This is the largest project to date to directly examine not only welfare measures of different genotypes of broiler chickens but also nutrient utilization and other potential costs.
This is the largest project to date to directly examine not only welfare measures of different genotypes of broiler chickens but also nutrient utilization and other potential costs.
As global animal protein sources, chicken eggs and meat are produced more efficiently than all other traditional animal proteins in terms of water consumption, energy requirements, and land use. Significant improvements in genetic selection over the past fifty years have resulted in larger, leaner, more efficient meat chickens produced weeks earlier, and commercial laying hens that achieve early sexual maturity, long-lasting peak egg production and extended egg-laying. However, these high levels of production have come at a cost. Commercial strains of broiler meat chickens may be behaviourally impaired due to the discord between their body weight, leg strength, and cardiovascular system, and their high level of productivity often necessitates significant antibiotic use.
For laying hens, greater egg production increases internal demands for calcium (for shell formation), in turn weakening the skeleton, and rendering birds prone to osteoporosis and greater risks for bone fractures. Both within Canada and world-wide, there is increasing consumer preference for poultry products with “higher animal welfare” and that are perceived to be safer and healthier for people. This includes meat chickens that grow more slowly, are raised without antibiotics and fed all-vegetable diets as well as laying hens kept in non-cage housing systems that improve musculoskeletal development through exercise but also greatly increase risks of collisions, leading to fractures and higher mortality. Solutions are needed to resolve the disconnect between highly efficient production of poultry products and concerns about animal welfare and human health.
This research team is integrating data from studies on genetics, nutrition, physiology and behaviour to focus on two lines of research.
The first line of research aims to enhance skeletal development of laying hens when they are young and understand behavioural attributes of hens that confer or protect from risk of skeletal damage. By adjusting bird management (housing, space, and nutrition) as their skeleton develops and they transition through sexual maturity, the researchers can apply intervention strategies that target key periods of growth, maturation and calcium acquisition. Research has already improved our understanding of the general motor skills, physiology and behaviour of hens with and without skeletal injuries. The current project will help to identify housing-system designs that mitigate risks and support hens already affected by compromised bone health.
In the team’s second line of research, conventional, fast growing strains of broiler chickens were used to determine the best variables by which to evaluate the welfare, behaviour, health, meat quality and productivity of broilers. The team also validated new methodologies for remote and continuous collection of data on activity levels within a group setting. With this knowledge, the team is now studying multiple strains of slower growing broiler chickens to compare their welfare, productivity and nutrient utilization.
To date, over 80 multi-national restaurants, grocery chains, food manufacturers, and food service providers including McDonalds, Costco, Unilever and Aramark have committed to sourcing only cage free eggs over the next 10 years. Additionally, 86 multinational food companies, including Tim Hortons, Kraft-Heinz, Nestle, Compass Group and Starbucks have pledged to purchase meat from slower growing genetics, or otherwise improve the welfare of their broiler chickens by 2024.
It is currently estimated that upwards of 80% of laying hens can experience skeletal injuries (keel bone fractures) in non-cage systems. With an estimated 16M Canadian laying hens destined for housing in non-cage systems in the next 15 years, this research can have a significant impact on the welfare of laying hens on Canadian farms and assist egg farmers during this major transition to ensure economic viability.
It has been estimated that the increased feed, water and energy required to produce the same amount of meat using a slower growing broiler chickens will have significant environmental implications. This is the largest project to date to directly examine not only welfare measures of different genotypes of broiler chickens but also nutrient utilization and other potential costs.
Partners: Burnbrae Farms, Egg Farmers of Canada, Egg Farmers of Ontario, Global Animal Partnership, Hendrix Genetics, Lohmann Tierzucht, Ontario Ministry of Agriculture, Food and Rural Affairs.
Collaborators: Niel Karrow (Guelph), Leonardo Susta (Guelph), Michele Guerin (Guelph), Ruth Newberry (Norwegian University of Life Sciences), Bret Tobalske (University of Montana).
