Common feeding practices for stabled horses kept on non-edible bedding impair their welfare, researchers in Germany have concluded.
It is common for boxed horses to receive two or three meals of roughage during the day.
For horses, this is very different to the way they prefer to eat in a pasture environment, Miriam Baumgartner and her colleages wrote in the open-access journal Animals.
Welfare, they say, is impaired because most horses pause their feed intake for too long during the night when kept on non-edible bedding.
They found in their study that the average nocturnal feed intake interruption of horses observed in individual housing systems on non-edible bedding was 9 hours.
“A horse would not take a voluntary feed intake pause of approximately 9 hours because of its almost permanent motivation to forage.”
If they have a choice, horses will not interrupt their feed intake for more than 4 hours.
Under natural conditions, horses spend most of their time foraging and grazing. Around 12 to 16 hours of each 24-hour period are spent eating.
About 60% to 70% of the daytime and 30% to 40% of the night time is spent on feed intake.
Even when stabled, horses that have feed available all the time divide their feed into about 10 meals, comparable to free-ranging horses.
“Neither during the day, nor at night, do horses pause voluntarily for longer than 3 to 4 hours between meals, nor do they fast,” the study team from the Technical University of Munich and the Ludwig Maximilian University of Munich said.
“It is a basic high priority need of every horse to take in roughage continuously.”
To ensure welfare, any feeding pause should not last for more than 4 hours, they said. “However, this basic need is often neglected in practice.”
They devised an experiment to assess the welfare of stabled horses that are fed restrictively — that is, when meals comprising roughage are provided at set times, as opposed to being continuously available.
They analyzed whether the feed intake behaviour of horses on edible straw bedding differed from those on non-edible bedding.
The study involved observing 30 horses on non-edible bedding (wood shavings) and 74 on edible bedding (straw). The animals were housed across 10 farms.
During the study period, all horses were allowed to graze for about 6 hours a day, with a minimum of two hours off the grass before their final evening hay.
The researchers assessed the length of the forced feed-intake interruption overnight of horses housed on shavings when no additional roughage was available.
All the horses were fed roughage twice or three times a day, depending on the farm.
“Our results showed that with this restrictive feeding practice, the horses were not able to eat any roughage for approximately 9 hours during the night.”
Horses on non-edible bedding altered their feed intake behaviour. They finished their hay meal faster and took fewer pauses during the meal than horses on edible bedding.
When compared to horses on straw, horses on shavings paused their feed intake less frequently.
They described this behaviour as a “rebound effect”. “If the basic high priority need of the horse to continuously engage in feed intake is neglected and the horses’ access to roughage (straw) is limited, the horses will accelerate their feed intake of the roughage and eat almost non-stop.”
This altered feed-intake behaviour indicates impaired welfare, they said. The horses’ natural feeding needs are not being satisfied on non-edible bedding under a restrictive feeding programme.
“We conclude that special feeding patterns have to be implemented (e.g., automated forage feeding systems) to avoid any impairment of the horses’ welfare if kept on non-edible bedding.”
They say further studies should be carried out in order to assess additional behavioural and physiological effects of restrictive feeding practices when there is no additional straw available.
Restrictive feeding of roughage for horses kept on non-edible bedding such as shavings or straw pellets can be regarded as inadequate, they said.
The authors noted previous research that showed horses restrictively fed hay when housed on shavings show abnormal repetitive behaviour more often than horses kept on straw.
Discussing their findings, the researchers said the importance of continuous roughage intake for the physical and mental health of horses is often underestimated in practice.
“The digestive system of the horses is in construction and function adapted to long feeding periods and a continuous feed intake, distributed over the 24-hour day. Any major deviation from this disrupts the digestive process and leads to behavioural disorders and even stereotypies.
“In order to respect the psychological and physical well-being of the horses, one has to be aware of the fact that the feed intake behaviour is a basic high priority need of the horse.
“Excessive feed intake pauses as found in the present study represent a risk of pain, suffering and harm.
“For this reason, a German court confirmed in its judgment (2019, file number RN 4 K 17.1298, Regensburg Administrative Court) that it has to be ensured that the maximum duration of feed intake pauses is 4 hours and that the duration of feed intake must at least be 12 hours.”
The study team comprised Baumgartner, Theresa Boisson and Margit Zeitler-Feicht, all with the Technical University of Munich, and Michael Erhard, with the Ludwig-Maximilians-University in Munich.
Baumgartner, M.; Boisson, T.; Erhard, M.H.; Zeitler-Feicht, M.H. Common Feeding Practices Pose A Risk to the Welfare of Horses When Kept on Non-Edible Bedding. Animals 2020, 10, 411.