Two studies aim to improve end-of-life welfare

The end of the production cycle when broilers and layers are transported to the slaughterhouse can be a vulnerable time for birds and handlers.

European researchers evaluate poultry handling methods

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The end of the production cycle when broilers and layers are transported to the slaughterhouse can be a vulnerable time for birds and handlers. Catching, carrying and crating for transport purposes can be challenging and cause stress and other physical welfare concerns, such as fractures, dislocations and muscle injuries. Prolonging handling time isn’t the solution either, as it can increase overall costs, exhaust workers and create additional stress for the birds. Two separate research groups evaluate current depopulation techniques with the aim of improving end-of-life welfare.

Researchers from the Norwegian Meat and Poultry Research Centre and the Norwegian University of Life Sciences evaluated two broiler catching methods in two flocks. Suboptimal handling may lead to injuries and mortality, said Kathe Elise Kittelsen, a veterinarian at the Norwegian Meat and Poultry Research Centre.

The study looked at several parameters, including crating time, the number of birds per drawer, wing and leg fractures as a result of catching and crating, and the number of dead-on-arrival birds.

The study evaluated two catching methods. Birds were either caught by two legs and carried upside down, or caught under the abdomen and carried upright to transport modules. Since it is banned in Norway, the one-leg catching method was not evaluated.

Two hybrids were included in the study, Hubbard JA 787, a slower growing breed, and Ross 308, a more active, slightly heavier bird. Broiler house parameters were the exact same in both studies, as was flock size.

“Overall, the results indicate that catching under the abdomen in an upright position may improve broiler welfare in terms of the investigated indicators in this study,” said Kittelsen.

“Both catchers and researchers were surprised that the upright, under the abdomen method was faster compared to catching by a grip in both legs,” she added. “However, the upright method requires more squats and as such is perceived as more exhausting to catchers.”

To the researchers’ surprise, no broken legs were observed during the course of the study. A few wing fractures, however, did occur.

As the project was only a pilot study, Kittelsen does not know how these results will translate in commercial barns.

“We do not know how a more exhausting catching method will affect the time it takes to depopulate big houses with many thousand broilers,” she said, adding that she would like to continue the study further.

In Switzerland, researcher Chris Gerpe, under the supervision of Michael Toscano, evaluated depopulation of end-of-lay hens in open aviary systems. Gerpe and Toscano conduct research at the Center for Proper Housing, Poultry and Rabbits (ZTHZ) in Switzerland.

The study looked at three parameters. First, it evaluated injuries sustained during depopulation. Then, it compared results in three differently lighted situations: complete blackness, modified head torches and pre-installed LED blue lights with a wavelength of 400 nanometers, a frequency that poultry do not see well. Finally, Gerpe evaluated handling time, which he says are associated with stress.

“Preliminary results from our first study estimated that approximately 8 per cent of hens sustained an injury that potentially – injuries categorized as fresh can be up to two days old – occurred during depopulation,” said Gerpe.

During the second part of the study, Gerpe noted that providing carts for the crates so hens could be packed inside the barn, rather than being carried and carted outside, could reduce handling time.

While Gerpe is still analyzing the bulk of the data, he was able to make a few observational points. First, he suggested closing the nest box areas and using grids to prevent hens from hiding under the aviary. Catchers should remove birds found on the floor first, he added, warning catchers of potential falls due to litter on the floor.

“Judging from our personal experience, we recommend that the producer should not engage in the actual depopulation procedures, but rather take the role of a supervisor or organizer to ensure that the process runs smoothly,” he said.

Gerpe added that the aim is not to promote the alternative handling method as the new stardand, rather to highlight the potential for improvement in terms of animal welfare.

ZHTZ is a collaborative effort between the University of Bern and Switzerland’s Federal Food Safety and Veterinary Office.

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