The effect of delaying the onset of laying in pullets with a low-calcium diet on subsequent egg production

1. A low‐calcium diet (0.5 g calcium/kg) was used to prevent the onset of laying in young pullets. 2. It was fed at 16 weeks of age to five separate groups (groups 2 to 6) each of 50 to 60 birds. 3. Group 2 was fed on a normal layers’ diet at 23 weeks of age, group 3 at 27 weeks, group 4 at 31 weeks, group 5 at 35 weeks and group 6 at 55 weeks while the control group (group 1) of similar size to groups 2 to 6 was subjected to a normal commercial treatment for laying stock. 4. In all the experimental groups the onset of sexual maturity occurred normally, but only one or two eggs were laid before laying ceased under the influence of the treatment. 5. Laying re‐started when the hens were fed on a normal diet and production rapidly rose to a high level. 6. Groups 1, 2 and 3 differed little in the total number of eggs produced up to 72 weeks of age. 7. In all experimental groups there were fewer very small, small and medium eggs than in the control group. 8. It is suggested that the use of a low‐calcium diet b...