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Rapport2006Öppen tillgång

Welfare during handling and killing of spent hens

Atkinson, Sophie; Algers, Bo


Every year there are approximately 5.8 million spent hens removed in Sweden from at least 500 different farms (SJV, 2006; Svenska Ägg, 2006). Approximately 256 farms depopulate over 5000 hens at any one time. Flock sizes generally range between 10, 000 to 30,000 hens. The largest farm has approximately 300,000 laying hens and depopulates over 90,000 hens at any one time. There are four methods for the depopulation of hens: - Killing hens on farm by releasing carbon dioxide (CO2) at high concentrations in to layer sheds - Killing hens on farm by releasing Cyanide (HCN) at high concentrations in to layer sheds - Killing on farm by way of a portable electrical water-bath stun/neck cut kill apparatus - Sending hens by road transport to slaughter at a commercial abattoir that uses an electrical water-bath stun/neck cut kill system The killing method egg producers use is largely influenced by farm location. There is now only one abattoir in Sweden that processes spent hens. This abattoir is not within reasonable transport distances to some farms causing high transport costs and excessive transport duration for the hens. These farms therefore practice on-farm killing. In the 1980´s cyanide gas was used for on farm killing, but since year 2001, CO2 gassings have mostly been used. Killing of spent hens with CO2 or HCN is actually not permitted under Swedish law (SJVFS 2001-75, chapter 6, part 1). However, farmers can apply to the Swedish animal welfare authority for an exemption from this regulation. The farmer must apply for a permit for every flock they wish to kill. In 2005, approximately 19 farms (11 from Gotland) were given permission to depopulate their layer shed using CO2 gas. The number of hens ranged from the smallest flock size of 1100 to the largest of 88,000 hens. The total number of hens gassed with CO2 was 364, 600 hens, 34% which came from Gotland and 66% from the mainland, mostly around the Kalmar area (Swedish Animal Welfare Agency, 2006). Many producers with hens in loose house systems prefer to practice on farm killing due to welfare concerns with the catching, caging and transportation necessary when sending hens to slaughter. The carcasses of hens killed on farm by gassing must be sent to a specialised animal rendering plant for burning at cost to the farmer. In northern Sweden, there are 14 egg producers (the smallest with 3000 hens, the largest with 44,000 hens). These farmers practice on farm killing of hens with a small electrical water-bath stunning apparatus that is transportable and shared between them. The hens are then sent to the rendering plant. At least 140,000 hens are killed this way (Norrlansägg, 2006). There is one small company that offers on farm hen killing services for the purposes of processing the hens to pet food. The company travels to the farm with a portable electrical water-bath stunning apparatus, similar to the one used in northern Sweden, and hens are killed, debled and defeathered on the farm. The farmer does not have to pay for the disposal of the carcasses, as the carcasses are used by the company for pet food production providing some subsidy for the service. This company provided on farm killing and carcass removal services to approximately 20 farms in 2005 (Stefans and Nillans Foder, 2006). Nearly 80% or 3.1 million hens were sent to abattoir slaughter in the year 2005 (Svenskt Fågelkött AB, 2006). These hens are transported to the abattoir by the company’s own trucks. Transport distances vary from local to as far away as 714kms to the north, and 370kms to the south. Approximately 370 farms send hens to this abattoir. The farmer must pay for the transport and slaughter of these hens which are sent as fresh and frozen carcasses to Germany for soup and buljong production. Another aspect on the depopulation of birds is the need for depopulation to stop the spread of contagious disease such as e.g. Avian influenza. In an outbreak in the Netherlands 2003 more than 30 million birds were killed within a few weeks in order to stop the spread of the disease. During this outbreak CO2 stunning and killing was used instead of HCN mainly due to the risks of using HCN for human health during operating procedures, but also because enough HCN was not available on the market (Ooms, pers. comm. 2006). If a disease outbreak of such a kind should occur in Sweden a stamping out strategy needs to be applied where the welfare concerns are met in accordance with the “OIE GUIDELINES FOR THE KILLING OFANIMALS FOR DISEASE CONTROL PURPOSES”. Swedish on farm killing methods have been little studied from a welfare perspective. Therefore this study aimed to get a better understanding of hen welfare by observing different killing methods, and investigating the possibilities of making changes to improve hen welfare

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Rapport (Sveriges lantbruksuniversitet, Institutionen för husdjurens miljö och hälsa)
2006, nummer: 9
Utgivare: Department of Animal Environment and Health, Swedish University of Agricultural Sciences