Slow-growing chickens shown to have improved welfare

University of Guelph study shows many bird welfare indicators related to chicken growth rate.



Sep 11, 2020


Raising slower-growing broiler chickens means less efficiency for producers and potentially higher costs for consumers, but it would improve bird welfare, according to a large and comprehensive study of broiler chicken welfare by researchers at the University of Guelph in Ontario.


The team hopes the study will lead poultry breeders and producers to select traits associated with better welfare, an announcement from the university said.


This is a potentially costly move, but one that may end up benefitting the industry by lending support to higher animal welfare standards and improved meat quality favored by consumers, Guelph animal biosciences professor Tina Widowski said.


“We found that, overall, many indicators of welfare are directly related to rate of growth,” said Widowski, who led a team of experts in poultry welfare, nutrition, physiology and meat science at the University of Guelph.


Developed mostly through selective breeding, fast-growing birds reach market weight of about 2 kg in about 35 days and satisfy consumers’ desire for large, uniform chicken breasts. By changing their body shape, this breeding has yielded large breast muscles but also short legs that make it difficult for chickens to perform normal activities, the researchers said.


Animal welfare concerns have led to development of slower-growing breeds that take at least a week longer to reach market weight, the university said. Raising chickens more slowly adds expense for producers, especially in extra feed costs.


The researchers studied more than 7,500 chickens raised at the University of Guelph’s Arkell Research Station. They looked at 16 genetic strains bred for four growth rates as well as other traits.


Outfitting the birds with wearable devices, they compared mobility and activity. An obstacle...