Abstract:
The effects on body weight and laying performance of restricting the feeding time of medium weight crossbred pullets to 6 or 8 hours in every 48 hours from 6, 9 or 12 to 20 weeks of age were studied in a factorial experiment. Before the start of the restriction programme, half of the pullets were fed ad libitum; the other half were not fed on Wednesday and Sunday of each week from three weeks of age. The control birds were fed ad libitum throughout the rearing phase. The feed intake and the weight of pullets at the end of the restriction programme at 20 weeks were reduced by between 17 and 40 per cent and between 18 and 33 per cent, respectively, compared with the control, depending on the early feeding regime and the duration of restriction. The average age at 50 per cent production of the restricted treatments was delayed by 15 days compared with the controls. No significant difference was found in the laying performance of the restricted birds or between any of these and the controls. The restricted birds however were less efficient in converting their feed to eggs than the control birds. Rearing and adult mortality were not affected by restriction. The results suggested that for maximum economic return the restriction programme should not be delayed beyond 6 weeks and should continue to 20 weeks of age. Delaying the start of the restriction programme beyond 6 to 9 or 12 weeks of age will reduce the saving in feed intake from approximately 35 to about 29 and 17 per cent of feed consumed by full-fed birds at 20 weeks respectively.