Improved farrowing pens can save piglets

Twelve newborn piglets scurry around pig number 2908. The newly formed family is part of a project that will contribute to reducing piglet mortality. Along with the sow and litter in the neighbouring pen, they are part of a research project that aims to reduce the number of piglets that die and ensure that the sow takes best possible care of her litter. The project receives support from the Research Council of Norway's Food Programme and the Foundation for Research Levy on Agricultural Products/the Agricultural Agreement Research Fund.

International challenge

"Several European countries aim to reduce the loss of piglets using a system in which the sow can move around freely. In Norway, the mortality rate among piglets is around 15 per cent, and most of them die during the first 48 hours after birth. Starvation and crushing are the most common causes of death, often in combination with hypothermia," explains Inger Lise Andersen, Associate Professor of Ethology (the study of animal behaviour) at the University of Life Sciences (UMB) at Ås south of Oslo.

The Norwegian researchers are collaborating with their colleagues at the University of Sydney in Australia on the project that is now being carried out.

As close to their mother as possible

Associate Professor Andersen believes that she has found a solution to the mortality problem: a unique farrowing pen that takes account of the sow's biology and behavioural requirements while providing greater safety for the piglets.

Today, all free-range sows are moved to farrowing pens when the birth is approaching. The sow and litter stay there until the piglets are around five weeks old. The pen usually has a separate corner with heating lamps for the piglets.

"Initially, we tried to develop the best possible piglet corner. But no matter what we did, the piglets preferred to lie close to their mother rather than be separated from her during the first few days. And it is often in this period that they die," says Associate Professor Andersen.

Safe haven for the piglets

So it was time for some fresh thinking. The result is an open pen with an activity area and a nest area. The areas are separated by a barrier that only the sow can cross at first. This means that she gets peace and quiet in the activity area for eating and dunging, while the nest area is reserved for suckling and sleeping.

In the nest area, the piglets lie on rubber mats, and the slotted floor in the activity area is also covered in rubber. This seems to prevent shoulder sores and leg problems in the sow. To prevent the 200-kilo sow from lying on the piglets, a sloping panel has been installed that slopes down from the actual pen wall. This means that the piglets can retreat to the space between the wall and the sloping panel when their mother lies down.

The nest area also has floor heating in two zones that can be controlled separately. This means that the sow, whose body temperature is higher when she lactates, can lie in a nest area without floor heating, while the piglets can lie on the heated floor.

Big litters not an advantage

Installed cameras follow the life in the pen, and the researchers analyse how the sow takes care of her litter and how she uses the pen. The results are promising.

"We have now reached a piglet mortality rate of around nine per cent, compared with an average of 15 per cent under the current system. The sow quickly calms down when she is moved to the pen, she is calm around the time of farrowing and uses the pen the way we intended. The piglets are also growing nicely," says Associate Professor Andersen.

When sows have exceptionally big litters, the researchers see that several piglets do not make it.

"We have found that the sows have a biological capacity of 10-12 piglets in one litter. Anything above that requires external help in the form of assistance from the farmer. In our trial, we interfere as little as possible," she says, and believes that this has an effect on the mortality rate.

Needs to be tested on a larger scale

So far, the pen has only been tested on a limited number of pigs at UMB and its partner institution, the University of Sydney. Improvements will have to be made and testing is required on a larger scale before the pen can be put into commercial production.

"We hope to start a collaboration that involves testing 40 pens on ordinary pig farms," says Associate Professor Andersen. The goal is to carry out tests on a total of 120 sows.

She believes firmly in the pen as an overall concept and also points out that some of the components can be used to advantage in other farrowing pens. Rubber mats in the nest area and rubber covering of slotted floors are particularly interesting products.

"Our goals for this work are better animal welfare and greater economic security for the farmer in that more pigs survive," Inger Lise Andersen concludes.