The effect of feed deprivation and subsequent refeeding on the bone characteristics of aged hens.
In an attempt to improve skeletal integrity of older caged laying hens, birds were held without feed for 4 to 8 d and then refed. Feed deprivation caused an immediate loss in breaking force of the tibia (P < 0.05). Although bone strength increased during subsequent refeeding, values did not return to prefast levels (P < 0.05). Feed withdrawal did cause a reduction in modulus of elasticity of the tibia (P < 0.05), which is a potential benefit for bones that are more resilient to damage; this characteristic was maintained through 30 d of feeding. Histological examination of the tibia hinted at some bone remodelling during refeeding following withdrawal, although the magnitude of these changes was of limited biological significance. These data suggest that simple feed withdrawal for 4 or 8 d is insufficient to bring about a meaningful improvement in skeletal integrity of the older caged laying hen.
Newman
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Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Leeson
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D000375:Aging; D000818:Animals; D001696:Biomechanical Phenomena; D001842:Bone and Bones / Q000502:physiology*; D002645:Chickens / Q000502:physiology*; D005260:Female; D005502:Food; D005508:Food Deprivation; D013977:Tibia / Q000033:anatomy & histology / Q000502:physiology