14 DAY TRIAL // The reason why pigs are ecstatic when they find themselves in a puddle of mud left scientists intrigued for centuries. Over the years, they learned that the animals may in fact be keeping themselves cool by doing so, but a new research demonstrates that other reasons may be at play here as well.
Investigators who conducted a review of the existing literature on the topic propose that taking mud baths is a sign of well-being in the pigs. If this is true, then this raises an important animal welfare issues, seeing how most farmers to not provide their pigs with access to mud pits.
With no possibility of wallowing at their discretion, these animals may experience stress and other negative mental side-effects, say Wageningen University and Research Center expert Marc Bracke.
Details of the extensive review he and his team conducted appear in the April online issue of the esteemed journal Applied Animal Behavior Science. The conclusions cover an analysis of 66 research papers conducted on the connection between mud pits and wallowing, LiveScience reports.
This type of behavior was analyzed in a number of wallowing species, including pigs and wild boars, among others. The investigations propose a large number of explanations for this habit.
Some researchers believe that the animals knowingly cover themselves in mud to escape the scorching heat of the Sun, whereas others explored a potential role that mud baths may play in parasite removal. A group of experts expanded on the idea that the habit contributes to temperature regulation.
In the new study, Bracke determined that indeed the latter theory offered the strongest motivation for pigs and other species to wallow. This is primarily owed to a physical limitation that pigs have – the creature have very few sweat glands.
On the other hand, they do carry an excessive amount of fat, and have a body shape that contributes to retaining heat in the core. A mud bath was found to reduce average temperatures at skin level by as much as 3.6 degrees Fahrenheit (2 degrees Celsius).
This study demonstrates that farmers who deprive their pigs of this small luxury – and opt instead for air conditioned barns – may be actually harming their own meat production levels.
“This could involve a repetition of the mistake made by animal scientists and farmers who previously suggested that farm animals do not need to forage (search for food) when they are provided with nutritious food,” Bracke says.
“That view has lead to serious welfare problems such as feather pecking and tail biting,” he concludes.