Calcium intake in relation to ovulation and oviposition when access to oyster shell is time-restricted or unrestricted.
White Leghorn hens were fed either a conventional diet containing 40 gCa/kg from oyster shell, or one low in Ca (3 g/kg) with oyster shell offered separately. In experiment 1 access to oyster shell was unrestricted; in experiment 2. Access was time-restricted to the first 6 h of the photophase of the 14L:10D photoperiod. Irrespective of time-restriction, hens offered oyster shell laid heavier eggs, but shell thickness was reduced. On days on which only ovulation occurred, time-restricted hens consumed significantly less Ca than unrestricted hens. In contrast, on days on which only oviposition occurred, time-restricted hens consumed significantly more Ca than unrestricted hens. These results suggest that when access to oyster shell is time-restricted to morning hours Ca consumption occurs in response to a Ca deficit persisting from the previous period of shell calcification.
Millam
J R
JR
Kridis
M
M
Vohra
P
P
D000818:Animals; D002136:Calcium, Dietary; D002645:Chickens / Q000502:physiology*; D004528:Egg Shell; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D010058:Oviposition; D010060:Ovulation; D013997:Time Factors
D002136:Calcium, Dietary