Dietary phosphorus and egg shell thickness in the domestic fowl

Publisher Website
Google Scholar
Abstract
The influence of two diets, differing only in their phosphorus content, on egg shell thickness was compared in 24 pullets in a change‐over experiment lasting 8 weeks. The mean shell thickness of the eggs laid on the low‐phosphorus diet (0.46 per cent total phosphorus) was 2 per cent greater than the mean thickness expressed interms of mg./cm.2 on the high‐phosphorus diet (1 per cent total phosphorus), and this difference was statistically significant. It is suggested that the increase in shell thickness on the low‐phosphorus diet was due to increased absorption and retention of dietary calcium, but this suggestion could not be confirmed experimentally in two balance periods of 6 days each owing to the great variations in calcium retention observed both between and within birds. The skeletal weights of birds killed after laying for approximately 11 months on one or other of the two rations showed no correlation between dietary treatment and skeletal weight, percentage egg production or mean shell thickness.