The Effect of Photoperiod and Feeding Time on Broiler Breeder Eggshell Quality and Oviposition Time

This study was conducted to determine the effect of photoperiod and feeding time on oviposition time and eggshell quality of broiler breeders. Five experiments were conducted in total. The effect of photoperiod on oviposition time was tested in Experiments '1 and 2. Experiment 1 involved 3200 33-week old broiler breeder hens housed in floor pens and subjected to photoperiods of 10, 11, 12, 13, 14 or 16 h. Experiment 2 used 120 37-week old broiler breeders, housed in individual cages in each of two light-proof rooms; one room on 8-h and the other on 16-h photoperiods. Birds in Experiment 1 were also used to determine the effect of photoperiod on eggshell quality, although they were 52 weeks of age when shell quality was assessed. The effect of feeding time on the aforementioned parameters was tested in three experiments. Experiment 3 involved 432 24-week old broiler breeders housed in individual cages and 'subjected to a 14-h photoperiod from 07.00 to 21.00. The birds were fed at 07.30,09.30, 11.30, 13.30 or 15.30. In one further treatment, birds were fed half the daily feed allocation at 07.30 and half at 15.30. Experiment 4 made use of 800 57-week old broiler breeder females housed on litter floor pens and subjected to a 14-h photoperiod from 05.00 to 19.00. The birds were fed at 07.30, 10.00, 13.00 or 15.30. In Experiment 5, 240 35-week old broiler breeder females were subjected to a 16-h photoperiod from 07.00 to 23.00. The feeding times tested in Experiment 5 were 07.30, 10.00, 13.00 and 15.30. Mean oviposition time was delayed relative to dawn by approximately 0.5h for each I-h increase in photoperiod up to 14 h, but was similar for 14 and 16-h photoperiods. The time when half a day's eggs were laid was also delayed relative to dawn by approximately 0.5 h for each I-h increase in photoperiod, although this trend continued through to 16 h. The rate of change in mean oviposition time for.each I-h increase in :S14-h photoperiod was similar to that reported for early and modern egg-type hybrids,