Nutritional means to enhance skeletal development in pullets and subsequent effects on layers productivity, bone health and welfare

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Canadian supply managed egg production system has 1,021 registered egg farms with a total of approximately20 million layers and contributes $1.28B to Canada's GDP. Bone health manifested as osteoporosis is apersistent problem in layers under different housing systems with detrimental effects on flock productivity andegg shell quality and thus profitability. Bone quality is influenced by genetics, housing system environment andnutrition. However, the trends of decreased sexual maturity without concurrent refinement in mineral contentof the feed may juxtapose with the hen's increased capacity to produce more eggs with less feed (more calciumoutput and less input) such that bone mineralization is impaired during rearing and /or lay cycle giving rise tomortality and morbidity stemming from metabolic calcium insufficiency and osteoporosis. Studies to improvehen skeletal health often focus on manipulating environment and nutrition during the laying. However, aspullets develop a mature frame size by 12 weeks of age followed by formation of medullary bone aroundsexual maturation, supplementing calcium during active lay may be too late to improve bone density andquality. Our hypothesis is that proper skeletal development is essential for high levels egg production andchallenges of alternative housing for modern layers. Studies will be conducted to investigate the role of feedstructure (manipulation of fiber fraction and limestone particle size) and optimal calcium, phosphorous andvitamin D supplementation on skeletal development pullets and subsequent effects in productivity, egg shellquality, livability and welfare in hens. This is a timely research and will provide valuable information to theegg industry in light of the forthcoming changes in Canadian hen housing systems. The project will employ avariety of experimental, statistical, and analytical techniques thus providing excellent opportunities for thetraining of highly qualified personnel. Specifically, the research project will support training of 1 PhD, 2 MScby thesis, 1 MSc by coursework, 2 undergraduate students and 1 Postdoctoral Fellow as well as a technician.