Main research question/goal
How does the number of animals per square meter influence the welfare and production characteristics of broiler chickens and fattening rabbits? Which density induces a change in behaviour? When do health problems occur? What is the maximum density at which feed is still converted efficiently? If a certain density does not result in a negative impact on the parameters mentioned above, does this mean that the animals have as much space as they would like? How important is (extra) space to animals?Research approach
Three experiments are conducted. In the first experiment we house broilers at eight stocking densities between 2.4 and 21.8 birds/m2. We measure their growth and feed intake as well as several welfare parameters. We observe how the animals distribute themselves over the available space to discern how much space they prefer to have. In the second experiment we apply a similar setup to fattening rabbits housed at seven densities between 5 and 20 animals/m2. In the third experiment we determine how hard broilers are willing to work for extra space. This information is used to discern how important (extra) space is to broilers.Relevance/Valorisation
We have found some remarkable results: only very high densities impact negatively on production characteristics (growth and feed intake). However, starting at a much lower density, we have noted a disturbance of resting behaviour, weaker legs which were more often deformed, and an increase in footpad dermatitis. The impact of density on behaviour and welfare is less pronounced for the fattening rabbits. However, we have found that the rabbits’ bodies are less symmetrical when stocked at a higher density, which may indicate increased stress levels. Analysis of the distribution of animals over their pen shows that broilers prefer to have more space than is available to them starting at a density of 6 birds/m2. For rabbits this crossover point is found at 10 animals/m2. Broilers are also willing to work hard for extra space, which indicates that extra space is important to them.
Collectief 'Eigen Inbreng'
IWT - Instituut voor de aanmoediging door wetenschap en technologie in Vlaanderen