Transport to the slaughterhouse and the time spent in the slaughterhouse are often very stressful for farm animals. A comparative study by the Research Institute of Organic Agriculture FiBL shows that on-farm slaughter can significantly reduce stress for animals.
When farm animals are killed at the slaughterhouse, they are exposed to various stress factors beforehand, for example separation from the herd, transport, meeting unfamiliar animals and people, often long waiting times in unfamiliar and close surroundings, and unfamiliar sounds and smells. One way to minimise stress is to kill the animals on the farm and transport the bled animals to a slaughterhouse for processing. On-farm killing and pasture killing have been permitted in Switzerland since July 2020 and in the EU since March 2021. Around one hundred Swiss farms have obtained the necessary approval for this so far.
A new FiBL study compares the slaughter of two groups of eleven and ten fattening animals from the same farm: the animals in the first group were killed in the slaughterhouse, those in the second group on the farm. The environmental conditions before the day of slaughter were comparable for all animals. The behaviour of the animals was observed shortly before stunning and blood samples were taken during bleeding.
Slaughterhouse: stress hormone cortisol up to twenty times higher
Levels of the stress-indicating parameters cortisol, lactate and glucose in the blood of animals slaughtered in the slaughterhouse were significantly higher than the levels of animals killed on the farm. Cortisol levels – the most important characteristic for measuring physiological stress – were on average twenty times higher in animals killed at the slaughterhouse than in animals killed on-farm. This is an unexpectedly large difference; a 2017 study had found an average slaughterhouse value ten times higher.
Calm behaviour immediately before stunning occurred only in farm killings, while restless and nervous behaviour occurred more than twice as often in the slaughterhouse than before farm killings. These results demonstrate that farm killing can minimise animal stress.
- The stress-indicating parameters in the blood and the behaviour of the animals at farm killings prove a significantly lower stress level and thus better animal welfare than at slaughterhouse killings. Therefore, on-farm killings are recommended.
- Further studies in different slaughterhouses and with different systems of farm killing would be useful to further identify the stress-triggering factors so that they become avoidable.
- Stress before slaughter can also lead to reduced meat quality. The connection between meat quality and stress has been proven by many studies. In contrast, studies on meat quality as a function of slaughter methods are largely lacking.