Students: Mohsen Mohammadigeisar (PDF), Charlene Hanlon (PhD), Tanka Khanal (PhD), Bishwo Pokharel (PhD), Midian N. dos Santos (PhD), Misha Ross (PhD), Daniel Rothschild (MSc), Zhenzhen Liu (MSc), Lorri Jensen (MSc), Danielle Fawcett (MSc), Rahul Sharma, Isabelle Kwon, Stephanie Kamalanathan, Francesca Ruberto Cain.
Popular press associated with project
WattAgNet.com (authored by Austin Alonzo). April 2018. Do engagements, natural environments help broiler welfare?
WattAgNet.com (authored by Austin Alonzo). April 2018. Impacts of slower broiler growth, natural lighting.
WattAgNet.com (authored by Austin Alonzo and Kathleen McLaughlin). March 2018. 9 broiler welfare questions answered by experts. Link
WattAgNet.com (authored by Terrence O’Keefe). January 2018. Comparing the welfare of different broiler breeds. Link
Canadian Poultry Magazine (authored by Treena Hein). October 2017. Cover story: The whole story. Whole Foods wants all the chicken it sells to be slow-growth. Link
Invited presentations associated with project
Torrey, S. 2018. University of Saskatchewan Poultry Welfare group. ‘Slow growing broiler welfare.’ Saskatoon, Saskatchewan.
Torrey, S. 2018. International Production and Processing Expo, WattAgNet Panel. ‘Slow growing broiler welfare’ Atlanta, Georgia.
Torrey, S. 2017. Poultry Health Research Network. ‘Will slow growth improve broiler welfare?’ Guelph, Ontario.
Torrey, S. 2017. Ontario Broiler Hatching Egg and Chick Commission Board Meeting. ‘Research Update’. Guelph, Ontario.
Torrey, S. 2017. Global Animal Partnership 2nd Annual Better Chicken Welfare Initiative Meeting. ‘Optimizing broiler welfare’. Stevensville, Maryland
Submitted conference abstracts associated with project
Elias, C. Martin, B. Tobalske and A. Harlander, 2017. Footpad dermatitis does not affect environmental usage in laying hens . Proceedings of the Xth European Symp Poultry Welfare, p. m170 Link
Liu, Z., Torrey, S., Newberry, R., and T. Widowski. Assessing the welfare of fast-growing broilers reared in pens with or without enrichment. Submitted for Campbell Centre for the Study of Animal Welfare Research Symposium.
Jensen, L. and T.M. Widowski (2018) Too close for comfort? Effects of stocking density on the comfort behaviours of three strains of pullets in furnished cages. Submitted for Congress of the International Society for Applied Ethology, PEI, July 2018
Jensen, L., T.M. Widowski, (2018) Effects stocking density on the perching behavior of 3 strains of pullets. Submitted for 2018 PSA, San Antonio, TX, July 23-26.
Khanal, T., T Widowski, G Bedecarrats, E. Kiarie. 2018. Effects of pre-lay dietary calcium and strain on age, bodyweight, femur weight, ash retention and calcium intake at first egg in pullets. Submitted for 2018 PSA, San Antonio, TX, July 23-26.
Rothschild, D., Widowski, T.M., Karrow, N.A., Susta, L., Kiarie, E., Mandell, I, and S. Torrey 2018. The effects of a low-nutrient diet on the prevalence of right ventricle hypertrophy and bursal atrophy in two strains of fast-growing broilers. Submitted for 2018 PSA, San Antonio, TX, July 23-26.
Santos, M.N., Widowski, T., Kiarie, E., Mandell, I, Mohammadigeisar, M., and S. Torrey. The impact of low-nutrient and conventional diets on lameness, leg parameters and tibia ash concentration of two fast-growing genotypes of broiler chickens. Submitted for 2018 PSA, San Antonio, TX, July 23-26.
Refereed journal articles
Casey-Trott, T.M., Widowski, T.M., 2018. Validation of accelerometer to quantify inactivity in laying hens with and without keel bone fractures. Animal Welfare 27:103-114.
