Even when transporting broiler chickens, reality is more complex than slogans, and more space does not necessarily mean better animal welfare.

When we talk about animal welfare, we generally also think about space. For example, in common perception, more space per chicken automatically means less stress, fewer injuries, and better health. This intuitive logic has also inspired the most recent European recommendations on broiler chicken transport. Yet, reality, as often happens, is far less straightforward and more space doesn’t mean more welfare.

Surprising results of the Hungarian study: more space, more problems

Two Hungarian researchers, Dr Attila Csorbai, Director at Hungary’s Poultry Product Council (BTT), and Dr László Szőllősi, Associate Professor at the University of Debrecen, put this assumption to the test through a comparative study in collaboration with two industrial slaughterhouses. The experiment was simple: load two trucks with broilers from the same farm, travelling under identical conditions of distance, staff, and timing. The only difference was the loading density: one truck followed current EU rules, while the other complied with the new recommendations of the European Food Safety Authority (EFSA) that prescribe more space per bird.

The expectation was to see improvements in welfare indicators: fewer bruises, fewer fractures. Instead, the data revealed the opposite. In trucks loaded with reduced density, mortality and injury rates actually increased. The reason lies in movement dynamics: with more room available, chickens tended to move around more during transport, losing balance, slipping, or hitting the sides of the crates. This resulted in more wing and leg fractures as well as a higher number of bruises.

The study found a correlation between increased space during transport and the frequency of bruising: the likelihood of bruising exceeding 4% increased linearly, from about 20% (for 180 cm²/kg space) to 60% (for 230 cm²/kg space). Based on this, the study suggested that transport containers with less space per individual could be more effective at preventing bruising, as the birds support each other’s bodies, reducing the risk of falling and minimising the need to spread wings and legs to maintain balance. In other words, increased freedom of movement became an additional risk, especially on roads where braking, curves, and vibrations are unavoidable.

Impact of fewer birds per trip: a heavy bill for the environment and rising economic costs

From a logistical perspective, the consequences are immediate: neither the environment nor the parties benefit. With more space per chicken, a truck can carry 20–30% fewer birds compared to standard capacity. This means more trips are required (a 30-40% increase) to transport the same number of animals. More journeys mean higher fuel consumption and more greenhouse gas emissions, and a larger ecological footprint for the activity. According to the study’s data, carbon dioxide emissions per kilogram of live weight transported increased by more than 20% when loading was conducted under the new rules.

On top of that, water consumption for vehicle and container washing inevitably increases as the number of trips grows. The study also reported efficiency losses on slaughter lines. In highly automated plants, hooks along the processing line are calibrated to achieve a minimum number of birds per crate. With fewer birds being loaded, some hooks remain empty, slowing down the entire process and raising fixed costs per bird processed.

On the economic side, reduced density translates into a double disadvantage. On one hand, more animals die or get injured, reducing the amount of usable raw material. On the other hand, fewer birds per trip raises the transport cost per kilogram of meat. To this, one must add the higher costs of water, detergents, and disinfectants needed to wash trucks and crates, which increase in proportion to the number of journeys.

The lesson to be learned: welfare is a matter more complex than space

The Hungarian case study does not claim to offer definitive answers, but it questions the idea that animal welfare can be measured solely in square centimetres. Many other factors are at play: climatic conditions (for example, in cold weather, higher density may help birds keep each other warm), loading and unloading techniques, container design, and handler training. Ignoring these variables risks turning a well-intentioned reform into a counterproductive measure.

The core message is clear: EU policies on animal welfare must consider not only ethical goals but also practical and economic consequences. A measure that worsens animal health, raises producers’ costs, and increases environmental impact cannot be considered sustainable. More movement may be associated with greater stress on the animals, which should be avoided from an animal welfare perspective.

Before introducing structural changes, broader studies are needed, conducted across different climates, transport distances, and crate designs, to achieve a truly comprehensive picture. Therefore, similar studies are recommended to be conducted not only at the Hungarian level but also internationally.