BEHAVIOR AND HORMONE CONCENTRATIONS IN NEST DEPRIVED AND RENESTING HENS

1. Nest and egg deprivation is a procedure traditionally used to disru pt incubation behaviour expression in commercial flocks. The aim of th is study was to establish how nest deprivation affects the subsequent changes in behaviour and hormone secretion and whether readiness to re nest is related to hormone concentration before and during nest depriv ation. 2. Incubating broiler breeder hens were deprived of their nest either in their familiar environment, by blocking the nest entrance in the home cage or in an unfamiliar environment, by transfer in a diffe rent cage. After 3 days of nest deprivation, next access was allowed a nd readiness to incubate tested. 3. Both methods of nest deprivation r esulted in the expression of similar behaviours associated with the di sruption of incubation, and similar increases in plasma LH and oestrad iol and decreases in plasma prolactin. The percentage (approximate to 70%) of hens which renested after either method of nest deprivation di d not differ significantly. 4. Readiness to renest was not related to the concentrations of plasma prolactin measured before or during the 3 days of nest deprivation. However, hens which would later renest coul d be identified by using behavioural criteria. They emitted more avoid ance trills before, and sat on the wire floor for longer periods durin g, the nest deprivation period than the others.