SoL controller

After bleeding, the pigs are conveyed into a scalding tunnel while hanging. This is followed by further slaughtering steps. Before entering the scalding tunnel, we check the pigs one more time for any unusual movement using 3D technology. This further step ensures that death has in fact occurred, and that the pigs have been bled out correctly. This technology, also called SoL controller (Signs of Life), is state-of-the-art and is used by only a few slaughterhouses. The inventor of this device, Dr. Andreas Briese, was awarded third place as part of the Lower Saxony Digitalization Award competition. Briese developed the technology, among other things, in our slaughterhouse and with our support.

Stunning with helium: Statement

We are aware of the industry’s successful attempts to stun pigs with helium. Helium cannot be used in our current facilities because it rises as a gas, making it unsuitable for our use. We maintain an active interest in improved stunning technology, and support any form of further development. We believe that helium as a stunning gas can, in principle, provide a new alternative. However, the helium systems used in the tests we are aware of were only designed for individual animals under laboratory conditions. We are open to further developments of the existing technology or new techniques, and will be happy to support any respective market introductions.


We use a Butina CO₂ system to stun our animals. The stunning process begins by herding the animals into groups of 12. They are then driven in mechanically or by an employee of the stunning unit. The drive has a slight incline and is brightly lit. Pigs walk more calmly and relaxed when they walk up an incline into a bright area. Because of their social nature, it is a stressful situation for pigs to be separated from the group before stunning. Therefore, all steps are performed in a small group prior to stunning.

When stunning with carbon dioxide, the pigs are herded into gondolas in groups and then lowered via an elevator into a pit with a high CO₂ concentration. There, the pigs inhale the carbon dioxide, leading to a reduction in blood pH, acidification of the blood, and acidification of the cerebrospinal fluid of the central nervous system. The transmission of nerve impulses is reduced. Eventually, the animals become unconscious. Before the onset of unconsciousness, the pigs may show defensive reactions in the form of vocalizations, head shaking, and gasping. This phase of gasping for air is stronger or weaker depending on whether the pigs are relaxed or tense before stunning

The exact concentration of CO₂ is monitored via sensors. This allows us to ensure that exactly the right concentration is always applied. Too high of a CO₂ concentration would lead to a strong defensive reaction by the pigs. In turn, too low of a concentration would not sufficiently stun the animals. Stunning is applied for a duration of 150 seconds (120 seconds is required by law). The stunned animals are then immediately bled out.

For a slaughterhouse of our size, this form of stunning is currently still without an alternative. Another option, for example, would be stunning with electric forceps. The disadvantage of this is that the animals would have to be separated from the group for stunning, creating an additional stress factor. Furthermore, when employees use forceps, possible stunning errors cannot be ruled out. The use of electric tongs can also have a negative effect on the quality of the meat, which can be seen for example in blood stains on some meat products. We only use electric tongs in individual cases in the waiting area, or for post-stunning. The CO₂ stunning technique we currently use admittedly has its critics. However, taking all aspects into account, it remains the best method.

Waiting area

After unloading, the animals are herded by an employee into waiting pens where they have the opportunity to rest for about 20 minutes. Rested and relaxed pigs are essential for the stunning process. The delivery of the pigs and the waiting area are under video surveillance around the clock.