Abstract: A method is provided for reducing animal reactions when exposed to a pre-stunning relaxation gas and/or stunning gas during a pre-stunning and/or stunning process. The method includes: exposing at least one animal to a pre-stunning relaxation gas and/or stunning gas for an exposure period; exposing the at least one animal to at least one smell additive at least during a part of said exposure period, in particular during an initial part of said exposure period.

Abstract: A method of reducing stress level in animals such as pigs may include: sealable enclosing the animals in at least one chamber; exposing the animals to a gas mixture comprising oxygen and at least one type of physiologically inert gas; gradually decreasing the oxygen concentration from a maximum level, to a minimum level; gradually increasing the at least one physiologically inert gas concentration from a minimum level to a maximum level; wherein the minimum level of the oxygen concentration is higher than the anaesthetic causing concentration for the animals.

Abstract: When stunning animals e.g. by CO2-stunning aversive reactions may be seen among the animals as a reaction to the high concentration of CO2. To avoid the aversive reactions animals can be pre-stunned before being final-stunned and perhaps killed or slaughtered when stunned. Pre-stunning of animals may be performed with a combination of gas for pre-stunning comprising at least air and/or O2 together with CO2 e.g. in a concentration below 40%, at least air and/or O2 together with N2O, or at least air and/or O2 together with N2O and CO2, where CO2 may bi in a concentration below 40%. For larger animals such as pigs pre-stunning is performed for less than 60 seconds. A stunning system may comprise means for pre-stunning of animals before performing a final-stunning and may include gas storage for re-use of the pre-stunning gas.

Abstract: When stunning animals e.g. by CO2-stunning aversive reactions may be seen among the animals as a reaction to the high concentration of CO2. To avoid the aversive reactions animals can be pre-stunned before being final-stunned and perhaps killed or slaughtered when stunned. Pre-stunning of animals may be performed with a combination of gas for pre-stunning comprising at least air and/or O2 together with CO2 e.g. in a concentration below 40%, at least air and/or O2 together with N2O, or at least air and/or O2 together with N2O and CO2, where CO2 may bi in a concentration below 40%. For larger animals such as pigs pre-stunning is performed for less than 60 seconds. A stunning system may comprise means for pre-stunning of animals before performing a final-stunning and may include gas storage for re-use of the pre-stunning gas.