We are particularly concerned about four key issues that can have a big effect on meat chicken welfare. One of the issues – growth rate – concerns the bird itself, whereas the other three are to do with how the birds are managed.
Meat chickens have been genetically selected to grow quickly. The time from when the birds first hatch to appearing on the supermarket shelves can be as little as five weeks. This rapid weight gain can cause severe health problems, such as lameness and heart defects. We believe that only genetically slower growing breeds should be used, which are less likely to develop these welfare problems.
Stocking density refers to the amount of floor space each bird has within a building and is expressed as bird weight per square metre. High stocking densities can lead to poor welfare by preventing chickens from moving around and exercising properly, and also by causing the condition of the air and litter (flooring) to become poor.
When stocking densities are higher than 30 kilogrammes per square metre there is a big increase in the risk of serious welfare problems developing. Many meat chickens are reared at stocking densities of 38 kilogrammes per square metre or higher. At such high stocking densities, problems such as lameness and skin diseases can be much more common. High stocking densities also make it difficult for birds to perform many of their natural behaviours.
Light levels are usually measured in ‘lux‘ - for example, a brightly lit room is around 400 lux, and natural daylight is around 30,000 to 100,000 lux. In contrast, chickens only have to be provided with artificial light at 20 lux. Chickens have well developed colour vision and, like ourselves, it is their dominant sense and has been designed for use in brightly lit conditions. As natural light is much brighter than the artificially lit environments used in poultry houses, and provides the full spectrum of light, daylight is necessary for chickens to use this sense to its full potential.
The majority of chickens do not have items in their environment that allow them to carry out their natural behaviours such as perching and investigation. A more stimulating, enriched environment (for example, as shown in this picture of chickens reared to RSPCA welfare standards) encourages birds to be more active, which can help reduce leg problems. Chickens provided with an enriched environment (for example, containing straw bales, perches and objects to peck at) walk and run more and sit down less than those kept without any form of enrichment.
The risk of all the above welfare problems occurring can be greatly reduced by rearing chickens according to higher welfare standards such as our RSPCA welfare standards. As well as developing detailed recommendations for how we believe all meat chickens should be reared, we’ve also been working hard in a number of other ways to improve the lives of as many chickens as possible.