdoor paddock or exercised, during which time their stalls were cleaned and new bedding was added to keep a depth of about 10 cm (4 inches). All the horses tried both kinds of bedding.

Every day the researchers monitored ammonium, carbon dioxide, and dust levels in the air at about the height of a horse’s nose. They performed blood analyses, fecal analyses, and hoof evaluations regularly on the horses and took their vital signs (heart rate, respiratory rate, temperature). They also closely investigated the horses’ respiratory tracts for signs of inflammation or infection, including laboratory analyses of fluids and surface cells.

For the barn staff, the researchers evaluated the levels of gas and dust through a device worn on their collars during stall cleaning.

Ammonia content was six to eight times higher in stalls bedded with wood shavings compared to peat, Saastamoinen said. In fact, the ammonia content in the middle of the peat-bedded stalls was near zero, due to peat’s high ability to bind ammonia. Dust and carbon dioxide levels, however, were similar in both kinds of stalls.

Barn workers spent an average of 13 minutes per day per stall, Saastamoinen said. During that time they were exposed to high levels of ammonium gas in the wood shaving stalls, which could compromise their respiratory health. However, in the peat stalls there was no significant ammonium gas exposure.

Additionally, general health appeared improved in horses on peat bedding, with better respiratory tract analysis results as the season progressed, he said. Gas and dust accumulation in the stable environment can cause respiratory systems to worsen over the cold season as horses spend more time indoors. Horses on wood shavings tended to have more signs of respiratory problems over the study period, but those on peat shavings tended to improve or stabilize over time.

The horses also had better moisture content in their hooves (without reaching unhealthy levels of moisture) on peat bedding, Saastamoinen said, improving elasticity and general hoof health.

They also found that peat bedding was more economical, as it was consumed at a rate of only 59% compared to wood shavings, Saastamoinen said. And peat appears to be more environmentally friendly, as well, not only producing lower quantities of manure but also composting rapidly, with good nitrogen binding, which is important as a fertilizer. “It is important to recycle the nutrients of the horse manure and, thus, act as ecologically as possible,” he said.

Practically speaking, peat is easy to work with and costs about the same as wood shavings, depending on the region, he said. But in some areas, he cautioned, it could be hard to find. It’s also critical to choose peat that has been produced for bedding purposes, he added, because the structure is different from that produced for energy. Peat produced for energy contains smaller particles and a lower moisture content, which can create more dust in stables.

“It’s easy to work with peat because it is quite light to handle, and its consumption is not so large because of its good properties, such as its good ability to bind water and moisture,” said Saastamoinen. “Cleaning a peat stall is not more difficult compared to other materials—I think that this issue depends on the routines and also the tools you are using in mucking out and replacing bedding.”

Regardless of bedding choice, good ventilation in the barn is critical, he added, as this will help distribute the gases and dust to reduce negative health effects on both horse and human.

“When choosing the bedding material, the first things to consider are the well-being of the horse (and health effects to the stable workers) and then the impacts on nature and environment,” Saastamoinen said.

The study, “Reducing Respiratory Health Risks to Horses and Workers: A Comparison of Two Stall Bedding Materials,” will appear in an upcoming issue of Animals.